diff --git a/buildenv/jenkins/common/build.groovy b/buildenv/jenkins/common/build.groovy
index 16dcbc1dec3..439731c5889 100644
--- a/buildenv/jenkins/common/build.groovy
+++ b/buildenv/jenkins/common/build.groovy
@@ -113,17 +113,17 @@ def checkout_pullrequest() {
     // Cannot depend on a change from the same repo as the source repo
     def SOURCE_REPO_MESSAGE
     switch (params.ghprbGhRepository) {
-        case "eclipse/openj9-omr":
+        case ~/.*\/openj9-omr/:
             omr_bool = true
             OMR_PR = params.ghprbPullId
             SOURCE_REPO_MESSAGE = "PullRequest source repo appears to be OpenJ9-OMR"
             break
-        case "eclipse/openj9":
+        case ~/.*\/openj9/:
             openj9_bool = true
             OPENJ9_PR = params.ghprbPullId
             SOURCE_REPO_MESSAGE = "PullRequest source repo appears to be OpenJ9"
             break
-        case ~/ibmruntimes(.*)/:
+        case ~/.*openj9-openjdk-jdk.*/:
             openjdk_bool = true
             OPENJDK_PR = params.ghprbPullId
             SOURCE_REPO_MESSAGE = "PullRequest source repo appears to be OpenJDK"
@@ -198,7 +198,7 @@ def checkout_pullrequest() {
         checkout_pullrequest(OPENJDK_PR, "ibmruntimes/openj9-openjdk-jdk${JDK_REPO_SUFFIX}")
     }
 
-    sh "bash ./get_source.sh ${EXTRA_GETSOURCE_OPTIONS}"
+    sh "bash ./get_source.sh ${EXTRA_GETSOURCE_OPTIONS} ${OPENJ9_REPO_OPTION} ${OPENJ9_BRANCH_OPTION} ${OPENJ9_SHA_OPTION} ${OMR_REPO_OPTION} ${OMR_BRANCH_OPTION} ${OMR_SHA_OPTION}"
 
     // Checkout dependent PRs, if any were specified
     if (openj9_bool) {
@@ -225,6 +225,8 @@ def checkout_pullrequest(ID, REPO) {
                 fetchRef("pull/${ID}/merge", "pr/${ID}/merge" )
                 checkoutRef ("pr/${ID}/merge")
             } catch (e) {
+                // If merge ref doesn't exist, checkout PR base branch.
+                // Not going to fix this to work for internal PRs.
                 def JSONFILE = ""
                 def BASEREF = ""
                 def URL = "https://api.github.com/repos/${REPO}/pulls/${ID}"
diff --git a/buildenv/jenkins/common/pipeline-functions.groovy b/buildenv/jenkins/common/pipeline-functions.groovy
index 832f2a8bf6b..94964005bb1 100644
--- a/buildenv/jenkins/common/pipeline-functions.groovy
+++ b/buildenv/jenkins/common/pipeline-functions.groovy
@@ -714,14 +714,19 @@ def setup_pull_request_single_comment(parsedComment) {
     // Setup JDK VERSIONS
     switch (ghprbGhRepository) {
         case ~/.*openj9-openjdk-jdk.*/:
+            // <org>/openj9-openjdk-jdk<version>(-zos)?
             def tmp_version = ghprbGhRepository.substring(ghprbGhRepository.indexOf('-jdk')+4)
             if ("${tmp_version}" == "") {
                 tmp_version = 'next'
             }
+            if (tmp_version.contains('-')) {
+                // Strip off '-zos'
+                tmp_version = tmp_version.substring(0, tmp_version.indexOf('-'))
+            }
             RELEASES.add(tmp_version)
             minCommentSize = 3
             break
-        case "eclipse/openj9":
+        case ~/.*\/openj9(-omr)?/:
             def tmpVersions = parsedComment[3+offset].tokenize(',')
             tmpVersions.each { version ->
                 echo "VERSION:'${version}'"
diff --git a/buildenv/jenkins/jobs/pipelines/Pipeline-Build-Test-All.groovy b/buildenv/jenkins/jobs/pipelines/Pipeline-Build-Test-All.groovy
index 0eceb1c9399..1e91e76db81 100644
--- a/buildenv/jenkins/jobs/pipelines/Pipeline-Build-Test-All.groovy
+++ b/buildenv/jenkins/jobs/pipelines/Pipeline-Build-Test-All.groovy
@@ -135,7 +135,8 @@ SHORT_NAMES = ['all' : ['ppc64le_linux','ppc64le_linux_xl','s390x_linux','s390x_
             'osxxl' : ['x86-64_mac_xl'],
             'alinux64' : ['aarch64_linux'],
             'alinux64xl' : ['aarch64_linux_xl'],
-            'alinux64largeheap' : ['aarch64_linux_xl']]
+            'alinux64largeheap' : ['aarch64_linux_xl'],
+            'zos' : ['s390x_zos']]
 
 // Initialize all PARAMETERS (params) to Groovy Variables even if they are not passed
 echo "Initialize all PARAMETERS..."
@@ -191,14 +192,14 @@ echo "SCM_REPO:'${SCM_REPO}'"
 SCM_BRANCH = 'refs/heads/master'
 if (params.SCM_BRANCH) {
     SCM_BRANCH = params.SCM_BRANCH
-} else if (ghprbPullId && ghprbGhRepository == 'eclipse/openj9') {
+} else if (ghprbPullId && ghprbGhRepository ==~ /.*\/openj9/) {
     SCM_BRANCH = sha1
 }
 echo "SCM_BRANCH:'${SCM_BRANCH}'"
 SCM_REFSPEC = ''
 if (params.SCM_REFSPEC) {
     SCM_REFSPEC = params.SCM_REFSPEC
-} else if (ghprbPullId && ghprbGhRepository == 'eclipse/openj9') {
+} else if (ghprbPullId && ghprbGhRepository ==~ /.*\/openj9/) {
     SCM_REFSPEC = "+refs/pull/${ghprbPullId}/merge:refs/remotes/origin/pr/${ghprbPullId}/merge"
 }
 echo "SCM_REFSPEC:'${SCM_REFSPEC}'"
diff --git a/buildenv/jenkins/variables/defaults.yml b/buildenv/jenkins/variables/defaults.yml
index 5c8898be894..1532c9cc64f 100644
--- a/buildenv/jenkins/variables/defaults.yml
+++ b/buildenv/jenkins/variables/defaults.yml
@@ -183,8 +183,7 @@ ppc64le_linux:
   node_labels:
     build: 'ci.role.build && hw.arch.ppc64le && sw.os.ubuntu'
   extra_configure_options:
-    8: '--enable-jitserver'
-    11: '--enable-jitserver'
+    all: '--enable-jitserver'
   build_env:
     vars: 'PATH+GCC7=/usr/local/gcc-7.5.0/bin LD_LIBRARY_PATH=/usr/local/gcc-7.5.0/lib64:$LD_LIBRARY_PATH'
 #========================================#
@@ -199,10 +198,8 @@ ppc64le_linux_xl:
   extends: ['ppc64le_linux', 'largeheap']
   excluded_tests:
     8:
-      - sanity.openjdk
       - special.system
     11:
-      - sanity.openjdk
       - special.system
 #========================================#
 # Linux PPCLE 64bits Compressed Pointers /w JITSERVER
@@ -237,10 +234,7 @@ s390x_linux:
 s390x_linux_xl:
   extends: ['s390x_linux', 'largeheap']
   excluded_tests:
-    8:
-      - sanity.openjdk
-    11:
-      - sanity.openjdk
+     11:
       - special.system
 #========================================#
 # Linux S390 64bits Compressed Pointers /w JITSERVER
@@ -253,10 +247,10 @@ s390x_linux_jit:
 ppc64_aix:
   extends: ['debuginfo', 'freemarker', 'openjdk_reference_repo', 'openssl']
   boot_jdk:
-    8: '/usr/java7'
-    11: '/usr/java11_64'
-    14: '/usr/java13_64'
-    next: '/usr/java13_64'
+    8: '/opt/java7'
+    11: '/opt/java11_64'
+    14: '/opt/java13_64'
+    next: '/opt/java13_64'
   release:
     all: 'aix-ppc64-server-release'
     8: 'aix-ppc64-normal-server-release'
@@ -276,10 +270,6 @@ ppc64_aix:
       14: 'PATH+XLC=/opt/IBM/xlC/16.1.0/bin:/opt/IBM/xlc/16.1.0/bin CC=xlclang CXX=xlclang++'
       next: 'PATH+XLC=/opt/IBM/xlC/16.1.0/bin:/opt/IBM/xlc/16.1.0/bin CC=xlclang CXX=xlclang++'
   excluded_tests:
-    8:
-      - sanity.openjdk
-    11:
-      - sanity.openjdk
       - special.system
 #========================================#
 # Linux x86 64bits Compressed Pointers
@@ -298,8 +288,7 @@ x86-64_linux:
   node_labels:
     build: 'ci.role.build && hw.arch.x86 && sw.os.cent.6'
   extra_configure_options:
-    8: '--enable-jitserver'
-    11: '--enable-jitserver'
+    all: '--enable-jitserver'
   build_env:
     cmd: 'source /home/jenkins/set_gcc7.5.0_env'
     vars: 'OPENJ9_JAVA_OPTIONS=-Xdump:system+java:events=systhrow,filter=java/lang/ClassCastException,request=exclusive+prepwalk+preempt'
@@ -323,10 +312,7 @@ x86-64_linux_xl:
   extends: ['x86-64_linux', 'largeheap']
   excluded_tests:
     8:
-      - sanity.openjdk
       - special.system
-    11:
-      - sanity.openjdk
 #========================================#
 # Linux x86 64bits Compressed Pointers / Valhalla
 #========================================#
@@ -375,10 +361,7 @@ x86-64_windows:
   build_env:
     vars: 'PATH+TOOLS=/cygdrive/c/openjdk/LLVM64/bin:/cygdrive/c/openjdk/nasm-2.13.03'
   excluded_tests:
-    8:
-      - sanity.openjdk
     11:
-      - sanity.openjdk
       - special.system
 #========================================#
 # Windows x86 64bits Large Heap
@@ -405,10 +388,7 @@ x86-32_windows:
       8: 'PATH+TOOLS=/cygdrive/c/openjdk/LLVM32/bin:/cygdrive/c/openjdk/nasm-2.13.03'
   excluded_tests:
     8:
-      - sanity.openjdk
       - special.system
-    11:
-      - sanity.openjdk
 #========================================#
 # OSX x86 64bits Compressed Pointers
 #========================================#
@@ -436,10 +416,7 @@ x86-64_mac:
       all: 'OPENJ9_JAVA_OPTIONS=-Xdump:system+java:events=systhrow,filter=java/lang/ClassCastException,request=exclusive+prepwalk+preempt'
       8: 'MACOSX_DEPLOYMENT_TARGET=10.9.0 SDKPATH=/Users/jenkins/Xcode4/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.8.sdk'
   excluded_tests:
-    8:
-      - sanity.openjdk
     11:
-      - sanity.openjdk
       - special.system
 #========================================#
 # OSX x86 64bits Large Heap
diff --git a/debugtools/DDR_VM/src/com/ibm/j9ddr/vm29/j9/stackwalker/JITRegMap.java b/debugtools/DDR_VM/src/com/ibm/j9ddr/vm29/j9/stackwalker/JITRegMap.java
index 1a371bd5e29..bdf8fdabe84 100644
--- a/debugtools/DDR_VM/src/com/ibm/j9ddr/vm29/j9/stackwalker/JITRegMap.java
+++ b/debugtools/DDR_VM/src/com/ibm/j9ddr/vm29/j9/stackwalker/JITRegMap.java
@@ -429,7 +429,10 @@ public class JITRegMap {
 					0x11,   /* jit_r17 */
 					0x12,   /* jit_r18 */
 					0x13,   /* jit_r19 */
-					0x14    /* jit_r20 */
+					0x14,   /* jit_r20 */
+					0x1D,   /* jit_r29 */
+					0x1E,   /* jit_r30 */
+					0x1F    /* jit_r31 */
 			};
 
 			jitCalleeSavedRegisterList = new int[] {
diff --git a/debugtools/DDR_VM/src/com/ibm/j9ddr/vm29/j9/stackwalker/JITStackWalker.java b/debugtools/DDR_VM/src/com/ibm/j9ddr/vm29/j9/stackwalker/JITStackWalker.java
index 24e97352919..4c050e71682 100644
--- a/debugtools/DDR_VM/src/com/ibm/j9ddr/vm29/j9/stackwalker/JITStackWalker.java
+++ b/debugtools/DDR_VM/src/com/ibm/j9ddr/vm29/j9/stackwalker/JITStackWalker.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2009, 2019 IBM Corp. and others
+ * Copyright (c) 2009, 2020 IBM Corp. and others
  *
  * This program and the accompanying materials are made available under
  * the terms of the Eclipse Public License 2.0 which accompanies this
@@ -293,10 +293,6 @@ public FrameCallbackResult jitWalkStackFrames(WalkState walkState)
 			walkState.arg0EA = walkState.i2jState.a0();
 			returnSP = walkState.i2jState.returnSP();
 			walkState.previousFrameFlags = new UDATA(0);
-			if (returnSP.anyBitsIn(J9_STACK_FLAGS_ARGS_ALIGNED)) {
-				swPrintf(walkState, 2, "I2J args were copied for alignment");
-				walkState.previousFrameFlags = new UDATA(J9_STACK_FLAGS_JIT_ARGS_ALIGNED);
-			}
 			walkState.walkSP = returnSP.untag(3L);
 			swPrintf(walkState, 2, "I2J values: PC = {0}, A0 = {1}, walkSP = {2}, literals = {3}, JIT PC = {4}, pcAddress = {5}, decomp = {6}", 
 					walkState.pc.getHexAddress(),
diff --git a/doc/compiler/memory/MemoryManager.md b/doc/compiler/memory/MemoryManager.md
index 6c77fe5a334..7bb8bf0899f 100644
--- a/doc/compiler/memory/MemoryManager.md
+++ b/doc/compiler/memory/MemoryManager.md
@@ -1,5 +1,5 @@
 <!--
-Copyright (c) 2017, 2018 IBM Corp. and others
+Copyright (c) 2017, 2020 IBM Corp. and others
 
 This program and the accompanying materials are made available under
 the terms of the Eclipse Public License 2.0 which accompanies this
@@ -224,3 +224,20 @@ calling it `TR::PersistentSegmentProvider`, and have it use
 `TR::PersistentAllocator`. The `TR::Region` would then be provided this 
 `TR::PersistentSegmentProvider` object.
 
+The mechanism for limiting the memory usage during compilation can be summarized as:
+
+Default size of system segments allocatd by `J9::SystemSegmentProvider` is 16 MB. 
+These system segments are then carved into smaller segments based on the size requested
+which is rounded up to 64 KB. The cumulative memory usage of these system segments is limited 
+by the value of the option `scratchSpaceLimit`. When the scratch space limit is not a multiple
+of system segment size, it is possible that the total memory allocated using system segments
+would go beyond the scratch space limit. However, the logic in `J9::SystemSegmentProvider::request`
+would ensures that the compiler does not touch memory beyond the scratch space limit.
+So the physical memory usage due to scratch space stays with the limit specified. 
+If a request is made that would cause physical memory usage to go beyond the limit,
+then `J9::SystemSegmentProvider::request` would throw `std::bad_alloc`.
+
+When allocating a new system segment `J9::SegmentAllocator::allocate` also checks that the system
+has enough free physical memory. This is done by verifying that the free physical memory is more
+than the system segment size (=16 MB) plus an additional buffer, which is governed by the 
+option `safeReservePhysicalMemoryValue`. If this condition fails, then the compilation thread is suspended.
diff --git a/jcl/src/java.base/share/classes/com/ibm/oti/reflect/AnnotationParser.java b/jcl/src/java.base/share/classes/com/ibm/oti/reflect/AnnotationParser.java
index bf4411d47e3..59b9d8d0b4c 100644
--- a/jcl/src/java.base/share/classes/com/ibm/oti/reflect/AnnotationParser.java
+++ b/jcl/src/java.base/share/classes/com/ibm/oti/reflect/AnnotationParser.java
@@ -2,7 +2,7 @@
 package com.ibm.oti.reflect;
 
 /*******************************************************************************
- * Copyright (c) 2010, 2017 IBM Corp. and others
+ * Copyright (c) 2010, 2020 IBM Corp. and others
  *
  * This program and the accompanying materials are made available under
  * the terms of the Eclipse Public License 2.0 which accompanies this
@@ -25,6 +25,9 @@
 
 import java.lang.annotation.Annotation;
 import java.nio.ByteBuffer;
+import java.lang.reflect.Method;
+import java.lang.reflect.Field;
+import java.lang.reflect.Constructor;
 /*[IF Sidecar19-SE]
 import jdk.internal.reflect.ConstantPool;
 /*[ELSE]*/
@@ -33,23 +36,23 @@
 
 public class AnnotationParser {
 
-	public static Annotation[] parseAnnotations(java.lang.reflect.Field field) {
+	public static Annotation[] parseAnnotations(Field field) {
 		return parseAnnotations(getAnnotationsData(field), field.getDeclaringClass());
 	}
 
-	public static Annotation[] parseAnnotations(java.lang.reflect.Constructor constructor) {
+	public static Annotation[] parseAnnotations(Constructor constructor) {
 		return parseAnnotations(getAnnotationsData(constructor), constructor.getDeclaringClass());
 	}
 
-	public static Annotation[] parseAnnotations(java.lang.reflect.Method method) {
+	public static Annotation[] parseAnnotations(Method method) {
 		return parseAnnotations(getAnnotationsData(method), method.getDeclaringClass());
 	}
 
-	public static Annotation[][] parseParameterAnnotations(java.lang.reflect.Constructor constructor) {
+	public static Annotation[][] parseParameterAnnotations(Constructor constructor) {
 		return parseParameterAnnotations(getParameterAnnotationsData(constructor), constructor.getDeclaringClass(), constructor.getParameterTypes().length);
 	}
 
-	public static Annotation[][] parseParameterAnnotations(java.lang.reflect.Method method) {
+	public static Annotation[][] parseParameterAnnotations(Method method) {
 		return parseParameterAnnotations(getParameterAnnotationsData(method), method.getDeclaringClass(), method.getParameterTypes().length);
 	}
 	
@@ -65,7 +68,7 @@ public static  byte[] getAnnotationsData(java.lang.Class clazz) {
 		return result;
 	};
 	
-	public static Object parseDefaultValue(java.lang.reflect.Method method) {
+	public static Object parseDefaultValue(Method method) {
 		byte[] elementValueData = getDefaultValueData(method);
 		if (elementValueData == null) return null;
 		ByteBuffer buf = ByteBuffer.wrap(elementValueData);
@@ -103,12 +106,12 @@ public static Annotation[] parseAnnotations(byte[] annotationsData, Class clazz)
 						clazz));
 	}
 
-	private static native byte[] getAnnotationsData(java.lang.reflect.Field field);
-	private static native byte[] getAnnotationsData(java.lang.reflect.Constructor constructor);
-	private static native byte[] getAnnotationsData(java.lang.reflect.Method method);
-	private static native byte[] getParameterAnnotationsData(java.lang.reflect.Constructor constructor);
-	private static native byte[] getParameterAnnotationsData(java.lang.reflect.Method method);
-	private static native byte[] getDefaultValueData(java.lang.reflect.Method method);
+	private static native byte[] getAnnotationsData(Field field);
+	private static native byte[] getAnnotationsData(Constructor constructor);
+	private static native byte[] getAnnotationsData(Method method);
+	private static native byte[] getParameterAnnotationsData(Constructor constructor);
+	private static native byte[] getParameterAnnotationsData(Method method);
+	private static native byte[] getDefaultValueData(Method method);
 	static native ConstantPool getConstantPool(Class clazz);
 	private static native byte[] getAnnotationsDataImpl(java.lang.Class clazz);
 
diff --git a/jcl/src/java.base/share/classes/com/ibm/oti/reflect/Constructor.java b/jcl/src/java.base/share/classes/com/ibm/oti/reflect/Constructor.java
deleted file mode 100644
index 67ae8666592..00000000000
--- a/jcl/src/java.base/share/classes/com/ibm/oti/reflect/Constructor.java
+++ /dev/null
@@ -1,58 +0,0 @@
-/*[INCLUDE-IF Sidecar16]*/
-package com.ibm.oti.reflect;
-
-/*******************************************************************************
- * Copyright (c) 2005, 2010 IBM Corp. and others
- *
- * This program and the accompanying materials are made available under
- * the terms of the Eclipse Public License 2.0 which accompanies this
- * distribution and is available at https://www.eclipse.org/legal/epl-2.0/
- * or the Apache License, Version 2.0 which accompanies this distribution and
- * is available at https://www.apache.org/licenses/LICENSE-2.0.
- *
- * This Source Code may also be made available under the following
- * Secondary Licenses when the conditions for such availability set
- * forth in the Eclipse Public License, v. 2.0 are satisfied: GNU
- * General Public License, version 2 with the GNU Classpath
- * Exception [1] and GNU General Public License, version 2 with the
- * OpenJDK Assembly Exception [2].
- *
- * [1] https://www.gnu.org/software/classpath/license.html
- * [2] http://openjdk.java.net/legal/assembly-exception.html
- *
- * SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0 WITH Classpath-exception-2.0 OR LicenseRef-GPL-2.0 WITH Assembly-exception
- *******************************************************************************/
-
-import java.lang.annotation.Annotation;
-import java.lang.ref.SoftReference;
-
-public class Constructor {
-	private java.lang.reflect.Constructor constructor;
-	private SoftReference<Annotations> annotations;
-	
-public Constructor(java.lang.reflect.Constructor constructor) {
-	this.constructor = constructor;
-}
-
-private synchronized Annotations getAnnotations() {
-	Annotations ans;
-	if (annotations == null || (ans = annotations.get()) == null) {
-		annotations = new SoftReference<Annotations>(ans = new Annotations(AnnotationParser.parseAnnotations(constructor)));
-	}
-	return ans;
-}
-
-public <T extends Annotation> T getAnnotation(Class<T> cl) {
-	if (cl == null) throw new NullPointerException();
-	return getAnnotations().getAnnotation(cl);
-}
-
-public Annotation[] getDeclaredAnnotations() {
-	return getAnnotations().getAnnotations().clone();
-}
-
-public Annotation[][] getParameterAnnotations() {
-	return AnnotationParser.parseParameterAnnotations(constructor);
-}
-
-}
diff --git a/jcl/src/java.base/share/classes/com/ibm/oti/reflect/Field.java b/jcl/src/java.base/share/classes/com/ibm/oti/reflect/Field.java
deleted file mode 100644
index 9752e8fa0e1..00000000000
--- a/jcl/src/java.base/share/classes/com/ibm/oti/reflect/Field.java
+++ /dev/null
@@ -1,54 +0,0 @@
-/*[INCLUDE-IF Sidecar16]*/
-package com.ibm.oti.reflect;
-
-/*******************************************************************************
- * Copyright (c) 2005, 2010 IBM Corp. and others
- *
- * This program and the accompanying materials are made available under
- * the terms of the Eclipse Public License 2.0 which accompanies this
- * distribution and is available at https://www.eclipse.org/legal/epl-2.0/
- * or the Apache License, Version 2.0 which accompanies this distribution and
- * is available at https://www.apache.org/licenses/LICENSE-2.0.
- *
- * This Source Code may also be made available under the following
- * Secondary Licenses when the conditions for such availability set
- * forth in the Eclipse Public License, v. 2.0 are satisfied: GNU
- * General Public License, version 2 with the GNU Classpath
- * Exception [1] and GNU General Public License, version 2 with the
- * OpenJDK Assembly Exception [2].
- *
- * [1] https://www.gnu.org/software/classpath/license.html
- * [2] http://openjdk.java.net/legal/assembly-exception.html
- *
- * SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0 WITH Classpath-exception-2.0 OR LicenseRef-GPL-2.0 WITH Assembly-exception
- *******************************************************************************/
-
-import java.lang.annotation.Annotation;
-import java.lang.ref.SoftReference;
-
-public class Field {
-	private java.lang.reflect.Field field;
-	private SoftReference<Annotations> annotations;
-	
-public Field(java.lang.reflect.Field field) {
-	this.field = field;
-}
-
-private synchronized Annotations getAnnotations() {
-	Annotations ans;
-	if (annotations == null || (ans = annotations.get()) == null) {
-		annotations = new SoftReference<Annotations>(ans = new Annotations(AnnotationParser.parseAnnotations(field)));
-	}
-	return ans;
-}
-
-public <T extends Annotation> T getAnnotation(Class<T> cl) {
-	if (cl == null) throw new NullPointerException();
-	return getAnnotations().getAnnotation(cl);
-}
-
-public Annotation[] getDeclaredAnnotations() {
-	return getAnnotations().getAnnotations().clone();
-}
-
-}
diff --git a/jcl/src/java.base/share/classes/com/ibm/oti/reflect/Method.java b/jcl/src/java.base/share/classes/com/ibm/oti/reflect/Method.java
deleted file mode 100644
index 4d10a2ed1a5..00000000000
--- a/jcl/src/java.base/share/classes/com/ibm/oti/reflect/Method.java
+++ /dev/null
@@ -1,71 +0,0 @@
-/*[INCLUDE-IF Sidecar16]*/
-package com.ibm.oti.reflect;
-
-/*******************************************************************************
- * Copyright (c) 2005, 2014 IBM Corp. and others
- *
- * This program and the accompanying materials are made available under
- * the terms of the Eclipse Public License 2.0 which accompanies this
- * distribution and is available at https://www.eclipse.org/legal/epl-2.0/
- * or the Apache License, Version 2.0 which accompanies this distribution and
- * is available at https://www.apache.org/licenses/LICENSE-2.0.
- *
- * This Source Code may also be made available under the following
- * Secondary Licenses when the conditions for such availability set
- * forth in the Eclipse Public License, v. 2.0 are satisfied: GNU
- * General Public License, version 2 with the GNU Classpath
- * Exception [1] and GNU General Public License, version 2 with the
- * OpenJDK Assembly Exception [2].
- *
- * [1] https://www.gnu.org/software/classpath/license.html
- * [2] http://openjdk.java.net/legal/assembly-exception.html
- *
- * SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0 WITH Classpath-exception-2.0 OR LicenseRef-GPL-2.0 WITH Assembly-exception
- *******************************************************************************/
-
-import java.lang.annotation.Annotation;
-import java.lang.ref.SoftReference;
-
-
-public class Method {
-	private final java.lang.reflect.Method method;
-	private SoftReference<Annotations> annotations;
-	private SoftReference<Object> srDefaultValue;
-	
-public Method(java.lang.reflect.Method method) {
-	this.method = method;
-}
-
-private synchronized Annotations getAnnotations() {
-	Annotations ans;
-	if (annotations == null || (ans = annotations.get()) == null) {
-		annotations = new SoftReference<Annotations>(ans = new Annotations(AnnotationParser.parseAnnotations(method)));
-	}
-	return ans;
-}
-
-public <T extends Annotation> T getAnnotation(Class<T> cl) {
-	if (cl == null) throw new NullPointerException();
-	return getAnnotations().getAnnotation(cl);
-}
-
-
-public Annotation[] getDeclaredAnnotations() {
-	return getAnnotations().getAnnotations().clone();
-}
-
-public Object getDefaultValue() {
-	Object defaultValue;
-	synchronized(this) {
-		if (srDefaultValue == null || (defaultValue = srDefaultValue.get()) == null) {
-			srDefaultValue = new SoftReference<Object>(defaultValue = AnnotationParser.parseDefaultValue(method));
-		}
-	}
-	return defaultValue;
-}
-
-public Annotation[][] getParameterAnnotations() {
-	return AnnotationParser.parseParameterAnnotations(method);
-}
-
-}
diff --git a/jcl/src/java.base/share/classes/java/lang/Class.java b/jcl/src/java.base/share/classes/java/lang/Class.java
index f88394868fd..842a6dff13b 100644
--- a/jcl/src/java.base/share/classes/java/lang/Class.java
+++ b/jcl/src/java.base/share/classes/java/lang/Class.java
@@ -2019,7 +2019,9 @@ private boolean useModularSearch(String absoluteResName, Module thisModule, Clas
 	boolean visible = false;
 
 	if (thisModule.isNamed()) {
-		final Module callerModule = callerClass.getModule();
+		// When the caller class is null, assuming it is loaded by module java.base.
+		// See https://github.com/eclipse/openj9/issues/8993 for more info.
+		final Module callerModule = callerClass == null ? Class.class.getModule() : callerClass.getModule();
 		visible = (thisModule == callerModule);
 		if (!visible) {
 			visible = absoluteResName.endsWith(".class"); //$NON-NLS-1$
diff --git a/jcl/src/openj9.dtfj/share/classes/com/ibm/dtfj/corereaders/CoreReaderSupport.java b/jcl/src/openj9.dtfj/share/classes/com/ibm/dtfj/corereaders/CoreReaderSupport.java
index a11a782ef1b..a1a473e4975 100644
--- a/jcl/src/openj9.dtfj/share/classes/com/ibm/dtfj/corereaders/CoreReaderSupport.java
+++ b/jcl/src/openj9.dtfj/share/classes/com/ibm/dtfj/corereaders/CoreReaderSupport.java
@@ -1,6 +1,6 @@
 /*[INCLUDE-IF Sidecar18-SE]*/
 /*******************************************************************************
- * Copyright (c) 2004, 2017 IBM Corp. and others
+ * Copyright (c) 2004, 2020 IBM Corp. and others
  *
  * This program and the accompanying materials are made available under
  * the terms of the Eclipse Public License 2.0 which accompanies this
@@ -72,6 +72,7 @@ protected byte[] coreReadBytes(int n) throws IOException {
 		return _reader.readBytes(n);
 	}
 
+	@Override
 	public IAbstractAddressSpace getAddressSpace() {
 		if (null == _addressSpace) {
 			MemoryRange[] ranges = getMemoryRangesAsArray();
@@ -89,6 +90,7 @@ public IAbstractAddressSpace getAddressSpace() {
 		return _addressSpace;
 	}
 	
+	@Override
 	public boolean isTruncated() {
 		return false;
 	}
@@ -110,7 +112,8 @@ protected boolean coreCheckOffset (long location) throws IOException {
 		coreSeek(currentPos);
 		return canRead;
 	}
-	
+
+	@Override
 	public void releaseResources() throws IOException {
 		_reader.releaseResources();
 	}
diff --git a/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/CombinedContext.java b/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/CombinedContext.java
index aa3781fd309..2fbda46c845 100644
--- a/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/CombinedContext.java
+++ b/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/CombinedContext.java
@@ -1,6 +1,6 @@
 /*[INCLUDE-IF Sidecar18-SE]*/
 /*******************************************************************************
- * Copyright (c) 2011, 2017 IBM Corp. and others
+ * Copyright (c) 2011, 2020 IBM Corp. and others
  *
  * This program and the accompanying materials are made available under
  * the terms of the Eclipse Public License 2.0 which accompanies this
@@ -201,38 +201,38 @@ private boolean isDDRCommand(String cmdline) {
 	 */
 	public void startDDRInteractiveSession(Image image, PrintStream out) {
 		ddrAvailable = false;
-		//late bind / reflect to the DDR -interactive main class so as not to provide a compile time link
-		Class<?> ddriClass = null;
+		// late bind / reflect to the DDR -interactive main class so as not to provide a compile time link
+		Class<?> ddriClass;
 		try {
-			//ddriClass = Class.forName(DDR_INTERACTIVE_CLASS, true, image.getClass().getClassLoader());
 			ddriClass = Class.forName(DDR_INTERACTIVE_CLASS, true, image.getClass().getClassLoader());
 		} catch (ClassNotFoundException e) {
 			logger.fine("DDR is not enabled for " + image.getSource() + " (context " + id + "). It may be pre-DDR or not a core file e.g. javacore or PHD");
 			return;
 		}
-		Constructor<?> constructor = null;
+		Constructor<?> constructor;
 		try {
-			constructor = ddriClass.getConstructor(new Class[]{List.class, PrintStream.class});
+			constructor = ddriClass.getConstructor(List.class, PrintStream.class);
 		} catch (Exception e) {
 			logger.log(Level.FINE, "Error getting DDR Interactive constructor", e);
 			return;
 		}
 		try {
-			ArrayList<Object> contexts = new ArrayList<Object>();
-			contexts.add((DTFJContext)this);
+			List<Object> contexts = new ArrayList<>(1);
+			contexts.add(this);
 			ddriObject = constructor.newInstance(contexts, out);
-			ddriMethod = ddriObject.getClass().getMethod("processLine", new Class[]{String.class});
+			ddriMethod = ddriObject.getClass().getMethod("processLine", String.class);
 			ddrAvailable = true;
 			if (hasPropertyBeenSet(VERBOSE_MODE_PROPERTY)) {
 				out.println("DTFJ DDR is enabled for this core dump");
 			}
-		} catch(InvocationTargetException e) {
-			if((e.getCause() != null) && (e.getCause() instanceof UnsupportedOperationException)) {
-				//this is thrown if DDR is not supported for this DTFJ Image e.g. it's pre-DDR, or a javacore etc.
+		} catch (InvocationTargetException e) {
+			Throwable cause = e.getCause();
+			if ((cause != null) && (cause instanceof UnsupportedOperationException)) {
+				// this is thrown if DDR is not supported for this DTFJ Image e.g. it's pre-DDR, or a javacore etc.
 				logger.fine("DDR is not enabled for " + image.getSource() + " (context " + id + "). It may be pre-DDR or not a core file e.g. javacore or PHD");
 			} else {
-				//for an invocation exception show the cause not the reflection exception
-				ddrStartupException = e.getCause();
+				// for an invocation exception show the cause not the reflection exception
+				ddrStartupException = cause;
 				logger.log(Level.FINE, "Error creating DDR Interactive instance", e.getCause());
 			}
 		} catch (Exception e) {
diff --git a/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/DeadlockCommand.java b/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/DeadlockCommand.java
index 4b3cdbcf5c9..952d1bf5fb0 100644
--- a/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/DeadlockCommand.java
+++ b/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/DeadlockCommand.java
@@ -1,6 +1,6 @@
 /*[INCLUDE-IF Sidecar18-SE]*/
 /*******************************************************************************
- * Copyright (c) 2004, 2018 IBM Corp. and others
+ * Copyright (c) 2004, 2020 IBM Corp. and others
  *
  * This program and the accompanying materials are made available under
  * the terms of the Eclipse Public License 2.0 which accompanies this
@@ -24,8 +24,6 @@
 
 import java.io.PrintStream;
 import java.util.Iterator;
-import java.util.LinkedList;
-import java.util.List;
 import java.util.SortedMap;
 import java.util.TreeMap;
 import java.util.Vector;
@@ -65,9 +63,9 @@ public void run(String command, String[] args, IContext context, PrintStream out
 	
 	public void doCommand()
 	{
-		SortedMap monitorNodes = new TreeMap();
+		SortedMap<Long, MonitorNode> monitorNodes = new TreeMap<>();
 		JavaRuntime jr = ctx.getRuntime();
-		Iterator itMonitor = jr.getMonitors();
+		Iterator<?> itMonitor = jr.getMonitors();
 		int nodeListNum = 0;
 		
 		out.print("\n  deadlocks for runtime \n");
@@ -123,7 +121,7 @@ public void doCommand()
 		// heap. But the active ones can be found by walking the thread list and looking
 		// at the blocking objects. (Any others aren't blocking any threads anyway so aren't
 		// interesting.
-		Iterator itThread = jr.getThreads();
+		Iterator<?> itThread = jr.getThreads();
 		while (itThread.hasNext()) {
 			try {
 				Object o = itThread.next();
@@ -164,7 +162,7 @@ public void doCommand()
 			}
 		}
 
-		Iterator values = monitorNodes.values().iterator();
+		Iterator<?> values = monitorNodes.values().iterator();
 		
 		// Step 2. iterate over Hashtable and for every MonitorNode, iterate over monitor m1's
 		// enter waiters (JavaMonitor.getEnterWaiters()), which are JavaThreads, and for each 
@@ -172,7 +170,7 @@ public void doCommand()
 		while (values.hasNext()) {
 			MonitorNode currNode = (MonitorNode)values.next();
 			
-			Iterator itWaiters = currNode.getEnterWaiters();
+			Iterator<?> itWaiters = currNode.getEnterWaiters();
 			while (itWaiters.hasNext()) {
 				Object o = itWaiters.next();
 				if( !(o instanceof JavaThread) ) {
@@ -201,7 +199,7 @@ public void doCommand()
 
 		values = monitorNodes.values().iterator();
 		int visit = 1;
-		Vector lists = new Vector();
+		Vector<NodeList> lists = new Vector<>();
 		
 		// Step 3. iterate over Hashtable and for every MonitorNode m1:
 		// Step 3a. set a unique visit number, visit > 0 (visit++ would work)
@@ -349,7 +347,7 @@ public void doCommand()
 		}
 		
 		boolean lastListWasLoop = true;
-		Iterator itList = lists.iterator();
+		Iterator<NodeList> itList = lists.iterator();
 
 		// Step 5. print the lists
 		while (itList.hasNext())
diff --git a/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/FindCommand.java b/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/FindCommand.java
index 251638847a4..bd0e64079a0 100644
--- a/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/FindCommand.java
+++ b/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/FindCommand.java
@@ -1,6 +1,6 @@
 /*[INCLUDE-IF Sidecar18-SE]*/
 /*******************************************************************************
- * Copyright (c) 2004, 2019 IBM Corp. and others
+ * Copyright (c) 2004, 2020 IBM Corp. and others
  *
  * This program and the accompanying materials are made available under
  * the terms of the Eclipse Public License 2.0 which accompanies this
@@ -46,7 +46,7 @@ public class FindCommand extends BaseJdmpviewCommand{
 	 */	
 	FindAttribute findAtt = new FindAttribute();
 	StringBuffer sb = new StringBuffer();
-	ArrayList matches = new ArrayList();
+	ArrayList<Long> matches = new ArrayList<>();
 	
 	{
 		addCommand("find", "", "searches memory for a given string. Please run \"help find\" for details.");	
@@ -75,7 +75,7 @@ public void doCommand(String[] params){
 		if (!isParametersValid(params)) return;
 		determineModeFromPattern();
 		if (!parseParams(params)) return;
-		Iterator imageSections = ctx.getAddressSpace().getImageSections();
+		Iterator<?> imageSections = ctx.getAddressSpace().getImageSections();
 		
 		while(imageSections.hasNext()){
 			if (matches.size() > findAtt.numMatchesToDisplay) break;
@@ -83,7 +83,7 @@ public void doCommand(String[] params){
 			if (scanImageSection(imageSection)) break;
 		}
 		if (matches.size() > 0) 
-			findAtt.lastMatch = ((Long)matches.get(matches.size()-1)).longValue();
+			findAtt.lastMatch = matches.get(matches.size() - 1).longValue();
 		ctx.getProperties().put(Utils.FIND_ATTRIBUTES, findAtt);
 		doPrint();
 		if (matches.size() > 0) 
@@ -105,15 +105,15 @@ private void printLastMatchContent(){
 				+ findAtt.numBytesToPrint, out);
 	}
 	
-	private void doPrint(){
+	private void doPrint() {
 		int size = matches.size();
-		if(0 == size){
+		if (0 == size) {
 			sb.append("No matches found.\n");
 		}
 		else{
 			int limit = Math.min(findAtt.numMatchesToDisplay, size);
-			for(int i = 0; i < limit; i++){
-				long match = ((Long)matches.get(i)).longValue();
+			for (int i = 0; i < limit; i++) {
+				long match = matches.get(i).longValue();
 				sb.append("#" + i + ": " + "0x" + Long.toHexString(match) + "\n");
 			}
 		}
@@ -148,17 +148,17 @@ else if(findAtt.startAddress <= imageEndAddress && findAtt.startAddress >= image
 	private boolean scanRegion(long start, long end, ImageSection imageSection){
 		ImagePointer imagePointer = imageSection.getBaseAddress();
 		long i;
-		if (0 != start%findAtt.boundary) {
-			i = start - start%findAtt.boundary + findAtt.boundary;
+		if (0 != start % findAtt.boundary) {
+			i = start - start % findAtt.boundary + findAtt.boundary;
 		} else {
 			i = start;
 		}
 		int patternLength = findAtt.length();
 		byte[] bytes = findAtt.getBytes();
 		
-		for(; i <= end; i+=findAtt.boundary){
+		for (; i <= end; i += findAtt.boundary) {
 			int j;
-			for(j = 0; j < patternLength; j++){
+			for (j = 0; j < patternLength; j++) {
 				byte oneByte = bytes[j];
 				try {
 					if (getByteFromImage(imagePointer, i+j) == oneByte){
@@ -171,7 +171,7 @@ private boolean scanRegion(long start, long end, ImageSection imageSection){
 					return false;
 				}
 			}
-			if (j >= patternLength){
+			if (j >= patternLength) {
 				matches.add(Long.valueOf(i));
 				if (matches.size() == findAtt.numMatchesToDisplay) 
 					return true;
@@ -253,7 +253,7 @@ private void determineModeFromPattern(){
 	
 	private void alignBits(){
 		int patternLength = findAtt.pattern.length();
-		if (0 != patternLength%2){
+		if (0 != patternLength % 2) {
 			findAtt.pattern = "0" + findAtt.pattern;
 		}
 	}
diff --git a/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/OpenCommand.java b/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/OpenCommand.java
index b7d9d7b9bb8..05a7580bcd2 100644
--- a/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/OpenCommand.java
+++ b/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/OpenCommand.java
@@ -1,6 +1,6 @@
 /*[INCLUDE-IF Sidecar18-SE]*/
 /*******************************************************************************
- * Copyright (c) 2011, 2017 IBM Corp. and others
+ * Copyright (c) 2011, 2020 IBM Corp. and others
  *
  * This program and the accompanying materials are made available under
  * the terms of the Eclipse Public License 2.0 which accompanies this
@@ -47,7 +47,6 @@
 import com.ibm.dtfj.java.JavaRuntime;
 import com.ibm.dtfj.utils.file.FileManager;
 import com.ibm.java.diagnostics.utils.IContext;
-import com.ibm.java.diagnostics.utils.IDTFJContext;
 import com.ibm.java.diagnostics.utils.commands.CommandException;
 import com.ibm.jvm.dtfjview.CombinedContext;
 import com.ibm.jvm.dtfjview.JdmpviewContextManager;
@@ -264,4 +263,3 @@ public void printDetailedHelp(PrintStream out) {
 	}
 
 }
-
diff --git a/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/infocommands/InfoClassCommand.java b/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/infocommands/InfoClassCommand.java
index 798c000b1c9..7b0ad3bcb8c 100644
--- a/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/infocommands/InfoClassCommand.java
+++ b/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/infocommands/InfoClassCommand.java
@@ -1,6 +1,6 @@
 /*[INCLUDE-IF Sidecar18-SE]*/
 /*******************************************************************************
- * Copyright (c) 2004, 2017 IBM Corp. and others
+ * Copyright (c) 2004, 2020 IBM Corp. and others
  *
  * This program and the accompanying materials are made available under
  * the terms of the Eclipse Public License 2.0 which accompanies this
@@ -35,7 +35,6 @@
 
 import com.ibm.dtfj.image.CorruptData;
 import com.ibm.dtfj.image.CorruptDataException;
-import com.ibm.dtfj.image.DataUnavailable;
 import com.ibm.dtfj.java.JavaClass;
 import com.ibm.dtfj.java.JavaClassLoader;
 import com.ibm.dtfj.java.JavaHeap;
@@ -245,12 +244,12 @@ private void cacheRuntimeClasses() {
 		JavaRuntime runtime = ctx.getRuntime();
 		classInstanceCounts.put(runtime, classesOfThisRuntime);
 
-		Iterator itClassLoader = runtime.getJavaClassLoaders();
+		Iterator<?> itClassLoader = runtime.getJavaClassLoaders();
 
 		while (itClassLoader.hasNext()) {
 			JavaClassLoader jcl = (JavaClassLoader)itClassLoader.next();
 			
-			Iterator itClass = jcl.getDefinedClasses();
+			Iterator<?> itClass = jcl.getDefinedClasses();
 			while (itClass.hasNext()) {
 				Object obj = itClass.next();
 				if(obj instanceof JavaClass) {
@@ -319,7 +318,7 @@ private void countClassInstances() {
 		long corruptClassCount = 0;
 		long corruptClassNameCount = 0;
 		
-		Iterator itHeap = runtime.getHeaps();
+		Iterator<?> itHeap = runtime.getHeaps();
 		while (itHeap.hasNext()) {
 			Object heap = itHeap.next();
 			if(heap instanceof CorruptData) {
@@ -327,7 +326,7 @@ private void countClassInstances() {
 				continue;
 			}
 			JavaHeap jh = (JavaHeap)heap;
-			Iterator itObject = jh.getObjects();
+			Iterator<?> itObject = jh.getObjects();
 			
 			// Walk through all objects in this heap, accumulating counts and total memory size by class
 			while (itObject.hasNext()) {
diff --git a/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/infocommands/InfoHeapCommand.java b/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/infocommands/InfoHeapCommand.java
index 6a541271302..09442c72383 100644
--- a/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/infocommands/InfoHeapCommand.java
+++ b/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/infocommands/InfoHeapCommand.java
@@ -1,6 +1,6 @@
 /*[INCLUDE-IF Sidecar18-SE]*/
 /*******************************************************************************
- * Copyright (c) 2004, 2017 IBM Corp. and others
+ * Copyright (c) 2004, 2020 IBM Corp. and others
  *
  * This program and the accompanying materials are made available under
  * the terms of the Eclipse Public License 2.0 which accompanies this
@@ -72,8 +72,7 @@ public void run(String command, String[] args, IContext context, PrintStream out
 
 
 	private void printHeapInfo(String param, JavaRuntime runtime, PrintStream out){
-		
-		Iterator itHeaps = runtime.getHeaps();
+		Iterator<?> itHeaps = runtime.getHeaps();
 		int countheaps = 1;
 		
 		while (itHeaps.hasNext())
@@ -92,8 +91,7 @@ private void printHeapInfo(String param, JavaRuntime runtime, PrintStream out){
 		}
 	}
 	private void printSectionInfo(JavaHeap theHeap, PrintStream out){
-		
-		Iterator itSections = theHeap.getSections();
+		Iterator<?> itSections = theHeap.getSections();
 		int countSections = 1;
 		
 		while (itSections.hasNext()){
@@ -118,8 +116,7 @@ private void printSectionInfo(JavaHeap theHeap, PrintStream out){
 	private boolean searchForHeap(String param, JavaRuntime jr, PrintStream out){
 		
 		boolean foundHeap = false;
-		
-		Iterator itHeaps = jr.getHeaps();
+		Iterator<?> itHeaps = jr.getHeaps();
 		int countheaps = 1;
 		
 		while (itHeaps.hasNext())
@@ -148,7 +145,7 @@ private void printOccupancyInfo(JavaHeap theHeap, PrintStream out){
 		long totalObjects = 0;				//total number of objects on the heap
 		long totalCorruptObjects = 0;		//total number of corrupt objects 
 		
-		Iterator itSections = theHeap.getSections();
+		Iterator<?> itSections = theHeap.getSections();
 		Object obj = null;					//object returned from various iterators
 		CorruptData cdata = null;			//corrupt data
 		while (itSections.hasNext()){
@@ -167,7 +164,7 @@ private void printOccupancyInfo(JavaHeap theHeap, PrintStream out){
 		}
 		out.print("\t  Size of heap: "+ size + " bytes\n");
 		
-		Iterator itObjects = theHeap.getObjects();
+		Iterator<?> itObjects = theHeap.getObjects();
 		try{
 			while (itObjects.hasNext()){
 				obj = itObjects.next();
diff --git a/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/infocommands/InfoJitmCommand.java b/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/infocommands/InfoJitmCommand.java
index fdb250b9884..a02f8d2d928 100644
--- a/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/infocommands/InfoJitmCommand.java
+++ b/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/infocommands/InfoJitmCommand.java
@@ -1,6 +1,6 @@
 /*[INCLUDE-IF Sidecar18-SE]*/
 /*******************************************************************************
- * Copyright (c) 2004, 2017 IBM Corp. and others
+ * Copyright (c) 2004, 2020 IBM Corp. and others
  *
  * This program and the accompanying materials are made available under
  * the terms of the Eclipse Public License 2.0 which accompanies this
@@ -58,16 +58,16 @@ public void run(String command, String[] args, IContext context, PrintStream out
 	
 	private void showJITdMethods() {
 		JavaRuntime jr = ctx.getRuntime();
-		Iterator itJavaClassLoader = jr.getJavaClassLoaders();
+		Iterator<?> itJavaClassLoader = jr.getJavaClassLoaders();
 		while (itJavaClassLoader.hasNext())
 		{
 			JavaClassLoader jcl = (JavaClassLoader)itJavaClassLoader.next();
-			Iterator itJavaClass = jcl.getDefinedClasses();
+			Iterator<?> itJavaClass = jcl.getDefinedClasses();
 			
 			while (itJavaClass.hasNext())
 			{
 				JavaClass jc = (JavaClass)itJavaClass.next();
-				Iterator itJavaMethod = jc.getDeclaredMethods();
+				Iterator<?> itJavaMethod = jc.getDeclaredMethods();
 				
 				String jcName;
 				try {
@@ -96,7 +96,7 @@ private void showJITdMethods() {
 
 					if (jm.getCompiledSections().hasNext())
 					{
-						Iterator itImageSection = jm.getCompiledSections();
+						Iterator<?> itImageSection = jm.getCompiledSections();
 						while (itImageSection.hasNext())
 						{
 							ImageSection is = (ImageSection)itImageSection.next();
diff --git a/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/infocommands/InfoLockCommand.java b/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/infocommands/InfoLockCommand.java
index e4c932d54a3..646fefcf234 100644
--- a/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/infocommands/InfoLockCommand.java
+++ b/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/infocommands/InfoLockCommand.java
@@ -1,6 +1,6 @@
 /*[INCLUDE-IF Sidecar18-SE]*/
 /*******************************************************************************
- * Copyright (c) 2004, 2017 IBM Corp. and others
+ * Copyright (c) 2004, 2020 IBM Corp. and others
  *
  * This program and the accompanying materials are made available under
  * the terms of the Eclipse Public License 2.0 which accompanies this
@@ -36,12 +36,10 @@
 import com.ibm.dtfj.image.ImageThread;
 import com.ibm.dtfj.image.MemoryAccessException;
 import com.ibm.dtfj.java.JavaClass;
-import com.ibm.dtfj.java.JavaField;
 import com.ibm.dtfj.java.JavaMonitor;
 import com.ibm.dtfj.java.JavaObject;
 import com.ibm.dtfj.java.JavaRuntime;
 import com.ibm.dtfj.java.JavaThread;
-import com.ibm.dtfj.runtime.ManagedRuntime;
 import com.ibm.java.diagnostics.utils.IContext;
 import com.ibm.java.diagnostics.utils.commands.CommandException;
 import com.ibm.java.diagnostics.utils.plugins.DTFJPlugin;
@@ -68,9 +66,9 @@ public void run(String command, String[] args, IContext context, PrintStream out
 	}
 	
 	private void showSystemLocks() {
-		Vector vMonitorsWithLockedObjects = new Vector();
+		Vector<JavaMonitor> vMonitorsWithLockedObjects = new Vector<>();
 		JavaRuntime jRuntime = ctx.getRuntime();
-		Iterator monitors = jRuntime.getMonitors();
+		Iterator<?> monitors = jRuntime.getMonitors();
 		
 		out.println("\nSystem locks...");
 		while (monitors.hasNext()){
@@ -110,7 +108,7 @@ private void showSystemLocks() {
 	private void showWaiters(JavaMonitor jMonitor)
 			throws CorruptDataException {
 		// List any threads waiting on enter or notify for this monitor
-		Iterator itEnterWaiter = jMonitor.getEnterWaiters();
+		Iterator<?> itEnterWaiter = jMonitor.getEnterWaiters();
 		while (itEnterWaiter.hasNext()) {
 			Object t = itEnterWaiter.next();
 			if( !(t instanceof JavaThread) ) {
@@ -125,7 +123,7 @@ private void showWaiters(JavaMonitor jMonitor)
 				logger.log(Level.FINE, Exceptions.getDataUnavailableString(), dae);
 			}
 		}
-		Iterator itNotifyWaiter = jMonitor.getNotifyWaiters();
+		Iterator<?> itNotifyWaiter = jMonitor.getNotifyWaiters();
 		while (itNotifyWaiter.hasNext()) {
 			Object t = itNotifyWaiter.next();
 			if( !(t instanceof JavaThread) ) {
@@ -142,15 +140,15 @@ private void showWaiters(JavaMonitor jMonitor)
 		}
 	}
 	
-	private void showLockedObjects(Vector vMonitorsWithLockedObjects) {
+	private void showLockedObjects(Vector<JavaMonitor> vMonitorsWithLockedObjects) {
 		out.println("\nObject Locks in use...");
 		if (0 == vMonitorsWithLockedObjects.size()){
 			out.println("\t...None.");
 			return;
 		}
-		Iterator lockedObjects = vMonitorsWithLockedObjects.iterator();
+		Iterator<JavaMonitor> lockedObjects = vMonitorsWithLockedObjects.iterator();
 		while(lockedObjects.hasNext()){
-			JavaMonitor jMonitor = (JavaMonitor)lockedObjects.next();
+			JavaMonitor jMonitor = lockedObjects.next();
 			JavaObject jObject = jMonitor.getObject();
 			try{
 				JavaThread owner = jMonitor.getOwner();
@@ -182,22 +180,22 @@ private void showLockedObjects(Vector vMonitorsWithLockedObjects) {
 	
 	private void showJavaUtilConcurrentLocks() {
 		// A map of lock objects and their waiting threads.
-		Map locksToThreads = new HashMap();
+		Map<JavaObject, List<JavaThread>> locksToThreads = new HashMap<>();
 		JavaRuntime jr = ctx.getRuntime();
-		Iterator itThread = jr.getThreads();
+		Iterator<?> itThread = jr.getThreads();
 		while (itThread.hasNext()) {
 			try {
 				Object o = itThread.next();
-				if( !(o instanceof JavaThread) ) {
+				if (!(o instanceof JavaThread)) {
 					continue;
 				}
-				JavaThread jt = (JavaThread)o;
-				if( (jt.getState() & JavaThread.STATE_PARKED) != 0 ) {
+				JavaThread jt = (JavaThread) o;
+				if ((jt.getState() & JavaThread.STATE_PARKED) != 0) {
 					JavaObject lock = jt.getBlockingObject();
-					if( lock != null ) {
-						List parkedList = (List)locksToThreads.get(lock);
-						if( parkedList == null ) {
-							parkedList = new LinkedList();
+					if (lock != null) {
+						List<JavaThread> parkedList = locksToThreads.get(lock);
+						if (parkedList == null) {
+							parkedList = new LinkedList<>();
 							locksToThreads.put(lock, parkedList);
 						}
 						parkedList.add(jt);
@@ -216,11 +214,10 @@ private void showJavaUtilConcurrentLocks() {
 			out.println("\t...None.");
 			out.println();
 		}
-		for( Object e: locksToThreads.entrySet() ) {
+		for (Map.Entry<JavaObject, List<JavaThread>> entry : locksToThreads.entrySet()) {
 			try {
-				Map.Entry entry = (Map.Entry)e;
-				JavaObject lock = (JavaObject)entry.getKey();
-				List threads = (List)entry.getValue();
+				JavaObject lock = entry.getKey();
+				List<JavaThread> threads = entry.getValue();
 				String threadName = "<unowned>";
 				JavaThread lockOwnerThread = Utils.getParkBlockerOwner(lock, ctx.getRuntime());
 				if( lockOwnerThread != null ) {
diff --git a/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/infocommands/InfoMemoryCommand.java b/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/infocommands/InfoMemoryCommand.java
index 892171734da..36e3b01f630 100644
--- a/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/infocommands/InfoMemoryCommand.java
+++ b/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/infocommands/InfoMemoryCommand.java
@@ -1,6 +1,6 @@
 /*[INCLUDE-IF Sidecar18-SE]*/
 /*******************************************************************************
- * Copyright (c) 2013, 2017 IBM Corp. and others
+ * Copyright (c) 2013, 2020 IBM Corp. and others
  *
  * This program and the accompanying materials are made available under
  * the terms of the Eclipse Public License 2.0 which accompanies this
@@ -56,7 +56,7 @@ public void run(String command, String[] args, IContext context, PrintStream out
 		JavaRuntime runtime = ctx.getRuntime();
 
 		try {
-			Iterator memoryCategories = runtime.getMemoryCategories();
+			Iterator<?> memoryCategories = runtime.getMemoryCategories();
 			printAllMemoryCategories(out, memoryCategories);
 			printDbgmallocWarning(out, runtime);
 		} catch (DataUnavailable du) {
@@ -100,7 +100,7 @@ private void printDbgmallocWarning(PrintStream out, JavaRuntime runtime) {
 	 * @param out the PrintStream to write to.
 	 * @param memoryCategories the memory categories to write
 	 */
-	private void printAllMemoryCategories(PrintStream out, Iterator memoryCategories) {
+	private void printAllMemoryCategories(PrintStream out, Iterator<?> memoryCategories) {
 		try {
 			while (memoryCategories.hasNext()) {
 				Object obj = memoryCategories.next();
@@ -147,7 +147,7 @@ private void printCategory(JavaRuntimeMemoryCategory category, LinkedList<Intege
 				/* Only descend if there's really more data in sub categories unaccounted for. */
 				if( category.getDeepBytes() > category.getShallowBytes() ) {
 					
-					Iterator memoryCategories = category.getChildren();
+					Iterator<?> memoryCategories = category.getChildren();
 					JavaRuntimeMemoryCategory other = getOtherCategory(category);
 					
 					while (memoryCategories.hasNext()) {
@@ -187,7 +187,7 @@ private void printCategory(JavaRuntimeMemoryCategory category, LinkedList<Intege
 	private static int countPrintableChildren(JavaRuntimeMemoryCategory category) throws CorruptDataException {
 		int children = 0;
 		if (category.getDeepBytes() > category.getShallowBytes()) {
-			Iterator memoryCategories = category.getChildren();
+			Iterator<?> memoryCategories = category.getChildren();
 			while (memoryCategories.hasNext()) {
 				Object obj = memoryCategories.next();
 				if( obj instanceof JavaRuntimeMemoryCategory) {
diff --git a/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/infocommands/InfoMmapCommand.java b/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/infocommands/InfoMmapCommand.java
index 14cb3155725..43cb6d24381 100644
--- a/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/infocommands/InfoMmapCommand.java
+++ b/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/infocommands/InfoMmapCommand.java
@@ -1,6 +1,6 @@
 /*[INCLUDE-IF Sidecar18-SE]*/
 /*******************************************************************************
- * Copyright (c) 2004, 2017 IBM Corp. and others
+ * Copyright (c) 2004, 2020 IBM Corp. and others
  *
  * This program and the accompanying materials are made available under
  * the terms of the Eclipse Public License 2.0 which accompanies this
@@ -77,10 +77,10 @@ public void run(String command, String[] args, IContext context, PrintStream out
 			}
 		}
 
-		List<ImageSection> sortedSections = new LinkedList<ImageSection>();
-		Iterator<ImageSection> imageSections = ctx.getAddressSpace().getImageSections();
-		while( imageSections.hasNext() ) {
-			sortedSections.add(imageSections.next());
+		List<ImageSection> sortedSections = new LinkedList<>();
+		Iterator<?> imageSections = ctx.getAddressSpace().getImageSections();
+		while (imageSections.hasNext()) {
+			sortedSections.add((ImageSection) imageSections.next());
 		}
 		if( sortOrder != null ) {
 			Collections.sort(sortedSections, sortOrder);
@@ -101,11 +101,11 @@ public void run(String command, String[] args, IContext context, PrintStream out
 		out.println();
 		long totalSize = 0;
 		long totalSizeRwx = 0;
-		Iterator sortedIterator = sortedSections.iterator();
-		while(sortedIterator.hasNext()){
-			ImageSection imageSection = (ImageSection)sortedIterator.next();
-			if( addressPointer != null ) {
-				if( imageSection.getBaseAddress().getAddress() <= addressPointer.getAddress() &&
+		Iterator<ImageSection> sortedIterator = sortedSections.iterator();
+		while (sortedIterator.hasNext()) {
+			ImageSection imageSection = sortedIterator.next();
+			if (addressPointer != null) {
+				if (imageSection.getBaseAddress().getAddress() <= addressPointer.getAddress() &&
 					imageSection.getBaseAddress().add(imageSection.getSize()).getAddress() > addressPointer.getAddress() ) {
 					// Print this address
 				} else {
diff --git a/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/infocommands/InfoSymCommand.java b/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/infocommands/InfoSymCommand.java
index 8409b857fd8..a8326906842 100644
--- a/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/infocommands/InfoSymCommand.java
+++ b/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/infocommands/InfoSymCommand.java
@@ -1,6 +1,6 @@
 /*[INCLUDE-IF Sidecar18-SE]*/
 /*******************************************************************************
- * Copyright (c) 2004, 2017 IBM Corp. and others
+ * Copyright (c) 2004, 2020 IBM Corp. and others
  *
  * This program and the accompanying materials are made available under
  * the terms of the Eclipse Public License 2.0 which accompanies this
@@ -99,7 +99,7 @@ private void listModules(String moduleName) {
 		} catch (CorruptDataException e) {
 			out.println(Exceptions.getCorruptDataExceptionString());
 		}
-		Iterator iLibs;
+		Iterator<?> iLibs;
 		try {
 			iLibs = ip.getLibraries();
 		} catch (DataUnavailable du) {
@@ -157,7 +157,7 @@ private void printModule(ImageModule imageModule, boolean printSymbols) {
 			// if we do not have the load address, simply omit it
 		}
 
-		Iterator itSection = imageModule.getSections();
+		Iterator<?> itSection = imageModule.getSections();
 		
 		if (itSection.hasNext()) {
 			out.print(", sections:\n");		
@@ -190,7 +190,7 @@ private void printModule(ImageModule imageModule, boolean printSymbols) {
 		}
 		if (printSymbols) {
 			out.print("\t  " + "symbols:\n");
-			Iterator itSymbols = imageModule.getSymbols();
+			Iterator<?> itSymbols = imageModule.getSymbols();
 			while (itSymbols.hasNext()) {
 				Object next = itSymbols.next();
 				if (next instanceof ImageSymbol) {
diff --git a/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/infocommands/InfoThreadCommand.java b/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/infocommands/InfoThreadCommand.java
index 180dc29f5e4..1b7aa42b230 100644
--- a/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/infocommands/InfoThreadCommand.java
+++ b/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/infocommands/InfoThreadCommand.java
@@ -1,6 +1,6 @@
 /*[INCLUDE-IF Sidecar18-SE]*/
 /*******************************************************************************
- * Copyright (c) 2004, 2019 IBM Corp. and others
+ * Copyright (c) 2004, 2020 IBM Corp. and others
  *
  * This program and the accompanying materials are made available under
  * the terms of the Eclipse Public License 2.0 which accompanies this
@@ -33,7 +33,6 @@
 import java.util.Map;
 import java.util.logging.Level;
 import java.util.stream.Collectors;
-import java.util.stream.IntStream;
 
 import com.ibm.dtfj.image.CorruptData;
 import com.ibm.dtfj.image.CorruptDataException;
diff --git a/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/xcommands/XJCommand.java b/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/xcommands/XJCommand.java
index 38531564e4f..e6c64034ede 100644
--- a/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/xcommands/XJCommand.java
+++ b/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/xcommands/XJCommand.java
@@ -1,6 +1,6 @@
 /*[INCLUDE-IF Sidecar18-SE]*/
 /*******************************************************************************
- * Copyright (c) 2004, 2017 IBM Corp. and others
+ * Copyright (c) 2004, 2020 IBM Corp. and others
  *
  * This program and the accompanying materials are made available under
  * the terms of the Eclipse Public License 2.0 which accompanies this
@@ -28,7 +28,6 @@
 import com.ibm.dtfj.image.CorruptData;
 import com.ibm.dtfj.image.CorruptDataException;
 import com.ibm.dtfj.image.DataUnavailable;
-import com.ibm.dtfj.image.ImagePointer;
 import com.ibm.dtfj.java.JavaClass;
 import com.ibm.dtfj.java.JavaHeap;
 import com.ibm.dtfj.java.JavaObject;
@@ -45,8 +44,7 @@ public class XJCommand extends XCommand {
 	{
 		addCommand("x/j", "<object address> | <class name>", "displays information about a particular object or all objects of a class");	
 	}
-	
-	
+
 	@Override
 	public boolean recognises(String command, IContext context) {
 		if(super.recognises(command, context)) {
@@ -61,8 +59,7 @@ public void doCommand(String[] args)
 		String param = args[0];
 		Long objAddress;
 		String objName;
-		
-		
+
 		objAddress = Utils.longFromStringWithPrefix(param);
 		if (null == objAddress)
 		{
diff --git a/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/xcommands/XKCommand.java b/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/xcommands/XKCommand.java
index 364dfd9461c..4a29f9d963b 100644
--- a/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/xcommands/XKCommand.java
+++ b/jcl/src/openj9.dtfjview/share/classes/com/ibm/jvm/dtfjview/commands/xcommands/XKCommand.java
@@ -1,6 +1,6 @@
 /*[INCLUDE-IF Sidecar18-SE]*/
 /*******************************************************************************
- * Copyright (c) 2004, 2017 IBM Corp. and others
+ * Copyright (c) 2004, 2020 IBM Corp. and others
  *
  * This program and the accompanying materials are made available under
  * the terms of the Eclipse Public License 2.0 which accompanies this
@@ -123,7 +123,7 @@ public void doCommand(String[] args)
 	private boolean printSymbol(long pointer, long diff, int pointerSize)
 	{
 		ImageProcess ip = ctx.getProcess();
-		Iterator itModule;
+		Iterator<?> itModule;
 		try {
 			itModule = ip.getLibraries();
 		} catch (CorruptDataException e) {
@@ -135,7 +135,7 @@ private boolean printSymbol(long pointer, long diff, int pointerSize)
 		}
 		while (null != itModule && itModule.hasNext()) {
 			ImageModule im = (ImageModule)itModule.next();
-			Iterator itImageSection = im.getSections();
+			Iterator<?> itImageSection = im.getSections();
 			while (itImageSection.hasNext()) {
 				ImageSection is = (ImageSection)itImageSection.next();
 				long startAddr = is.getBaseAddress().getAddress();
@@ -145,7 +145,7 @@ private boolean printSymbol(long pointer, long diff, int pointerSize)
 					/* can we find a matching symbol? */
 					long maxDifference = pointer - startAddr;
 					ImageSymbol bestSymbol = null;
-					for (Iterator iter = im.getSymbols(); iter.hasNext();) {
+					for (Iterator<?> iter = im.getSymbols(); iter.hasNext();) {
 						Object next = iter.next();
 						if (next instanceof CorruptData)
 							continue;
diff --git a/runtime/cmake/caches/aix_ppc-64.cmake b/runtime/cmake/caches/aix_ppc-64.cmake
index 03d8ad0d31b..051a1041cec 100644
--- a/runtime/cmake/caches/aix_ppc-64.cmake
+++ b/runtime/cmake/caches/aix_ppc-64.cmake
@@ -20,25 +20,33 @@
 # SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0 WITH Classpath-exception-2.0 OR LicenseRef-GPL-2.0 WITH Assembly-exception
 ################################################################################
 
-
-#TODO Platform hacks
+#TODO: Env vars should be auto detected by platform
 set(J9VM_ARCH_POWER ON CACHE BOOL "")
 set(J9VM_ENV_DATA64 ON CACHE BOOL "")
+set(J9VM_ENV_DLPAR ON CACHE BOOL "")
 set(J9VM_ENV_HAS_FPU ON CACHE BOOL "")
 set(J9VM_ENV_SHARED_LIBS_CALLEE_GLOBAL_TABLE_SETUP OFF CACHE BOOL "")
 set(J9VM_ENV_SHARED_LIBS_USE_GLOBAL_TABLE ON CACHE BOOL "")
 
-set(OMR_GC_TLH_PREFETCH_FTA OFF CACHE BOOL "")
-set(J9VM_JIT_RUNTIME_INSTRUMENTATION ON CACHE BOOL "")
-set(J9VM_PORT_RUNTIME_INSTRUMENTATION ON CACHE BOOL "")
-set(J9VM_MODULE_CODEGEN_PPC ON CACHE BOOL "")
 set(J9VM_GC_IDLE_HEAP_MANAGER OFF CACHE BOOL "")
+set(J9VM_GC_TLH_PREFETCH_FTA OFF CACHE BOOL "")
+set(J9VM_GC_SUBPOOLS_ALIAS ON CACHE BOOL "")
 set(J9VM_INTERP_ATOMIC_FREE_JNI ON CACHE BOOL "")
 set(J9VM_INTERP_ATOMIC_FREE_JNI_USES_FLUSH ON CACHE BOOL "")
 set(J9VM_INTERP_TWO_PASS_EXCLUSIVE ON CACHE BOOL "")
+set(J9VM_JIT_RUNTIME_INSTRUMENTATION ON CACHE BOOL "")
+set(J9VM_MODULE_CODEGEN_PPC ON CACHE BOOL "")
 set(J9VM_OPT_SWITCH_STACKS_FOR_SIGNAL_HANDLER OFF CACHE BOOL "")
+set(J9VM_PORT_RUNTIME_INSTRUMENTATION ON CACHE BOOL "")
 set(J9VM_THR_ASYNC_NAME_UPDATE OFF CACHE BOOL "")
 
+
+set(OMR_GC_CONCURRENT_SCAVENGER ON CACHE BOOL "")
+set(OMR_GC_HEAP_CARD_TABLE ON CACHE BOOL "")
+set(OMR_THR_SPIN_WAKE_CONTROL OFF CACHE BOOL "")
+set(OMR_THR_THREE_TIER_LOCKING OFF CACHE BOOL "")
+set(OMR_THR_YIELD_ALG OFF CACHE BOOL "")
+
 # Note: In CMake, 'set's on cache variables only apply if the cache variable
 # is not already set. Thus any cache varaibles set in this file, override
 # anything set in common.cmake
diff --git a/runtime/cmake/omr_config.cmake b/runtime/cmake/omr_config.cmake
index b5dd876b4a3..b6ebdb9e4a9 100644
--- a/runtime/cmake/omr_config.cmake
+++ b/runtime/cmake/omr_config.cmake
@@ -1,5 +1,5 @@
 ################################################################################
-# Copyright (c) 2018, 2019 IBM Corp. and others
+# Copyright (c) 2018, 2020 IBM Corp. and others
 #
 # This program and the accompanying materials are made available under
 # the terms of the Eclipse Public License 2.0 which accompanies this
@@ -28,3 +28,4 @@ set(OMR_DDR OFF CACHE BOOL "")
 set(OMR_EXAMPLE OFF CACHE INTERNAL "")
 set(OMR_FVTEST OFF CACHE INTERNAL "")
 set(OMR_GC ON CACHE INTERNAL "")
+set(OMRPORT_OMRSIG_SUPPORT ON CACHE INTERNAL "")
diff --git a/runtime/cmake/platform/toolcfg/xlc.cmake b/runtime/cmake/platform/toolcfg/xlc.cmake
index d5b7e87414d..84d7e316817 100644
--- a/runtime/cmake/platform/toolcfg/xlc.cmake
+++ b/runtime/cmake/platform/toolcfg/xlc.cmake
@@ -20,12 +20,12 @@
 # SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0 WITH Classpath-exception-2.0 OR LicenseRef-GPL-2.0 WITH Assembly-exception
 ################################################################################
 
-list(APPEND OMR_PLATFORM_COMPILE_OPTIONS -O3)
+list(APPEND OMR_PLATFORM_COMPILE_OPTIONS -O3 -g)
 
-list(APPEND OMR_PLATFORM_CXX_COMPILE_OPTIONS -qsuppress=1540-1087:1540-1088:1540-1090)
+list(APPEND OMR_PLATFORM_CXX_COMPILE_OPTIONS -qnortti -qsuppress=1540-1087:1540-1088:1540-1090)
 
 # OMR_PLATFORM_CXX_COMPILE_OPTIONS gets applied to the jit (which needs exceptions),
 # so we put these in the CMAKE_CXX_FLAGS instead
-set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -qnortti -qnoeh")
+set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -qnoeh")
 
 set(CMAKE_ASM_FLAGS "${CMAKE_ASM_FLAGS} -qpic=large")
diff --git a/runtime/codert_vm/dlt.c b/runtime/codert_vm/dlt.c
index 0c3101a8beb..901ad8f53c1 100644
--- a/runtime/codert_vm/dlt.c
+++ b/runtime/codert_vm/dlt.c
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2001, 2014 IBM Corp. and others
+ * Copyright (c) 2001, 2020 IBM Corp. and others
  *
  * This program and the accompanying materials are made available under
  * the terms of the Eclipse Public License 2.0 which accompanies this
@@ -194,7 +194,6 @@ setUpForDLT(J9VMThread * currentThread, J9StackWalkState * walkState)
 		if (J9_ARE_ANY_BITS_SET((UDATA)sp, sizeof(UDATA))) {
 			Trc_DLT_setUpForDLT_Aligning_Arguments(currentThread);
 			memmove((walkState->sp = sp - 1), sp, argCount * sizeof(UDATA));
-			returnSP = (UDATA *) ((UDATA) returnSP | J9_STACK_FLAGS_ARGS_ALIGNED);
 		}
 		elsState->returnSP = returnSP;
 	}
diff --git a/runtime/codert_vm/jswalk.c b/runtime/codert_vm/jswalk.c
index c2b2ee38068..18d59ff3610 100644
--- a/runtime/codert_vm/jswalk.c
+++ b/runtime/codert_vm/jswalk.c
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 1991, 2019 IBM Corp. and others
+ * Copyright (c) 1991, 2020 IBM Corp. and others
  *
  * This program and the accompanying materials are made available under
  * the terms of the Eclipse Public License 2.0 which accompanies this
@@ -291,12 +291,6 @@ i2jTransition: ;
 	walkState->arg0EA = (UDATA *) walkState->i2jState->a0;
 	returnSP = walkState->i2jState->returnSP;
 	walkState->previousFrameFlags = 0;
-	if (((UDATA) returnSP) & J9_STACK_FLAGS_ARGS_ALIGNED) {
-#ifdef J9VM_INTERP_STACKWALK_TRACING
-		swPrintf(walkState, 2, "I2J args were copied for alignment\n");
-#endif
-		walkState->previousFrameFlags = J9_STACK_FLAGS_JIT_ARGS_ALIGNED;
-	}
 	walkState->walkSP = (UDATA *) UNTAG2(returnSP, UDATA *);
 #ifdef J9VM_INTERP_STACKWALK_TRACING
 	swPrintf(walkState, 2, "I2J values: PC = %p, A0 = %p, walkSP = %p, literals = %p, JIT PC = %p, pcAddress = %p, decomp = %p\n", walkState->pc,
diff --git a/runtime/compiler/build/files/common.mk b/runtime/compiler/build/files/common.mk
index 8ecce35ed14..3ba1bbe8b0f 100644
--- a/runtime/compiler/build/files/common.mk
+++ b/runtime/compiler/build/files/common.mk
@@ -275,6 +275,7 @@ JIT_PRODUCT_SOURCE_FILES+=\
     compiler/control/DLLMain.cpp \
     compiler/control/HookedByTheJit.cpp \
     compiler/control/J9Options.cpp \
+    compiler/control/JitDump.cpp \
     compiler/control/MethodToBeCompiled.cpp \
     compiler/control/rossa.cpp \
     compiler/env/ClassLoaderTable.cpp \
diff --git a/runtime/compiler/codegen/J9CodeGenerator.cpp b/runtime/compiler/codegen/J9CodeGenerator.cpp
index 971b8c2cf27..c55bf65fb72 100644
--- a/runtime/compiler/codegen/J9CodeGenerator.cpp
+++ b/runtime/compiler/codegen/J9CodeGenerator.cpp
@@ -4654,7 +4654,7 @@ J9::CodeGenerator::registerAssumptions()
       if (self()->comp()->isOutOfProcessCompilation())
          {
          // For JITServer we need to build a list of assumptions that will be sent to client at end of compilation
-         intptr_t offset = i->getBinaryEncoding() - self()->getCodeStart();
+         intptr_t offset = i->getBinaryEncoding() - self()->getBinaryBufferStart();
          SerializedRuntimeAssumption* sar = 
             new (self()->trHeapMemory()) SerializedRuntimeAssumption(RuntimeAssumptionOnRegisterNative, (uintptr_t)method, offset);
          self()->comp()->getSerializedRuntimeAssumptions().push_front(sar);
@@ -4673,7 +4673,7 @@ J9::CodeGenerator::jitAddPicToPatchOnClassUnload(void *classPointer, void *addre
 #ifdef J9VM_OPT_JITSERVER
    if (self()->comp()->isOutOfProcessCompilation())
       {
-      intptr_t offset = (uint8_t*)addressToBePatched - self()->getCodeStart();
+      intptr_t offset = (uint8_t*)addressToBePatched - self()->getBinaryBufferStart();
       SerializedRuntimeAssumption* sar = 
          new (self()->trHeapMemory()) SerializedRuntimeAssumption(RuntimeAssumptionOnClassUnload, (uintptr_t)classPointer, offset, sizeof(uintptr_t));
       self()->comp()->getSerializedRuntimeAssumptions().push_front(sar);
@@ -4692,7 +4692,7 @@ J9::CodeGenerator::jitAdd32BitPicToPatchOnClassUnload(void *classPointer, void *
 #ifdef J9VM_OPT_JITSERVER
    if (self()->comp()->isOutOfProcessCompilation())
       {
-      intptr_t offset = (uint8_t*)addressToBePatched - self()->getCodeStart();
+      intptr_t offset = (uint8_t*)addressToBePatched - self()->getBinaryBufferStart();
       SerializedRuntimeAssumption* sar = 
          new (self()->trHeapMemory()) SerializedRuntimeAssumption(RuntimeAssumptionOnClassUnload, (uintptr_t)classPointer, offset, 4);
       self()->comp()->getSerializedRuntimeAssumptions().push_front(sar);
@@ -4715,7 +4715,7 @@ J9::CodeGenerator::jitAddPicToPatchOnClassRedefinition(void *classPointer, void
          {
          TR_RuntimeAssumptionKind kind = unresolved ? RuntimeAssumptionOnClassRedefinitionUPIC : RuntimeAssumptionOnClassRedefinitionPIC;
          uintptr_t key = unresolved ? (uintptr_t)-1 : (uintptr_t)classPointer;
-         intptr_t offset = (uint8_t*)addressToBePatched - self()->getCodeStart();
+         intptr_t offset = (uint8_t*)addressToBePatched - self()->getBinaryBufferStart();
          SerializedRuntimeAssumption* sar = 
             new (self()->trHeapMemory()) SerializedRuntimeAssumption(kind, key, offset, sizeof(uintptr_t));
          self()->comp()->getSerializedRuntimeAssumptions().push_front(sar);
@@ -4739,7 +4739,7 @@ J9::CodeGenerator::jitAdd32BitPicToPatchOnClassRedefinition(void *classPointer,
          {
          TR_RuntimeAssumptionKind kind = unresolved ? RuntimeAssumptionOnClassRedefinitionUPIC : RuntimeAssumptionOnClassRedefinitionPIC;
          uintptr_t key = unresolved ? (uintptr_t)-1 : (uintptr_t)classPointer;
-         intptr_t offset = (uint8_t*)addressToBePatched - self()->getCodeStart();
+         intptr_t offset = (uint8_t*)addressToBePatched - self()->getBinaryBufferStart();
          SerializedRuntimeAssumption* sar = 
             new (self()->trHeapMemory()) SerializedRuntimeAssumption(kind, key, offset, 4);
          self()->comp()->getSerializedRuntimeAssumptions().push_front(sar);
diff --git a/runtime/compiler/codegen/J9RecognizedMethodsEnum.hpp b/runtime/compiler/codegen/J9RecognizedMethodsEnum.hpp
index 095e84bc16c..4f09713c732 100644
--- a/runtime/compiler/codegen/J9RecognizedMethodsEnum.hpp
+++ b/runtime/compiler/codegen/J9RecognizedMethodsEnum.hpp
@@ -205,6 +205,7 @@
 
    java_lang_StringUTF16_getChar,
    java_lang_StringUTF16_indexOf,
+   java_lang_StringUTF16_newBytesFor,
    java_lang_StringUTF16_toBytes,
 
    java_lang_StringBuffer_append,
diff --git a/runtime/compiler/control/BasePersistentLogger.hpp b/runtime/compiler/control/BasePersistentLogger.hpp
index d18cc955ca8..206be9abe6b 100644
--- a/runtime/compiler/control/BasePersistentLogger.hpp
+++ b/runtime/compiler/control/BasePersistentLogger.hpp
@@ -1,6 +1,7 @@
 #ifndef JITSERVERLOGGER_BASEPERSISTENTLOGGER_H
 #define JITSERVERLOGGER_BASEPERSISTENTLOGGER_H
 #include <stdint.h>
+#include "j9.h"
 
 class BasePersistentLogger
    {
@@ -10,11 +11,9 @@ class BasePersistentLogger
       const char* _databaseUsername;
       const char* _databasePassword;
       const char* _databaseName;
-
    public:
       virtual bool connect() = 0;
       virtual void disconnect() = 0;
-      
       BasePersistentLogger(const char * databaseIP, uint32_t databasePort, const char * databaseName)
          {
          _databaseIP = databaseIP;
@@ -32,7 +31,7 @@ class BasePersistentLogger
          _databaseUsername = databaseUsername;
          _databasePassword = databasePassword;
          }
-      virtual bool logMethod(const char* method, uint64_t clientID, const char *logContent) = 0;
+      virtual bool logMethod(const char* method, uint64_t clientID, const char *logContent, J9JITConfig* j9JitConfig) = 0;
    };
 
 #endif //JITSERVERLOGGER_BASEPERSISTENTLOGGER_H
diff --git a/runtime/compiler/control/CMakeLists.txt b/runtime/compiler/control/CMakeLists.txt
index e67497fd3fc..571aef739fb 100644
--- a/runtime/compiler/control/CMakeLists.txt
+++ b/runtime/compiler/control/CMakeLists.txt
@@ -27,6 +27,7 @@ j9jit_files(
 	control/HookedByTheJit.cpp
 	control/J9Options.cpp
 	control/J9Recompilation.cpp
+	control/JitDump.cpp
 	control/MethodToBeCompiled.cpp
 	control/rossa.cpp
 )
diff --git a/runtime/compiler/control/CassandraLogger.cpp b/runtime/compiler/control/CassandraLogger.cpp
index f505ac8a361..95429935926 100644
--- a/runtime/compiler/control/CassandraLogger.cpp
+++ b/runtime/compiler/control/CassandraLogger.cpp
@@ -1,11 +1,8 @@
-#include <time.h>
 #include <stdio.h>
-
 #include "CassandraLogger.hpp"
 #include "LoadDBLibs.hpp"
-CassandraLogger::CassandraLogger(const char *databaseIP,
-uint32_t databasePort,
-const char *databaseName): BasePersistentLogger(databaseIP, databasePort, databaseName)
+CassandraLogger::CassandraLogger(const char *databaseIP, uint32_t databasePort,
+      const char *databaseName): BasePersistentLogger(databaseIP, databasePort, databaseName)
    {
    _session = NULL;
    _connectFuture = NULL;
@@ -26,7 +23,6 @@ bool CassandraLogger::createKeySpace()
    char queryString[256]; 
    snprintf(queryString, 256, "CREATE KEYSPACE IF NOT EXISTS %s  WITH REPLICATION = {'class':'SimpleStrategy','replication_factor':1};", _databaseName); 
    OCassStatement* statement = Ocass_statement_new(queryString, 0);
-
    OCassFuture* queryFuture = Ocass_session_execute(_session, statement);
    Ocass_statement_free(statement);
    if (Ocass_future_error_code(queryFuture) != 0)
@@ -36,14 +32,11 @@ bool CassandraLogger::createKeySpace()
       size_t messageLength;
       Ocass_future_error_message(queryFuture, &message, &messageLength);
       fprintf(stderr, "PersistentLogging - Cassandra Database Keyspace Creation Error: '%.*s'\n", (int)messageLength, message);
-      
       Ocass_future_free(queryFuture);
       return false;
       }
-
    Ocass_future_free(queryFuture);
    return true;
-
 }
 bool CassandraLogger::createTable(const char *tableName) 
    {
@@ -59,11 +52,9 @@ bool CassandraLogger::createTable(const char *tableName)
       size_t messageLength;
       Ocass_future_error_message(queryFuture, &message, &messageLength);
       fprintf(stderr, "Persistent Logging - Cassandra Database Table Creation Error: '%.*s'\n", (int)messageLength, message);
-      
       Ocass_future_free(queryFuture);
       return false;
       }
-
    Ocass_future_free(queryFuture);
    return true;
    }
@@ -82,9 +73,7 @@ bool CassandraLogger::connect()
       Ocass_session_free(_session);
       Ocass_cluster_free(_cluster);
       return false;
-
       }
-
    /* Add contact points */
    int rc_set_ip = Ocass_cluster_set_contact_points(_cluster, _databaseIP);
    if (rc_set_ip != 0)
@@ -93,9 +82,7 @@ bool CassandraLogger::connect()
       Ocass_session_free(_session);
       Ocass_cluster_free(_cluster);
       return false;
-
       }
-
    /*Set port number*/
    int rc_set_port = Ocass_cluster_set_port(_cluster, _databasePort);
    if (rc_set_port != 0)
@@ -103,14 +90,10 @@ bool CassandraLogger::connect()
       fprintf(stderr, "Persistent Logging - Cassandra Database Error: %s\n",Ocass_error_desc(rc_set_port));
       Ocass_session_free(_session);
       Ocass_cluster_free(_cluster);
-      
       return false;
-
       }
-
    /* Provide the cluster object as configuration to connect the session */
    _connectFuture = Ocass_session_connect(_session, _cluster);
-
    if (Ocass_future_error_code(_connectFuture) != 0)
       {
       /* Display connection error message */
@@ -124,23 +107,20 @@ bool CassandraLogger::connect()
       return false;
       }
    return true;
-
    }
 
 
-bool CassandraLogger::logMethod(const char *method, uint64_t clientID, const char *logContent)
+bool CassandraLogger::logMethod(const char *method, uint64_t clientID, const char *logContent, J9JITConfig* j9JitConfig)
    {
-      
    // create table space and table first
-   if (!createKeySpace()) return false;
+   if (!createKeySpace()) 
+      return false;
    const char* tableName = "logs";
-   if (!createTable(tableName)) return false;
+   if (!createTable(tableName)) 
+      return false;
    char queryString[256];
-   
    snprintf(queryString, 256, "INSERT INTO %s.%s (clientID, methodName, logContent, insertionDate, insertionTime) VALUES (?, ?, ?, ?, ?)", _databaseName,tableName);
-   OCassStatement* statement
-   = Ocass_statement_new(queryString, 5);
-
+   OCassStatement* statement = Ocass_statement_new(queryString, 5);
    /* Bind the values using the indices of the bind variables */
    char strClientID[64];
    snprintf(strClientID, 64, "%lu", clientID);
@@ -151,7 +131,6 @@ bool CassandraLogger::logMethod(const char *method, uint64_t clientID, const cha
       Ocass_statement_free(statement);
       return false;
       }
-
    int rc_set_bind_method = Ocass_statement_bind_string(statement, 1, method);
    if (rc_set_bind_pk != 0)
       {
@@ -160,23 +139,20 @@ bool CassandraLogger::logMethod(const char *method, uint64_t clientID, const cha
       return false;
       }
    int rc_set_bind_log_content = Ocass_statement_bind_string(statement, 2, logContent);
-
    if (rc_set_bind_log_content != 0)
       {
       fprintf(stderr, "Persistent Logging - Cassandra Database Error: %s\n",Ocass_error_desc(rc_set_bind_log_content));
       Ocass_statement_free(statement);
       return false;
       }
-
-   time_t now = time(NULL); /* Time in seconds from Epoch */
+   PORT_ACCESS_FROM_JITCONFIG(j9JitConfig);
+   uint64_t now = j9time_current_time_millis() / 1000; /* Time in seconds from Epoch */
    /* Converts the time since the Epoch in seconds to the 'date' type */
    Ocass_uint32_t year_month_day_of_insertion = Ocass_date_from_epoch(now);
    /* Converts the time since the Epoch in seconds to the 'time' type */
    Ocass_int64_t time_of_insertion = Ocass_time_from_epoch(now);
-
    /* 'date' uses an unsigned 32-bit integer */
    int rc_set_bind_insertion_date = Ocass_statement_bind_uint32(statement, 3, year_month_day_of_insertion);
-   
    if (rc_set_bind_insertion_date != 0)
       {
       fprintf(stderr, "Persistent Logging - Cassandra Database Error: %s\n", Ocass_error_desc(rc_set_bind_insertion_date));
@@ -191,9 +167,7 @@ bool CassandraLogger::logMethod(const char *method, uint64_t clientID, const cha
       Ocass_statement_free(statement);
       return false;
       }
-
    OCassFuture* queryFuture = Ocass_session_execute(_session, statement);
-
    /* Statement objects can be freed immediately after being executed */
    Ocass_statement_free(statement);
    if (Ocass_future_error_code(queryFuture) != 0)
@@ -206,12 +180,10 @@ bool CassandraLogger::logMethod(const char *method, uint64_t clientID, const cha
       Ocass_future_free(queryFuture);
       return false;
       }
-
    Ocass_future_free(queryFuture);
    return true; 
    }
 
-
 void CassandraLogger::disconnect()
    {
    Ocass_future_free(_connectFuture);
diff --git a/runtime/compiler/control/CassandraLogger.hpp b/runtime/compiler/control/CassandraLogger.hpp
index 358028eb74f..6c7b4a80d74 100644
--- a/runtime/compiler/control/CassandraLogger.hpp
+++ b/runtime/compiler/control/CassandraLogger.hpp
@@ -5,24 +5,19 @@
 #include "BasePersistentLogger.hpp"
 class CassandraLogger : public BasePersistentLogger
    {
-
    private:
       OCassCluster* _cluster;
       OCassSession* _session;
       OCassFuture* _connectFuture;
       bool createKeySpace();
       bool createTable(const char *tableName);
-      
-      
    public: 
-
       bool connect() override;
       void disconnect() override;
       CassandraLogger(const char *databaseIP, uint32_t databasePort, const char *databaseName,
                      const char *databaseUsername, const char *databasePassword);
       CassandraLogger(const char *databaseIP, uint32_t databasePort, const char *databaseName);
-      bool logMethod(const char *method, uint64_t clientID, const char *logContent) override;
-      
+      bool logMethod(const char *method, uint64_t clientID, const char *logContent, J9JITConfig* j9JitConfig) override;
    };
 
 #endif // CASSANDRALOGGER_H
\ No newline at end of file
diff --git a/runtime/compiler/control/CompilationThread.cpp b/runtime/compiler/control/CompilationThread.cpp
index 4abb064876d..9002a3b039e 100644
--- a/runtime/compiler/control/CompilationThread.cpp
+++ b/runtime/compiler/control/CompilationThread.cpp
@@ -49,6 +49,7 @@
 #include "codegen/PrivateLinkage.hpp"
 #include "compile/CompilationTypes.hpp"
 #include "compile/ResolvedMethod.hpp"
+#include "control/JitDump.hpp"
 #include "control/Recompilation.hpp"
 #include "control/RecompilationInfo.hpp"
 #include "control/MethodToBeCompiled.hpp"
@@ -194,19 +195,6 @@ TR::CompilationInfoPerThreadBase::setCompilation(TR::Compilation *compiler)
    _compiler = compiler;
    }
 
-#ifdef J9VM_RAS_DUMP_AGENTS
-static UDATA
-blankDumpSignalHandler(struct J9PortLibrary *portLibrary, U_32 gpType, void *gpInfo, void *arg)
-   {
-   J9VMThread *vmThread = (J9VMThread *) arg;
-   TR_VerboseLog::writeLineLocked(TR_Vlog_JITDUMP, "vmThread=%p Recursive crash occurred. Aborting JIT dump.", vmThread);
-
-   // Returning J9PORT_SIG_EXCEPTION_RETURN will make us come back to the same crashing instruction over and over
-   //
-   return J9PORT_SIG_EXCEPTION_RETURN; // FIXME: is this the right return type? - This appears to be the right return type
-   }
-#endif
-
 #if defined(J9VM_OPT_JITSERVER)
 thread_local TR::CompilationInfoPerThread *TR::compInfoPT;
 #endif /* defined(J9VM_OPT_JITSERVER) */
diff --git a/runtime/compiler/control/DLLMain.cpp b/runtime/compiler/control/DLLMain.cpp
index 7ddf55433dc..2ead34fa0e6 100644
--- a/runtime/compiler/control/DLLMain.cpp
+++ b/runtime/compiler/control/DLLMain.cpp
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2000, 2018 IBM Corp. and others
+ * Copyright (c) 2000, 2020 IBM Corp. and others
  *
  * This program and the accompanying materials are made available under
  * the terms of the Eclipse Public License 2.0 which accompanies this
@@ -30,6 +30,9 @@
 #include "env/VMJ9.h"
 #include "runtime/IProfiler.hpp"
 #include "runtime/J9Profiler.hpp"
+#if defined(J9VM_OPT_JITSERVER)
+#include "runtime/Listener.hpp"
+#endif /* J9VM_OPT_JITSERVER */
 #include "runtime/codertinit.hpp"
 #include "rossa.h"
 
@@ -589,6 +592,16 @@ IDATA J9VMDllMain(J9JavaVM* vm, IDATA stage, void * reserved)
                TR_J9VMBase *trvm = TR_J9VMBase::get(vm->jitConfig, 0);
                if (!trvm->isAOT_DEPRECATED_DO_NOT_USE() && trvm->_compInfo)
                   {
+#if defined(J9VM_OPT_JITSERVER)
+                  if (trvm->_compInfo->getPersistentInfo()->getRemoteCompilationMode() == JITServer::SERVER)
+                     {
+                     TR_Listener *listener = ((TR_JitPrivateConfig*)(vm->jitConfig->privateConfig))->listener;
+                     if (listener)
+                        {
+                        listener->stop();
+                        }
+                     }
+#endif /* defined(J9VM_OPT_JITSERVER) */
                   trvm->_compInfo->stopCompilationThreads();
                   }
                JitShutdown(vm->jitConfig);
diff --git a/runtime/compiler/control/HookedByTheJit.cpp b/runtime/compiler/control/HookedByTheJit.cpp
index 4111ac97642..02756eced74 100644
--- a/runtime/compiler/control/HookedByTheJit.cpp
+++ b/runtime/compiler/control/HookedByTheJit.cpp
@@ -116,15 +116,6 @@ struct LDA {
 };
 #endif
 
-#define STACK_WALK_DEPTH 16
-
-// struct to remember a method for JIT dump
-typedef struct TR_MethodToBeCompiledForDump {
-   J9Method   *_method;
-   void       *_oldStartPC;
-   TR_Hotness  _optLevel;
-} TR_MethodToBeCompiledForDump;
-
 #ifdef J9VM_JIT_RUNTIME_INSTRUMENTATION
 // extern until function is added to oti/jitprotos.h
 extern "C" void shutdownJITRuntimeInstrumentation(J9JavaVM *vm);
@@ -1686,651 +1677,6 @@ static void initThreadAfterCreation(J9VMThread *vmThread)
    return;
    }
 
-#ifdef J9VM_RAS_DUMP_AGENTS
-
-typedef struct DumpCurrentILParamenters
-   {
-   DumpCurrentILParamenters(
-         TR::Compilation *comp,
-         J9VMThread *vmThread,
-         J9JITConfig *jitConfig,
-         TR::FILE *logFile
-      )  :
-      _comp(comp),
-      _vmThread(vmThread),
-      _jitConfig(jitConfig),
-      _logFile(logFile)
-      {}
-
-   TR::Compilation *_comp;
-   J9VMThread      *_vmThread;
-   J9JITConfig     *_jitConfig;
-   TR::FILE        *_logFile;
-   } DumpCurrentILParamenters;
-
-static UDATA
-blankDumpCurrentILSignalHandler(struct J9PortLibrary *portLibrary, U_32 gpType, void *gpInfo, void *arg)
-   {
-   J9VMThread *vmThread = (J9VMThread *) arg;
-   TR_VerboseLog::writeLineLocked(TR_Vlog_JITDUMP, "vmThread=%p Crashed while printing out current IL.", vmThread);
-   return J9PORT_SIG_EXCEPTION_RETURN;
-   }
-
-static void jitDumpFailedBecause(J9VMThread *currentThread, const char* message)
-   {
-   if (TR::Options::getCmdLineOptions()->getVerboseOption(TR_VerboseDump))
-      TR_VerboseLog::writeLineLocked(TR_Vlog_JITDUMP, "JIT dump failed because %s", message);
-   Trc_JIT_DumpFail(currentThread, message);
-   return;
-   }
-
-static void stackWalkEndingBecause(const char* message)
-   {
-   if (TR::Options::getCmdLineOptions()->getVerboseOption(TR_VerboseDump))
-      TR_VerboseLog::writeLineLocked(TR_Vlog_JITDUMP, "stack walk ending because %s", message);
-   return;
-   }
-
-static UDATA dumpCurrentILProtected(J9PortLibrary *portLib, void * opaqueParameters)
-   {
-   DumpCurrentILParamenters *p = static_cast<DumpCurrentILParamenters *>(opaqueParameters);
-   TR::Compilation *comp       = p->_comp;
-   J9VMThread *vmThread        = p->_vmThread;
-   J9JITConfig *jitConfig      = p->_jitConfig;
-   TR::FILE *logFile           = p->_logFile;
-
-   comp->findOrCreateDebug();
-
-   TR::Options *options = comp->getOptions();
-   TR_Debug *dbg = comp->getDebug();
-   TR_J9VMBase * fe = TR_J9VMBase::get(jitConfig, vmThread);
-
-   if (logFile != NULL)
-      {
-      comp->setOutFile(logFile);
-      options->setOption(TR_TraceAll);
-      options->setOption(TR_TraceKnownObjectGraph);
-      dbg->setFile(logFile);
-
-      trfprintf(logFile,"<currentIL>\n");
-
-      // Print Bytecodes
-      TR::IlGeneratorMethodDetails & details = comp->ilGenRequest().details();
-      TR::ResolvedMethodSymbol *resolvedMethod = comp->getMethodSymbol();
-      TR::SymbolReferenceTable *symRefTab = comp->getSymRefTab();
-      TR_J9ByteCodeIlGenerator bci(details, resolvedMethod, fe, comp, symRefTab);
-      bci.printByteCodes();
-
-      dbg->printMethodHotness();
-      comp->dumpMethodTrees("Trees");
-      dbg->print(logFile, comp->getSymRefTab());
-
-      int bitMask = J9VMSTATE_JIT_CODEGEN | 0x0000FF00; // 0xFF?? is Codegen Phase
-      if ( ((vmThread->omrVMThread->vmState) & bitMask) == bitMask )  // if we are in the Codegen Phase
-         {
-         dbg->dumpMethodInstrs(logFile, "Post Binary Instructions", false, true);
-
-         dbg->print(logFile,comp->cg()->getSnippetList(), true);  // print Warm Snippets
-         dbg->print(logFile,comp->cg()->getSnippetList(), false);
-
-         dbg->dumpMixedModeDisassembly();
-         }
-
-      // leaving to the very end in case there is a crash before this point.
-      comp->verifyTrees(comp->getMethodSymbol());
-      comp->verifyBlocks(comp->getMethodSymbol());
-
-      trfprintf(logFile, "</currentIL>\n");
-      }
-
-   return 0;
-   }
-
-static void dumpCurrentIL(TR::Compilation *comp, J9VMThread *vmThread, J9JITConfig *jitConfig, TR::FILE *logFile )
-   {
-   /* Acquire VM Access */
-   bool alreadyHaveVMAccess = ((vmThread->publicFlags & J9_PUBLIC_FLAGS_VM_ACCESS) != 0);
-   bool haveAcquiredVMAccess = false;
-   if (!alreadyHaveVMAccess)
-      if (0 == vmThread->javaVM->internalVMFunctions->internalTryAcquireVMAccessWithMask(vmThread, J9_PUBLIC_FLAGS_HALT_THREAD_ANY_NO_JAVA_SUSPEND))
-         haveAcquiredVMAccess = true;
-
-   PORT_ACCESS_FROM_JITCONFIG(jitConfig);
-
-   DumpCurrentILParamenters p(
-      comp,
-      vmThread,
-      jitConfig,
-      logFile
-      );
-
-   UDATA result = 0;
-
-#if defined(J9VM_PORT_SIGNAL_SUPPORT)
-   U_32 flags = J9PORT_SIG_FLAG_MAY_RETURN |
-                J9PORT_SIG_FLAG_SIGSEGV | J9PORT_SIG_FLAG_SIGFPE |
-                J9PORT_SIG_FLAG_SIGILL  | J9PORT_SIG_FLAG_SIGBUS;
-
-   static char *noSignalWrapper = feGetEnv("TR_NoSignalWrapper");
-
-   if (!noSignalWrapper && j9sig_can_protect(flags))
-      {
-      UDATA protectedResult;
-
-      protectedResult = j9sig_protect((j9sig_protected_fn)dumpCurrentILProtected, static_cast<void *>(&p),
-                                         (j9sig_handler_fn)blankDumpCurrentILSignalHandler, vmThread,
-                                         flags, &result);
-      }
-   else
-#endif
-      result = dumpCurrentILProtected(privatePortLibrary, &p);
-
-
-   /* Release VM Access */
-   if (!alreadyHaveVMAccess)
-      if (haveAcquiredVMAccess)
-         vmThread->javaVM->internalVMFunctions->internalReleaseVMAccess(vmThread);
-   }
-
-// Stack frame iterator. Iterates until STACK_WALK_DEPTH frames or the top are reached.
-static UDATA logStackIterator(J9VMThread *currentThread, J9StackWalkState *walkState)
-   {
-   Trc_JIT_DumpWalkingFrame(currentThread);
-
-   // stop iterating if the walk state is null
-   if (!walkState)
-      {
-      stackWalkEndingBecause("got a null walkState");
-      return J9_STACKWALK_STOP_ITERATING;
-      }
-
-   // get user data from walk state
-   TR_MethodToBeCompiledForDump* jittedMethodsOnStack = (TR_MethodToBeCompiledForDump *) walkState->userData1;
-   int *currentMethodIndex                            = (int *) walkState->userData2;
-
-   // also stop iterating if passed user data is null
-   if (currentMethodIndex == 0 || jittedMethodsOnStack == 0)
-      {
-      stackWalkEndingBecause("one or both user data are null");
-      return J9_STACKWALK_STOP_ITERATING;
-      }
-
-   // also stop iterating if enough frames have been reached
-   if ((*currentMethodIndex) >= STACK_WALK_DEPTH)
-      {
-      stackWalkEndingBecause("reached limit on number of methods to recompile");
-      return J9_STACKWALK_STOP_ITERATING;
-      }
-
-   // if the frame has jit metadata, then it belongs to a JITed method
-   if (walkState->jitInfo)
-      {
-      // NOTE: method is the one (J9Method, a.k.a. TR_OpaqueMethodBlock) that gets
-      //       passed to IlGeneratorMethodDetails
-      TR_ASSERT(walkState->method, "Found method metadata on the stack, but method is null.");
-
-      // get method's body info (can be null)
-      TR_PersistentJittedBodyInfo* bodyInfo = TR::Recompilation::getJittedBodyInfoFromPC((void*) walkState->jitInfo->startPC);
-
-      // get global configuration options
-      TR::Options *options = TR::Options::getCmdLineOptions();
-
-      // get global opt level
-      // NOTE: getOptLevel returns -1 if it is not set
-      TR_Hotness globalOptLevel = (TR_Hotness) (-1);
-      if (options)
-         globalOptLevel = (TR_Hotness) options->getFixedOptLevel();
-
-      // add the method to our list ONLY if level can be determined; it can be determined
-      // either from body info (if it exists), or from fixed level (if it was set)
-      if (bodyInfo || (globalOptLevel != (-1)))
-         {
-         // set the method
-         jittedMethodsOnStack[*currentMethodIndex]._method = walkState->method;
-
-         // set the method's oldStartPC:
-         //    if bodyInfo exists, then we can do a recompilation (use startPCAfterPreviousCompile)
-         //    if not, then we can't, and we do a first-time compilation (use 0)
-         if (bodyInfo)
-            jittedMethodsOnStack[*currentMethodIndex]._oldStartPC = bodyInfo->getStartPCAfterPreviousCompile();
-         else
-            jittedMethodsOnStack[*currentMethodIndex]._oldStartPC = 0;
-
-         // set the optLevel
-         if (bodyInfo)
-            jittedMethodsOnStack[*currentMethodIndex]._optLevel = bodyInfo->getHotness();
-         else
-            // NOTE: global optLevel is not -1, since we checked for that above
-            jittedMethodsOnStack[*currentMethodIndex]._optLevel = globalOptLevel;
-
-         // advance to the next method in the list
-         *currentMethodIndex = (*(currentMethodIndex) + 1);
-         }
-      }
-
-   return J9_STACKWALK_KEEP_ITERATING;
-   }
-
-/// Recompiles a method for the JIT dump
-static TR_CompilationErrorCode recompileMethodForLog(
-   J9VMThread         *vmThread,
-   J9Method           *ramMethod,
-   TR::CompilationInfo *compInfo,
-   TR_J9VMBase        *frontendOfThread,
-   TR_Hotness          optimizationLevel,
-   bool                profilingCompile,
-   void               *oldStartPC,
-   TR::FILE *logFile
-   )
-   {
-   if (TR::Options::getCmdLineOptions()->getVerboseOption(TR_VerboseDump))
-      TR_VerboseLog::writeLineLocked(TR_Vlog_JITDUMP, "recompiling a method for log: %p", ramMethod);
-
-   Trc_JIT_DumpCompilingMethod(vmThread, ramMethod, optimizationLevel, oldStartPC);
-
-   // the request to use Log should be passed to the compilation, via optimizationPlan
-   // then the option object created should use this to open the log; thus must create a new optimization plan
-   // the right optlevel would be set during the Options setting
-   TR_OptimizationPlan *plan = TR_OptimizationPlan::alloc(optimizationLevel);
-   if (!plan)
-      return compilationFailure;
-
-   if (profilingCompile)
-      plan->setInsertInstrumentation(true);
-
-   // pass the log file to the compilation
-   plan->setLogCompilation(logFile);
-
-   bool successfullyQueued = false;
-
-   trfprintf(logFile, "<logRecompilation>\n");
-
-   // actually request the compilation
-   if (TR::Options::getCmdLineOptions()->getVerboseOption(TR_VerboseDump))
-      TR_VerboseLog::writeLineLocked(TR_Vlog_JITDUMP, "dumpJitInfo: compileMethod() about to issued synchronously");
-   TR_CompilationErrorCode compErrCode;
-
-   // Set the VM state of the crashed thread so the diagnostic thread can use consume it
-   compInfo->setVMStateOfCrashedThread(vmThread->omrVMThread->vmState);
-
-   // create a compilation request
-   // NOTE: operator new() is overridden, and takes a storage object as a parameter
-   // TODO: this is indiscriminately compiling as J9::DumpMethodRequest, which is wrong;
-   //       should be fixed by checking if the method is indeed DLT, and compiling DLT if so
-      {
-      J9::DumpMethodDetails details( ramMethod);
-      compInfo->compileMethod(vmThread, details, oldStartPC, TR_no, &compErrCode, &successfullyQueued, plan);
-      }
-
-   if (TR::Options::getCmdLineOptions()->getVerboseOption(TR_VerboseDump))
-      TR_VerboseLog::writeLineLocked(TR_Vlog_JITDUMP, "dumpJitInfo: crashing thread returned from compileMethod() with errorCode=%d", compErrCode);
-
-   trfprintf(logFile, "</logRecompilation>\n");
-
-   // if the request failed, get rid of the optimization plan we made
-   if (!successfullyQueued)
-      TR_OptimizationPlan::freeOptimizationPlan(plan);
-
-   return compErrCode;
-   }
-
-/// Dumps JIT-specific crash info
-IDATA dumpJitInfo(J9VMThread *crashedThread, char *logFileLabel, J9RASdumpContext *context)
-   {
-   Trc_JIT_DumpStart(crashedThread);
-
-#if defined(J9VM_OPT_JITSERVER)
-   if (context && context->javaVM && context->javaVM->jitConfig)
-      {
-      J9JITConfig *jitConfig = context->javaVM->jitConfig;
-      TR::CompilationInfo *compInfo = TR::CompilationInfo::get(context->javaVM->jitConfig);
-      if (compInfo)
-         {
-         static char * isPrintJITServerMsgStats = feGetEnv("TR_PrintJITServerMsgStats");
-         if (isPrintJITServerMsgStats && compInfo->getPersistentInfo()->getRemoteCompilationMode() == JITServer::CLIENT)
-            JITServerHelpers::printJITServerMsgStats(jitConfig);
-         if (feGetEnv("TR_PrintJITServerCHTableStats"))
-            JITServerHelpers::printJITServerCHTableStats(jitConfig, compInfo);
-         if (feGetEnv("TR_PrintJITServerIPMsgStats"))
-            {
-            if (compInfo->getPersistentInfo()->getRemoteCompilationMode() == JITServer::SERVER)
-               {
-               TR_J9VMBase * vmj9 = (TR_J9VMBase *)(TR_J9VMBase::get(context->javaVM->jitConfig, 0));
-               JITServerIProfiler *iProfiler = (JITServerIProfiler *)vmj9->getIProfiler();
-               iProfiler->printStats();
-               }
-            }
-         }
-      }
-#endif
-
-   if (TR::Options::getCmdLineOptions()->getVerboseOption(TR_VerboseDump))
-      TR_VerboseLog::writeLineLocked(TR_Vlog_JITDUMP, "JIT dump initiated. Crashed vmThread=%p", crashedThread);
-
-   // if either one of the args is null, we can't really do anything
-   if (crashedThread == 0 || logFileLabel == 0)
-      {
-      jitDumpFailedBecause(crashedThread, "one or both arguments are null");
-      return 0;
-      }
-
-   // if VM is gone, can't do anything either
-   if (crashedThread->javaVM == 0)
-      {
-      jitDumpFailedBecause(crashedThread, "VM pointer is null");
-      return 0;
-      }
-
-   // get a hold of jitConfig in order to later get compinfo and frontend
-   J9JITConfig * jitConfig = crashedThread->javaVM->jitConfig;
-
-   // if jitConfig is gone, then we can't do anything either
-   if (jitConfig == 0)
-      {
-      jitDumpFailedBecause(crashedThread, "jitConfig is null");
-      return 0;
-      }
-   // get global compinfo
-   TR::CompilationInfo *compInfo = TR::CompilationInfo::get(jitConfig);
-   if (!compInfo)
-      {
-      jitDumpFailedBecause(crashedThread, "compInfo is null");
-      return 0;
-      }
-
-   // Must be able to allocate a frontend for this thread
-   TR_J9VMBase *frontendOfThread = TR_J9VMBase::get(jitConfig, crashedThread);
-   if (!frontendOfThread)
-      {
-      jitDumpFailedBecause(crashedThread, "thread's frontend is missing");
-      return 0;
-      }
-
-   // get global configuration options
-   TR::Options *options = TR::Options::getCmdLineOptions();
-   if (!options)
-      {
-      jitDumpFailedBecause(crashedThread, "No cmdLineOptions available");
-      return 0;
-      }
-
-
-   // open log file, using the postfixed timestamp if specified
-   TR::FILE *logFile;
-   char tmp[1025];
-   logFileLabel = frontendOfThread->getFormattedName(tmp, 1025, logFileLabel, NULL, false);
-   logFile = trfopen(logFileLabel, "ab", false);
-
-   trfprintf(logFile,
-      "<?xml version=\"1.0\" standalone=\"no\"?>\n"
-      "<jitDump>\n"
-      );
-
-
-   // if some thread holds exclusive VM access we cannot do much
-   if (J9_XACCESS_NONE != jitConfig->javaVM->exclusiveAccessState)
-      {
-      jitDumpFailedBecause(crashedThread, "some thread is holding exclusive VM access");
-      trfprintf(logFile, "Some thread is holding exclusive VM access. No log created.\n");
-      trfclose(logFile);
-      return 0;
-      }
-
-
-   // to avoid deadlock, release compilation monitor until we are no longer holding it
-   while (compInfo->getCompilationMonitor()->owned_by_self())
-      compInfo->releaseCompMonitor(crashedThread);
-
-   // Release other monitors as well. In particular CHTable and classUnloadMonitor must not be held
-   while (TR::MonitorTable::get()->getClassTableMutex()->owned_by_self())
-      frontendOfThread->releaseClassTableMutex(false);
-
-   //FIXME: how do I detect that someone is holding the classUnloadMonitor
-
-   // get crashed thread's own compinfo
-   TR::CompilationInfoPerThread *threadCompInfo = compInfo->getCompInfoForThread(crashedThread);
-
-   // Crashes on the diagnostic thread should not be processed
-   if (threadCompInfo && threadCompInfo->isDiagnosticThread())
-      {
-      jitDumpFailedBecause(crashedThread, "detected recursive crash");
-      trfprintf(logFile, "Detected recursive crash. No log created.\n");
-      trfclose(logFile);
-      return 0;
-      }
-
-   // get the method currently being compiled
-   TR_MethodToBeCompiled *currentMethodBeingCompiled = 0;
-   if (threadCompInfo)
-      currentMethodBeingCompiled = threadCompInfo->getMethodBeingCompiled();
-
-   /*
-    * at this stage, we know that we are good to orchestrate a dump
-    */
-
-   if (options->getOption(TR_VerboseDump))
-      TR_VerboseLog::writeLineLocked(TR_Vlog_JITDUMP, "dump agent obtained necessary information to perform dump");
-
-   // if we are currently compiling a method, wake everyone waiting for it to compile
-   if (currentMethodBeingCompiled && currentMethodBeingCompiled->getMonitor())
-      {
-      currentMethodBeingCompiled->getMonitor()->enter();
-      currentMethodBeingCompiled->getMonitor()->notifyAll();
-      currentMethodBeingCompiled->getMonitor()->exit();
-      if (TR::Options::getCmdLineOptions()->getVerboseOption(TR_VerboseDump))
-         TR_VerboseLog::writeLineLocked(TR_Vlog_JITDUMP, "dumpJitInfo notified all waiting threads");
-      }
-
-   // disable all non-essential compilations
-   compInfo->getPersistentInfo()->setDisableFurtherCompilation(true);
-   if (TR::Options::getCmdLineOptions()->getVerboseOption(TR_VerboseDump))
-      TR_VerboseLog::writeLineLocked(TR_Vlog_JITDUMP, "dumpJitInfo disabled further compilation");
-
-   // get the dump thread
-   TR::CompilationInfoPerThread *recompilationThreadInfo = compInfo->getCompilationInfoForDumpThread();
-   J9VMThread                  *recompilationThread = NULL;
-   if (recompilationThreadInfo)
-      recompilationThread = recompilationThreadInfo->getCompilationThread();
-
-   // purge the compilation queue if a thread was found
-   if (recompilationThread)
-      {
-      if (options->getVerboseOption(TR_VerboseDump))
-         TR_VerboseLog::writeLineLocked(TR_Vlog_JITDUMP, "dumpJitInfo: diagnostic compilation thread available. Will purge compilation queue");
-      compInfo->acquireCompMonitor(crashedThread);
-      compInfo->purgeMethodQueue(compilationFailure); // compilationFailure is a TR_CompilationErrorCode
-      compInfo->releaseCompMonitor(crashedThread);
-      }
-
-
-
-   // if our compinfo is null, we are an application thread
-   if (threadCompInfo == 0)
-      {
-      if (options->getVerboseOption(TR_VerboseDump))
-         TR_VerboseLog::writeLineLocked(TR_Vlog_JITDUMP, "crashed in application thread");
-      trfprintf(logFile, "#INFO: Crashed in application thread %p.\n", crashedThread);
-
-      // only bother doing anything if we have a healthy compilation thread available
-      if (recompilationThread)
-         {
-         // make space for methods to be recompiled
-         // FIXME: this is on the stack... is the stack big enough?
-         int currentMethodIndex = 0;
-         TR_MethodToBeCompiledForDump jittedMethodsOnStack[STACK_WALK_DEPTH] = { 0 };
-
-         // set up the stack walk object
-         J9StackWalkState walkState;
-
-         walkState.userData1 = (void *)jittedMethodsOnStack;
-         walkState.userData2 = (void *)&currentMethodIndex;
-         walkState.walkThread = crashedThread;
-         walkState.skipCount = 0;
-         walkState.maxFrames = STACK_WALK_DEPTH;
-         walkState.flags = (
-            // J9_STACKWALK_LINEAR |
-            // J9_STACKWALK_START_AT_JIT_FRAME |
-            // J9_STACKWALK_INCLUDE_NATIVES |
-            // J9_STACKWALK_HIDE_EXCEPTION_FRAMES |
-            // J9_STACKWALK_ITERATE_HIDDEN_JIT_FRAMES |
-            J9_STACKWALK_VISIBLE_ONLY |
-            J9_STACKWALK_SKIP_INLINES |
-            J9_STACKWALK_COUNT_SPECIFIED |
-            J9_STACKWALK_ITERATE_FRAMES
-            );
-         walkState.frameWalkFunction = logStackIterator;
-
-         /*
-          * NOTE [March 6th, 2013]:
-          *
-          *    Graham Chapman said:
-          *
-          *    This will make the stack walker jump back to the last
-          *    interpreter transition point if a bad return address is found,
-          *    rather than asserting.  You'll miss a bunch of frames, but
-          *    there's really nothing better to be done in that case.
-          */
-         walkState.errorMode = J9_STACKWALK_ERROR_MODE_IGNORE;
-
-         // actually walk the stack, adding all JITed methods to the queue
-         compInfo->acquireCompMonitor(crashedThread);
-         crashedThread->javaVM->walkStackFrames(crashedThread, &walkState);
-         compInfo->releaseCompMonitor(crashedThread);
-
-         if (options->getVerboseOption(TR_VerboseDump))
-            TR_VerboseLog::writeLineLocked(TR_Vlog_JITDUMP, "found %d JITed methods on Java stack", currentMethodIndex);
-         trfprintf(logFile, "#INFO: Found %d JITed methods on Java stack.\n", currentMethodIndex);
-
-         // resume the compilation thread
-         recompilationThreadInfo->resumeCompilationThread();
-
-         // compile our methods
-         for (int i = 0; i < currentMethodIndex; i++)
-            {
-            // skip if method is somehow null
-            if (!(jittedMethodsOnStack[i]._method))
-               continue;
-
-            TR_CompilationErrorCode compErrCode;
-            compErrCode = recompileMethodForLog(
-               crashedThread,
-               jittedMethodsOnStack[i]._method,
-               compInfo,
-               frontendOfThread,
-               jittedMethodsOnStack[i]._optLevel,
-               false,
-               jittedMethodsOnStack[i]._oldStartPC,
-               logFile
-               );
-            } // for
-
-         if (currentMethodIndex == 0)
-            trfprintf(logFile, "#INFO: DUMP FAILED: no methods to recompile\n");
-
-         if (options->getVerboseOption(TR_VerboseDump))
-            TR_VerboseLog::writeLineLocked(TR_Vlog_JITDUMP, "recompilations complete");
-
-         } // if recompilationThread
-      else
-         {
-         trfprintf(logFile, "#INFO: DUMP FAILED: no diagnostic thread\n");
-         jitDumpFailedBecause(crashedThread, "no thread available to compile for dump");
-         }
-
-      } // if threadcompinfo
-
-   // if our compinfo is not null, we are a compilation thread
-   else
-      {
-      if (options->getVerboseOption(TR_VerboseDump))
-         TR_VerboseLog::writeLineLocked(TR_Vlog_JITDUMP, "crashed in compilation thread");
-      trfprintf(logFile, "#INFO: Crashed in compilation thread %p.\n", crashedThread);
-
-      // get current compilation
-      TR::Compilation *comp = threadCompInfo->getCompilation();
-
-      // if the compilation is in progress, dump interesting things from it and then recompile
-      if (comp)
-         {
-         if (options->getVerboseOption(TR_VerboseDump))
-            TR_VerboseLog::writeLineLocked(TR_Vlog_JITDUMP, "dumpJitInfo: found comp object");
-
-         // dump IL of current compilation
-         dumpCurrentIL(comp, crashedThread, jitConfig, logFile);
-
-         // if there was an available compilation thread, recompile the current method
-         if (recompilationThread)
-            {
-            // only proceed to recompile if the method is a regular Java method
-            if (currentMethodBeingCompiled &&
-               currentMethodBeingCompiled->getMethodDetails().isOrdinaryMethod())
-               {
-               // resume the healthy compilation thread
-               recompilationThreadInfo->resumeCompilationThread();  // TODO: Postpone this so that the thread does not get to sleep again
-               if (options->getVerboseOption(TR_VerboseDump))
-                  TR_VerboseLog::writeLineLocked(TR_Vlog_JITDUMP, "dumpJitInfo: have resumed DiagCompThread");
-
-               // get old start PC if method was available
-               void *oldStartPC = 0;
-               if (currentMethodBeingCompiled)
-                  oldStartPC = currentMethodBeingCompiled->_oldStartPC;
-
-               // request the compilation
-               TR_CompilationErrorCode compErrCode;
-               compErrCode = recompileMethodForLog(
-                  crashedThread,
-                  (J9Method *)(comp->getCurrentMethod()->getPersistentIdentifier()),
-                  compInfo,
-                  frontendOfThread,
-                  (TR_Hotness)comp->getOptLevel(),
-                  comp->isProfilingCompilation(),
-                  oldStartPC,
-                  logFile
-                  );
-
-               if (options->getVerboseOption(TR_VerboseDump))
-                  TR_VerboseLog::writeLineLocked(TR_Vlog_JITDUMP, "recompilation complete");
-               }
-            else
-               {
-               trfprintf(logFile, "#INFO: DUMP FAILED: not recompiling DLT method\n");
-               jitDumpFailedBecause(crashedThread, "method was not a OrdinaryMethod");
-               }
-
-            } // if recompilationThread
-         else
-            {
-            trfprintf(logFile, "#INFO: DUMP FAILED: no diagnostic thread\n");
-            jitDumpFailedBecause(crashedThread, "no thread available to compile for dump");
-            }
-
-         } // if comp
-      else
-         {
-         trfprintf(logFile, "#INFO: DUMP FAILED: no compilation in progress to redo\n");
-         jitDumpFailedBecause(crashedThread, "found no in-progress compilation to redo");
-         }
-
-      } // if threadcompinfo
-
-   trfprintf(logFile, "</jitDump>\n");
-
-   // flush and close log file
-   trfflush(logFile);
-   trfclose(logFile);
-
-   // re-enable all non-essential compilations
-   compInfo->getPersistentInfo()->setDisableFurtherCompilation(false);
-
-   if (options && options->getVerboseOption(TR_VerboseDump))
-      TR_VerboseLog::writeLineLocked(TR_Vlog_JITDUMP, "JIT dump complete");
-
-
-   return 0;
-   } // dumpJitInfo
-
-#endif
-
 static void accumulateAndPrintDebugCounters(J9JITConfig *jitConfig)
    {
    TR_Debug *debug = TR::Options::getDebug();
@@ -3933,10 +3279,9 @@ void lowerCompilationLimitsOnLowVirtualMemory(TR::CompilationInfo *compInfo, J9V
             }
          }
 
-      // If the scratch space limit is still the default value, then change it now
-      if (TR::Options::getScratchSpaceLimit() == (DEFAULT_SCRATCH_SPACE_LIMIT_KB * 1024))
+      // Decrease the scratch space limit
+      if (TR::Options::getScratchSpaceLimit() > TR::Options::getScratchSpaceLimitKBWhenLowVirtualMemory()*1024)
          {
-         TR_ASSERT(DEFAULT_SCRATCH_SPACE_LIMIT_KB > TR::Options::getScratchSpaceLimitKBWhenLowVirtualMemory(), "assertion failure");
          TR::Options::setScratchSpaceLimit(TR::Options::getScratchSpaceLimitKBWhenLowVirtualMemory() * 1024);
          if (TR::Options::getCmdLineOptions()->getVerboseOption(TR_VerbosePerformance))
             {
diff --git a/runtime/compiler/control/J9Options.cpp b/runtime/compiler/control/J9Options.cpp
index eb73c497691..0ef54f214d5 100644
--- a/runtime/compiler/control/J9Options.cpp
+++ b/runtime/compiler/control/J9Options.cpp
@@ -1092,17 +1092,6 @@ static void JITServerParseCommonOptions(J9JavaVM *vm, TR::CompilationInfo *compI
    int32_t xxJITServerPersistentLoggingDatabaseNameArgIndex = FIND_ARG_IN_VMARGS(STARTSWITH_MATCH, xxJITServerPersistentLoggingDatabaseNameOption, 0);
    int32_t xxJITServerPersistentLoggingDatabaseUsernameArgIndex = FIND_ARG_IN_VMARGS(STARTSWITH_MATCH, xxJITServerPersistentLoggingDatabaseUsernameOption, 0);
    int32_t xxJITServerPersistentLoggingDatabasePasswordArgIndex = FIND_ARG_IN_VMARGS(STARTSWITH_MATCH, xxJITServerPersistentLoggingDatabasePasswordOption, 0);
-#endif // defined(MONGO_LOGGER) || ...
-   
-   if (xxJITServerPortArgIndex >= 0)
-      {
-      uint32_t port=0;
-      IDATA ret = GET_INTEGER_VALUE(xxJITServerPortArgIndex, xxJITServerPortOption, port);
-      if (ret == OPTION_OK)
-         compInfo->getPersistentInfo()->setJITServerPort(port);
-      }
-
-#if defined(MONGO_LOGGER) || defined(CASSANDRA_LOGGER)
    if (xxJITServerPersistentLoggingArgIndex >= 0)
       {
       bool enable = false;
@@ -1144,6 +1133,13 @@ static void JITServerParseCommonOptions(J9JavaVM *vm, TR::CompilationInfo *compI
       compInfo->getPersistentInfo()->setJITServerPersistentLoggingDatabaseAddress(address);
       }
 #endif // defined(MONGO_LOGGER) || ...
+   if (xxJITServerPortArgIndex >= 0)
+   {
+   uint32_t port=0;
+   IDATA ret = GET_INTEGER_VALUE(xxJITServerPortArgIndex, xxJITServerPortOption, port);
+   if (ret == OPTION_OK)
+      compInfo->getPersistentInfo()->setJITServerPort(port);
+   }
 
    if (xxJITServerTimeoutArgIndex >= 0)
       {
diff --git a/runtime/compiler/control/JITClientCompilationThread.cpp b/runtime/compiler/control/JITClientCompilationThread.cpp
index d62d62935a4..8d21030d7d8 100644
--- a/runtime/compiler/control/JITClientCompilationThread.cpp
+++ b/runtime/compiler/control/JITClientCompilationThread.cpp
@@ -120,7 +120,7 @@ handler_IProfiler_profilingSample(JITServer::ClientStream *client, TR_J9VM *fe,
    if (wholeMethodInfo)
       {
       // Serialize all the information related to this method
-      abort = iProfiler->serializeAndSendIProfileInfoForMethod(method, comp, client, usePersistentCache);
+      abort = iProfiler->serializeAndSendIProfileInfoForMethod(method, comp, client, usePersistentCache, isCompiled);
       }
    if (!wholeMethodInfo || abort) // Send information just for this entry
       {
@@ -135,11 +135,11 @@ handler_IProfiler_profilingSample(JITServer::ClientStream *client, TR_J9VM *fe,
             auto storage = (TR_IPBCDataStorageHeader*)&entryBytes[0];
             uintptr_t methodStartAddress = (uintptr_t)TR::Compiler->mtd.bytecodeStart(method);
             entry->serialize(methodStartAddress, storage, comp->getPersistentInfo());
-            client->write(JITServer::MessageType::IProfiler_profilingSample, entryBytes, false, usePersistentCache);
+            client->write(JITServer::MessageType::IProfiler_profilingSample, entryBytes, false, usePersistentCache, isCompiled);
             }
          else
             {
-            client->write(JITServer::MessageType::IProfiler_profilingSample, std::string(), false, usePersistentCache);
+            client->write(JITServer::MessageType::IProfiler_profilingSample, std::string(), false, usePersistentCache, isCompiled);
             }
          // Unlock the entry
          if (auto callGraphEntry = entry->asIPBCDataCallGraph())
@@ -148,7 +148,7 @@ handler_IProfiler_profilingSample(JITServer::ClientStream *client, TR_J9VM *fe,
          }
       else // No valid info for specified bytecode index
          {
-         client->write(JITServer::MessageType::IProfiler_profilingSample, std::string(), false, usePersistentCache);
+         client->write(JITServer::MessageType::IProfiler_profilingSample, std::string(), false, usePersistentCache, isCompiled);
          }
       }
    }
@@ -285,11 +285,14 @@ handleServerMessage(JITServer::ClientStream *client, TR_J9VM *fe, JITServer::Mes
          break;
       case MessageType::VM_getClassFromSignature:
          {
+         // Need to get a non-AOT frontend because the AOT frontend also
+         // performs some class validation which we want to do at the server
+         TR_J9VMBase *fej9 = TR_J9VMBase::get(vmThread->javaVM->jitConfig, vmThread);
          auto recv = client->getRecvData<std::string, TR_OpaqueMethodBlock *, bool>();
          std::string sig = std::get<0>(recv);
          auto method = std::get<1>(recv);
          bool isVettedForAOT = std::get<2>(recv);
-         auto clazz = fe->getClassFromSignature(sig.c_str(), sig.length(), method, isVettedForAOT);
+         auto clazz = fej9->getClassFromSignature(sig.c_str(), sig.length(), method, isVettedForAOT);
          client->write(response, clazz);
          }
          break;
@@ -1880,26 +1883,6 @@ handleServerMessage(JITServer::ClientStream *client, TR_J9VM *fe, JITServer::Mes
          client->write(response, methodInfo, isRomClassForMethodInSC, sameLoaders, sameClass);
          }
          break;
-      case MessageType::ResolvedRelocatableMethod_storeValidationRecordIfNecessary:
-         {
-         auto recv = client->getRecvData<J9Method *, J9ConstantPool *, int32_t, bool, J9Class *>();
-         auto ramMethod = std::get<0>(recv);
-         auto constantPool = std::get<1>(recv);
-         auto cpIndex = std::get<2>(recv);
-         bool isStatic = std::get<3>(recv);
-         J9Class *definingClass = std::get<4>(recv);
-         J9Class *clazz = (J9Class *) J9_CLASS_FROM_METHOD(ramMethod);
-         if (!definingClass)
-            {
-            definingClass = (J9Class *) TR_ResolvedJ9Method::definingClassFromCPFieldRef(comp, constantPool, cpIndex, isStatic);
-            }
-         UDATA *classChain = NULL;
-         if (definingClass)
-            classChain = fe->sharedCache()->rememberClass(definingClass);
-
-         client->write(response, clazz, definingClass, classChain);
-         }
-         break;
       case MessageType::ResolvedRelocatableMethod_getFieldType:
          {
          auto recv = client->getRecvData<int32_t, TR_ResolvedJ9Method *>();
@@ -2614,7 +2597,8 @@ handleServerMessage(JITServer::ClientStream *client, TR_J9VM *fe, JITServer::Mes
          auto count = std::get<2>(recv);
          TR_IProfiler * iProfiler = fe->getIProfiler();
          iProfiler->setCallCount(method, bcIndex, count, comp);
-         client->write(response, JITServer::Void());
+
+         client->write(response, TR::CompilationInfo::isCompiled((J9Method *)method));
          }
          break;
       case MessageType::Recompilation_getExistingMethodInfo:
@@ -2652,8 +2636,9 @@ handleServerMessage(JITServer::ClientStream *client, TR_J9VM *fe, JITServer::Mes
          break;
       case MessageType::KnownObjectTable_getOrCreateIndexAt:
          {
-         uintptr_t *objectPointerReference = std::get<0>(client->getRecvData<uintptr_t*>());
-         client->write(response, knot->getOrCreateIndexAt(objectPointerReference));
+         uintptr_t *objectPointerReferenceServerQuery = std::get<0>(client->getRecvData<uintptr_t*>());
+         TR::KnownObjectTable::Index index = knot->getOrCreateIndexAt(objectPointerReferenceServerQuery);
+         client->write(response, index, knot->getPointerLocation(index));
          }
          break;
       case MessageType::KnownObjectTable_getPointer:
@@ -3288,7 +3273,7 @@ remoteCompile(
             // this list will be copied into the metadata
             for (auto& it : serializedRuntimeAssumptions)
                {
-               uint8_t *addrToPatch = (uint8_t*)(metaData->startPC + it.getOffsetFromStartPC());
+               uint8_t *addrToPatch = (uint8_t*)(metaData->codeCacheAlloc + it.getOffsetFromBinaryBufferStart());
                switch (it.getKind()) 
                   {
                   case RuntimeAssumptionOnRegisterNative:
diff --git a/runtime/compiler/control/JITServerCompilationThread.cpp b/runtime/compiler/control/JITServerCompilationThread.cpp
index 954edec882e..ab0f97d05f0 100644
--- a/runtime/compiler/control/JITServerCompilationThread.cpp
+++ b/runtime/compiler/control/JITServerCompilationThread.cpp
@@ -120,12 +120,14 @@ outOfProcessCompilationEnd(
       bool isConnected = logger.connect();
       if (isConnected)
          {
-         if (!logger.logMethod(methodSignature, clientUID, logFileStr.c_str()))
+         if (!logger.logMethod(methodSignature, clientUID, logFileStr.c_str(),compInfoPT->getJitConfig()))
             fprintf(stderr, "JITServer: Persistent Logging Error - Database insert failed, skipping persistent logging.");
          logger.disconnect();
          }
       else
-         fprintf(stderr, "JITServer: Persistent Logging Error - Database connection failed.\n");
+         {
+         fprintf(stderr, "JITServer: Persistent Logging Error - Database connection failed.\n"); 
+         }
       }
 #endif // defined(MONGO_LOGGER) || defined(CASSANDRA_LOGGER)
 
diff --git a/runtime/compiler/control/JitDump.cpp b/runtime/compiler/control/JitDump.cpp
new file mode 100644
index 00000000000..71b350adfa4
--- /dev/null
+++ b/runtime/compiler/control/JitDump.cpp
@@ -0,0 +1,698 @@
+/*******************************************************************************
+ * Copyright (c) 2020, 2020 IBM Corp. and others
+ *
+ * This program and the accompanying materials are made available under
+ * the terms of the Eclipse Public License 2.0 which accompanies this
+ * distribution and is available at https://www.eclipse.org/legal/epl-2.0/
+ * or the Apache License, Version 2.0 which accompanies this distribution and
+ * is available at https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * This Source Code may also be made available under the following
+ * Secondary Licenses when the conditions for such availability set
+ * forth in the Eclipse Public License, v. 2.0 are satisfied: GNU
+ * General Public License, version 2 with the GNU Classpath
+ * Exception [1] and GNU General Public License, version 2 with the
+ * OpenJDK Assembly Exception [2].
+ *
+ * [1] https://www.gnu.org/software/classpath/license.html
+ * [2] http://openjdk.java.net/legal/assembly-exception.html
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0 WITH Classpath-exception-2.0 OR LicenseRef-GPL-2.0 WITH Assembly-exception
+ *******************************************************************************/
+
+#include "control/JitDump.hpp"
+
+#include "codegen/CodeGenerator.hpp"
+#include "env/VMJ9.h"
+#include "control/MethodToBeCompiled.hpp"
+#include "control/CompilationRuntime.hpp"
+#include "control/CompilationThread.hpp"
+#include "env/ut_j9jit.h"
+#include "ilgen/J9ByteCodeIlGenerator.hpp"
+#if defined(J9VM_OPT_JITSERVER)
+#include "control/JITServerHelpers.hpp"
+#include "runtime/JITServerIProfiler.hpp"
+#include "runtime/JITServerStatisticsThread.hpp"
+#include "runtime/Listener.hpp"
+#endif
+
+UDATA
+blankDumpSignalHandler(struct J9PortLibrary *portLibrary, U_32 gpType, void *gpInfo, void *arg)
+   {
+   J9VMThread *vmThread = (J9VMThread *) arg;
+   TR_VerboseLog::writeLineLocked(TR_Vlog_JITDUMP, "vmThread=%p Recursive crash occurred. Aborting JIT dump.", vmThread);
+
+   // Returning J9PORT_SIG_EXCEPTION_RETURN will make us come back to the same crashing instruction over and over
+   //
+   return J9PORT_SIG_EXCEPTION_RETURN;
+   }
+
+typedef struct DumpCurrentILParamenters
+   {
+   DumpCurrentILParamenters(
+         TR::Compilation *comp,
+         J9VMThread *vmThread,
+         J9JITConfig *jitConfig,
+         TR::FILE *logFile
+      )  :
+      _comp(comp),
+      _vmThread(vmThread),
+      _jitConfig(jitConfig),
+      _logFile(logFile)
+      {}
+
+   TR::Compilation *_comp;
+   J9VMThread      *_vmThread;
+   J9JITConfig     *_jitConfig;
+   TR::FILE        *_logFile;
+   } DumpCurrentILParamenters;
+
+static UDATA
+blankDumpCurrentILSignalHandler(struct J9PortLibrary *portLibrary, U_32 gpType, void *gpInfo, void *arg)
+   {
+   J9VMThread *vmThread = (J9VMThread *) arg;
+   TR_VerboseLog::writeLineLocked(TR_Vlog_JITDUMP, "vmThread=%p Crashed while printing out current IL.", vmThread);
+   return J9PORT_SIG_EXCEPTION_RETURN;
+   }
+
+static void jitDumpFailedBecause(J9VMThread *currentThread, const char* message)
+   {
+   if (TR::Options::getCmdLineOptions()->getVerboseOption(TR_VerboseDump))
+      TR_VerboseLog::writeLineLocked(TR_Vlog_JITDUMP, "JIT dump failed because %s", message);
+   Trc_JIT_DumpFail(currentThread, message);
+   return;
+   }
+
+static void stackWalkEndingBecause(const char* message)
+   {
+   if (TR::Options::getCmdLineOptions()->getVerboseOption(TR_VerboseDump))
+      TR_VerboseLog::writeLineLocked(TR_Vlog_JITDUMP, "stack walk ending because %s", message);
+   return;
+   }
+
+static UDATA dumpCurrentILProtected(J9PortLibrary *portLib, void * opaqueParameters)
+   {
+   DumpCurrentILParamenters *p = static_cast<DumpCurrentILParamenters *>(opaqueParameters);
+   TR::Compilation *comp       = p->_comp;
+   J9VMThread *vmThread        = p->_vmThread;
+   J9JITConfig *jitConfig      = p->_jitConfig;
+   TR::FILE *logFile           = p->_logFile;
+
+   comp->findOrCreateDebug();
+
+   TR::Options *options = comp->getOptions();
+   TR_Debug *dbg = comp->getDebug();
+   TR_J9VMBase * fe = TR_J9VMBase::get(jitConfig, vmThread);
+
+   if (logFile != NULL)
+      {
+      comp->setOutFile(logFile);
+      options->setOption(TR_TraceAll);
+      options->setOption(TR_TraceKnownObjectGraph);
+      dbg->setFile(logFile);
+
+      trfprintf(logFile,"<currentIL>\n");
+
+      // Print Bytecodes
+      TR::IlGeneratorMethodDetails & details = comp->ilGenRequest().details();
+      TR::ResolvedMethodSymbol *resolvedMethod = comp->getMethodSymbol();
+      TR::SymbolReferenceTable *symRefTab = comp->getSymRefTab();
+      TR_J9ByteCodeIlGenerator bci(details, resolvedMethod, fe, comp, symRefTab);
+      bci.printByteCodes();
+
+      dbg->printMethodHotness();
+      comp->dumpMethodTrees("Trees");
+      dbg->print(logFile, comp->getSymRefTab());
+
+      int bitMask = J9VMSTATE_JIT_CODEGEN | 0x0000FF00; // 0xFF?? is Codegen Phase
+      if ( ((vmThread->omrVMThread->vmState) & bitMask) == bitMask )  // if we are in the Codegen Phase
+         {
+         dbg->dumpMethodInstrs(logFile, "Post Binary Instructions", false, true);
+
+         dbg->print(logFile,comp->cg()->getSnippetList(), true);  // print Warm Snippets
+         dbg->print(logFile,comp->cg()->getSnippetList(), false);
+
+         dbg->dumpMixedModeDisassembly();
+         }
+
+      // leaving to the very end in case there is a crash before this point.
+      comp->verifyTrees(comp->getMethodSymbol());
+      comp->verifyBlocks(comp->getMethodSymbol());
+
+      trfprintf(logFile, "</currentIL>\n");
+      }
+
+   return 0;
+   }
+
+static void dumpCurrentIL(TR::Compilation *comp, J9VMThread *vmThread, J9JITConfig *jitConfig, TR::FILE *logFile )
+   {
+   /* Acquire VM Access */
+   bool alreadyHaveVMAccess = ((vmThread->publicFlags & J9_PUBLIC_FLAGS_VM_ACCESS) != 0);
+   bool haveAcquiredVMAccess = false;
+   if (!alreadyHaveVMAccess)
+      if (0 == vmThread->javaVM->internalVMFunctions->internalTryAcquireVMAccessWithMask(vmThread, J9_PUBLIC_FLAGS_HALT_THREAD_ANY_NO_JAVA_SUSPEND))
+         haveAcquiredVMAccess = true;
+
+   PORT_ACCESS_FROM_JITCONFIG(jitConfig);
+
+   DumpCurrentILParamenters p(
+      comp,
+      vmThread,
+      jitConfig,
+      logFile
+      );
+
+   UDATA result = 0;
+
+#if defined(J9VM_PORT_SIGNAL_SUPPORT)
+   U_32 flags = J9PORT_SIG_FLAG_MAY_RETURN |
+                J9PORT_SIG_FLAG_SIGSEGV | J9PORT_SIG_FLAG_SIGFPE |
+                J9PORT_SIG_FLAG_SIGILL  | J9PORT_SIG_FLAG_SIGBUS;
+
+   static char *noSignalWrapper = feGetEnv("TR_NoSignalWrapper");
+
+   if (!noSignalWrapper && j9sig_can_protect(flags))
+      {
+      UDATA protectedResult;
+
+      protectedResult = j9sig_protect((j9sig_protected_fn)dumpCurrentILProtected, static_cast<void *>(&p),
+                                         (j9sig_handler_fn)blankDumpCurrentILSignalHandler, vmThread,
+                                         flags, &result);
+      }
+   else
+#endif
+      result = dumpCurrentILProtected(privatePortLibrary, &p);
+
+
+   /* Release VM Access */
+   if (!alreadyHaveVMAccess)
+      if (haveAcquiredVMAccess)
+         vmThread->javaVM->internalVMFunctions->internalReleaseVMAccess(vmThread);
+   }
+
+#define STACK_WALK_DEPTH 16
+
+// struct to remember a method for JIT dump
+typedef struct TR_MethodToBeCompiledForDump {
+   J9Method   *_method;
+   void       *_oldStartPC;
+   TR_Hotness  _optLevel;
+} TR_MethodToBeCompiledForDump;
+
+// Stack frame iterator. Iterates until STACK_WALK_DEPTH frames or the top are reached.
+static UDATA logStackIterator(J9VMThread *currentThread, J9StackWalkState *walkState)
+   {
+   Trc_JIT_DumpWalkingFrame(currentThread);
+
+   // stop iterating if the walk state is null
+   if (!walkState)
+      {
+      stackWalkEndingBecause("got a null walkState");
+      return J9_STACKWALK_STOP_ITERATING;
+      }
+
+   // get user data from walk state
+   TR_MethodToBeCompiledForDump* jittedMethodsOnStack = (TR_MethodToBeCompiledForDump *) walkState->userData1;
+   int *currentMethodIndex                            = (int *) walkState->userData2;
+
+   // also stop iterating if passed user data is null
+   if (currentMethodIndex == 0 || jittedMethodsOnStack == 0)
+      {
+      stackWalkEndingBecause("one or both user data are null");
+      return J9_STACKWALK_STOP_ITERATING;
+      }
+
+   // also stop iterating if enough frames have been reached
+   if ((*currentMethodIndex) >= STACK_WALK_DEPTH)
+      {
+      stackWalkEndingBecause("reached limit on number of methods to recompile");
+      return J9_STACKWALK_STOP_ITERATING;
+      }
+
+   // if the frame has jit metadata, then it belongs to a JITed method
+   if (walkState->jitInfo)
+      {
+      // NOTE: method is the one (J9Method, a.k.a. TR_OpaqueMethodBlock) that gets
+      //       passed to IlGeneratorMethodDetails
+      TR_ASSERT(walkState->method, "Found method metadata on the stack, but method is null.");
+
+      // get method's body info (can be null)
+      TR_PersistentJittedBodyInfo* bodyInfo = TR::Recompilation::getJittedBodyInfoFromPC((void*) walkState->jitInfo->startPC);
+
+      // get global configuration options
+      TR::Options *options = TR::Options::getCmdLineOptions();
+
+      // get global opt level
+      // NOTE: getOptLevel returns -1 if it is not set
+      TR_Hotness globalOptLevel = (TR_Hotness) (-1);
+      if (options)
+         globalOptLevel = (TR_Hotness) options->getFixedOptLevel();
+
+      // add the method to our list ONLY if level can be determined; it can be determined
+      // either from body info (if it exists), or from fixed level (if it was set)
+      if (bodyInfo || (globalOptLevel != (-1)))
+         {
+         // set the method
+         jittedMethodsOnStack[*currentMethodIndex]._method = walkState->method;
+
+         // set the method's oldStartPC:
+         //    if bodyInfo exists, then we can do a recompilation (use startPCAfterPreviousCompile)
+         //    if not, then we can't, and we do a first-time compilation (use 0)
+         if (bodyInfo)
+            jittedMethodsOnStack[*currentMethodIndex]._oldStartPC = bodyInfo->getStartPCAfterPreviousCompile();
+         else
+            jittedMethodsOnStack[*currentMethodIndex]._oldStartPC = 0;
+
+         // set the optLevel
+         if (bodyInfo)
+            jittedMethodsOnStack[*currentMethodIndex]._optLevel = bodyInfo->getHotness();
+         else
+            // NOTE: global optLevel is not -1, since we checked for that above
+            jittedMethodsOnStack[*currentMethodIndex]._optLevel = globalOptLevel;
+
+         // advance to the next method in the list
+         *currentMethodIndex = (*(currentMethodIndex) + 1);
+         }
+      }
+
+   return J9_STACKWALK_KEEP_ITERATING;
+   }
+
+/// Recompiles a method for the JIT dump
+static TR_CompilationErrorCode recompileMethodForLog(
+   J9VMThread         *vmThread,
+   J9Method           *ramMethod,
+   TR::CompilationInfo *compInfo,
+   TR_J9VMBase        *frontendOfThread,
+   TR_Hotness          optimizationLevel,
+   bool                profilingCompile,
+   void               *oldStartPC,
+   TR::FILE *logFile
+   )
+   {
+   if (TR::Options::getCmdLineOptions()->getVerboseOption(TR_VerboseDump))
+      TR_VerboseLog::writeLineLocked(TR_Vlog_JITDUMP, "recompiling a method for log: %p", ramMethod);
+
+   Trc_JIT_DumpCompilingMethod(vmThread, ramMethod, optimizationLevel, oldStartPC);
+
+   // the request to use Log should be passed to the compilation, via optimizationPlan
+   // then the option object created should use this to open the log; thus must create a new optimization plan
+   // the right optlevel would be set during the Options setting
+   TR_OptimizationPlan *plan = TR_OptimizationPlan::alloc(optimizationLevel);
+   if (!plan)
+      return compilationFailure;
+
+   if (profilingCompile)
+      plan->setInsertInstrumentation(true);
+
+   // pass the log file to the compilation
+   plan->setLogCompilation(logFile);
+
+   bool successfullyQueued = false;
+
+   trfprintf(logFile, "<logRecompilation>\n");
+
+   // actually request the compilation
+   if (TR::Options::getCmdLineOptions()->getVerboseOption(TR_VerboseDump))
+      TR_VerboseLog::writeLineLocked(TR_Vlog_JITDUMP, "dumpJitInfo: compileMethod() about to issued synchronously");
+   TR_CompilationErrorCode compErrCode;
+
+   // Set the VM state of the crashed thread so the diagnostic thread can use consume it
+   compInfo->setVMStateOfCrashedThread(vmThread->omrVMThread->vmState);
+
+   // create a compilation request
+   // NOTE: operator new() is overridden, and takes a storage object as a parameter
+   // TODO: this is indiscriminately compiling as J9::DumpMethodRequest, which is wrong;
+   //       should be fixed by checking if the method is indeed DLT, and compiling DLT if so
+      {
+      J9::DumpMethodDetails details( ramMethod);
+      compInfo->compileMethod(vmThread, details, oldStartPC, TR_no, &compErrCode, &successfullyQueued, plan);
+      }
+
+   if (TR::Options::getCmdLineOptions()->getVerboseOption(TR_VerboseDump))
+      TR_VerboseLog::writeLineLocked(TR_Vlog_JITDUMP, "dumpJitInfo: crashing thread returned from compileMethod() with errorCode=%d", compErrCode);
+
+   trfprintf(logFile, "</logRecompilation>\n");
+
+   // if the request failed, get rid of the optimization plan we made
+   if (!successfullyQueued)
+      TR_OptimizationPlan::freeOptimizationPlan(plan);
+
+   return compErrCode;
+   }
+
+/// Dumps JIT-specific crash info
+IDATA dumpJitInfo(J9VMThread *crashedThread, char *logFileLabel, J9RASdumpContext *context)
+   {
+   Trc_JIT_DumpStart(crashedThread);
+
+#if defined(J9VM_OPT_JITSERVER)
+   if (context && context->javaVM && context->javaVM->jitConfig)
+      {
+      J9JITConfig *jitConfig = context->javaVM->jitConfig;
+      TR::CompilationInfo *compInfo = TR::CompilationInfo::get(context->javaVM->jitConfig);
+      if (compInfo)
+         {
+         static char * isPrintJITServerMsgStats = feGetEnv("TR_PrintJITServerMsgStats");
+         if (isPrintJITServerMsgStats && compInfo->getPersistentInfo()->getRemoteCompilationMode() == JITServer::CLIENT)
+            JITServerHelpers::printJITServerMsgStats(jitConfig);
+         if (feGetEnv("TR_PrintJITServerCHTableStats"))
+            JITServerHelpers::printJITServerCHTableStats(jitConfig, compInfo);
+         if (feGetEnv("TR_PrintJITServerIPMsgStats"))
+            {
+            if (compInfo->getPersistentInfo()->getRemoteCompilationMode() == JITServer::SERVER)
+               {
+               TR_J9VMBase * vmj9 = (TR_J9VMBase *)(TR_J9VMBase::get(context->javaVM->jitConfig, 0));
+               JITServerIProfiler *iProfiler = (JITServerIProfiler *)vmj9->getIProfiler();
+               iProfiler->printStats();
+               }
+            }
+         }
+      }
+#endif
+
+   if (TR::Options::getCmdLineOptions()->getVerboseOption(TR_VerboseDump))
+      TR_VerboseLog::writeLineLocked(TR_Vlog_JITDUMP, "JIT dump initiated. Crashed vmThread=%p", crashedThread);
+
+   // if either one of the args is null, we can't really do anything
+   if (crashedThread == 0 || logFileLabel == 0)
+      {
+      jitDumpFailedBecause(crashedThread, "one or both arguments are null");
+      return 0;
+      }
+
+   // if VM is gone, can't do anything either
+   if (crashedThread->javaVM == 0)
+      {
+      jitDumpFailedBecause(crashedThread, "VM pointer is null");
+      return 0;
+      }
+
+   // get a hold of jitConfig in order to later get compinfo and frontend
+   J9JITConfig * jitConfig = crashedThread->javaVM->jitConfig;
+
+   // if jitConfig is gone, then we can't do anything either
+   if (jitConfig == 0)
+      {
+      jitDumpFailedBecause(crashedThread, "jitConfig is null");
+      return 0;
+      }
+   // get global compinfo
+   TR::CompilationInfo *compInfo = TR::CompilationInfo::get(jitConfig);
+   if (!compInfo)
+      {
+      jitDumpFailedBecause(crashedThread, "compInfo is null");
+      return 0;
+      }
+
+   // Must be able to allocate a frontend for this thread
+   TR_J9VMBase *frontendOfThread = TR_J9VMBase::get(jitConfig, crashedThread);
+   if (!frontendOfThread)
+      {
+      jitDumpFailedBecause(crashedThread, "thread's frontend is missing");
+      return 0;
+      }
+
+   // get global configuration options
+   TR::Options *options = TR::Options::getCmdLineOptions();
+   if (!options)
+      {
+      jitDumpFailedBecause(crashedThread, "No cmdLineOptions available");
+      return 0;
+      }
+
+
+   // open log file, using the postfixed timestamp if specified
+   TR::FILE *logFile;
+   char tmp[1025];
+   logFileLabel = frontendOfThread->getFormattedName(tmp, 1025, logFileLabel, NULL, false);
+   logFile = trfopen(logFileLabel, "ab", false);
+
+   trfprintf(logFile,
+      "<?xml version=\"1.0\" standalone=\"no\"?>\n"
+      "<jitDump>\n"
+      );
+
+
+   // if some thread holds exclusive VM access we cannot do much
+   if (J9_XACCESS_NONE != jitConfig->javaVM->exclusiveAccessState)
+      {
+      jitDumpFailedBecause(crashedThread, "some thread is holding exclusive VM access");
+      trfprintf(logFile, "Some thread is holding exclusive VM access. No log created.\n");
+      trfclose(logFile);
+      return 0;
+      }
+
+
+   // to avoid deadlock, release compilation monitor until we are no longer holding it
+   while (compInfo->getCompilationMonitor()->owned_by_self())
+      compInfo->releaseCompMonitor(crashedThread);
+
+   // Release other monitors as well. In particular CHTable and classUnloadMonitor must not be held
+   while (TR::MonitorTable::get()->getClassTableMutex()->owned_by_self())
+      frontendOfThread->releaseClassTableMutex(false);
+
+   //FIXME: how do I detect that someone is holding the classUnloadMonitor
+
+   // get crashed thread's own compinfo
+   TR::CompilationInfoPerThread *threadCompInfo = compInfo->getCompInfoForThread(crashedThread);
+
+   // Crashes on the diagnostic thread should not be processed
+   if (threadCompInfo && threadCompInfo->isDiagnosticThread())
+      {
+      jitDumpFailedBecause(crashedThread, "detected recursive crash");
+      trfprintf(logFile, "Detected recursive crash. No log created.\n");
+      trfclose(logFile);
+      return 0;
+      }
+
+   // get the method currently being compiled
+   TR_MethodToBeCompiled *currentMethodBeingCompiled = 0;
+   if (threadCompInfo)
+      currentMethodBeingCompiled = threadCompInfo->getMethodBeingCompiled();
+
+   /*
+    * at this stage, we know that we are good to orchestrate a dump
+    */
+
+   if (options->getOption(TR_VerboseDump))
+      TR_VerboseLog::writeLineLocked(TR_Vlog_JITDUMP, "dump agent obtained necessary information to perform dump");
+
+   // if we are currently compiling a method, wake everyone waiting for it to compile
+   if (currentMethodBeingCompiled && currentMethodBeingCompiled->getMonitor())
+      {
+      currentMethodBeingCompiled->getMonitor()->enter();
+      currentMethodBeingCompiled->getMonitor()->notifyAll();
+      currentMethodBeingCompiled->getMonitor()->exit();
+      if (TR::Options::getCmdLineOptions()->getVerboseOption(TR_VerboseDump))
+         TR_VerboseLog::writeLineLocked(TR_Vlog_JITDUMP, "dumpJitInfo notified all waiting threads");
+      }
+
+   // disable all non-essential compilations
+   compInfo->getPersistentInfo()->setDisableFurtherCompilation(true);
+   if (TR::Options::getCmdLineOptions()->getVerboseOption(TR_VerboseDump))
+      TR_VerboseLog::writeLineLocked(TR_Vlog_JITDUMP, "dumpJitInfo disabled further compilation");
+
+   // get the dump thread
+   TR::CompilationInfoPerThread *recompilationThreadInfo = compInfo->getCompilationInfoForDumpThread();
+   J9VMThread                  *recompilationThread = NULL;
+   if (recompilationThreadInfo)
+      recompilationThread = recompilationThreadInfo->getCompilationThread();
+
+   // purge the compilation queue if a thread was found
+   if (recompilationThread)
+      {
+      if (options->getVerboseOption(TR_VerboseDump))
+         TR_VerboseLog::writeLineLocked(TR_Vlog_JITDUMP, "dumpJitInfo: diagnostic compilation thread available. Will purge compilation queue");
+      compInfo->acquireCompMonitor(crashedThread);
+      compInfo->purgeMethodQueue(compilationFailure); // compilationFailure is a TR_CompilationErrorCode
+      compInfo->releaseCompMonitor(crashedThread);
+      }
+
+
+
+   // if our compinfo is null, we are an application thread
+   if (threadCompInfo == 0)
+      {
+      if (options->getVerboseOption(TR_VerboseDump))
+         TR_VerboseLog::writeLineLocked(TR_Vlog_JITDUMP, "crashed in application thread");
+      trfprintf(logFile, "#INFO: Crashed in application thread %p.\n", crashedThread);
+
+      // only bother doing anything if we have a healthy compilation thread available
+      if (recompilationThread)
+         {
+         // make space for methods to be recompiled
+         // FIXME: this is on the stack... is the stack big enough?
+         int currentMethodIndex = 0;
+         TR_MethodToBeCompiledForDump jittedMethodsOnStack[STACK_WALK_DEPTH] = { 0 };
+
+         // set up the stack walk object
+         J9StackWalkState walkState;
+
+         walkState.userData1 = (void *)jittedMethodsOnStack;
+         walkState.userData2 = (void *)&currentMethodIndex;
+         walkState.walkThread = crashedThread;
+         walkState.skipCount = 0;
+         walkState.maxFrames = STACK_WALK_DEPTH;
+         walkState.flags = (
+            // J9_STACKWALK_LINEAR |
+            // J9_STACKWALK_START_AT_JIT_FRAME |
+            // J9_STACKWALK_INCLUDE_NATIVES |
+            // J9_STACKWALK_HIDE_EXCEPTION_FRAMES |
+            // J9_STACKWALK_ITERATE_HIDDEN_JIT_FRAMES |
+            J9_STACKWALK_VISIBLE_ONLY |
+            J9_STACKWALK_SKIP_INLINES |
+            J9_STACKWALK_COUNT_SPECIFIED |
+            J9_STACKWALK_ITERATE_FRAMES
+            );
+         walkState.frameWalkFunction = logStackIterator;
+
+         /*
+          * NOTE [March 6th, 2013]:
+          *
+          *    Graham Chapman said:
+          *
+          *    This will make the stack walker jump back to the last
+          *    interpreter transition point if a bad return address is found,
+          *    rather than asserting.  You'll miss a bunch of frames, but
+          *    there's really nothing better to be done in that case.
+          */
+         walkState.errorMode = J9_STACKWALK_ERROR_MODE_IGNORE;
+
+         // actually walk the stack, adding all JITed methods to the queue
+         compInfo->acquireCompMonitor(crashedThread);
+         crashedThread->javaVM->walkStackFrames(crashedThread, &walkState);
+         compInfo->releaseCompMonitor(crashedThread);
+
+         if (options->getVerboseOption(TR_VerboseDump))
+            TR_VerboseLog::writeLineLocked(TR_Vlog_JITDUMP, "found %d JITed methods on Java stack", currentMethodIndex);
+         trfprintf(logFile, "#INFO: Found %d JITed methods on Java stack.\n", currentMethodIndex);
+
+         // resume the compilation thread
+         recompilationThreadInfo->resumeCompilationThread();
+
+         // compile our methods
+         for (int i = 0; i < currentMethodIndex; i++)
+            {
+            // skip if method is somehow null
+            if (!(jittedMethodsOnStack[i]._method))
+               continue;
+
+            TR_CompilationErrorCode compErrCode;
+            compErrCode = recompileMethodForLog(
+               crashedThread,
+               jittedMethodsOnStack[i]._method,
+               compInfo,
+               frontendOfThread,
+               jittedMethodsOnStack[i]._optLevel,
+               false,
+               jittedMethodsOnStack[i]._oldStartPC,
+               logFile
+               );
+            } // for
+
+         if (currentMethodIndex == 0)
+            trfprintf(logFile, "#INFO: DUMP FAILED: no methods to recompile\n");
+
+         if (options->getVerboseOption(TR_VerboseDump))
+            TR_VerboseLog::writeLineLocked(TR_Vlog_JITDUMP, "recompilations complete");
+
+         } // if recompilationThread
+      else
+         {
+         trfprintf(logFile, "#INFO: DUMP FAILED: no diagnostic thread\n");
+         jitDumpFailedBecause(crashedThread, "no thread available to compile for dump");
+         }
+
+      } // if threadcompinfo
+
+   // if our compinfo is not null, we are a compilation thread
+   else
+      {
+      if (options->getVerboseOption(TR_VerboseDump))
+         TR_VerboseLog::writeLineLocked(TR_Vlog_JITDUMP, "crashed in compilation thread");
+      trfprintf(logFile, "#INFO: Crashed in compilation thread %p.\n", crashedThread);
+
+      // get current compilation
+      TR::Compilation *comp = threadCompInfo->getCompilation();
+
+      // if the compilation is in progress, dump interesting things from it and then recompile
+      if (comp)
+         {
+         if (options->getVerboseOption(TR_VerboseDump))
+            TR_VerboseLog::writeLineLocked(TR_Vlog_JITDUMP, "dumpJitInfo: found comp object");
+
+         // dump IL of current compilation
+         dumpCurrentIL(comp, crashedThread, jitConfig, logFile);
+
+         // if there was an available compilation thread, recompile the current method
+         if (recompilationThread)
+            {
+            // only proceed to recompile if the method is a regular Java method
+            if (currentMethodBeingCompiled &&
+               currentMethodBeingCompiled->getMethodDetails().isOrdinaryMethod())
+               {
+               // resume the healthy compilation thread
+               recompilationThreadInfo->resumeCompilationThread();  // TODO: Postpone this so that the thread does not get to sleep again
+               if (options->getVerboseOption(TR_VerboseDump))
+                  TR_VerboseLog::writeLineLocked(TR_Vlog_JITDUMP, "dumpJitInfo: have resumed DiagCompThread");
+
+               // get old start PC if method was available
+               void *oldStartPC = 0;
+               if (currentMethodBeingCompiled)
+                  oldStartPC = currentMethodBeingCompiled->_oldStartPC;
+
+               // request the compilation
+               TR_CompilationErrorCode compErrCode;
+               compErrCode = recompileMethodForLog(
+                  crashedThread,
+                  (J9Method *)(comp->getCurrentMethod()->getPersistentIdentifier()),
+                  compInfo,
+                  frontendOfThread,
+                  (TR_Hotness)comp->getOptLevel(),
+                  comp->isProfilingCompilation(),
+                  oldStartPC,
+                  logFile
+                  );
+
+               if (options->getVerboseOption(TR_VerboseDump))
+                  TR_VerboseLog::writeLineLocked(TR_Vlog_JITDUMP, "recompilation complete");
+               }
+            else
+               {
+               trfprintf(logFile, "#INFO: DUMP FAILED: not recompiling DLT method\n");
+               jitDumpFailedBecause(crashedThread, "method was not a OrdinaryMethod");
+               }
+
+            } // if recompilationThread
+         else
+            {
+            trfprintf(logFile, "#INFO: DUMP FAILED: no diagnostic thread\n");
+            jitDumpFailedBecause(crashedThread, "no thread available to compile for dump");
+            }
+
+         } // if comp
+      else
+         {
+         trfprintf(logFile, "#INFO: DUMP FAILED: no compilation in progress to redo\n");
+         jitDumpFailedBecause(crashedThread, "found no in-progress compilation to redo");
+         }
+
+      } // if threadcompinfo
+
+   trfprintf(logFile, "</jitDump>\n");
+
+   // flush and close log file
+   trfflush(logFile);
+   trfclose(logFile);
+
+   // re-enable all non-essential compilations
+   compInfo->getPersistentInfo()->setDisableFurtherCompilation(false);
+
+   if (options && options->getVerboseOption(TR_VerboseDump))
+      TR_VerboseLog::writeLineLocked(TR_Vlog_JITDUMP, "JIT dump complete");
+
+
+   return 0;
+   } // dumpJitInfo
diff --git a/runtime/util/sleephelp.c b/runtime/compiler/control/JitDump.hpp
similarity index 78%
rename from runtime/util/sleephelp.c
rename to runtime/compiler/control/JitDump.hpp
index d5e43dd01cc..4118e28ed14 100644
--- a/runtime/util/sleephelp.c
+++ b/runtime/compiler/control/JitDump.hpp
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 1991, 2014 IBM Corp. and others
+ * Copyright (c) 2020, 2020 IBM Corp. and others
  *
  * This program and the accompanying materials are made available under
  * the terms of the Eclipse Public License 2.0 which accompanies this
@@ -19,17 +19,11 @@
  *
  * SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0 WITH Classpath-exception-2.0 OR LicenseRef-GPL-2.0 WITH Assembly-exception
  *******************************************************************************/
+#include "j9.h"
+#include "j9nonbuilder.h"
 
-#include "omrthread.h"
-#include "j9protos.h"
-#include "util_internal.h"
-
-IDATA
-callThreadSleep(IDATA sleepTime)
-{
-	return omrthread_sleep(sleepTime);
-}
-
-
-
+extern J9_CFUNC UDATA
+blankDumpSignalHandler(struct J9PortLibrary *portLibrary, U_32 gpType, void *gpInfo, void *arg);
 
+extern J9_CFUNC intptr_t
+dumpJitInfo(J9VMThread * currentThread, char *label, J9RASdumpContext *context);
diff --git a/runtime/compiler/control/LoadDBLibs.cpp b/runtime/compiler/control/LoadDBLibs.cpp
index d9060997f57..c5f6d089d4b 100644
--- a/runtime/compiler/control/LoadDBLibs.cpp
+++ b/runtime/compiler/control/LoadDBLibs.cpp
@@ -101,7 +101,7 @@ namespace JITServer
          handle = loadLibmongoc();
          if (!handle)
             {
-            printf("#JITServer: Failed to load libmongoc\n");
+            fprintf(stderr, "#JITServer: Failed to load libmongoc\n");
             return false;
             }
 
diff --git a/runtime/compiler/control/MongoLogger.cpp b/runtime/compiler/control/MongoLogger.cpp
index ba8be02ab0d..ace05753a42 100644
--- a/runtime/compiler/control/MongoLogger.cpp
+++ b/runtime/compiler/control/MongoLogger.cpp
@@ -1,3 +1,25 @@
+/*******************************************************************************
+ * Copyright (c) 2020, 2020 IBM Corp. and others
+ *
+ * This program and the accompanying materials are made available under
+ * the terms of the Eclipse Public License 2.0 which accompanies this
+ * distribution and is available at https://www.eclipse.org/legal/epl-2.0/
+ * or the Apache License, Version 2.0 which accompanies this distribution and
+ * is available at https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * This Source Code may also be made available under the following
+ * Secondary Licenses when the conditions for such availability set
+ * forth in the Eclipse Public License, v. 2.0 are satisfied: GNU
+ * General Public License, version 2 with the GNU Classpath
+ * Exception [1] and GNU General Public License, version 2 with the
+ * OpenJDK Assembly Exception [2].
+ *
+ * [1] https://www.gnu.org/software/classpath/license.html
+ * [2] http://openjdk.java.net/legal/assembly-exception.html
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0 WITH Classpath-exception-2.0 OR LicenseRef-GPL-2.0 WITH Assembly-exception
+ *******************************************************************************/
+
 #include "MongoLogger.hpp"
 #include <ctime>
 #include <stdio.h>
@@ -125,7 +147,7 @@ void MongoLogger::disconnect()
    return;
    }
 
-bool MongoLogger::logMethod(const char* method, uint64_t clientID, const char* logContent)
+bool MongoLogger::logMethod(const char* method, uint64_t clientID, const char* logContent, J9JITConfig* j9JitConfig)
    {
    struct timespec t;
    clock_gettime(CLOCK_REALTIME, &t);
diff --git a/runtime/compiler/control/MongoLogger.hpp b/runtime/compiler/control/MongoLogger.hpp
index ce793e3b462..be5fc177e97 100644
--- a/runtime/compiler/control/MongoLogger.hpp
+++ b/runtime/compiler/control/MongoLogger.hpp
@@ -1,3 +1,25 @@
+/*******************************************************************************
+ * Copyright (c) 2020, 2020 IBM Corp. and others
+ *
+ * This program and the accompanying materials are made available under
+ * the terms of the Eclipse Public License 2.0 which accompanies this
+ * distribution and is available at https://www.eclipse.org/legal/epl-2.0/
+ * or the Apache License, Version 2.0 which accompanies this distribution and
+ * is available at https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * This Source Code may also be made available under the following
+ * Secondary Licenses when the conditions for such availability set
+ * forth in the Eclipse Public License, v. 2.0 are satisfied: GNU
+ * General Public License, version 2 with the GNU Classpath
+ * Exception [1] and GNU General Public License, version 2 with the
+ * OpenJDK Assembly Exception [2].
+ *
+ * [1] https://www.gnu.org/software/classpath/license.html
+ * [2] http://openjdk.java.net/legal/assembly-exception.html
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0 WITH Classpath-exception-2.0 OR LicenseRef-GPL-2.0 WITH Assembly-exception
+ *******************************************************************************/
+
 #ifndef MONGOLOGGER_HPP
 #define MONGOLOGGER_HPP
 
@@ -30,7 +52,7 @@ class MongoLogger : public BasePersistentLogger
 
    ~MongoLogger();
 
-   bool logMethod(const char* method, uint64_t clientID, const char* logContent) override;
+   bool logMethod(const char* method, uint64_t clientID, const char* logContent, J9JITConfig* j9JitConfig) override;
    };
 
 #endif //MONGOLOGGER_HPP
diff --git a/runtime/compiler/control/rossa.cpp b/runtime/compiler/control/rossa.cpp
index f62593628cb..1d96dbcb3e5 100644
--- a/runtime/compiler/control/rossa.cpp
+++ b/runtime/compiler/control/rossa.cpp
@@ -51,6 +51,7 @@
 #include "codegen/PrivateLinkage.hpp"
 #include "control/CompilationRuntime.hpp"
 #include "control/CompilationThread.hpp"
+#include "control/JitDump.hpp"
 #include "control/Recompilation.hpp"
 #include "control/RecompilationInfo.hpp"
 #include "runtime/ArtifactManager.hpp"
@@ -128,10 +129,6 @@ extern "C" {
 struct J9RASdumpContext;
 }
 
-#ifdef J9VM_RAS_DUMP_AGENTS
-extern "C" intptr_t dumpJitInfo(J9VMThread * currentThread, char *label, J9RASdumpContext *context);
-#endif
-
 #if defined(TR_TARGET_X86) && defined(TR_HOST_32BIT)
 extern TR_X86CPUIDBuffer *queryX86TargetCPUID(void * javaVM);
 #endif
@@ -636,9 +633,22 @@ freeJITConfig(J9JITConfig * jitConfig)
 extern "C" void
 jitExclusiveVMShutdownPending(J9VMThread * vmThread)
    {
-   #ifndef SMALL_APPTHREAD
-      getCompilationInfo(vmThread->javaVM->jitConfig)->stopCompilationThreads();
-   #endif
+#ifndef SMALL_APPTHREAD
+   J9JavaVM *javaVM = vmThread->javaVM;
+#if defined(J9VM_OPT_JITSERVER)
+   TR::CompilationInfo * compInfo = getCompilationInfo(javaVM->jitConfig);
+   if (compInfo->getPersistentInfo()->getRemoteCompilationMode() == JITServer::SERVER)
+      {
+      TR_Listener *listener = ((TR_JitPrivateConfig*)(javaVM->jitConfig->privateConfig))->listener;
+      if (listener)
+         {
+         listener->stop();
+         }
+      }
+#endif /* defined(J9VM_OPT_JITSERVER) */
+
+   getCompilationInfo(javaVM->jitConfig)->stopCompilationThreads();
+#endif
    }
 
 // Code cache callbacks to be used by the VM
diff --git a/runtime/compiler/env/J9ClassEnv.cpp b/runtime/compiler/env/J9ClassEnv.cpp
index a3d8ae7b6d6..2e455b86d20 100644
--- a/runtime/compiler/env/J9ClassEnv.cpp
+++ b/runtime/compiler/env/J9ClassEnv.cpp
@@ -37,7 +37,10 @@
 #include "j9cfg.h"
 #include "j9fieldsInfo.h"
 #include "rommeth.h"
+#include "runtime/RuntimeAssumptions.hpp"
 
+class TR_PersistentClassInfo;
+template <typename ListKind> class List;
 
 /*  REQUIRES STATE (_vmThread).  MOVE vmThread to COMPILATION
 
@@ -644,3 +647,127 @@ J9::ClassEnv::isValueTypeClass(TR_OpaqueClassBlock *clazz)
    J9Class *j9class = reinterpret_cast<J9Class*>(clazz);
    return J9_IS_J9CLASS_VALUETYPE(j9class);
    }
+
+bool
+J9::ClassEnv::isZeroInitializable(TR_OpaqueClassBlock *clazz)
+   {
+   return (self()->classFlagsValue(clazz) & J9ClassContainsUnflattenedFlattenables) == 0;
+   }
+
+bool 
+J9::ClassEnv::containesZeroOrOneConcreteClass(TR::Compilation *comp, List<TR_PersistentClassInfo>* subClasses)
+   {
+   int count = 0;
+#if defined(J9VM_OPT_JITSERVER)
+   if (comp->isOutOfProcessCompilation())
+      {
+      ListIterator<TR_PersistentClassInfo> j(subClasses);
+      TR_ScratchList<TR_PersistentClassInfo> subClassesNotCached(comp->trMemory());
+   
+      // Process classes cached at the server first
+      ClientSessionData * clientData = TR::compInfoPT->getClientData();
+      for (TR_PersistentClassInfo *ptClassInfo = j.getFirst(); ptClassInfo; ptClassInfo = j.getNext())
+         {
+         TR_OpaqueClassBlock *clazz = ptClassInfo->getClassId();
+         J9Class *j9clazz = TR::Compiler->cls.convertClassOffsetToClassPtr(clazz);
+         auto romClass = JITServerHelpers::getRemoteROMClassIfCached(clientData, j9clazz);
+         if (romClass == NULL)
+            {
+            subClassesNotCached.add(ptClassInfo);
+            }
+         else
+            {
+            if (!TR::Compiler->cls.isInterfaceClass(comp, clazz) && !TR::Compiler->cls.isAbstractClass(comp, clazz))
+               {
+               if (++count > 1)
+                  return false;
+               }
+            }
+         }
+      // Traverse through classes that are not cached on server
+      ListIterator<TR_PersistentClassInfo> i(&subClassesNotCached);
+      for (TR_PersistentClassInfo *ptClassInfo = i.getFirst(); ptClassInfo; ptClassInfo = i.getNext())
+         {
+         TR_OpaqueClassBlock *clazz = ptClassInfo->getClassId();
+         if (!TR::Compiler->cls.isInterfaceClass(comp, clazz) && !TR::Compiler->cls.isAbstractClass(comp, clazz))
+            {
+            if (++count > 1)
+               return false;
+            }
+         }
+      }
+   else // non-jitserver
+#endif /* defined(J9VM_OPT_JITSERVER) */
+      {
+      ListIterator<TR_PersistentClassInfo> i(subClasses);
+      for (TR_PersistentClassInfo *ptClassInfo = i.getFirst(); ptClassInfo; ptClassInfo = i.getNext())
+         {
+         TR_OpaqueClassBlock *clazz = ptClassInfo->getClassId();
+         if (!TR::Compiler->cls.isInterfaceClass(comp, clazz) && !TR::Compiler->cls.isAbstractClass(comp, clazz))
+            {
+            if (++count > 1)
+               return false;
+            }
+         }
+      }
+   return true;
+   }
+
+bool 
+J9::ClassEnv::containsZeroOrOneConcreteClass(TR::Compilation *comp, List<TR_PersistentClassInfo>* subClasses)
+   {
+   int count = 0;
+#if defined(J9VM_OPT_JITSERVER)
+   if (comp->isOutOfProcessCompilation())
+      {
+      ListIterator<TR_PersistentClassInfo> j(subClasses);
+      TR_ScratchList<TR_PersistentClassInfo> subClassesNotCached(comp->trMemory());
+   
+      // Process classes cached at the server first
+      ClientSessionData * clientData = TR::compInfoPT->getClientData();
+      for (TR_PersistentClassInfo *ptClassInfo = j.getFirst(); ptClassInfo; ptClassInfo = j.getNext())
+         {
+         TR_OpaqueClassBlock *clazz = ptClassInfo->getClassId();
+         J9Class *j9clazz = TR::Compiler->cls.convertClassOffsetToClassPtr(clazz);
+         auto romClass = JITServerHelpers::getRemoteROMClassIfCached(clientData, j9clazz);
+         if (romClass == NULL)
+            {
+            subClassesNotCached.add(ptClassInfo);
+            }
+         else
+            {
+            if (!TR::Compiler->cls.isInterfaceClass(comp, clazz) && !TR::Compiler->cls.isAbstractClass(comp, clazz))
+               {
+               if (++count > 1)
+                  return false;
+               }
+            }
+         }
+      // Traverse through classes that are not cached on server
+      ListIterator<TR_PersistentClassInfo> i(&subClassesNotCached);
+      for (TR_PersistentClassInfo *ptClassInfo = i.getFirst(); ptClassInfo; ptClassInfo = i.getNext())
+         {
+         TR_OpaqueClassBlock *clazz = ptClassInfo->getClassId();
+         if (!TR::Compiler->cls.isInterfaceClass(comp, clazz) && !TR::Compiler->cls.isAbstractClass(comp, clazz))
+            {
+            if (++count > 1)
+               return false;
+            }
+         }
+      }
+   else // non-jitserver
+#endif /* defined(J9VM_OPT_JITSERVER) */
+      {
+      ListIterator<TR_PersistentClassInfo> i(subClasses);
+      for (TR_PersistentClassInfo *ptClassInfo = i.getFirst(); ptClassInfo; ptClassInfo = i.getNext())
+         {
+         TR_OpaqueClassBlock *clazz = ptClassInfo->getClassId();
+         if (!TR::Compiler->cls.isInterfaceClass(comp, clazz) && !TR::Compiler->cls.isAbstractClass(comp, clazz))
+            {
+            if (++count > 1)
+               return false;
+            }
+         }
+      }
+   return true;
+   }
diff --git a/runtime/compiler/env/J9ClassEnv.hpp b/runtime/compiler/env/J9ClassEnv.hpp
index 68b743623c8..e8e03b12b69 100644
--- a/runtime/compiler/env/J9ClassEnv.hpp
+++ b/runtime/compiler/env/J9ClassEnv.hpp
@@ -43,6 +43,8 @@ namespace J9 { typedef J9::ClassEnv ClassEnvConnector; }
 namespace TR { class SymbolReference; }
 namespace TR { class TypeLayout; }
 namespace TR { class Region; }
+class TR_PersistentClassInfo;
+template <typename ListKind> class List;
 
 namespace J9
 {
@@ -89,6 +91,24 @@ class OMR_EXTENSIBLE ClassEnv : public OMR::ClassEnvConnector
    bool isAbstractClass(TR::Compilation *comp, TR_OpaqueClassBlock *clazzPointer);
    bool isInterfaceClass(TR::Compilation *comp, TR_OpaqueClassBlock *clazzPointer);
    bool isValueTypeClass(TR_OpaqueClassBlock *);
+
+   /**
+    * \brief
+    *    Checks whether instances of the specified class can be trivially initialized by
+    *    "zeroing" their fields.
+    *    In the case of OpenJ9, this tests whether any field is of a value type that has not been
+    *    "flattened" (that is, had the value type's fields inlined into this class).  Such a value
+    *    type field must be initialized with the default value of the type.
+    *
+    * \param clazz
+    *    The class that is to be checked
+    *
+    * \return
+    *    `true` if instances of the specified class can be initialized by zeroing their fields;
+    *    `false` otherwise (that is, if the class has value type fields whose fields have not
+    *    been inlined)
+    */
+   bool isZeroInitializable(TR_OpaqueClassBlock *clazz);
    bool isEnumClass(TR::Compilation *comp, TR_OpaqueClassBlock *clazzPointer, TR_ResolvedMethod *method);
    bool isPrimitiveClass(TR::Compilation *comp, TR_OpaqueClassBlock *clazz);
    bool isAnonymousClass(TR::Compilation *comp, TR_OpaqueClassBlock *clazz);
@@ -151,6 +171,24 @@ class OMR_EXTENSIBLE ClassEnv : public OMR::ClassEnvConnector
    intptr_t getVFTEntry(TR::Compilation *comp, TR_OpaqueClassBlock* clazz, int32_t offset);
    uint8_t *getROMClassRefName(TR::Compilation *comp, TR_OpaqueClassBlock *clazz, uint32_t cpIndex, int &classRefLen);
    J9ROMConstantPoolItem *getROMConstantPool(TR::Compilation *comp, TR_OpaqueClassBlock *clazz);
+
+   /**
+    * @brief Determine if a list of classes contains less than two concrete classes.
+    * A class is considered concrete if it is not an interface or an abstract class
+    * @param subClasses List of subclasses to be checked.
+    * @return Returns 'true' if the given list of classes contains less than 
+    * 2 concrete classses and false otherwise.
+    */
+   bool containesZeroOrOneConcreteClass(TR::Compilation *comp, List<TR_PersistentClassInfo>* subClasses);
+
+   /**
+    * @brief Determine if a list of classes contains less than two concrete classes.
+    * A class is considered concrete if it is not an interface or an abstract class
+    * @param subClasses List of subclasses to be checked.
+    * @return Returns 'true' if the given list of classes contains less than 
+    * 2 concrete classses and false otherwise.
+    */
+   bool containsZeroOrOneConcreteClass(TR::Compilation *comp, List<TR_PersistentClassInfo>* subClasses);
    };
 
 }
diff --git a/runtime/compiler/env/J9KnownObjectTable.cpp b/runtime/compiler/env/J9KnownObjectTable.cpp
index 2d12016bfdc..d25b95fc03a 100644
--- a/runtime/compiler/env/J9KnownObjectTable.cpp
+++ b/runtime/compiler/env/J9KnownObjectTable.cpp
@@ -62,103 +62,6 @@ J9::KnownObjectTable::isNull(Index index)
    }
 
 
-TR::KnownObjectTable::Index
-J9::KnownObjectTable::getIndex(uintptr_t objectPointer)
-   {
-   if (objectPointer == 0)
-      return 0; // Special Index value for NULL
-
-   uint32_t nextIndex = self()->getEndIndex();
-#if defined(J9VM_OPT_JITSERVER)
-   if (self()->comp()->isOutOfProcessCompilation())
-      {
-      TR_ASSERT_FATAL(false, "It is not safe to call getIndex() at the server. The object pointer could have become stale at the client.");
-      auto stream = TR::CompilationInfo::getStream();
-      stream->write(JITServer::MessageType::KnownObjectTable_getOrCreateIndex, objectPointer);
-      auto recv = stream->read<TR::KnownObjectTable::Index, uintptr_t *>();
-
-      TR::KnownObjectTable::Index index = std::get<0>(recv);
-      uintptr_t *objectReferenceLocation = std::get<1>(recv);
-      TR_ASSERT_FATAL(index <= nextIndex, "The KOT index %d at the client is greater than the KOT index %d at the server", index, nextIndex);
-
-      if (index < nextIndex)
-         {
-         return index;
-         }
-      else
-         {
-         updateKnownObjectTableAtServer(index, objectReferenceLocation);
-         }
-      }
-   else
-#endif /* defined(J9VM_OPT_JITSERVER) */
-      {
-      TR_J9VMBase *fej9 = (TR_J9VMBase *)(self()->fe());
-      TR_ASSERT(fej9->haveAccess(), "Must haveAccess in J9::KnownObjectTable::getIndex");
-
-      // Search for existing matching entry
-      //
-      for (uint32_t i = 1; i < nextIndex; i++)
-         if (*_references.element(i) == objectPointer)
-            return i;
-
-      // No luck -- allocate a new one
-      //
-      J9VMThread *thread = getJ9VMThreadFromTR_VM(self()->fe());
-      TR_ASSERT(thread, "assertion failure");
-      _references.setSize(nextIndex+1);
-      _references[nextIndex] = (uintptr_t*)thread->javaVM->internalVMFunctions->j9jni_createLocalRef((JNIEnv*)thread, (j9object_t)objectPointer);
-      }
-
-   return nextIndex;
-   }
-
-
-TR::KnownObjectTable::Index
-J9::KnownObjectTable::getIndex(uintptr_t objectPointer, bool isArrayWithConstantElements)
-   {
-   TR::KnownObjectTable::Index index = self()->getIndex(objectPointer);
-   if (isArrayWithConstantElements)
-      {
-      self()->addArrayWithConstantElements(index);
-      }
-   return index;
-   }
-
-
-TR::KnownObjectTable::Index
-J9::KnownObjectTable::getIndexAt(uintptr_t *objectReferenceLocation)
-   {
-   TR::KnownObjectTable::Index result = UNKNOWN;
-#if defined(J9VM_OPT_JITSERVER)
-   if (self()->comp()->isOutOfProcessCompilation())
-      {
-      auto stream = TR::CompilationInfo::getStream();
-      stream->write(JITServer::MessageType::KnownObjectTable_getOrCreateIndexAt, objectReferenceLocation);
-      result = std::get<0>(stream->read<TR::KnownObjectTable::Index>());
-
-      updateKnownObjectTableAtServer(result, objectReferenceLocation);
-      }
-   else
-#endif /* defined(J9VM_OPT_JITSERVER) */
-      {
-      TR::VMAccessCriticalSection getIndexAtCriticalSection(self()->comp());
-      uintptr_t objectPointer = *objectReferenceLocation; // Note: object references held as uintptr_t must never be compressed refs
-      result = self()->getIndex(objectPointer);
-      }
-   return result;
-   }
-
-TR::KnownObjectTable::Index
-J9::KnownObjectTable::getIndexAt(uintptr_t *objectReferenceLocation, bool isArrayWithConstantElements)
-   {
-   Index result = self()->getIndexAt(objectReferenceLocation);
-   if (isArrayWithConstantElements)
-      self()->addArrayWithConstantElements(result);
-   return result;
-   }
-
-
 TR::KnownObjectTable::Index
 J9::KnownObjectTable::getOrCreateIndex(uintptr_t objectPointer)
    {
@@ -232,9 +135,12 @@ J9::KnownObjectTable::getOrCreateIndexAt(uintptr_t *objectReferenceLocation)
       {
       auto stream = TR::CompilationInfo::getStream();
       stream->write(JITServer::MessageType::KnownObjectTable_getOrCreateIndexAt, objectReferenceLocation);
-      result = std::get<0>(stream->read<TR::KnownObjectTable::Index>());
+      auto recv = stream->read<TR::KnownObjectTable::Index, uintptr_t *>();
+
+      result = std::get<0>(recv);
+      uintptr_t *objectReferenceLocationClient = std::get<1>(recv);
 
-      updateKnownObjectTableAtServer(result, objectReferenceLocation);
+      updateKnownObjectTableAtServer(result, objectReferenceLocationClient);
       }
    else
 #endif /* defined(J9VM_OPT_JITSERVER) */
@@ -324,10 +230,10 @@ J9::KnownObjectTable::getPointerLocation(Index index)
 
 #if defined(J9VM_OPT_JITSERVER)
 void
-J9::KnownObjectTable::updateKnownObjectTableAtServer(Index index, uintptr_t *objectReferenceLocation)
+J9::KnownObjectTable::updateKnownObjectTableAtServer(Index index, uintptr_t *objectReferenceLocationClient)
    {
    TR_ASSERT_FATAL(self()->comp()->isOutOfProcessCompilation(), "updateKnownObjectTableAtServer should only be called at the server");
-   TR_ASSERT(objectReferenceLocation, "objectReferenceLocation should not be NULL");
+   TR_ASSERT(objectReferenceLocationClient, "objectReferenceLocationClient should not be NULL");
 
    if (index == TR::KnownObjectTable::UNKNOWN)
       return;
@@ -337,13 +243,14 @@ J9::KnownObjectTable::updateKnownObjectTableAtServer(Index index, uintptr_t *obj
    if (index == nextIndex)
       {
       _references.setSize(nextIndex+1);
-      _references[nextIndex] = objectReferenceLocation;
+      _references[nextIndex] = objectReferenceLocationClient;
       }
    else if (index < nextIndex)
       {
-      TR_ASSERT((objectReferenceLocation == _references[index]), "_references[%d]=%p is not the same as the client KOT[%d]=%p. _references.size()=%u",
-                  index, _references[index], index, objectReferenceLocation, nextIndex);
-      _references[index] = objectReferenceLocation;
+      TR_ASSERT((objectReferenceLocationClient == _references[index]),
+            "comp %p: server _references[%d]=%p is not the same as the client _references[%d]=%p (total size = %u)",
+            self()->comp(), index, _references[index], index, objectReferenceLocationClient, nextIndex);
+      _references[index] = objectReferenceLocationClient;
       }
    else
       {
diff --git a/runtime/compiler/env/J9KnownObjectTable.hpp b/runtime/compiler/env/J9KnownObjectTable.hpp
index e4c193c116d..3b8a878d4ac 100644
--- a/runtime/compiler/env/J9KnownObjectTable.hpp
+++ b/runtime/compiler/env/J9KnownObjectTable.hpp
@@ -86,8 +86,6 @@ class OMR_EXTENSIBLE KnownObjectTable : public OMR::KnownObjectTableConnector
    TR::KnownObjectTable *self();
 
    Index getEndIndex();
-   Index getIndex(uintptr_t objectPointer);
-   Index getIndex(uintptr_t objectPointer, bool isArrayWithConstantElements);
    Index getOrCreateIndex(uintptr_t objectPointer);
    Index getOrCreateIndex(uintptr_t objectPointer, bool isArrayWithConstantElements);
    uintptr_t *getPointerLocation(Index index);
@@ -95,8 +93,6 @@ class OMR_EXTENSIBLE KnownObjectTable : public OMR::KnownObjectTableConnector
 
    void dumpTo(TR::FILE *file, TR::Compilation *comp);
 
-   Index getIndexAt(uintptr_t *objectReferenceLocation);
-   Index getIndexAt(uintptr_t *objectReferenceLocation, bool isArrayWithConstantElements);
    Index getOrCreateIndexAt(uintptr_t *objectReferenceLocation);
    Index getOrCreateIndexAt(uintptr_t *objectReferenceLocation, bool isArrayWithConstantElements);
    Index getExistingIndexAt(uintptr_t *objectReferenceLocation);
@@ -104,7 +100,7 @@ class OMR_EXTENSIBLE KnownObjectTable : public OMR::KnownObjectTableConnector
    uintptr_t getPointer(Index index);
 
 #if defined(J9VM_OPT_JITSERVER)
-   void updateKnownObjectTableAtServer(Index index, uintptr_t *objectReferenceLocation);
+   void updateKnownObjectTableAtServer(Index index, uintptr_t *objectReferenceLocationClient);
    void getKnownObjectTableDumpInfo(std::vector<TR_KnownObjectTableDumpInfo> &knotDumpInfoList);
 #endif /* defined(J9VM_OPT_JITSERVER) */
 
diff --git a/runtime/compiler/env/J9PersistentInfo.hpp b/runtime/compiler/env/J9PersistentInfo.hpp
index b9a94014d66..b6da7a19907 100644
--- a/runtime/compiler/env/J9PersistentInfo.hpp
+++ b/runtime/compiler/env/J9PersistentInfo.hpp
@@ -135,11 +135,11 @@ class PersistentInfo : public OMR::PersistentInfoConnector
          _JITServerPort(38400),
 #if defined(MONGO_LOGGER) || defined(CASSANDRA_LOGGER)
          _JITServerPersistentLogging(false),
-         #if defined(CASSANDRA_LOGGER)
+#if defined(CASSANDRA_LOGGER)
          _JITServerPersistentLoggingDatabasePort(9042),
-         #elif defined(MONGO_LOGGER)
+#elif defined(MONGO_LOGGER)
          _JITServerPersistentLoggingDatabasePort(27017),
-         #endif //MONGO_LOGGER elif CASSANDRA_LOGGER
+#endif //MONGO_LOGGER elif CASSANDRA_LOGGER
          _JITServerPersistentLoggingDatabaseAddress("127.0.0.1"),
          _JITServerPersistentLoggingDatabaseUsername("admin"),
          _JITServerPersistentLoggingDatabaseName("jitserver_logs"),
diff --git a/runtime/compiler/env/SystemSegmentProvider.cpp b/runtime/compiler/env/SystemSegmentProvider.cpp
index 1e19bae9723..28905b2fd92 100644
--- a/runtime/compiler/env/SystemSegmentProvider.cpp
+++ b/runtime/compiler/env/SystemSegmentProvider.cpp
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2000, 2018 IBM Corp. and others
+ * Copyright (c) 2000, 2020 IBM Corp. and others
  *
  * This program and the accompanying materials are made available under
  * the terms of the Eclipse Public License 2.0 which accompanies this
@@ -89,6 +89,10 @@ J9::SystemSegmentProvider::request(size_t requiredSize)
       return recycledSegment;
       }
 
+   if (_regionBytesAllocated + roundedSize > _allocationLimit)
+      {
+      throw std::bad_alloc();
+      }
    if (remaining(_currentSystemSegment) >= roundedSize)
       {
       // Only allocate small segments from _currentSystemSegment
@@ -97,10 +101,6 @@ J9::SystemSegmentProvider::request(size_t requiredSize)
       }
 
    size_t systemSegmentSize = std::max(roundedSize, _systemSegmentSize);
-   if (_systemBytesAllocated + systemSegmentSize > _allocationLimit )
-      {
-      throw std::bad_alloc();
-      }
 
    J9MemorySegment &newSegment = _systemSegmentAllocator.request(systemSegmentSize);
    TR_ASSERT(
diff --git a/runtime/compiler/env/VMJ9.cpp b/runtime/compiler/env/VMJ9.cpp
index 34c444b6012..5a02f36b314 100644
--- a/runtime/compiler/env/VMJ9.cpp
+++ b/runtime/compiler/env/VMJ9.cpp
@@ -8351,28 +8351,6 @@ TR_J9VM::getROMMethodFromRAMMethod(J9Method *ramMethod)
    return J9_ROM_METHOD_FROM_RAM_METHOD(ramMethod);
    }
 
-bool 
-TR_J9VM::noMultipleConcreteClasses(List<TR_PersistentClassInfo>* subClasses)
-   {
-   TR::Compilation *comp = _compInfoPT->getCompilation();
-   int count = 0;
-   ListIterator<TR_PersistentClassInfo> i(subClasses);
-   for (TR_PersistentClassInfo *ptClassInfo = i.getFirst(); ptClassInfo; ptClassInfo = i.getNext())
-      {
-      TR_OpaqueClassBlock *clazz = ptClassInfo->getClassId();
-      if (!TR::Compiler->cls.isInterfaceClass(comp, clazz) && !TR::Compiler->cls.isAbstractClass(comp, clazz))
-         {
-         count++;
-         }
-      if (count > 1)
-         {
-         return false;
-         }
-      }
-
-   return true;
-   }
-
 //////////////////////////////////////////////////////////
 // TR_J9SharedCacheVM
 //////////////////////////////////////////////////////////
diff --git a/runtime/compiler/env/VMJ9.h b/runtime/compiler/env/VMJ9.h
index ca1eaef6f32..11a4075ac48 100644
--- a/runtime/compiler/env/VMJ9.h
+++ b/runtime/compiler/env/VMJ9.h
@@ -1127,8 +1127,6 @@ class TR_J9VM : public TR_J9VMBase
 
    TR_OpaqueClassBlock * getClassFromSignature(const char * sig, int32_t sigLength, J9ConstantPool * constantPool);
 
-   virtual bool noMultipleConcreteClasses(List<TR_PersistentClassInfo>* subClasses);
-
 private:
    void transformJavaLangClassIsArrayOrIsPrimitive( TR::Compilation *, TR::Node * callNode,  TR::TreeTop * treeTop, int32_t andMask);
    void transformJavaLangClassIsArray( TR::Compilation *, TR::Node * callNode,  TR::TreeTop * treeTop);
diff --git a/runtime/compiler/env/VMJ9Server.cpp b/runtime/compiler/env/VMJ9Server.cpp
index aaee006f148..ad537a66a53 100644
--- a/runtime/compiler/env/VMJ9Server.cpp
+++ b/runtime/compiler/env/VMJ9Server.cpp
@@ -1837,55 +1837,6 @@ TR_J9ServerVM::getObjectSizeClass(uintptr_t objectSize)
    return 0;
    }
 
-bool 
-TR_J9ServerVM::noMultipleConcreteClasses(List<TR_PersistentClassInfo>* subClasses)
-   {
-   TR::Compilation *comp = _compInfoPT->getCompilation();
-   int count = 0;
-   TR_ScratchList<TR_PersistentClassInfo> subClassesNotCached(comp->trMemory());
-
-   // Process classes caches at the server first
-   ListIterator<TR_PersistentClassInfo> i(subClasses);
-   for (TR_PersistentClassInfo *ptClassInfo = i.getFirst(); ptClassInfo; ptClassInfo = i.getNext())
-      {
-      TR_OpaqueClassBlock *clazz = ptClassInfo->getClassId();
-      J9Class *j9clazz = TR::Compiler->cls.convertClassOffsetToClassPtr(clazz);
-      auto romClass = JITServerHelpers::getRemoteROMClassIfCached(_compInfoPT->getClientData(), j9clazz);
-      if (romClass == NULL)
-         {
-         subClassesNotCached.add(ptClassInfo);
-         }
-      else
-         {
-         if (!TR::Compiler->cls.isInterfaceClass(comp, clazz) && !TR::Compiler->cls.isAbstractClass(comp, clazz))
-            {
-            count++;
-            }
-         if (count > 1)
-            {
-            return false;
-            }
-         }
-      }
-
-   // Traverse though classes that are not cached on server
-   ListIterator<TR_PersistentClassInfo> j(&subClassesNotCached);
-   for (TR_PersistentClassInfo *ptClassInfo = j.getFirst(); ptClassInfo; ptClassInfo = j.getNext())
-      {
-      TR_OpaqueClassBlock *clazz = ptClassInfo->getClassId();
-      if (!TR::Compiler->cls.isInterfaceClass(comp, clazz) && !TR::Compiler->cls.isAbstractClass(comp, clazz))
-         {
-         count++;
-         }
-      if (count > 1)
-         {
-         return false;
-         }
-      }
-
-   return true;
-   }
-
 bool
 TR_J9SharedCacheServerVM::isClassLibraryMethod(TR_OpaqueMethodBlock *method, bool vettedForAOT)
    {
diff --git a/runtime/compiler/env/VMJ9Server.hpp b/runtime/compiler/env/VMJ9Server.hpp
index 4ba0876e1bd..fc999eaf3b9 100644
--- a/runtime/compiler/env/VMJ9Server.hpp
+++ b/runtime/compiler/env/VMJ9Server.hpp
@@ -187,7 +187,6 @@ class TR_J9ServerVM: public TR_J9VM
    virtual J9ROMMethod *getROMMethodFromRAMMethod(J9Method *ramMethod) override;
    virtual bool getReportByteCodeInfoAtCatchBlock() override;
    virtual void *getInvokeExactThunkHelperAddress(TR::Compilation *comp, TR::SymbolReference *glueSymRef, TR::DataType dataType) override;
-   virtual bool noMultipleConcreteClasses(List<TR_PersistentClassInfo>* subClasses) override;
 
    virtual uintptr_t getCellSizeForSizeClass(uintptr_t) override;
    virtual uintptr_t getObjectSizeClass(uintptr_t) override;
diff --git a/runtime/compiler/env/j9method.cpp b/runtime/compiler/env/j9method.cpp
index 6a3ec0dabc3..1f742dce686 100644
--- a/runtime/compiler/env/j9method.cpp
+++ b/runtime/compiler/env/j9method.cpp
@@ -3526,6 +3526,7 @@ void TR_ResolvedJ9Method::construct()
       {
       { x(TR::java_lang_StringUTF16_getChar,                                  "getChar",        "([BI)C")},
       { x(TR::java_lang_StringUTF16_indexOf,                                  "indexOf",        "([BI[BII)I")},
+      { x(TR::java_lang_StringUTF16_newBytesFor,                              "newBytesFor",    "(I)[B")},
       { x(TR::java_lang_StringUTF16_toBytes,                                  "toBytes",        "([CII)[B")},
       { TR::unknownMethod }
       };
diff --git a/runtime/compiler/env/j9methodServer.cpp b/runtime/compiler/env/j9methodServer.cpp
index 3166b59e7d7..5f215b90c88 100644
--- a/runtime/compiler/env/j9methodServer.cpp
+++ b/runtime/compiler/env/j9methodServer.cpp
@@ -2037,69 +2037,56 @@ bool
 TR_ResolvedRelocatableJ9JITServerMethod::storeValidationRecordIfNecessary(TR::Compilation * comp, J9ConstantPool *constantPool, int32_t cpIndex, TR_ExternalRelocationTargetKind reloKind, J9Method *ramMethod, J9Class *definingClass)
    {
    TR_J9VMBase *fej9 = (TR_J9VMBase *) comp->fe();
+
    bool storeClassInfo = true;
    bool fieldInfoCanBeUsed = false;
    TR_AOTStats *aotStats = ((TR_JitPrivateConfig *)fej9->_jitConfig->privateConfig)->aotStats;
    bool isStatic = (reloKind == TR_ValidateStaticField);
 
-   UDATA *classChain = NULL;
-   auto clientData = _fe->_compInfoPT->getClientData();
-   PersistentUnorderedMap<J9Class *, UDATA *> &classChainCache = clientData->getClassChainDataCache();
-   if (definingClass)
-      {
-      // if defining class is known, check if we already have a corresponding class chain cached
-      OMR::CriticalSection classChainDataMapMonitor(clientData->getClassChainDataMapMonitor());
-      auto it = classChainCache.find(definingClass);
-      if (it != classChainCache.end())
-         classChain = it->second;
-      }
-
-   if (!classChain)
+   if (comp->getDebug())
       {
-      _stream->write(JITServer::MessageType::ResolvedRelocatableMethod_storeValidationRecordIfNecessary, ramMethod, constantPool, cpIndex, isStatic, definingClass);
-      // 1. RAM class of ramMethod
-      // 2. defining class
-      // 3. class chain
-      auto recv = _stream->read<J9Class *, J9Class *, UDATA *>();
-
-      J9Class *clazz = std::get<0>(recv);
+      // guard this code with debug check, to avoid
+      // sending extra messages when not tracing
       traceMsg(comp, "storeValidationRecordIfNecessary:\n");
       traceMsg(comp, "\tconstantPool %p cpIndex %d\n", constantPool, cpIndex);
       traceMsg(comp, "\treloKind %d isStatic %d\n", reloKind, isStatic);
-      J9UTF8 *methodClassName = J9ROMCLASS_CLASSNAME(TR::Compiler->cls.romClassOf((TR_OpaqueClassBlock *) clazz));
-      traceMsg(comp, "\tmethod %p from class %p %.*s\n", ramMethod, clazz, J9UTF8_LENGTH(methodClassName), J9UTF8_DATA(methodClassName));
+      J9UTF8 *methodClassName =
+         J9ROMCLASS_CLASSNAME(
+            TR::Compiler->cls.romClassOf(
+               fej9->getClassOfMethod(reinterpret_cast<TR_OpaqueMethodBlock *>(ramMethod))));
+      traceMsg(comp,
+               "\tmethod %p from class %p %.*s\n",
+               ramMethod,
+               fej9->getClassOfMethod(reinterpret_cast<TR_OpaqueMethodBlock *>(ramMethod)),
+               J9UTF8_LENGTH(methodClassName),
+               J9UTF8_DATA(methodClassName));
       traceMsg(comp, "\tdefiningClass %p\n", definingClass);
+      }
 
-      if (!definingClass)
-         {
-         definingClass = std::get<1>(recv);
-         traceMsg(comp, "\tdefiningClass recomputed from cp as %p\n", definingClass);
-         }
+   if (!definingClass)
+      {
+      definingClass = (J9Class *) TR_ResolvedJ9JITServerMethod::definingClassFromCPFieldRef(comp, cpIndex, isStatic);
+      traceMsg(comp, "\tdefiningClass recomputed from cp as %p\n", definingClass);
+      }
 
-      if (!definingClass)
-         {
-         if (aotStats)
-            aotStats->numDefiningClassNotFound++;
-         return false;
-         }
+   if (!definingClass)
+      {
+      if (aotStats)
+         aotStats->numDefiningClassNotFound++;
+      return false;
+      }
 
+   if (comp->getDebug())
+      {
       J9UTF8 *className = J9ROMCLASS_CLASSNAME(TR::Compiler->cls.romClassOf((TR_OpaqueClassBlock *) definingClass));
       traceMsg(comp, "\tdefiningClass name %.*s\n", J9UTF8_LENGTH(className), J9UTF8_DATA(className));
-
-      // all kinds of validations may need to rely on the entire class chain, so make sure we can build one first
-      classChain = std::get<2>(recv);
       }
 
+   // all kinds of validations may need to rely on the entire class chain, so make sure we can build one first
+   void *classChain = fej9->sharedCache()->rememberClass(definingClass);
    if (!classChain)
       return false;
 
-      {
-      // class chain and defining class found, cache here
-      OMR::CriticalSection classChainDataMapMonitor(clientData->getClassChainDataMapMonitor());
-      classChainCache.insert(std::make_pair(definingClass, classChain));
-      }
-   
-
    bool inLocalList = false;
    TR::list<TR::AOTClassInfo*>* aotClassInfo = comp->_aotClassInfo;
    if (!aotClassInfo->empty())
diff --git a/runtime/compiler/exceptions/AOTFailure.hpp b/runtime/compiler/exceptions/AOTFailure.hpp
index b5ef1b8d3fa..46b3b49b71b 100644
--- a/runtime/compiler/exceptions/AOTFailure.hpp
+++ b/runtime/compiler/exceptions/AOTFailure.hpp
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2000, 2019 IBM Corp. and others
+ * Copyright (c) 2000, 2020 IBM Corp. and others
  *
  * This program and the accompanying materials are made available under
  * the terms of the Eclipse Public License 2.0 which accompanies this
@@ -60,6 +60,36 @@ class AOTHasInvokeSpecialInInterface : public virtual TR::RecoverableILGenExcept
    virtual const char* what() const throw() { return "AOT Has Invoke Special in Interface"; }
    };
 
+/**
+ * AOT Has Constant Dynamic exception type.
+ *
+ * Thrown when a method that has a constant dynamic is AOT Compiled.
+ */
+class AOTHasConstantDynamic : public virtual TR::RecoverableILGenException
+   {
+   virtual const char* what() const throw() { return "AOT Has Constant Dynamic"; }
+   };
+
+/**
+ * AOT Has Method Handle Constant exception type.
+ *
+ * Thrown when a method that has a method handle constant is AOT Compiled.
+ */
+class AOTHasMethodHandleConstant : public virtual TR::RecoverableILGenException
+   {
+   virtual const char* what() const throw() { return "AOT Has Method Handle Constant"; }
+   };
+
+/**
+ * AOT Has Method Type Constant exception type.
+ *
+ * Thrown when a method that has a method type constant is AOT Compiled.
+ */
+class AOTHasMethodTypeConstant : public virtual TR::RecoverableILGenException
+   {
+   virtual const char* what() const throw() { return "AOT Has Method Type Constant"; }
+   };
+
 /**
  * AOT Relocation Failure exception type.
  *
diff --git a/runtime/compiler/ilgen/J9ByteCodeIlGenerator.hpp b/runtime/compiler/ilgen/J9ByteCodeIlGenerator.hpp
index cdb46927cae..bd875257593 100644
--- a/runtime/compiler/ilgen/J9ByteCodeIlGenerator.hpp
+++ b/runtime/compiler/ilgen/J9ByteCodeIlGenerator.hpp
@@ -162,7 +162,7 @@ class TR_J9ByteCodeIlGenerator : public TR_IlGenerator, public TR_J9ByteCodeIter
    // GenLoadStore
    //
    void         loadInstance(int32_t);
-   void         loadInstance(TR::SymbolReference *, int32_t);
+   void         loadInstance(TR::SymbolReference *);
    void         loadStatic(int32_t);
    void         loadAuto(TR::DataType type, int32_t slot, bool isAdjunct = false);
    TR::Node     *loadSymbol(TR::ILOpCodes, TR::SymbolReference *);
diff --git a/runtime/compiler/ilgen/Walker.cpp b/runtime/compiler/ilgen/Walker.cpp
index 5c5d94180ac..e2b18e2c594 100644
--- a/runtime/compiler/ilgen/Walker.cpp
+++ b/runtime/compiler/ilgen/Walker.cpp
@@ -560,12 +560,21 @@ TR::Block * TR_J9ByteCodeIlGenerator::walker(TR::Block * prevBlock)
             break;
             }
          case J9BCwithfield:
+            if (TR::Compiler->om.areValueTypesEnabled())
+               {
+               genWithField(next2Bytes());
+               _bcIndex += 3;
+               }
+            else
+               {
+               fej9()->unsupportedByteCode(comp(), opcode);
+               }
+            break;
          case J9BCbreakpoint:
             fej9()->unsupportedByteCode(comp(), opcode);
          case J9BCunknown:
             fej9()->unknownByteCode(comp(), opcode);
             break;
-
          default:
          	break;
          }
@@ -4920,14 +4929,18 @@ TR_J9ByteCodeIlGenerator::loadAuto(TR::DataType type, int32_t slot, bool isAdjun
    push(load);
    }
 
-
 void
 TR_J9ByteCodeIlGenerator::loadInstance(int32_t cpIndex)
    {
    if (_generateReadBarriersForFieldWatch && comp()->compileRelocatableCode())
       comp()->failCompilation<J9::AOTNoSupportForAOTFailure>("NO support for AOT in field watch");
-
    TR::SymbolReference * symRef = symRefTab()->findOrCreateShadowSymbol(_methodSymbol, cpIndex, false);
+   loadInstance(symRef);
+   }
+
+void
+TR_J9ByteCodeIlGenerator::loadInstance(TR::SymbolReference * symRef)
+   {
    TR::Symbol * symbol = symRef->getSymbol();
    TR::DataType type = symbol->getDataType();
 
@@ -4964,7 +4977,7 @@ TR_J9ByteCodeIlGenerator::loadInstance(int32_t cpIndex)
              !strncmp(className, BDCLASS, BDCLASSLEN))
          {
          int32_t fieldLen=0;
-         char * fieldName =  _methodSymbol->getResolvedMethod()->fieldNameChars(cpIndex, fieldLen);
+         char * fieldName =  _methodSymbol->getResolvedMethod()->fieldNameChars(symRef->getCPIndex(), fieldLen);
          if (fieldName != NULL && BDFIELDLEN == strlen(fieldName) && !strncmp(fieldName, BDFIELD, BDFIELDLEN))
             {
             load->setIsBigDecimalLoad();
@@ -5469,6 +5482,13 @@ TR_J9ByteCodeIlGenerator::loadFromCP(TR::DataType type, int32_t cpIndex)
       case TR::Address:
          if (method()->isConstantDynamic(cpIndex))
             {
+            if (comp()->compileRelocatableCode())
+               {
+               if (comp()->getOption(TR_TraceILGen))
+                  traceMsg(comp(), "  Constant Dynamic not supported in AOT.\n");
+               comp()->failCompilation<J9::AOTHasConstantDynamic>("Constant Dynamic not supported in AOT.");
+               }
+
             bool isCondyUnresolved = _methodSymbol->getResolvedMethod()->isUnresolvedConstantDynamic(cpIndex);
             J9UTF8 *returnTypeUtf8 = (J9UTF8 *)_methodSymbol->getResolvedMethod()->getConstantDynamicTypeFromCP(cpIndex);
             int returnTypeUtf8Length = J9UTF8_LENGTH(returnTypeUtf8);
@@ -5691,11 +5711,23 @@ TR_J9ByteCodeIlGenerator::loadFromCP(TR::DataType type, int32_t cpIndex)
             }
          else if (method()->isMethodHandleConstant(cpIndex))
             {
+            if (comp()->compileRelocatableCode())
+               {
+               if (comp()->getOption(TR_TraceILGen))
+                  traceMsg(comp(), "  Method Handle Constant not supported in AOT.\n");
+               comp()->failCompilation<J9::AOTHasMethodHandleConstant>("Method Handle Constant not supported in AOT.");
+               }
             loadSymbol(TR::aload, symRefTab()->findOrCreateMethodHandleSymbol(_methodSymbol, cpIndex));
             }
          else
             {
             TR_ASSERT(method()->isMethodTypeConstant(cpIndex), "Address-type CP entry %d must be class, string, methodHandle, or methodType", cpIndex);
+            if (comp()->compileRelocatableCode())
+               {
+               if (comp()->getOption(TR_TraceILGen))
+                  traceMsg(comp(), "  Method Type Constant not supported in AOT.\n");
+               comp()->failCompilation<J9::AOTHasMethodTypeConstant>("Method Type Constant not supported in AOT.");
+               }
             loadSymbol(TR::aload, symRefTab()->findOrCreateMethodTypeSymbol(_methodSymbol, cpIndex));
             }
          break;
@@ -5981,6 +6013,101 @@ TR_J9ByteCodeIlGenerator::genNew(TR::ILOpCodes opCode)
          genFlush(0);
    }
 
+void
+TR_J9ByteCodeIlGenerator::genWithField(uint16_t fieldCpIndex)
+   {
+   const int32_t bcIndex = currentByteCodeIndex();
+   int32_t classCpIndex = method()->classCPIndexOfFieldOrStatic(fieldCpIndex);
+   TR_OpaqueClassBlock *valueClass = method()->getClassFromConstantPool(comp(), classCpIndex, true);
+   if (!valueClass)
+      {
+      if (isOutermostMethod())
+         {
+         TR::DebugCounter::incStaticDebugCounter(comp(),
+            TR::DebugCounter::debugCounterName(comp(),
+                  "ilgen.abort/unresolved/withfield/class/(%s)/bc=%d",
+                  comp()->signature(),
+                  bcIndex));
+         }
+      else
+         {
+         TR::DebugCounter::incStaticDebugCounter(comp(),
+            TR::DebugCounter::debugCounterName(comp(),
+               "ilgen.abort/unresolved/withfield/class/(%s)/bc=%d/root=(%s)",
+               _method->signature(comp()->trMemory()),
+               bcIndex,
+               comp()->signature()));
+         }
+      comp()->failCompilation<TR::UnsupportedValueTypeOperation>("Unresolved class encountered for withfieldbytecode instruction");
+      }
+
+   bool isStore = false;
+   TR::SymbolReference * symRef = symRefTab()->findOrCreateShadowSymbol(_methodSymbol, fieldCpIndex, isStore);
+   if (symRef->isUnresolved())
+      {
+      if (isOutermostMethod())
+         {
+         TR::DebugCounter::incStaticDebugCounter(comp(),
+            TR::DebugCounter::debugCounterName(comp(),
+                  "ilgen.abort/unresolved/withfield/field/(%s)/bc=%d",
+                  comp()->signature(),
+                  bcIndex));
+         }
+      else
+         {
+         TR::DebugCounter::incStaticDebugCounter(comp(),
+            TR::DebugCounter::debugCounterName(comp(),
+               "ilgen.abort/unresolved/withfield/field/(%s)/bc=%d/root=(%s)",
+               _method->signature(comp()->trMemory()),
+               bcIndex,
+               comp()->signature()));
+         }
+      comp()->failCompilation<TR::UnsupportedValueTypeOperation>("Unresolved field encountered for withfield bytecode instruction");
+      }
+
+   TR::Node *newFieldValue = pop();
+   TR::Node *originalObject = pop();
+
+   /*
+    * Insert nullchk for the original object as requested by the JVM spec.
+    * Especially in case of value type class with a single field, the nullchk is still
+    * necessary even though the original object is actually not needed.
+    */
+   TR::Node *passThruNode = TR::Node::create(TR::PassThrough, 1, originalObject);
+   genTreeTop(genNullCheck(passThruNode));
+
+   loadClassObject(valueClass);
+   const TR::TypeLayout *typeLayout = comp()->typeLayout(valueClass);
+   size_t fieldCount = typeLayout->count();
+
+   for (size_t idx = 0; idx < fieldCount; idx++)
+      {
+      const TR::TypeLayoutEntry &fieldEntry = typeLayout->entry(idx);
+      if (fieldEntry._offset == symRef->getOffset())
+         push(newFieldValue);
+      else
+         {
+         auto* fieldSymRef = comp()->getSymRefTab()->findOrFabricateShadowSymbol(valueClass,
+                                                                     fieldEntry._datatype,
+                                                                     fieldEntry._offset,
+                                                                     fieldEntry._isVolatile,
+                                                                     fieldEntry._isPrivate,
+                                                                     fieldEntry._isFinal,
+                                                                     fieldEntry._fieldname,
+                                                                     fieldEntry._typeSignature
+                                                                     );
+         push(originalObject);
+         loadInstance(fieldSymRef);
+         }
+      }
+
+   TR::Node *newValueNode = genNodeAndPopChildren(TR::newvalue, fieldCount+1, symRefTab()->findOrCreateNewValueSymbolRef(_methodSymbol));
+   newValueNode->setIdentityless(true);
+   genTreeTop(newValueNode);
+   push(newValueNode);
+   genFlush(0);
+   }
+
 void
 TR_J9ByteCodeIlGenerator::genDefaultValue(uint16_t cpIndex)
    {
diff --git a/runtime/compiler/net/MessageTypes.hpp b/runtime/compiler/net/MessageTypes.hpp
index 083aa0b642c..75f9c9cd4f7 100644
--- a/runtime/compiler/net/MessageTypes.hpp
+++ b/runtime/compiler/net/MessageTypes.hpp
@@ -97,7 +97,6 @@ enum MessageType : uint16_t
    ResolvedMethod_definingClassFromCPFieldRef,
 
    ResolvedRelocatableMethod_createResolvedRelocatableJ9Method,
-   ResolvedRelocatableMethod_storeValidationRecordIfNecessary,
    ResolvedRelocatableMethod_fieldAttributes,
    ResolvedRelocatableMethod_staticAttributes,
    ResolvedRelocatableMethod_getFieldType,
@@ -367,7 +366,6 @@ static const char *messageNames[MessageType_ARRAYSIZE] =
    "ResolvedMethod_dynamicConstant", // 63
    "ResolvedMethod_definingClassFromCPFieldRef", // 64
    "ResolvedRelocatableMethod_createResolvedRelocatableJ9Method", // 65
-   "ResolvedRelocatableMethod_storeValidationRecordIfNecessary", // 66
    "ResolvedRelocatableMethod_fieldAttributes", // 67
    "ResolvedRelocatableMethod_staticAttributes", // 68
    "ResolvedRelocatableMethod_getFieldType", // 69
diff --git a/runtime/compiler/net/ServerStream.cpp b/runtime/compiler/net/ServerStream.cpp
index ead55c56c2c..b60fd6270cf 100644
--- a/runtime/compiler/net/ServerStream.cpp
+++ b/runtime/compiler/net/ServerStream.cpp
@@ -20,23 +20,7 @@
  * SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0 WITH Classpath-exception-2.0 OR LicenseRef-GPL-2.0 WITH Assembly-exception
  *******************************************************************************/
 
-#include <chrono>
-#include <sys/types.h>
-#include <sys/socket.h>
-#include <sys/un.h>
-#include <netdb.h>
-#include <netinet/in.h>
-#include <netinet/tcp.h>	/* for TCP_NODELAY option */
-#include <fcntl.h>
-#include <arpa/inet.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <unistd.h> /// gethostname, read, write
-#include <openssl/err.h>
 #include "ServerStream.hpp"
-#include "control/CompilationRuntime.hpp"
-#include "env/TRMemory.hpp"
-#include "net/LoadSSLLibs.hpp"
 
 namespace JITServer
 {
@@ -49,234 +33,4 @@ ServerStream::ServerStream(int connfd, BIO *ssl)
    initStream(connfd, ssl);
    _numConnectionsOpened++;
    }
-
-SSL_CTX *createSSLContext(TR::PersistentInfo *info)
-   {
-   SSL_CTX *ctx = (*OSSL_CTX_new)((*OSSLv23_server_method)());
-
-   if (!ctx)
-      {
-      perror("can't create SSL context");
-      (*OERR_print_errors_fp)(stderr);
-      exit(1);
-      }
-
-   const char *sessionIDContext = "JITServer";
-   (*OSSL_CTX_set_session_id_context)(ctx, (const unsigned char*)sessionIDContext, strlen(sessionIDContext));
-
-   if ((*OSSL_CTX_set_ecdh_auto)(ctx, 1) != 1)
-      {
-      perror("failed to configure SSL ecdh");
-      (*OERR_print_errors_fp)(stderr);
-      exit(1);
-      }
-
-   TR::CompilationInfo *compInfo = TR::CompilationInfo::get();
-   auto &sslKeys = compInfo->getJITServerSslKeys();
-   auto &sslCerts = compInfo->getJITServerSslCerts();
-   auto &sslRootCerts = compInfo->getJITServerSslRootCerts();
-
-   TR_ASSERT_FATAL(sslKeys.size() == 1 && sslCerts.size() == 1, "only one key and cert is supported for now");
-   TR_ASSERT_FATAL(sslRootCerts.size() == 0, "server does not understand root certs yet");
-
-   // Parse and set private key
-   BIO *keyMem = (*OBIO_new_mem_buf)(&sslKeys[0][0], sslKeys[0].size());
-   if (!keyMem)
-      {
-      perror("cannot create memory buffer for private key (OOM?)");
-      (*OERR_print_errors_fp)(stderr);
-      exit(1);
-      }
-   EVP_PKEY *privKey = (*OPEM_read_bio_PrivateKey)(keyMem, NULL, NULL, NULL);
-   if (!privKey)
-      {
-      perror("cannot parse private key");
-      (*OERR_print_errors_fp)(stderr);
-      exit(1);
-      }
-   if ((*OSSL_CTX_use_PrivateKey)(ctx, privKey) != 1)
-      {
-      perror("cannot use private key");
-      (*OERR_print_errors_fp)(stderr);
-      exit(1);
-      }
-
-   // Parse and set certificate
-   BIO *certMem = (*OBIO_new_mem_buf)(&sslCerts[0][0], sslCerts[0].size());
-   if (!certMem)
-      {
-      perror("cannot create memory buffer for cert (OOM?)");
-      (*OERR_print_errors_fp)(stderr);
-      exit(1);
-      }
-   X509 *certificate = (*OPEM_read_bio_X509)(certMem, NULL, NULL, NULL);
-   if (!certificate)
-      {
-      perror("cannot parse cert");
-      (*OERR_print_errors_fp)(stderr);
-      exit(1);
-      }
-   if ((*OSSL_CTX_use_certificate)(ctx, certificate) != 1)
-      {
-      perror("cannot use cert");
-      (*OERR_print_errors_fp)(stderr);
-      exit(1);
-      }
-
-   // Verify key and cert are valid
-   if ((*OSSL_CTX_check_private_key)(ctx) != 1)
-      {
-      perror("private key check failed");
-      (*OERR_print_errors_fp)(stderr);
-      exit(1);
-      }
-
-   // verify server identity using standard method
-   (*OSSL_CTX_set_verify)(ctx, SSL_VERIFY_PEER, NULL);
-
-   if (TR::Options::getVerboseOption(TR_VerboseJITServer))
-      TR_VerboseLog::writeLineLocked(TR_Vlog_JITServer, "Successfully initialized SSL context (%s)\n", (*OOpenSSL_version)(0));
-
-   return ctx;
-   }
-
-static bool
-handleOpenSSLConnectionError(int connfd, SSL *&ssl, BIO *&bio, const char *errMsg)
-{
-   if (TR::Options::getVerboseOption(TR_VerboseJITServer))
-       TR_VerboseLog::writeLineLocked(TR_Vlog_JITServer, "%s: errno=%d", errMsg, errno);
-   (*OERR_print_errors_fp)(stderr);
-
-   close(connfd);
-   if (bio)
-      {
-      (*OBIO_free_all)(bio);
-      bio = NULL;
-      }
-   if (ssl)
-      {
-      (*OSSL_free)(ssl);
-      ssl = NULL;
-      }
-   return false;
-}
-
-static bool
-acceptOpenSSLConnection(SSL_CTX *sslCtx, int connfd, BIO *&bio)
-   {
-   SSL *ssl = (*OSSL_new)(sslCtx);
-   if (!ssl)
-      return handleOpenSSLConnectionError(connfd, ssl, bio, "Error creating SSL connection");
-
-   (*OSSL_set_accept_state)(ssl);
-
-   if ((*OSSL_set_fd)(ssl, connfd) != 1)
-      return handleOpenSSLConnectionError(connfd, ssl, bio, "Error setting SSL file descriptor");
-
-   if ((*OSSL_accept)(ssl) <= 0)
-      return handleOpenSSLConnectionError(connfd, ssl, bio, "Error accepting SSL connection");
-
-   bio = (*OBIO_new_ssl)(sslCtx, false);
-   if (!bio)
-      return handleOpenSSLConnectionError(connfd, ssl, bio, "Error creating new BIO");
-
-   if ((*OBIO_ctrl)(bio, BIO_C_SET_SSL, true, (char *)ssl) != 1) // BIO_set_ssl(bio, ssl, true)
-      return handleOpenSSLConnectionError(connfd, ssl, bio, "Error setting BIO SSL");
-
-   if (TR::Options::getVerboseOption(TR_VerboseJITServer))
-      TR_VerboseLog::writeLineLocked(TR_Vlog_JITServer, "SSL connection on socket 0x%x, Version: %s, Cipher: %s\n",
-                                                     connfd, (*OSSL_get_version)(ssl), (*OSSL_get_cipher)(ssl));
-   return true;
-   }
-
-void
-ServerStream::serveRemoteCompilationRequests(BaseCompileDispatcher *compiler, TR::PersistentInfo *info)
-   {
-   SSL_CTX *sslCtx = NULL;
-   if (CommunicationStream::useSSL())
-      {
-      CommunicationStream::initSSL();
-      sslCtx = createSSLContext(info);
-      }
-
-   uint32_t port = info->getJITServerPort();
-   uint32_t timeoutMs = info->getSocketTimeout();
-   int sockfd = socket(AF_INET, SOCK_STREAM, 0);
-   if (sockfd < 0)
-      {
-      perror("can't open server socket");
-      exit(1);
-      }
-
-   // see `man 7 socket` for option explanations
-   int flag = true;
-   if (setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, (void *)&flag, sizeof(flag)) < 0)
-      {
-      perror("Can't set SO_REUSEADDR");
-      exit(-1);
-      }
-   if (setsockopt(sockfd, SOL_SOCKET, SO_KEEPALIVE, (void *)&flag, sizeof(flag)) < 0)
-      {
-      perror("Can't set SO_KEEPALIVE");
-      exit(-1);
-      }
-
-   struct sockaddr_in serv_addr;
-   memset((char *)&serv_addr, 0, sizeof(serv_addr));
-   serv_addr.sin_family = AF_INET;
-   serv_addr.sin_addr.s_addr = htonl(INADDR_ANY);
-   serv_addr.sin_port = htons(port);
-
-   if (bind(sockfd, (struct sockaddr *)&serv_addr, sizeof(serv_addr)) < 0)
-      {
-      perror("can't bind server address");
-      exit(1);
-      }
-   if (listen(sockfd, SOMAXCONN) < 0)
-      {
-      perror("listen failed");
-      exit(1);
-      }
-
-   while (true)
-      {
-      struct sockaddr_in cli_addr;
-      socklen_t clilen = sizeof(cli_addr);
-
-      int connfd = accept(sockfd, (struct sockaddr *)&cli_addr, &clilen);
-      if (connfd < 0)
-         {
-         if (TR::Options::getVerboseOption(TR_VerboseJITServer))
-            TR_VerboseLog::writeLineLocked(TR_Vlog_JITServer, "Error accepting connection: errno=%d", errno);
-         continue;
-         }
-
-      struct timeval timeoutMsForConnection = {(timeoutMs / 1000), ((timeoutMs % 1000) * 1000)};
-      if (setsockopt(connfd, SOL_SOCKET, SO_RCVTIMEO, (void *)&timeoutMsForConnection, sizeof(timeoutMsForConnection)) < 0)
-         {
-         perror("Can't set option SO_RCVTIMEO on connfd socket");
-         exit(-1);
-         }
-      if (setsockopt(connfd, SOL_SOCKET, SO_SNDTIMEO, (void *)&timeoutMsForConnection, sizeof(timeoutMsForConnection)) < 0)
-         {
-         perror("Can't set option SO_SNDTIMEO on connfd socket");
-         exit(-1);
-         }
-
-      BIO *bio = NULL;
-      if (sslCtx && !acceptOpenSSLConnection(sslCtx, connfd, bio))
-         continue;
-
-      ServerStream *stream = new (PERSISTENT_NEW) ServerStream(connfd, bio);
-
-      compiler->compile(stream);
-      }
-
-   // The following piece of code will be executed only if the server shuts down properly
-   if (sslCtx)
-      {
-      (*OSSL_CTX_free)(sslCtx);
-      (*OEVP_cleanup)();
-      }
-   }
 }
diff --git a/runtime/compiler/net/ServerStream.hpp b/runtime/compiler/net/ServerStream.hpp
index c9468a527c4..cbf41bd8910 100644
--- a/runtime/compiler/net/ServerStream.hpp
+++ b/runtime/compiler/net/ServerStream.hpp
@@ -34,7 +34,6 @@ class SSLInputStream;
 
 namespace JITServer
 {
-class BaseCompileDispatcher;
 
 /**
    @class ServerStream
@@ -47,7 +46,7 @@ class BaseCompileDispatcher;
    2) Create a dedicated thread that will listen for incoming connection requests
    3) In this thread, instantiate a CompileDispatcher from a class defined in step (1)
       E.g.:    J9CompileDispatcher handler(jitConfig);
-   4) Call  "ServerStream::serveRemoteCompilationRequests(&handler, persistentInfo);"
+   4) Call  "TR_Listener::serveRemoteCompilationRequests(&handler);"
       which will wait for a connection, accept the connection, create a ServerStream and call
       handler->compile(stream) for further processing, e.g. add the stream
       to a compilation queue
@@ -227,21 +226,6 @@ class ServerStream : public CommunicationStream
       return _clientId;
       }
 
-   /**
-      @brief Function called to deal with incoming connection requests
-
-      This function opens a socket, binds it and then waits for incoming connection
-      requests by using `accept()` in an infinite loop. Once a connection is accepted
-      a ServerStream object is created (receiving the newly opened socket descriptor as
-      a parameter) and passed to the compilation handler. Typically, the compilation
-      handler places the ServerStream object in a queue and returns immediately so that
-      other connection requests can be accepted.
-      Note: because the function does not return, it must be executed on a separate thread.
-
-      @param [in] compiler Object that defines the behavior when a new connection is accepted
-      @param [in] info Pointer to PersistentInfo which contains the port and the timeout value for the connection
-   */
-   static void serveRemoteCompilationRequests(BaseCompileDispatcher *compiler, TR::PersistentInfo *info);
 
    // Statistics
    static int getNumConnectionsOpened() { return _numConnectionsOpened; }
@@ -254,20 +238,6 @@ class ServerStream : public CommunicationStream
    };
 
 
-/**
-   @class BaseCompileDispatcher
-   @brief Abstract class defining the interface for the compilation handler
-
-   Typically, an user would derive this class and provide an implementation for "compile()"
-   An instance of the derived class needs to be passed to serveRemoteCompilationRequests 
-   which internally calls "compile()"
- */
-class BaseCompileDispatcher
-   {
-public:
-   virtual void compile(ServerStream *stream) = 0;
-   };
-
 }
 
 #endif // SERVER_STREAM_H
diff --git a/runtime/compiler/optimizer/InlinerTempForJ9.cpp b/runtime/compiler/optimizer/InlinerTempForJ9.cpp
index e0add43e887..e8f565df8d6 100644
--- a/runtime/compiler/optimizer/InlinerTempForJ9.cpp
+++ b/runtime/compiler/optimizer/InlinerTempForJ9.cpp
@@ -375,6 +375,7 @@ TR_J9InlinerPolicy::alwaysWorthInlining(TR_ResolvedMethod * calleeMethod, TR::No
       case TR::java_lang_StringBuffer_lengthInternalUnsynchronized:
       case TR::java_lang_StringBuilder_capacityInternal:
       case TR::java_lang_StringBuilder_lengthInternal:
+      case TR::java_lang_StringUTF16_newBytesFor:
       case TR::java_util_HashMap_get:
       case TR::java_util_HashMap_getNode:
       case TR::java_lang_String_getChars_charArray:
diff --git a/runtime/compiler/optimizer/J9EstimateCodeSize.cpp b/runtime/compiler/optimizer/J9EstimateCodeSize.cpp
index 2321f9fb977..cfbd507092f 100644
--- a/runtime/compiler/optimizer/J9EstimateCodeSize.cpp
+++ b/runtime/compiler/optimizer/J9EstimateCodeSize.cpp
@@ -1239,7 +1239,8 @@ TR_J9EstimateCodeSize::realEstimateCodeSize(TR_CallTarget *calltarget, TR_CallSt
             TR::Node* parent = tt->getNode();
             TR::Node* callNode = tt->getNode()->getFirstChild();
             TR::SymbolReference* symRef =  callNode->getSymbolReference();
-            if (!callNode->getSymbolReference()->isUnresolved() && !visited.contains(callNode))
+            if (!callNode->getSymbolReference()->isUnresolved() && !visited.contains(callNode) &&
+               !callSites[callNode->getByteCodeIndex()]) // skip if the callsite has already been created for this byte code index
                {
                int i = callNode->getByteCodeIndex();
                visited.add(callNode);
@@ -1268,6 +1269,10 @@ TR_J9EstimateCodeSize::realEstimateCodeSize(TR_CallTarget *calltarget, TR_CallSt
                   //support counters
                   calltarget->addDeadCallee(callsite);
                   }
+
+               // clearing the node generated by peeking ilgen
+               // _callNode will be filled with node generated by actual ilgen @see TR_InlinerBase::findAndUpdateCallSiteInGraph
+               callsite->_callNode = NULL;
                }
             }
          }
diff --git a/runtime/compiler/p/codegen/J9TreeEvaluator.cpp b/runtime/compiler/p/codegen/J9TreeEvaluator.cpp
index 9f132dceff8..26f9f780253 100644
--- a/runtime/compiler/p/codegen/J9TreeEvaluator.cpp
+++ b/runtime/compiler/p/codegen/J9TreeEvaluator.cpp
@@ -988,8 +988,8 @@ J9::Power::TreeEvaluator::generateFillInDataBlockSequenceForUnresolvedField(TR::
    TR::Register *cndReg = cg->allocateRegister(TR_CCR);
    generateTrg1MemInstruction(cg, TR::InstOpCode::Op_load, node, scratchReg,
                      new (cg->trHeapMemory()) TR::MemoryReference(dataSnippetRegister, offsetInDataBlock, TR::Compiler->om.sizeofReferenceAddress(), cg));
-   generateTrg1Src1ImmInstruction(cg, TR::InstOpCode::andi_r, node, scratchReg, scratchReg, cndReg, -1);
-   generateConditionalBranchInstruction(cg, TR::InstOpCode::bne, node, unresolvedLabel, cndReg);
+   generateTrg1Src1ImmInstruction(cg, TR::InstOpCode::Op_cmpi, node, cndReg, scratchReg, -1);
+   generateConditionalBranchInstruction(cg, TR::InstOpCode::beq, node, unresolvedLabel, cndReg);
 
    generateReportOOL->swapInstructionListsWithCompilation();
 
diff --git a/runtime/compiler/runtime/CompileService.hpp b/runtime/compiler/runtime/CompileService.hpp
index da9d884784b..4c2812030e5 100644
--- a/runtime/compiler/runtime/CompileService.hpp
+++ b/runtime/compiler/runtime/CompileService.hpp
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2018, 2019 IBM Corp. and others
+ * Copyright (c) 2018, 2020 IBM Corp. and others
  *
  * This program and the accompanying materials are made available under
  * the terms of the Eclipse Public License 2.0 which accompanies this
@@ -25,6 +25,7 @@
 
 #include "vmaccess.h" // for acquireVMAccess and releaseVMAccess
 #include "net/ServerStream.hpp" // for JITServer::BaseCompileDispatcher
+#include "runtime/Listener.hpp"
 
 struct J9JITConfig;
 struct J9VMThread;
@@ -53,7 +54,7 @@ class VMAccessHolder
    This handler, 'compile(ServerStream *)', is executed by the listener thread when a new connection request has been received by JITServer
 */
 
-class J9CompileDispatcher : public JITServer::BaseCompileDispatcher
+class J9CompileDispatcher : public BaseCompileDispatcher
 {
 public:
    J9CompileDispatcher(J9JITConfig *jitConfig) : _jitConfig(jitConfig) { }
diff --git a/runtime/compiler/runtime/JITClientSession.cpp b/runtime/compiler/runtime/JITClientSession.cpp
index 91fca0a2586..43ffb223f58 100644
--- a/runtime/compiler/runtime/JITClientSession.cpp
+++ b/runtime/compiler/runtime/JITClientSession.cpp
@@ -228,7 +228,7 @@ ClientSessionData::getCachedIProfilerInfo(TR_OpaqueMethodBlock *method, uint32_t
    }
 
 bool
-ClientSessionData::cacheIProfilerInfo(TR_OpaqueMethodBlock *method, uint32_t byteCodeIndex, TR_IPBytecodeHashTableEntry *entry)
+ClientSessionData::cacheIProfilerInfo(TR_OpaqueMethodBlock *method, uint32_t byteCodeIndex, TR_IPBytecodeHashTableEntry *entry, bool isCompiled)
    {
    OMR::CriticalSection getRemoteROMClass(getROMMapMonitor());
    // check whether info about j9method exists
@@ -240,7 +240,6 @@ ClientSessionData::cacheIProfilerInfo(TR_OpaqueMethodBlock *method, uint32_t byt
       if (!iProfilerMap)
          {
          // Check and update if method is compiled when collecting profiling data
-         bool isCompiled = TR::CompilationInfo::isCompiled((J9Method*)method);
          if (isCompiled)
             it->second._isCompiledWhenProfiling = true;
 
diff --git a/runtime/compiler/runtime/JITClientSession.hpp b/runtime/compiler/runtime/JITClientSession.hpp
index e79bd823b6e..a898470d386 100644
--- a/runtime/compiler/runtime/JITClientSession.hpp
+++ b/runtime/compiler/runtime/JITClientSession.hpp
@@ -351,7 +351,7 @@ class ClientSessionData
    TR::Monitor *getClassMapMonitor() { return _classMapMonitor; }
    TR::Monitor *getClassChainDataMapMonitor() { return _classChainDataMapMonitor; }
    TR_IPBytecodeHashTableEntry *getCachedIProfilerInfo(TR_OpaqueMethodBlock *method, uint32_t byteCodeIndex, bool *methodInfoPresent);
-   bool cacheIProfilerInfo(TR_OpaqueMethodBlock *method, uint32_t byteCodeIndex, TR_IPBytecodeHashTableEntry *entry);
+   bool cacheIProfilerInfo(TR_OpaqueMethodBlock *method, uint32_t byteCodeIndex, TR_IPBytecodeHashTableEntry *entry, bool isCompiled);
    VMInfo *getOrCacheVMInfo(JITServer::ServerStream *stream);
    void clearCaches(); // destroys _chTableClassMap, _romClassMap and _J9MethodMap
    TR_AddressSet& getUnloadedClassAddresses()
diff --git a/runtime/compiler/runtime/JITServerIProfiler.cpp b/runtime/compiler/runtime/JITServerIProfiler.cpp
index 3f3b7c234c1..56d7734c979 100644
--- a/runtime/compiler/runtime/JITServerIProfiler.cpp
+++ b/runtime/compiler/runtime/JITServerIProfiler.cpp
@@ -201,10 +201,11 @@ JITServerIProfiler::profilingSample(TR_OpaqueMethodBlock *method, uint32_t byteC
          // Ask the client again and see if the two sources of information match
          auto stream = TR::CompilationInfo::getStream();
          stream->write(JITServer::MessageType::IProfiler_profilingSample, method, byteCodeIndex, (uintptr_t)1);
-         auto recv = stream->read<std::string, bool, bool>();
+         auto recv = stream->read<std::string, bool, bool, bool>();
          const std::string ipdata = std::get<0>(recv);
          bool wholeMethod = std::get<1>(recv); // indicates whether the client has sent info for entire method
          bool usePersistentCache = std::get<2>(recv);
+         bool isCompiled = std::get<3>(recv);
          TR_ASSERT(!wholeMethod, "Client should not have sent whole method info");
          uintptr_t methodStart = TR::Compiler->mtd.bytecodeStart(method);
          TR_IPBCDataStorageHeader *clientData = ipdata.empty() ? NULL : (TR_IPBCDataStorageHeader *) &ipdata[0];
@@ -237,10 +238,11 @@ JITServerIProfiler::profilingSample(TR_OpaqueMethodBlock *method, uint32_t byteC
    //
    auto stream = TR::CompilationInfo::getStream();
    stream->write(JITServer::MessageType::IProfiler_profilingSample, method, byteCodeIndex, (uintptr_t)(_useCaching ? 0 : 1));
-   auto recv = stream->read<std::string, bool, bool>();
+   auto recv = stream->read<std::string, bool, bool, bool>();
    const std::string ipdata = std::get<0>(recv);
    bool wholeMethod = std::get<1>(recv); // indicates whether the client sent info for entire method
    bool usePersistentCache = std::get<2>(recv); // indicates whether info can be saved in persistent memory, or only in heap memory
+   bool isCompiled = std::get<3>(recv);
    _statsIProfilerInfoMsgToClient++;
 
    bool doCache = _useCaching && wholeMethod;
@@ -254,10 +256,10 @@ JITServerIProfiler::profilingSample(TR_OpaqueMethodBlock *method, uint32_t byteC
          {
          // cache some empty data so that we don't ask again for this method
          // this method contains empty data
-         if (usePersistentCache && !clientSessionData->cacheIProfilerInfo(method, byteCodeIndex, NULL))
-               _statsIProfilerInfoCachingFailures++;
+         if (usePersistentCache && !clientSessionData->cacheIProfilerInfo(method, byteCodeIndex, NULL, isCompiled))
+            _statsIProfilerInfoCachingFailures++;
          else if (!usePersistentCache && !compInfoPT->cacheIProfilerInfo(method, byteCodeIndex, NULL))   
-               _statsIProfilerInfoCachingFailures++;
+            _statsIProfilerInfoCachingFailures++;
          }
       return NULL;
       }
@@ -300,7 +302,7 @@ JITServerIProfiler::profilingSample(TR_OpaqueMethodBlock *method, uint32_t byteC
                      bci += 2;
                   }
                }
-            if (usePersistentCache && !clientSessionData->cacheIProfilerInfo(method, bci, entry))
+            if (usePersistentCache && !clientSessionData->cacheIProfilerInfo(method, bci, entry, isCompiled))
                {
                // If caching failed we must delete the entry allocated with persistent memory
                _statsIProfilerInfoCachingFailures++;
@@ -496,14 +498,14 @@ JITServerIProfiler::setCallCount(TR_OpaqueMethodBlock *method, int32_t bcIndex,
       return;
 
    bool sendRemoteMessage = false; 
+   bool createNewEntry = false;
+   bool methodInfoPresentInPersistent = false;
    ClientSessionData *clientData = TR::compInfoPT->getClientData(); // Find clientSessionData
+   auto compInfoPT = (TR::CompilationInfoPerThreadRemote *) TR::compInfoPT;
    if (_useCaching)
       {
       OMR::CriticalSection getRemoteROMClass(clientData->getROMMapMonitor());
-      auto & j9methodMap = clientData->getJ9MethodMap();
-      bool methodInfoPresentInPersistent = false;
       bool methodInfoPresentInHeap = false;
-      auto compInfoPT = (TR::CompilationInfoPerThreadRemote *) TR::compInfoPT;
       // Check persistent cache first, then per-compilation cache
       TR_IPBytecodeHashTableEntry *entry = clientData->getCachedIProfilerInfo(method, bcIndex, &methodInfoPresentInPersistent);
       if (!methodInfoPresentInPersistent)
@@ -529,24 +531,10 @@ JITServerIProfiler::setCallCount(TR_OpaqueMethodBlock *method, int32_t bcIndex,
                // Nothing to do because the correct data is already in place
                }
             }
-         else
+         else // Info for this bcIndex is missing.
             {
-            // Info for this bcIndex is missing. 
-            // Create a new entry, add it to the cache and send a remote message as well
-            uintptr_t methodStart = TR::Compiler->mtd.bytecodeStart(method);
-            TR_AllocationKind allocKind = methodInfoPresentInPersistent ? persistentAlloc : heapAlloc;
-            TR_IPBCDataCallGraph *cgEntry = (TR_IPBCDataCallGraph*)comp->trMemory()->allocateMemory(sizeof(TR_IPBCDataCallGraph), allocKind, TR_Memory::IPBCDataCallGraph);
-            cgEntry = new (cgEntry) TR_IPBCDataCallGraph(methodStart + bcIndex);
-
-            CallSiteProfileInfo *csInfo = cgEntry->getCGData();
-            csInfo->_weight[0] = count;
-            // TODO: we should probably add some class as well
-            if (methodInfoPresentInPersistent)
-               clientData->cacheIProfilerInfo(method, bcIndex, cgEntry);
-            else
-               compInfoPT->cacheIProfilerInfo(method, bcIndex, cgEntry);
-
             sendRemoteMessage = true;
+            createNewEntry = true;
             }
          }
       else
@@ -563,7 +551,25 @@ JITServerIProfiler::setCallCount(TR_OpaqueMethodBlock *method, int32_t bcIndex,
       {
       auto stream = TR::CompilationInfo::getStream();
       stream->write(JITServer::MessageType::IProfiler_setCallCount, method, bcIndex, count);
-      stream->read<JITServer::Void>();
+      auto recv = stream->read<bool>();
+      bool isCompiled = std::get<0>(recv);
+
+      if (createNewEntry)
+         {
+         // Create a new entry, add it to the cache and send a remote message as well
+         uintptr_t methodStart = TR::Compiler->mtd.bytecodeStart(method);
+         TR_AllocationKind allocKind = methodInfoPresentInPersistent ? persistentAlloc : heapAlloc;
+         TR_IPBCDataCallGraph *cgEntry = (TR_IPBCDataCallGraph*)comp->trMemory()->allocateMemory(sizeof(TR_IPBCDataCallGraph), allocKind, TR_Memory::IPBCDataCallGraph);
+         cgEntry = new (cgEntry) TR_IPBCDataCallGraph(methodStart + bcIndex);
+
+         CallSiteProfileInfo *csInfo = cgEntry->getCGData();
+         csInfo->_weight[0] = count;
+         // TODO: we should probably add some class as well
+         if (methodInfoPresentInPersistent)
+            clientData->cacheIProfilerInfo(method, bcIndex, cgEntry, isCompiled);
+         else
+            compInfoPT->cacheIProfilerInfo(method, bcIndex, cgEntry);
+         }
       }
    }
 
@@ -733,7 +739,7 @@ JITClientIProfiler::serializeIProfilerMethodEntries(uintptr_t *pcEntries, uint32
  * @return Whether the operation was successful
  */
 bool
-JITClientIProfiler::serializeAndSendIProfileInfoForMethod(TR_OpaqueMethodBlock *method, TR::Compilation *comp, JITServer::ClientStream *client, bool usePersistentCache)
+JITClientIProfiler::serializeAndSendIProfileInfoForMethod(TR_OpaqueMethodBlock *method, TR::Compilation *comp, JITServer::ClientStream *client, bool usePersistentCache, bool isCompiled)
    {
    TR::StackMemoryRegion stackMemoryRegion(*comp->trMemory());
    uint32_t numEntries = 0;
@@ -762,11 +768,11 @@ JITClientIProfiler::serializeAndSendIProfileInfoForMethod(TR_OpaqueMethodBlock *
          intptr_t writtenBytes = serializeIProfilerMethodEntries(pcEntries, numEntries, (uintptr_t)&buffer[0], methodStart);
          TR_ASSERT(writtenBytes == bytesFootprint, "BST doesn't match expected footprint");
          // send the information to the server
-         client->write(JITServer::MessageType::IProfiler_profilingSample, buffer, true, usePersistentCache);
+         client->write(JITServer::MessageType::IProfiler_profilingSample, buffer, true, usePersistentCache, isCompiled);
          }
       else if (!numEntries && !abort)// Empty IProfiler data for this method
          {
-         client->write(JITServer::MessageType::IProfiler_profilingSample, std::string(), true, usePersistentCache);
+         client->write(JITServer::MessageType::IProfiler_profilingSample, std::string(), true, usePersistentCache, isCompiled);
          }
 
       // release any entry that has been locked by us
diff --git a/runtime/compiler/runtime/JITServerIProfiler.hpp b/runtime/compiler/runtime/JITServerIProfiler.hpp
index 6ae47706cd5..ef310c05baa 100644
--- a/runtime/compiler/runtime/JITServerIProfiler.hpp
+++ b/runtime/compiler/runtime/JITServerIProfiler.hpp
@@ -142,7 +142,7 @@ class JITClientIProfiler : public TR_IProfiler
    // Thus, any virtual function here must call the corresponding method in
    // the base class. It may be better not to override any methods though
  
-   bool serializeAndSendIProfileInfoForMethod(TR_OpaqueMethodBlock*method, TR::Compilation *comp, JITServer::ClientStream *client, bool usePersistentCache);
+   bool serializeAndSendIProfileInfoForMethod(TR_OpaqueMethodBlock*method, TR::Compilation *comp, JITServer::ClientStream *client, bool usePersistentCache, bool isCompiled);
    std::string serializeIProfilerMethodEntry(TR_OpaqueMethodBlock *omb);
 
 private:
diff --git a/runtime/compiler/runtime/Listener.cpp b/runtime/compiler/runtime/Listener.cpp
index a75b141cb1a..7e371a13c29 100644
--- a/runtime/compiler/runtime/Listener.cpp
+++ b/runtime/compiler/runtime/Listener.cpp
@@ -20,11 +20,168 @@
  * SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0 WITH Classpath-exception-2.0 OR LicenseRef-GPL-2.0 WITH Assembly-exception
  *******************************************************************************/
 
-#include "runtime/Listener.hpp"
-#include "net/ServerStream.hpp"
+#include <arpa/inet.h>
+#include <chrono>
+#include <fcntl.h>
+#include <netdb.h>
+#include <netinet/in.h>
+#include <netinet/tcp.h>	/* for TCP_NODELAY option */
+#include <openssl/err.h>
+#include <poll.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h> /// gethostname, read, write
+#include "control/CompilationRuntime.hpp"
+#include "env/TRMemory.hpp"
 #include "env/VMJ9.h"
+#include "net/CommunicationStream.hpp"
+#include "net/LoadSSLLibs.hpp"
+#include "net/ServerStream.hpp"
 #include "runtime/CompileService.hpp"
-#include "control/CompilationRuntime.hpp"
+#include "runtime/Listener.hpp"
+
+static SSL_CTX *
+createSSLContext(TR::PersistentInfo *info)
+   {
+   SSL_CTX *ctx = (*OSSL_CTX_new)((*OSSLv23_server_method)());
+
+   if (!ctx)
+      {
+      perror("can't create SSL context");
+      (*OERR_print_errors_fp)(stderr);
+      exit(1);
+      }
+
+   const char *sessionIDContext = "JITServer";
+   (*OSSL_CTX_set_session_id_context)(ctx, (const unsigned char*)sessionIDContext, strlen(sessionIDContext));
+
+   if ((*OSSL_CTX_set_ecdh_auto)(ctx, 1) != 1)
+      {
+      perror("failed to configure SSL ecdh");
+      (*OERR_print_errors_fp)(stderr);
+      exit(1);
+      }
+
+   TR::CompilationInfo *compInfo = TR::CompilationInfo::get();
+   auto &sslKeys = compInfo->getJITServerSslKeys();
+   auto &sslCerts = compInfo->getJITServerSslCerts();
+   auto &sslRootCerts = compInfo->getJITServerSslRootCerts();
+
+   TR_ASSERT_FATAL(sslKeys.size() == 1 && sslCerts.size() == 1, "only one key and cert is supported for now");
+   TR_ASSERT_FATAL(sslRootCerts.size() == 0, "server does not understand root certs yet");
+
+   // Parse and set private key
+   BIO *keyMem = (*OBIO_new_mem_buf)(&sslKeys[0][0], sslKeys[0].size());
+   if (!keyMem)
+      {
+      perror("cannot create memory buffer for private key (OOM?)");
+      (*OERR_print_errors_fp)(stderr);
+      exit(1);
+      }
+   EVP_PKEY *privKey = (*OPEM_read_bio_PrivateKey)(keyMem, NULL, NULL, NULL);
+   if (!privKey)
+      {
+      perror("cannot parse private key");
+      (*OERR_print_errors_fp)(stderr);
+      exit(1);
+      }
+   if ((*OSSL_CTX_use_PrivateKey)(ctx, privKey) != 1)
+      {
+      perror("cannot use private key");
+      (*OERR_print_errors_fp)(stderr);
+      exit(1);
+      }
+
+   // Parse and set certificate
+   BIO *certMem = (*OBIO_new_mem_buf)(&sslCerts[0][0], sslCerts[0].size());
+   if (!certMem)
+      {
+      perror("cannot create memory buffer for cert (OOM?)");
+      (*OERR_print_errors_fp)(stderr);
+      exit(1);
+      }
+   X509 *certificate = (*OPEM_read_bio_X509)(certMem, NULL, NULL, NULL);
+   if (!certificate)
+      {
+      perror("cannot parse cert");
+      (*OERR_print_errors_fp)(stderr);
+      exit(1);
+      }
+   if ((*OSSL_CTX_use_certificate)(ctx, certificate) != 1)
+      {
+      perror("cannot use cert");
+      (*OERR_print_errors_fp)(stderr);
+      exit(1);
+      }
+
+   // Verify key and cert are valid
+   if ((*OSSL_CTX_check_private_key)(ctx) != 1)
+      {
+      perror("private key check failed");
+      (*OERR_print_errors_fp)(stderr);
+      exit(1);
+      }
+
+   // verify server identity using standard method
+   (*OSSL_CTX_set_verify)(ctx, SSL_VERIFY_PEER, NULL);
+
+   if (TR::Options::getVerboseOption(TR_VerboseJITServer))
+      TR_VerboseLog::writeLineLocked(TR_Vlog_JITServer, "Successfully initialized SSL context (%s)\n", (*OOpenSSL_version)(0));
+
+   return ctx;
+   }
+
+static bool
+handleOpenSSLConnectionError(int connfd, SSL *&ssl, BIO *&bio, const char *errMsg)
+   {
+   if (TR::Options::getVerboseOption(TR_VerboseJITServer))
+       TR_VerboseLog::writeLineLocked(TR_Vlog_JITServer, "%s: errno=%d", errMsg, errno);
+   (*OERR_print_errors_fp)(stderr);
+
+   close(connfd);
+   if (bio)
+      {
+      (*OBIO_free_all)(bio);
+      bio = NULL;
+      }
+   if (ssl)
+      {
+      (*OSSL_free)(ssl);
+      ssl = NULL;
+      }
+   return false;
+   }
+
+static bool
+acceptOpenSSLConnection(SSL_CTX *sslCtx, int connfd, BIO *&bio)
+   {
+   SSL *ssl = (*OSSL_new)(sslCtx);
+   if (!ssl)
+      return handleOpenSSLConnectionError(connfd, ssl, bio, "Error creating SSL connection");
+
+   (*OSSL_set_accept_state)(ssl);
+
+   if ((*OSSL_set_fd)(ssl, connfd) != 1)
+      return handleOpenSSLConnectionError(connfd, ssl, bio, "Error setting SSL file descriptor");
+
+   if ((*OSSL_accept)(ssl) <= 0)
+      return handleOpenSSLConnectionError(connfd, ssl, bio, "Error accepting SSL connection");
+
+   bio = (*OBIO_new_ssl)(sslCtx, false);
+   if (!bio)
+      return handleOpenSSLConnectionError(connfd, ssl, bio, "Error creating new BIO");
+
+   if ((*OBIO_ctrl)(bio, BIO_C_SET_SSL, true, (char *)ssl) != 1) // BIO_set_ssl(bio, ssl, true)
+      return handleOpenSSLConnectionError(connfd, ssl, bio, "Error setting BIO SSL");
+
+   if (TR::Options::getVerboseOption(TR_VerboseJITServer))
+      TR_VerboseLog::writeLineLocked(TR_Vlog_JITServer, "SSL connection on socket 0x%x, Version: %s, Cipher: %s\n",
+                                                     connfd, (*OSSL_get_version)(ssl), (*OSSL_get_cipher)(ssl));
+   return true;
+   }
 
 TR_Listener::TR_Listener()
    : _listenerThread(NULL), _listenerMonitor(NULL), _listenerOSThread(NULL), 
@@ -32,6 +189,139 @@ TR_Listener::TR_Listener()
    {
    }
 
+void
+TR_Listener::serveRemoteCompilationRequests(BaseCompileDispatcher *compiler)
+   {
+   TR::PersistentInfo *info = getCompilationInfo(jitConfig)->getPersistentInfo();
+   SSL_CTX *sslCtx = NULL;
+   if (JITServer::CommunicationStream::useSSL())
+      {
+      JITServer::CommunicationStream::initSSL();
+      sslCtx = createSSLContext(info);
+      }
+
+   uint32_t port = info->getJITServerPort();
+   uint32_t timeoutMs = info->getSocketTimeout();
+   struct pollfd pfd = {0};
+   int sockfd = socket(AF_INET, SOCK_STREAM | SOCK_NONBLOCK, 0);
+   if (sockfd < 0)
+      {
+      perror("can't open server socket");
+      exit(1);
+      }
+
+   // see `man 7 socket` for option explanations
+   int flag = true;
+   if (setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, (void *)&flag, sizeof(flag)) < 0)
+      {
+      perror("Can't set SO_REUSEADDR");
+      exit(-1);
+      }
+   if (setsockopt(sockfd, SOL_SOCKET, SO_KEEPALIVE, (void *)&flag, sizeof(flag)) < 0)
+      {
+      perror("Can't set SO_KEEPALIVE");
+      exit(-1);
+      }
+
+   struct sockaddr_in serv_addr;
+   memset((char *)&serv_addr, 0, sizeof(serv_addr));
+   serv_addr.sin_family = AF_INET;
+   serv_addr.sin_addr.s_addr = htonl(INADDR_ANY);
+   serv_addr.sin_port = htons(port);
+
+   if (bind(sockfd, (struct sockaddr *)&serv_addr, sizeof(serv_addr)) < 0)
+      {
+      perror("can't bind server address");
+      exit(1);
+      }
+   if (listen(sockfd, SOMAXCONN) < 0)
+      {
+      perror("listen failed");
+      exit(1);
+      }
+
+   pfd.fd = sockfd;
+   pfd.events = POLLIN;
+
+   while (!getListenerThreadExitFlag())
+      {
+      int32_t rc = 0;
+      struct sockaddr_in cli_addr;
+      socklen_t clilen = sizeof(cli_addr);
+      int connfd = -1;
+
+      rc = poll(&pfd, 1, OPENJ9_LISTENER_POLL_TIMEOUT);
+      if (getListenerThreadExitFlag()) // if we are exiting, no need to check poll() status
+         {
+         break;
+         }
+      else if (0 == rc) // poll() timed out and no fd is ready
+         {
+         continue;
+         }
+      else if (rc < 0)
+         {
+         if (errno == EINTR)
+            {
+            continue;
+            }
+         else
+            {
+            perror("error in polling listening socket");
+            exit(1);
+            }
+         }
+      else if (pfd.revents != POLLIN)
+         {
+         fprintf(stderr, "Unexpected event occurred during poll for new connection: revents=%d\n", pfd.revents);
+         exit(1);
+         }
+      do
+         {
+         /* at this stage we should have a valid request for new connection */
+         connfd = accept(sockfd, (struct sockaddr *)&cli_addr, &clilen);
+         if (connfd < 0)
+            {
+            if ((EAGAIN != errno) && (EWOULDBLOCK != errno))
+               {
+               if (TR::Options::getVerboseOption(TR_VerboseJITServer))
+                  {
+                  TR_VerboseLog::writeLineLocked(TR_Vlog_JITServer, "Error accepting connection: errno=%d", errno);
+                  }
+               }
+            }
+         else
+            {
+            struct timeval timeoutMsForConnection = {(timeoutMs / 1000), ((timeoutMs % 1000) * 1000)};
+            if (setsockopt(connfd, SOL_SOCKET, SO_RCVTIMEO, (void *)&timeoutMsForConnection, sizeof(timeoutMsForConnection)) < 0)
+               {
+               perror("Can't set option SO_RCVTIMEO on connfd socket");
+               exit(-1);
+               }
+            if (setsockopt(connfd, SOL_SOCKET, SO_SNDTIMEO, (void *)&timeoutMsForConnection, sizeof(timeoutMsForConnection)) < 0)
+               {
+               perror("Can't set option SO_SNDTIMEO on connfd socket");
+               exit(-1);
+               }
+
+            BIO *bio = NULL;
+            if (sslCtx && !acceptOpenSSLConnection(sslCtx, connfd, bio))
+               continue;
+
+            JITServer::ServerStream *stream = new (PERSISTENT_NEW) JITServer::ServerStream(connfd, bio);
+            compiler->compile(stream);
+            }
+         } while ((-1 != connfd) && !getListenerThreadExitFlag());
+      }
+
+   // The following piece of code will be executed only if the server shuts down properly
+   if (sslCtx)
+      {
+      (*OSSL_CTX_free)(sslCtx);
+      (*OEVP_cleanup)();
+      }
+   }
+
 TR_Listener * TR_Listener::allocate()
    {
    TR_Listener * listener = new (PERSISTENT_NEW) TR_Listener();
@@ -63,11 +353,8 @@ static int32_t J9THREAD_PROC listenerThreadProc(void * entryarg)
    j9thread_set_name(j9thread_self(), "JITServer Listener");
 
    J9CompileDispatcher handler(jitConfig);
-   TR::PersistentInfo *info = getCompilationInfo(jitConfig)->getPersistentInfo();
-   JITServer::ServerStream::serveRemoteCompilationRequests(&handler, info);
+   listener->serveRemoteCompilationRequests(&handler);
 
-   // Note: the following code will never be executed, because 
-   // serveRemoteCompilationRequests() is executed "forever"
    if (TR::Options::getVerboseOption(TR_VerboseJITServer))
       TR_VerboseLog::writeLineLocked(TR_Vlog_JITServer, "Detaching JITServer listening thread");
 
@@ -123,10 +410,25 @@ void TR_Listener::startListenerThread(J9JavaVM *javaVM)
       }
    }
 
-int32_t TR_Listener::waitForListenerThreadExit(J9JavaVM *javaVM)
+int32_t
+TR_Listener::waitForListenerThreadExit(J9JavaVM *javaVM)
    {
    if (NULL != _listenerOSThread)
       return omrthread_join(_listenerOSThread);
    else
       return 0;
    }
+
+void
+TR_Listener::stop()
+   {
+   if (getListenerThread())
+      {
+      _listenerMonitor->enter();
+      setListenerThreadExitFlag();
+      _listenerMonitor->wait();
+      _listenerMonitor->exit();
+      TR::Monitor::destroy(_listenerMonitor);
+      _listenerMonitor = NULL;
+      }
+   }
diff --git a/runtime/compiler/runtime/Listener.hpp b/runtime/compiler/runtime/Listener.hpp
index d82377f6d3c..18e129388af 100644
--- a/runtime/compiler/runtime/Listener.hpp
+++ b/runtime/compiler/runtime/Listener.hpp
@@ -25,6 +25,7 @@
 
 #include "j9.h"
 #include "infra/Monitor.hpp"  // TR::Monitor
+#include "net/ServerStream.hpp"
 
  /**
     @class TR_Listener
@@ -34,15 +35,36 @@
     Typical sequence executed by a JITServer is:
     (1) Create a TR_Listener object with "allocate()" function
     (2) Start a listener thread with  listener->startListenerThread(javaVM);
- 
-    The current implementation does not provide code for nicely terminating the listener thread.
  */
+
+#define OPENJ9_LISTENER_POLL_TIMEOUT 100 // in milliseconds
+
+class BaseCompileDispatcher;
+
 class TR_Listener
    {
 public:
    TR_Listener();
    static TR_Listener* allocate();
    void startListenerThread(J9JavaVM *javaVM);
+   void stop();
+   /**
+      @brief Function called to deal with incoming connection requests
+
+      This function opens a socket (non-blocking), binds it and then waits for incoming
+      connection by polling on it with a timeout (see OPENJ9_LISTENER_POLL_TIMEOUT).
+      If it ever comes out of polling (due to timeout or a new connection request),
+      it checks the exit flag. If the flag is set, then the thread exits.
+      Otherwise, it establishes the connection using accept().
+      Once a connection is accepted a ServerStream object is created (receiving the newly
+      opened socket descriptor as a parameter) and passed to the compilation handler.
+      Typically, the compilation handler places the ServerStream object in a queue and
+      returns immediately so that other connection requests can be accepted.
+      Note: it must be executed on a separate thread as it needs to keep listening for new connections.
+
+      @param [in] compiler Object that defines the behavior when a new connection is accepted
+   */
+   void serveRemoteCompilationRequests(BaseCompileDispatcher *compiler);
    int32_t waitForListenerThreadExit(J9JavaVM *javaVM);
    void setAttachAttempted(bool b) { _listenerThreadAttachAttempted = b; }
    bool getAttachAttempted() const { return _listenerThreadAttachAttempted; }
@@ -63,4 +85,18 @@ class TR_Listener
    volatile bool _listenerThreadExitFlag;
    };
 
+/**
+   @class BaseCompileDispatcher
+   @brief Abstract class defining the interface for the compilation handler
+
+   Typically, an user would derive this class and provide an implementation for "compile()"
+   An instance of the derived class needs to be passed to serveRemoteCompilationRequests
+   which internally calls "compile()"
+ */
+class BaseCompileDispatcher
+   {
+public:
+   virtual void compile(JITServer::ServerStream *stream) = 0;
+   };
+
 #endif
diff --git a/runtime/compiler/runtime/RuntimeAssumptions.hpp b/runtime/compiler/runtime/RuntimeAssumptions.hpp
index 6c7caf4c7bc..27fd09dd29b 100644
--- a/runtime/compiler/runtime/RuntimeAssumptions.hpp
+++ b/runtime/compiler/runtime/RuntimeAssumptions.hpp
@@ -293,16 +293,16 @@ class TR_UnloadedClassPicSite : public OMR::ValueModifyRuntimeAssumption
 struct SerializedRuntimeAssumption
    {
    SerializedRuntimeAssumption(TR_RuntimeAssumptionKind kind, uintptr_t key, intptr_t offset, uint32_t size = 0)
-      : _kind(kind), _key(key), _offsetFromStartPC(offset), _size(size) {}
+      : _kind(kind), _key(key), _offsetFromBinaryBufferStart(offset), _size(size) {}
    TR_RuntimeAssumptionKind getKind() const { return _kind; }
    uintptr_t getKey() const { return _key; }
-   intptr_t getOffsetFromStartPC() const { return _offsetFromStartPC; }
+   intptr_t getOffsetFromBinaryBufferStart() const { return _offsetFromBinaryBufferStart; }
    uint32_t getSize() const { return _size; }
 
    TR_RuntimeAssumptionKind _kind;
    uint32_t   _size;
    uintptr_t _key;
-   intptr_t  _offsetFromStartPC; // can be negative
+   intptr_t  _offsetFromBinaryBufferStart;
    };
 #endif // J9VM_OPT_JITSERVER
 
diff --git a/runtime/compiler/runtime/Trampoline.cpp b/runtime/compiler/runtime/Trampoline.cpp
index 8b03e1eef88..a75e692d435 100644
--- a/runtime/compiler/runtime/Trampoline.cpp
+++ b/runtime/compiler/runtime/Trampoline.cpp
@@ -863,6 +863,10 @@ void armCodeCacheParameters(int32_t *trampolineSize, void **callBacks, int32_t *
 
 #define TRAMPOLINE_SIZE         16
 
+#if defined(TR_HOST_ARM64)
+extern void arm64CodeSync(uint8_t *, uint32_t);
+#endif
+
 void arm64CodeCacheConfig(int32_t ccSizeInByte, int32_t *numTempTrampolines)
    {
    *numTempTrampolines = 0;
@@ -880,6 +884,10 @@ void arm64CreateHelperTrampolines(void *trampPtr, int32_t numHelpers)
       *((intptr_t *)buffer) = (intptr_t)runtimeHelperValue((TR_RuntimeHelper)i);
       buffer += 2;
       }
+
+#if defined(TR_HOST_ARM64)
+   arm64CodeSync((uint8_t*)trampPtr, TRAMPOLINE_SIZE * numHelpers);
+#endif
    }
 
 void arm64CreateMethodTrampoline(void *trampPtr, void *startPC, void *method)
@@ -893,6 +901,10 @@ void arm64CreateMethodTrampoline(void *trampPtr, void *startPC, void *method)
    *buffer = 0xD61F0200; //BR R16
    buffer += 1;
    *((intptr_t *)buffer) = dispatcher;
+
+#if defined(TR_HOST_ARM64)
+   arm64CodeSync((uint8_t*)trampPtr, TRAMPOLINE_SIZE);
+#endif
    }
 
 bool arm64CodePatching(void *callee, void *callSite, void *currentPC, void *currentTramp, void *newAddrOfCallee, void *extra)
@@ -934,6 +946,9 @@ bool arm64CodePatching(void *callee, void *callSite, void *currentPC, void *curr
          else
             {
             *((uint64_t*)currentTramp+1) = (uint64_t)entryAddress;
+#if defined(TR_HOST_ARM64)
+            arm64CodeSync((uint8_t*)currentTramp+8, 8);
+#endif
             }
          }
 
@@ -944,6 +959,9 @@ bool arm64CodePatching(void *callee, void *callSite, void *currentPC, void *curr
       {
       branchInstr |= (distance >> 2) & 0x03ffffff;
       *(int32_t *)callSite = branchInstr;
+#if defined(TR_HOST_ARM64)
+      arm64CodeSync((uint8_t*)callSite, 4);
+#endif
       }
 
    return true;
diff --git a/runtime/compiler/z/env/J9CPU.cpp b/runtime/compiler/z/env/J9CPU.cpp
index 1ba0c868f5c..bfffb606baa 100644
--- a/runtime/compiler/z/env/J9CPU.cpp
+++ b/runtime/compiler/z/env/J9CPU.cpp
@@ -269,6 +269,11 @@ CPU::initializeS390ProcessorFeatures()
 
    if (TR::Compiler->target.cpu.getSupportsArch(TR::CPU::z14))
       {
+      if (j9sysinfo_processor_has_feature(processorDesc, J9PORT_S390_FEATURE_MISCELLANEOUS_INSTRUCTION_EXTENSION_2))
+         {
+         TR::Compiler->target.cpu.setSupportsMiscellaneousInstructionExtensions2Facility(true);
+         }
+
       if (j9sysinfo_processor_has_feature(processorDesc, J9PORT_S390_FEATURE_VECTOR_PACKED_DECIMAL))
          {
          TR::Compiler->target.cpu.setSupportsVectorPackedDecimalFacility(true);
diff --git a/runtime/j9vm/jvm.c b/runtime/j9vm/jvm.c
index 9f5b56802a3..99d0c01a620 100644
--- a/runtime/j9vm/jvm.c
+++ b/runtime/j9vm/jvm.c
@@ -294,6 +294,7 @@ static jint formatErrorMessage(int errorCode, char *inBuffer, jint inBufferLengt
 #if defined(J9VM_OPT_JITSERVER)
 static int32_t startJITServer(struct JITServer *);
 static int32_t waitForJITServerTermination(struct JITServer *);
+static int32_t destroyJITServer(struct JITServer **);
 #endif /* J9VM_OPT_JITSERVER */
 
 /**
@@ -1473,7 +1474,9 @@ static jint initializeReflectionGlobals(JNIEnv * env, BOOLEAN includeAccessors)
  *
  * DLL: jvm
  */
-jint JNICALL JNI_CreateJavaVM(JavaVM **pvm, void **penv, void *vm_args) {
+jint JNICALL
+JNI_CreateJavaVM(JavaVM **pvm, void **penv, void *vm_args)
+{
 	return JNI_CreateJavaVM_impl(pvm, penv, vm_args, FALSE);
 }
 
@@ -1492,6 +1495,7 @@ JITServer_CreateServer(JITServer **jitServer, void *serverArgs)
 	}
 	server->startJITServer = startJITServer;
 	server->waitForJITServerTermination = waitForJITServerTermination;
+	server->destroyJITServer = destroyJITServer;
 	rc = JNI_CreateJavaVM_impl(&server->jvm, (void **)&env, serverArgs, TRUE);
 
 	if (JNI_OK != rc) {
@@ -1504,6 +1508,7 @@ JITServer_CreateServer(JITServer **jitServer, void *serverArgs)
 _end:
 	if ((JITSERVER_OK != rc) && (NULL != server)) {
 		free(server);
+		*jitServer = NULL;
 	}
 	return rc;
 }
@@ -1513,7 +1518,7 @@ JITServer_CreateServer(JITServer **jitServer, void *serverArgs)
  *
  * @param jitServer pointer to the JITServer interface
  *
- * @returns zero on success, else negative error code
+ * @returns JITSERVER_OK on success, else negative error code
  */
 static int32_t
 startJITServer(JITServer *jitServer)
@@ -1543,7 +1548,7 @@ startJITServer(JITServer *jitServer)
  *
  * @param jitServer pointer to the JITServer interface
  *
- * @returns zero on success, else negative error code
+ * @returns JITSERVER_OK on success, else negative error code
  */
 static int32_t
 waitForJITServerTermination(JITServer *jitServer)
@@ -1567,6 +1572,31 @@ waitForJITServerTermination(JITServer *jitServer)
 	}
 	return rc;
 }
+
+/**
+ * Frees the resources allocated by JITServer_CreateServer.
+ *
+ * @param jitServer double pointer to the JITServer interface. Must not be NULL
+ *
+ * @returns JITSERVER_OK on success, else negative error code
+ *
+ * @note on return *jitServer is set to NULL
+ */
+static int32_t
+destroyJITServer(JITServer **jitServer)
+{
+	JavaVM *vm = (*jitServer)->jvm;
+	jint rc = (*vm)->DestroyJavaVM(vm);
+	free(*jitServer);
+	*jitServer = NULL;
+	if (JNI_OK == rc) {
+		rc = JITSERVER_OK;
+	} else {
+		rc = JITSERVER_DESTROY_ERROR;
+	}
+	return rc;
+}
+
 #endif /* J9VM_OPT_JITSERVER */
 
 /*
diff --git a/runtime/jitserver_launcher/jitserver.c b/runtime/jitserver_launcher/jitserver.c
index a7990b2b9c1..f9a170133be 100644
--- a/runtime/jitserver_launcher/jitserver.c
+++ b/runtime/jitserver_launcher/jitserver.c
@@ -360,6 +360,8 @@ main(int argc, char *argv[])
 		goto _end;
 	}
 
+	server->destroyJITServer(&server);
+
 	free(jvmLibPath);
 	free(options);
 
diff --git a/runtime/makelib/targets.mk.zos.inc.ftl b/runtime/makelib/targets.mk.zos.inc.ftl
index 25791bf44b0..a32f5b1e097 100644
--- a/runtime/makelib/targets.mk.zos.inc.ftl
+++ b/runtime/makelib/targets.mk.zos.inc.ftl
@@ -1,5 +1,5 @@
 <#--
-Copyright (c) 1998, 2019 IBM Corp. and others
+Copyright (c) 1998, 2020 IBM Corp. and others
 
 This program and the accompanying materials are made available under
 the terms of the Eclipse Public License 2.0 which accompanies this
@@ -68,7 +68,9 @@ ifdef j9vm_uma_supportsIpv6
   UMA_ZOS_FLAGS += -DIPv6_FUNCTION_SUPPORT
 endif
 
-UMA_ZOS_FLAGS += -DJ9ZOS390 -DLONGLONG -DJ9VM_TIERED_CODE_CACHE -D_ALL_SOURCE -D_XOPEN_SOURCE_EXTENDED -DIBM_ATOE -D_POSIX_SOURCE
+# _ISOC99_SOURCE Exposes c99 standard library changes which dont require c99 compiler support. (Also needed for c++, see below)
+# __STDC_LIMIT_MACROS Is needed to expose limit macros from <stdint.h> on c++ (also requires _ISOC99_SOURCE)
+UMA_ZOS_FLAGS += -DJ9ZOS390 -DLONGLONG -DJ9VM_TIERED_CODE_CACHE -D_ALL_SOURCE -D_XOPEN_SOURCE_EXTENDED -DIBM_ATOE -D_POSIX_SOURCE -D_ISOC99_SOURCE -D__STDC_LIMIT_MACROS
 UMA_ZOS_FLAGS += -I$(OMR_DIR)/util/a2e/headers $(UMA_OPTIMIZATION_FLAGS) $(UMA_OPTIMIZATION_LINKER_FLAGS) \
 	-Wc,"convlit(ISO8859-1),xplink,rostring,FLOAT(IEEE,FOLD,AFP),enum(4)" -Wa,goff -Wc,NOANSIALIAS -Wc,"inline(auto,noreport,600,5000)"
 UMA_ZOS_FLAGS += -Wc,"SERVICE(j${uma.buildinfo.build_date})" -Wc,"TARGET(zOSV1R13)"
diff --git a/runtime/oti/jitserver_api.h b/runtime/oti/jitserver_api.h
index 7f6f20b016c..11cc2770180 100644
--- a/runtime/oti/jitserver_api.h
+++ b/runtime/oti/jitserver_api.h
@@ -32,8 +32,32 @@ extern "C" {
 struct JITServer; /* Forward declaration */
 
 typedef struct JITServer {
+	/**
+	 * Starts an instance of JITServer.
+	 *
+	 * @param jitServer pointer to the JITServer interface
+	 *
+	 * @returns JITSERVER_OK on success, else negative error code
+	 */
 	int32_t (* startJITServer)(struct JITServer *);
+	/**
+	 * Wait for JITServer to terminate.
+	 *
+	 * @param jitServer pointer to the JITServer interface
+	 *
+	 * @returns JITSERVER_OK on success, else negative error code
+	 */
 	int32_t (* waitForJITServerTermination)(struct JITServer *);
+	/**
+	 * Frees the resources allocated by JITServer_CreateServer.
+	 *
+	 * @param jitServer double pointer to the JITServer interface. Must not be NULL
+	 *
+	 * @returns JITSERVER_OK on success, else negative error code
+	 *
+	 * @note on return *jitServer is set to NULL
+	 */
+	int32_t (* destroyJITServer)(struct JITServer **);
 	JavaVM *jvm;
 } JITServer;
 
diff --git a/runtime/oti/jitserver_error.h b/runtime/oti/jitserver_error.h
index 135d0b90041..87e77cb1632 100644
--- a/runtime/oti/jitserver_error.h
+++ b/runtime/oti/jitserver_error.h
@@ -30,4 +30,5 @@
 #define JITSERVER_STARTUP_FAILED -3
 #define JITSERVER_THREAD_ATTACH_FAILED -4
 #define JITSERVER_WAIT_TERM_FAILED -5
+#define JITSERVER_DESTROY_ERROR -6
 #endif /* jitserver_error_h */
diff --git a/runtime/oti/stackwalk.h b/runtime/oti/stackwalk.h
index 72b6300c26f..990be90e7a3 100644
--- a/runtime/oti/stackwalk.h
+++ b/runtime/oti/stackwalk.h
@@ -113,11 +113,11 @@ extern "C" {
 #define J9_STACK_FLAGS_UNUSED_0x80000000 0x80000000
 #define J9_STACK_FLAGS_JIT_CALL_IN_TYPE_J2_I 0x00000000
 #define J9_STACK_FLAGS_JNI_REFS_REDIRECTED 0x00010000
-#define J9_STACK_FLAGS_ARGS_ALIGNED 0x00000002
+#define J9_STACK_FLAGS_UNUSED_0x2 0x00000002
 #define J9_STACK_FLAGS_JIT_JNI_CALL_OUT_FRAME 0x20000000
 #define J9_STACK_FLAGS_RELEASE_VMACCESS 0x00020000
 #define J9_STACK_REPORT_FRAME_POP 0x00000001
-#define J9_STACK_FLAGS_JIT_ARGS_ALIGNED 0x04000000
+#define J9_STACK_FLAGS_JIT_UNUSED_0x04000000 0x04000000
 #define J9_JNI_PUSHED_REFERENCE_COUNT_MASK 0x000000FF
 #define J9_STACK_FLAGS_CALL_OUT_FRAME_ALLOCATED 0x00020000
 
diff --git a/runtime/oti/util_api.h b/runtime/oti/util_api.h
index 37e9e35263b..552ac768344 100644
--- a/runtime/oti/util_api.h
+++ b/runtime/oti/util_api.h
@@ -1652,17 +1652,6 @@ getOriginalROMMethod(J9Method * method);
 J9ROMMethod *
 getOriginalROMMethodUnchecked(J9Method * method);
 
-/* ---------------- sleephelp.c ---------------- */
-
-/**
-* @brief
-* @param sleepTime
-* @return IDATA
-*/
-IDATA
-callThreadSleep(IDATA sleepTime);
-
-
 /* ---------------- subclass.c ---------------- */
 
 /**
diff --git a/runtime/port/unix/j9sysinfo.c b/runtime/port/unix/j9sysinfo.c
index 9e0211b6455..01e6ee169cd 100644
--- a/runtime/port/unix/j9sysinfo.c
+++ b/runtime/port/unix/j9sysinfo.c
@@ -1675,8 +1675,15 @@ j9sysinfo_get_cache_info(struct J9PortLibrary *portLibrary, const J9CacheInfoQue
 	) {
 		/* L1 data cache line size */
 		int32_t rc = (int32_t)sysconf(_SC_LEVEL1_DCACHE_LINESIZE);
-		if (rc >= 0) {
+		if (rc > 0) {
 			result = rc;
+		} else if (rc == 0) {
+			/*
+			 * Cache line size is unavailable on some systems
+			 * Use 64 as the default value because Arm Cortex ARMv8-A cores
+			 * have L1 data cache lines of that size
+			 */
+			result = 64;
 		}
 	}
 #endif
diff --git a/runtime/util/CMakeLists.txt b/runtime/util/CMakeLists.txt
index 26edfd84bd4..07a1c749391 100644
--- a/runtime/util/CMakeLists.txt
+++ b/runtime/util/CMakeLists.txt
@@ -1,5 +1,5 @@
 ################################################################################
-# Copyright (c) 2017, 2019 IBM Corp. and others
+# Copyright (c) 2017, 2020 IBM Corp. and others
 #
 # This program and the accompanying materials are made available under
 # the terms of the Eclipse Public License 2.0 which accompanies this
@@ -80,7 +80,6 @@ add_library(j9util STATIC
 	romhelp.c
 	sendslot.c
 	shchelp_j9.c
-	sleephelp.c
 	srphashtable.c
 	strhelp.c
 	subclass.c
diff --git a/runtime/util/jitregs.c b/runtime/util/jitregs.c
index 50f15953df2..225ab30d5ab 100644
--- a/runtime/util/jitregs.c
+++ b/runtime/util/jitregs.c
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2016, 2019 IBM Corp. and others
+ * Copyright (c) 2016, 2020 IBM Corp. and others
  *
  * This program and the accompanying materials are made available under
  * the terms of the Eclipse Public License 2.0 which accompanies this
@@ -389,6 +389,9 @@ U_8 jitCalleeDestroyedRegisterList[] = {
 	0x12,	/* jit_r18 */
 	0x13,	/* jit_r19 */
 	0x14,	/* jit_r20 */
+	0x1D,   /* jit_r29 */
+	0x1E,   /* jit_r30 */
+	0x1F    /* jit_r31 */
 };
 U_8 jitCalleeSavedRegisterList[] = {
 	0x15,	/* jit_r21 */
diff --git a/runtime/vm/BytecodeInterpreter.hpp b/runtime/vm/BytecodeInterpreter.hpp
index 7b3f98eda5c..f7247c19090 100644
--- a/runtime/vm/BytecodeInterpreter.hpp
+++ b/runtime/vm/BytecodeInterpreter.hpp
@@ -48,6 +48,7 @@
 #include "MHInterpreter.hpp"
 #include "ObjectAccessBarrierAPI.hpp"
 #include "ObjectHash.hpp"
+#include "ValueTypeHelpers.hpp"
 #include "VMHelpers.hpp"
 #include "VMAccess.hpp"
 #include "ObjectAllocationAPI.hpp"
@@ -792,7 +793,6 @@ class INTERPRETER_CLASS
 		if (J9_ARE_ANY_BITS_SET((UDATA)_sp, sizeof(UDATA))) {
 			_sp -= 1;
 			memmove(_sp, _sp + 1, sizeof(UDATA) * argCount);
-			returnSP |= J9_STACK_FLAGS_ARGS_ALIGNED;
 		}
 		J9I2JState *i2jState = &_currentThread->entryLocalStorage->i2jState;
 		i2jState->returnSP = (UDATA*)returnSP;
@@ -822,7 +822,7 @@ class INTERPRETER_CLASS
 			returnPoint = jitConfig->jitExitInterpreter0;
 			break;
 		case ';':
-obj:;
+obj:
 		/* On 32-bit, object uses the "1" target (already loaded, so just break).
 		 * On 64-bit, object uses the "J" target (fall through)
 		 */
@@ -2019,40 +2019,50 @@ obj:;
 	}
 
 	VMINLINE VM_BytecodeAction
-	bindNative(REGISTER_ARGS_LIST)
+	resolveNativeAddressWithErrorHandling()
 	{
-		VM_BytecodeAction rc = GOTO_RUN_METHOD;
-		buildMethodFrame(REGISTER_ARGS, _sendMethod, jitStackFrameFlags(REGISTER_ARGS, 0));
-		updateVMStruct(REGISTER_ARGS);
 		UDATA bindRC = resolveNativeAddress(_currentThread, _sendMethod, TRUE);
 		if (J9_NATIVE_METHOD_BIND_OUT_OF_MEMORY == bindRC) {
 			_vm->memoryManagerFunctions->j9gc_modron_global_collect_with_overrides(_currentThread, J9MMCONSTANT_EXPLICIT_GC_NATIVE_OUT_OF_MEMORY);
 			bindRC = resolveNativeAddress(_currentThread, _sendMethod, TRUE);
 		}
-		switch(bindRC) {
-		case J9_NATIVE_METHOD_BIND_SUCCESS: {
-			VMStructHasBeenUpdated(REGISTER_ARGS);
-			J9SFMethodFrame *methodFrame = (J9SFMethodFrame*)_sp;
-			_currentThread->jitStackFrameFlags = methodFrame->specialFrameFlags & J9_SSF_JIT_NATIVE_TRANSITION_FRAME;
-			restoreSpecialStackFrameLeavingArgs(REGISTER_ARGS, ((UDATA*)(methodFrame + 1)) - 1);
-			break;
-		}
-		case J9_NATIVE_METHOD_BIND_OUT_OF_MEMORY:
-			setNativeBindOutOfMemoryError(_currentThread, _sendMethod);
-			VMStructHasBeenUpdated(REGISTER_ARGS);
-			rc = GOTO_THROW_CURRENT_EXCEPTION;
-			break;
-		case J9_NATIVE_METHOD_BIND_RECURSIVE:
-			setRecursiveBindError(_currentThread, _sendMethod);
-			VMStructHasBeenUpdated(REGISTER_ARGS);
-			rc = GOTO_THROW_CURRENT_EXCEPTION;
-			break;
-		default:
-			setNativeNotFoundError(_currentThread, _sendMethod);
-			VMStructHasBeenUpdated(REGISTER_ARGS);
+
+		VM_BytecodeAction rc = GOTO_RUN_METHOD;
+		if (J9_NATIVE_METHOD_BIND_SUCCESS != bindRC) {
 			rc = GOTO_THROW_CURRENT_EXCEPTION;
-			break;
+			switch(bindRC) {
+			case J9_NATIVE_METHOD_BIND_OUT_OF_MEMORY:
+				setNativeBindOutOfMemoryError(_currentThread, _sendMethod);
+				break;
+			case J9_NATIVE_METHOD_BIND_RECURSIVE:
+				setRecursiveBindError(_currentThread, _sendMethod);
+				break;
+			default:
+				setNativeNotFoundError(_currentThread, _sendMethod);
+				break;
+			}
+		}
+
+		return rc;
+	}
+
+	VMINLINE VM_BytecodeAction
+	bindNative(REGISTER_ARGS_LIST)
+	{
+		VM_BytecodeAction rc = GOTO_RUN_METHOD;
+
+		buildMethodFrame(REGISTER_ARGS, _sendMethod, jitStackFrameFlags(REGISTER_ARGS, 0));
+
+		updateVMStruct(REGISTER_ARGS);
+		rc = resolveNativeAddressWithErrorHandling();
+		VMStructHasBeenUpdated(REGISTER_ARGS);
+
+		if (GOTO_RUN_METHOD == rc) {
+			J9SFMethodFrame *methodFrame = (J9SFMethodFrame *)_sp;
+			_currentThread->jitStackFrameFlags = methodFrame->specialFrameFlags & J9_SSF_JIT_NATIVE_TRANSITION_FRAME;
+			restoreSpecialStackFrameLeavingArgs(REGISTER_ARGS, ((UDATA *)(methodFrame + 1)) - 1);
 		}
+
 		return rc;
 	}
 
@@ -2265,7 +2275,7 @@ obj:;
 			*(U_32 *)_sp = (U_32)_currentThread->returnValue;
 		}
 		rc = EXECUTE_BYTECODE;
-done:;
+done:
 		return rc;
 	}
 
@@ -4618,8 +4628,21 @@ done:;
 	outOfLineINL(REGISTER_ARGS_LIST)
 	{
 		updateVMStruct(REGISTER_ARGS);
+
 		J9OutOfLineINLMethod *target = (J9OutOfLineINLMethod *)(((UDATA)_sendMethod->extra) & ~J9_STARTPC_NOT_TRANSLATED);
-		VM_BytecodeAction rc = target(_currentThread, _sendMethod);
+		VM_BytecodeAction rc = GOTO_RUN_METHOD;
+		if (NULL == target) {
+			/* Resolve the native address and retry. */
+			rc = resolveNativeAddressWithErrorHandling();
+			if (GOTO_RUN_METHOD != rc) {
+				goto done;
+			}
+			target = (J9OutOfLineINLMethod *)(((UDATA)_sendMethod->extra) & ~J9_STARTPC_NOT_TRANSLATED);
+		}
+
+		Assert_VM_true(NULL != target);
+		rc = target(_currentThread, _sendMethod);
+done:
 		VMStructHasBeenUpdated(REGISTER_ARGS);
 		return rc;
 	}
@@ -7301,56 +7324,6 @@ done:;
 		return rc;
 	}
 
-	/*
-	 * Determine if the two objects are substitutable
-	 *
-	 * @param[in] lhs the lhs object of acmp bytecodes
-	 * @param[in] rhs the rhs object of acmp bytecodes
-	 * return true if they are substitutable and false otherwise
-	 */
-	VMINLINE bool
-	acmp(j9object_t lhs, j9object_t rhs)
-	{
-#if defined(J9VM_OPT_VALHALLA_VALUE_TYPES)
-		bool acmpResult = false;
-		if (rhs == lhs) {
-			acmpResult = true;
-		} else if ((NULL == rhs) || (NULL == lhs)) {
-			acmpResult = false;
-		} else {
-			J9Class * lhsClass = J9OBJECT_CLAZZ(_currentThread, lhs);
-			J9Class * rhsClass = J9OBJECT_CLAZZ(_currentThread, rhs);
-			if ((J9_IS_J9CLASS_VALUETYPE(rhsClass)
-				&& J9_IS_J9CLASS_VALUETYPE(lhsClass))
-				&& (rhsClass == lhsClass)
-			) {
-				acmpResult = isSubstitutable(lhs, rhs);
-			}
-		}
-		return acmpResult;
-#else /* J9VM_OPT_VALHALLA_VALUE_TYPES */
-		return (rhs == lhs);
-#endif /* J9VM_OPT_VALHALLA_VALUE_TYPES */
-	}
-
-#if defined(J9VM_OPT_VALHALLA_VALUE_TYPES)
-	/*
-	 * Determine if the two valueTypes are substitutable when rhs.class equals lhs.class
-	 *
-	 * @param[in] lhs the lhs object of acmp bytecodes and it's a valueType
-	 * @param[in] rhs the rhs object of acmp bytecodes and it's a valueType
-	 * return true if they are substitutable and false otherwise
-	 */
-	VMINLINE bool
-	isSubstitutable(j9object_t lhs, j9object_t rhs)
-	{
-		/*
-		 * TODO: this will be updated in a future PR.
-		 */
-		return false;
-	}
-#endif /* J9VM_OPT_VALHALLA_VALUE_TYPES */
-
 	/* ..., lhs, rhs => ... */
 	VMINLINE VM_BytecodeAction
 	ifacmpeq(REGISTER_ARGS_LIST)
@@ -7360,7 +7333,7 @@ done:;
 		j9object_t lhs = *(j9object_t*)(_sp + 1);
 		U_8 *profilingCursor = startProfilingRecord(REGISTER_ARGS, sizeof(U_8));
 		_sp += 2;
-		if(acmp(lhs, rhs)) {
+		if(VM_ValueTypeHelpers::acmp(_currentThread, _objectAccessBarrier, lhs, rhs)) {
 			_pc += *(I_16*)(_pc + 1);
 			if (NULL != profilingCursor) {
 				*profilingCursor = 1;
@@ -7384,7 +7357,7 @@ done:;
 		j9object_t lhs = *(j9object_t*)(_sp + 1);
 		U_8 *profilingCursor = startProfilingRecord(REGISTER_ARGS, sizeof(U_8));
 		_sp += 2;
-		if(!acmp(lhs, rhs)) {
+		if(!VM_ValueTypeHelpers::acmp(_currentThread, _objectAccessBarrier, lhs, rhs)) {
 			_pc += *(I_16*)(_pc + 1);
 			if (NULL != profilingCursor) {
 				*profilingCursor = 1;
@@ -8497,7 +8470,8 @@ done:;
 				goto done;
 			}
 
-			copyObjectRef = _objectAllocate.inlineAllocateObject(_currentThread, objectRefClass, false, false);
+			/* need to zero memset the memory so padding bytes are zeroed for memcmp-like comparisons */
+			copyObjectRef = _objectAllocate.inlineAllocateObject(_currentThread, objectRefClass, true, false);
 			if (NULL == copyObjectRef) {
 				buildGenericSpecialStackFrame(REGISTER_ARGS, 0);
 				pushObjectInSpecialFrame(REGISTER_ARGS, originalObjectRef);
diff --git a/runtime/vm/CMakeLists.txt b/runtime/vm/CMakeLists.txt
index 8c92ef56b45..abe5b7959a8 100644
--- a/runtime/vm/CMakeLists.txt
+++ b/runtime/vm/CMakeLists.txt
@@ -108,7 +108,7 @@ add_library(j9vm SHARED
 	threadhelp.cpp
 	threadpark.c
 	throwexception.c
-	valueTypeHelpers.cpp
+	ValueTypeHelpers.cpp
 	visible.c
 	VMAccess.cpp
 	vmbootlib.c
diff --git a/runtime/vm/ValueTypeHelpers.cpp b/runtime/vm/ValueTypeHelpers.cpp
new file mode 100644
index 00000000000..c793b4c1fb7
--- /dev/null
+++ b/runtime/vm/ValueTypeHelpers.cpp
@@ -0,0 +1,200 @@
+/*******************************************************************************
+ * Copyright (c) 2019, 2020 IBM Corp. and others
+ *
+ * This program and the accompanying materials are made available under
+ * the terms of the Eclipse Public License 2.0 which accompanies this
+ * distribution and is available at https://www.eclipse.org/legal/epl-2.0/
+ * or the Apache License, Version 2.0 which accompanies this distribution and
+ * is available at https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * This Source Code may also be made available under the following
+ * Secondary Licenses when the conditions for such availability set
+ * forth in the Eclipse Public License, v. 2.0 are satisfied: GNU
+ * General Public License, version 2 with the GNU Classpath
+ * Exception [1] and GNU General Public License, version 2 with the
+ * OpenJDK Assembly Exception [2].
+ *
+ * [1] https://www.gnu.org/software/classpath/license.html
+ * [2] http://openjdk.java.net/legal/assembly-exception.html
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0 WITH Classpath-exception-2.0 OR LicenseRef-GPL-2.0 WITH Assembly-exception
+ *******************************************************************************/
+
+#include "ValueTypeHelpers.hpp"
+
+#include "j9.h"
+#include "ut_j9vm.h"
+#include "ObjectAccessBarrierAPI.hpp"
+
+/*
+ * Determine if the two valueTypes are substitutable when rhs.class equals lhs.class
+ * and rhs and lhs are not null
+ *
+ * @param[in] lhs the lhs object address
+ * @param[in] rhs the rhs object address
+ * @param[in] startOffset the initial offset for the object
+ * @param[in] clazz the value type class
+ * return true if they are substitutable and false otherwise
+ */
+bool
+VM_ValueTypeHelpers::isSubstitutable(J9VMThread *currentThread, MM_ObjectAccessBarrierAPI objectAccessBarrier, j9object_t lhs, j9object_t rhs, UDATA startOffset, J9Class *clazz)
+{
+#if defined(J9VM_OPT_VALHALLA_VALUE_TYPES)
+	J9JavaVM *vm = currentThread->javaVM;
+	U_32 walkFlags = J9VM_FIELD_OFFSET_WALK_INCLUDE_INSTANCE;
+	J9ROMFieldOffsetWalkState state;
+	J9ROMFieldOffsetWalkResult *result = fieldOffsetsStartDo(vm, clazz->romClass, VM_VMHelpers::getSuperclass(clazz), &state, walkFlags, clazz->flattenedClassCache);
+	bool rc = true;
+
+	Assert_VM_notNull(lhs);
+	Assert_VM_notNull(rhs);
+	Assert_VM_true(J9OBJECT_CLAZZ(currentThread, lhs) == J9OBJECT_CLAZZ(currentThread, rhs));
+
+	/* If J9ClassCanSupportFastSubstitutability is set, we can use the barrier version of memcmp,
+	 * else we recursively check the fields manually. */
+	if (J9_ARE_ALL_BITS_SET(clazz->classFlags, J9ClassCanSupportFastSubstitutability)) {
+		rc = objectAccessBarrier.structuralFlattenedCompareObjects(currentThread, clazz, lhs, rhs, startOffset);
+	} else {
+		while (NULL != result->field) {
+			J9UTF8 *signature = J9ROMNAMEANDSIGNATURE_SIGNATURE(&result->field->nameAndSignature);
+			U_8 *sigChar = J9UTF8_DATA(signature);
+
+			switch (*sigChar) {
+			case 'Z': /* boolean */
+			case 'B': /* byte */
+			case 'C': /* char */
+			case 'I': /* int */
+			case 'S': { /* short */
+				I_32 lhsValue = objectAccessBarrier.inlineMixedObjectReadI32(currentThread, lhs, startOffset + result->offset);
+				I_32 rhsValue = objectAccessBarrier.inlineMixedObjectReadI32(currentThread, rhs, startOffset + result->offset);
+				if (lhsValue != rhsValue) {
+					rc = false;
+					goto done;
+				}
+				break;
+			}
+			case 'J': { /* long */
+				I_64 lhsValue = objectAccessBarrier.inlineMixedObjectReadI64(currentThread, lhs, startOffset + result->offset);
+				I_64 rhsValue = objectAccessBarrier.inlineMixedObjectReadI64(currentThread, rhs, startOffset + result->offset);
+				if (lhsValue != rhsValue) {
+					rc = false;
+					goto done;
+				}
+				break;
+			}
+			case 'D': { /* double */
+				U_64 lhsValue = objectAccessBarrier.inlineMixedObjectReadU64(currentThread, lhs, startOffset + result->offset);
+				U_64 rhsValue = objectAccessBarrier.inlineMixedObjectReadU64(currentThread, rhs, startOffset + result->offset);
+
+				if (!checkDoubleEquality(lhsValue, rhsValue)) {
+					rc = false;
+					goto done;
+				}
+				break;
+			}
+			case 'F': { /* float */
+				U_32 lhsValue = objectAccessBarrier.inlineMixedObjectReadU32(currentThread, lhs, startOffset + result->offset);
+				U_32 rhsValue = objectAccessBarrier.inlineMixedObjectReadU32(currentThread, rhs, startOffset + result->offset);
+
+				if (!checkFloatEquality(lhsValue, rhsValue)) {
+					rc = false;
+					goto done;
+				}
+				break;
+			}
+			case '[': { /* Array */
+				j9object_t lhsObject = objectAccessBarrier.inlineMixedObjectReadObject(currentThread, lhs, startOffset + result->offset);
+				j9object_t rhsObject = objectAccessBarrier.inlineMixedObjectReadObject(currentThread, rhs, startOffset + result->offset);
+				if (lhsObject != rhsObject) {
+					rc = false;
+					goto done;
+				}
+				break;
+			}
+			case 'L': { /* Nullable class type or interface type */
+				j9object_t lhsObject = objectAccessBarrier.inlineMixedObjectReadObject(currentThread, lhs, startOffset + result->offset);
+				j9object_t rhsObject = objectAccessBarrier.inlineMixedObjectReadObject(currentThread, rhs, startOffset + result->offset);
+
+				if (!VM_ValueTypeHelpers::acmp(currentThread, objectAccessBarrier, lhsObject, rhsObject)) {
+					rc = false;
+					goto done;
+				}
+				break;
+			}
+			case 'Q': { /* Null-free class type */
+				J9Class *fieldClass = findJ9ClassInFlattenedClassCache(clazz->flattenedClassCache, sigChar + 1, J9UTF8_LENGTH(signature) - 2);
+				rc = false;
+
+				if (J9_IS_J9CLASS_FLATTENED(fieldClass)) {
+					rc = isSubstitutable(currentThread, objectAccessBarrier, lhs, rhs, startOffset + result->offset, fieldClass);
+				} else {
+					j9object_t lhsFieldObject = objectAccessBarrier.inlineMixedObjectReadObject(currentThread, lhs, startOffset + result->offset);
+					j9object_t rhsFieldObject = objectAccessBarrier.inlineMixedObjectReadObject(currentThread, rhs, startOffset + result->offset);
+
+					if (lhsFieldObject == rhsFieldObject) {
+						rc = true;
+					} else {
+						/* When unflattened, we get our object from the specified offset, then increment past the header to the first field. */
+						rc = isSubstitutable(currentThread, objectAccessBarrier, lhsFieldObject, rhsFieldObject, J9VMTHREAD_OBJECT_HEADER_SIZE(currentThread), fieldClass);
+					}
+				}
+
+				if (false == rc) {
+					goto done;
+				}
+				break;
+			}
+			default:
+				Assert_VM_unreachable();
+			} /* switch */
+
+			result = fieldOffsetsNextDo(&state);
+		}
+	}
+
+done:
+	return rc;
+#else /* defined(J9VM_OPT_VALHALLA_VALUE_TYPES) */
+	Assert_VM_unreachable();
+	return true;
+#endif /* defined(J9VM_OPT_VALHALLA_VALUE_TYPES) */
+}
+
+extern "C" {
+void
+defaultValueWithUnflattenedFlattenables(J9VMThread *currentThread, J9Class *clazz, j9object_t instance)
+{
+        J9FlattenedClassCacheEntry * entry = NULL;
+        J9Class * entryClazz = NULL;
+        UDATA length = clazz->flattenedClassCache->numberOfEntries;
+        UDATA const objectHeaderSize = J9VMTHREAD_OBJECT_HEADER_SIZE(currentThread);
+        for (UDATA index = 0; index < length; index++) {
+                entry = J9_VM_FCC_ENTRY_FROM_CLASS(clazz, index);
+                entryClazz = entry->clazz;
+                if (J9_ARE_NO_BITS_SET(J9ClassIsFlattened, entryClazz->classFlags)) {
+                        if (entry->offset == UDATA_MAX) {
+                                J9Class *definingClass = NULL;
+                                J9ROMFieldShape *field = NULL;
+                                J9ROMFieldShape *entryField = entry->field;
+                                J9UTF8 *name = J9ROMFIELDSHAPE_NAME(entryField);
+                                J9UTF8 *signature = J9ROMFIELDSHAPE_SIGNATURE(entryField);
+                                entry->offset = instanceFieldOffset(currentThread, clazz, J9UTF8_DATA(name), J9UTF8_LENGTH(name), J9UTF8_DATA(signature), J9UTF8_LENGTH(signature), &definingClass, (UDATA *)&field, 0);
+                                Assert_VM_notNull(field);
+                        }
+                        MM_ObjectAccessBarrierAPI objectAccessBarrier(currentThread);
+                        objectAccessBarrier.inlineMixedObjectStoreObject(currentThread, 
+                                                                                instance, 
+                                                                                entry->offset + objectHeaderSize, 
+                                                                                entryClazz->flattenedClassCache->defaultValue, 
+                                                                                false);
+                }
+        }
+}
+
+BOOLEAN
+valueTypeCapableAcmp(J9VMThread *currentThread, j9object_t lhs, j9object_t rhs)
+{
+	MM_ObjectAccessBarrierAPI objectAccessBarrier(currentThread);
+	return VM_ValueTypeHelpers::acmp(currentThread, objectAccessBarrier, lhs, rhs);
+}
+} /* extern "C" */
diff --git a/runtime/vm/ValueTypeHelpers.hpp b/runtime/vm/ValueTypeHelpers.hpp
new file mode 100644
index 00000000000..92ca2b89e05
--- /dev/null
+++ b/runtime/vm/ValueTypeHelpers.hpp
@@ -0,0 +1,99 @@
+/*******************************************************************************
+ * Copyright (c) 2019, 2020 IBM Corp. and others
+ *
+ * This program and the accompanying materials are made available under
+ * the terms of the Eclipse Public License 2.0 which accompanies this
+ * distribution and is available at https://www.eclipse.org/legal/epl-2.0/
+ * or the Apache License, Version 2.0 which accompanies this distribution and
+ * is available at https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * This Source Code may also be made available under the following
+ * Secondary Licenses when the conditions for such availability set
+ * forth in the Eclipse Public License, v. 2.0 are satisfied: GNU
+ * General Public License, version 2 with the GNU Classpath
+ * Exception [1] and GNU General Public License, version 2 with the
+ * OpenJDK Assembly Exception [2].
+ *
+ * [1] https://www.gnu.org/software/classpath/license.html
+ * [2] http://openjdk.java.net/legal/assembly-exception.html
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0 WITH Classpath-exception-2.0 OR LicenseRef-GPL-2.0 WITH Assembly-exception
+ *******************************************************************************/
+
+#if !defined(VALUETYPEHELPERS_HPP_)
+#define VALUETYPEHELPERS_HPP_
+
+#include "j9.h"
+#include "fltconst.h"
+
+#include "ObjectAccessBarrierAPI.hpp"
+#include "VMHelpers.hpp"
+
+class VM_ValueTypeHelpers {
+	/*
+	 * Data members
+	 */
+private:
+
+protected:
+
+public:
+
+	/*
+	 * Function members
+	 */
+private:
+	static bool
+	isSubstitutable(J9VMThread *currentThread, MM_ObjectAccessBarrierAPI objectAccessBarrier, j9object_t lhs, j9object_t rhs, UDATA startOffset, J9Class *clazz);
+
+	static VMINLINE bool
+	checkDoubleEquality(U_64 a, U_64 b)
+	{
+		bool result = false;
+
+		if (a == b) {
+			result = true;
+		} else if (IS_NAN_DBL(*(jdouble*)&a) && IS_NAN_DBL(*(jdouble*)&b)) {
+			result = true;
+		}
+		return result;
+	}
+
+	static VMINLINE bool
+	checkFloatEquality(U_32 a, U_32 b)
+	{
+		bool result = false;
+
+		if (a == b) {
+			result = true;
+		} else if (IS_NAN_SNGL(*(jfloat*)&a) && IS_NAN_SNGL(*(jfloat*)&b)) {
+			result = true;
+		}
+		return result;
+	}
+protected:
+
+public:
+	static VMINLINE bool
+	acmp(J9VMThread *currentThread, MM_ObjectAccessBarrierAPI objectAccessBarrier, j9object_t lhs, j9object_t rhs)
+	{
+		bool acmpResult = (rhs == lhs);
+#if defined(J9VM_OPT_VALHALLA_VALUE_TYPES)
+		if (!acmpResult) {
+			if ((NULL != rhs) && (NULL != lhs)) {
+				J9Class * lhsClass = J9OBJECT_CLAZZ(_currentThread, lhs);
+				J9Class * rhsClass = J9OBJECT_CLAZZ(_currentThread, rhs);
+				if (J9_IS_J9CLASS_VALUETYPE(lhsClass)
+					&& (rhsClass == lhsClass)
+				) {
+					acmpResult = VM_ValueTypeHelpers::isSubstitutable(currentThread, objectAccessBarrier, lhs, rhs, J9VMTHREAD_OBJECT_HEADER_SIZE(currentThread), lhsClass);
+				}
+			}
+		}
+#endif /* J9VM_OPT_VALHALLA_VALUE_TYPES */
+		return acmpResult;
+	}
+
+};
+
+#endif /* VALUETYPEHELPERS_HPP_ */
diff --git a/runtime/vm/jvminit.c b/runtime/vm/jvminit.c
index 79929fe9688..4360baa4d8d 100644
--- a/runtime/vm/jvminit.c
+++ b/runtime/vm/jvminit.c
@@ -5888,6 +5888,14 @@ protectedInitializeJavaVM(J9PortLibrary* portLibrary, void * userData)
 	}
 #endif
 
+#if defined(J9VM_OPT_METHOD_HANDLE)
+	/* Enable i2j MethodHandle transitions by default */
+	vm->extendedRuntimeFlags |= J9_EXTENDED_RUNTIME_I2J_MH_TRANSITION_ENABLED;
+#endif
+
+	/* Default to using lazy in all but realtime */
+	vm->extendedRuntimeFlags |= J9_EXTENDED_RUNTIME_LAZY_SYMBOL_RESOLUTION;
+
 	/* Scans cmd-line arguments in order */
 	if (JNI_OK != processVMArgsFromFirstToLast(vm)) {
 		goto error;
@@ -6046,14 +6054,6 @@ protectedInitializeJavaVM(J9PortLibrary* portLibrary, void * userData)
 	if (JNI_OK != modifyDllLoadTable(vm, vm->dllLoadTable, vm->vmArgsArray)) {
 		goto error;
 	}
-	
-#if defined(J9VM_OPT_METHOD_HANDLE)
-	/* Enable i2j MethodHandle transitions by default */
-	vm->extendedRuntimeFlags |= J9_EXTENDED_RUNTIME_I2J_MH_TRANSITION_ENABLED;
-#endif
-
-	/* Default to using lazy in all but realtime */
-	vm->extendedRuntimeFlags |= J9_EXTENDED_RUNTIME_LAZY_SYMBOL_RESOLUTION;
 
 #if !defined(WIN32)
 	if (J9_ARE_ANY_BITS_SET(vm->extendedRuntimeFlags,J9_EXTENDED_RUNTIME_HANDLE_SIGXFSZ)) {
diff --git a/runtime/vm/valueTypeHelpers.cpp b/runtime/vm/valueTypeHelpers.cpp
deleted file mode 100644
index 089f71bc2e7..00000000000
--- a/runtime/vm/valueTypeHelpers.cpp
+++ /dev/null
@@ -1,83 +0,0 @@
-/*******************************************************************************
- * Copyright (c) 2019, 2020 IBM Corp. and others
- *
- * This program and the accompanying materials are made available under
- * the terms of the Eclipse Public License 2.0 which accompanies this
- * distribution and is available at https://www.eclipse.org/legal/epl-2.0/
- * or the Apache License, Version 2.0 which accompanies this distribution and
- * is available at https://www.apache.org/licenses/LICENSE-2.0.
- *
- * This Source Code may also be made available under the following
- * Secondary Licenses when the conditions for such availability set
- * forth in the Eclipse Public License, v. 2.0 are satisfied: GNU
- * General Public License, version 2 with the GNU Classpath
- * Exception [1] and GNU General Public License, version 2 with the
- * OpenJDK Assembly Exception [2].
- *
- * [1] https://www.gnu.org/software/classpath/license.html
- * [2] http://openjdk.java.net/legal/assembly-exception.html
- *
- * SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0 WITH Classpath-exception-2.0 OR LicenseRef-GPL-2.0 WITH Assembly-exception
- *******************************************************************************/
-
-#include "j9.h"
-#include "ut_j9vm.h"
-#include "ObjectAccessBarrierAPI.hpp"
-#include "valueTypeHelpers.hpp"
-
-extern "C" {
-void
-defaultValueWithUnflattenedFlattenables(J9VMThread *currentThread, J9Class *clazz, j9object_t instance)
-{
-        J9FlattenedClassCacheEntry * entry = NULL;
-        J9Class * entryClazz = NULL;
-        UDATA length = clazz->flattenedClassCache->numberOfEntries;
-        UDATA const objectHeaderSize = J9VMTHREAD_OBJECT_HEADER_SIZE(currentThread);
-        for (UDATA index = 0; index < length; index++) {
-                entry = J9_VM_FCC_ENTRY_FROM_CLASS(clazz, index);
-                entryClazz = entry->clazz;
-                if (J9_ARE_NO_BITS_SET(J9ClassIsFlattened, entryClazz->classFlags)) {
-                        if (entry->offset == UDATA_MAX) {
-                                J9Class *definingClass = NULL;
-                                J9ROMFieldShape *field = NULL;
-                                J9ROMFieldShape *entryField = entry->field;
-                                J9UTF8 *name = J9ROMFIELDSHAPE_NAME(entryField);
-                                J9UTF8 *signature = J9ROMFIELDSHAPE_SIGNATURE(entryField);
-                                entry->offset = instanceFieldOffset(currentThread, clazz, J9UTF8_DATA(name), J9UTF8_LENGTH(name), J9UTF8_DATA(signature), J9UTF8_LENGTH(signature), &definingClass, (UDATA *)&field, 0);
-                                Assert_VM_notNull(field);
-                        }
-                        MM_ObjectAccessBarrierAPI objectAccessBarrier(currentThread);
-                        objectAccessBarrier.inlineMixedObjectStoreObject(currentThread, 
-                                                                                instance, 
-                                                                                entry->offset + objectHeaderSize, 
-                                                                                entryClazz->flattenedClassCache->defaultValue, 
-                                                                                false);
-                }
-        }
-}
-
-BOOLEAN
-valueTypeCapableAcmp(J9VMThread *currentThread, j9object_t lhs, j9object_t rhs)
-{
-#if defined(J9VM_OPT_VALHALLA_VALUE_TYPES)
-		bool acmpResult = false;
-		if (rhs == lhs) {
-			acmpResult = true;
-		} else {
-			if ((NULL != rhs) && (NULL != lhs)) {
-				J9Class * lhsClass = J9OBJECT_CLAZZ(_currentThread, lhs);
-				J9Class * rhsClass = J9OBJECT_CLAZZ(_currentThread, rhs);
-				if ((J9_IS_J9CLASS_VALUETYPE(rhsClass)
-					&& J9_IS_J9CLASS_VALUETYPE(lhsClass))
-					&& (rhsClass == lhsClass)
-				) {
-					acmpResult = ValueTypeHelpers::isSubstitutable(currentThread, lhs, rhs, J9VMTHREAD_OBJECT_HEADER_SIZE(_currentThread), lhsClass);
-				}
-			}
-		}
-		return acmpResult;
-#else /* J9VM_OPT_VALHALLA_VALUE_TYPES */
-		return (rhs == lhs);
-#endif /* J9VM_OPT_VALHALLA_VALUE_TYPES */
-}
-} /* extern "C" */
diff --git a/runtime/vm/valueTypeHelpers.hpp b/runtime/vm/valueTypeHelpers.hpp
deleted file mode 100644
index 9e47c6c9944..00000000000
--- a/runtime/vm/valueTypeHelpers.hpp
+++ /dev/null
@@ -1,52 +0,0 @@
-/*******************************************************************************
- * Copyright (c) 2020, 2020 IBM Corp. and others
- *
- * This program and the accompanying materials are made available under
- * the terms of the Eclipse Public License 2.0 which accompanies this
- * distribution and is available at https://www.eclipse.org/legal/epl-2.0/
- * or the Apache License, Version 2.0 which accompanies this distribution and
- * is available at https://www.apache.org/licenses/LICENSE-2.0.
- *
- * This Source Code may also be made available under the following
- * Secondary Licenses when the conditions for such availability set
- * forth in the Eclipse Public License, v. 2.0 are satisfied: GNU
- * General Public License, version 2 with the GNU Classpath
- * Exception [1] and GNU General Public License, version 2 with the
- * OpenJDK Assembly Exception [2].
- *
- * [1] https://www.gnu.org/software/classpath/license.html
- * [2] http://openjdk.java.net/legal/assembly-exception.html
- *
- * SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0 WITH Classpath-exception-2.0 OR LicenseRef-GPL-2.0 WITH Assembly-exception
- *******************************************************************************/
-
-#if !defined(VALUETYPEHELPERS_HPP_)
-#define VALUETYPEHELPERS_HPP_
-
-class ValueTypeHelpers {
-	/*
-	 * Data members
-	 */
-private:
-
-protected:
-
-public:
-
-	/*
-	 * Function members
-	 */
-private:
-
-protected:
-
-public:
-	static bool
-	isSubstitutable(J9VMThread *currentThread, j9object_t lhs, j9object_t rhs, UDATA startOffset, J9Class *clazz)
-	{
-		return false;
-	}
-
-};
-
-#endif /* VALUETYPEHELPERS_HPP_ */
diff --git a/test/functional/DDR_Test/playlist.xml b/test/functional/DDR_Test/playlist.xml
index 751ca92c61a..99ef07f4233 100644
--- a/test/functional/DDR_Test/playlist.xml
+++ b/test/functional/DDR_Test/playlist.xml
@@ -46,7 +46,7 @@ SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0 WITH Classpath-excepti
 	-Dtest.list=$(Q)TestDDRExtensionGeneral$(Q) -DADDITIONALEXPORTS=$(ADDEXPORTS_JDKASM_UNNAMED) -f $(Q)$(TEST_RESROOT)$(D)tck_ddrext.xml$(Q); \
 	$(TEST_STATUS)</command>
 		<!-- temporarily disable this test on z/OS; github.com/eclipse/openj9/issues/1511 -->
-		<platformRequirements>^os.zos,^arch.aarch64</platformRequirements>
+		<platformRequirements>^os.zos</platformRequirements>
 		<levels>
 			<level>extended</level>
 		</levels>
@@ -82,7 +82,7 @@ SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0 WITH Classpath-excepti
 	-Dtest.list=$(Q)TestCallsites$(Q) -DADDITIONALEXPORTS=$(ADDEXPORTS_JDKASM_UNNAMED) -f $(Q)$(TEST_RESROOT)$(D)tck_ddrext.xml$(Q); \
 	$(TEST_STATUS)</command>
 		<!-- temporarily disable this test on z/OS; github.com/eclipse/openj9/issues/1511 -->
-		<platformRequirements>^os.zos,^arch.aarch64</platformRequirements>
+		<platformRequirements>^os.zos</platformRequirements>
 		<levels>
 			<level>extended</level>
 		</levels>
@@ -118,7 +118,7 @@ SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0 WITH Classpath-excepti
 	-Dtest.list=$(Q)TestJITExt$(Q) -DADDITIONALEXPORTS=$(ADDEXPORTS_JDKASM_UNNAMED) -DEXTRADUMPOPT=$(Q)-Xjit:count=0$(Q) -f $(Q)$(TEST_RESROOT)$(D)tck_ddrext.xml$(Q); \
 	$(TEST_STATUS)</command>
 		<!-- temporarily disable this test on z/OS; github.com/eclipse/openj9/issues/1511 -->
-		<platformRequirements>^os.zos,^arch.aarch64</platformRequirements>
+		<platformRequirements>^os.zos</platformRequirements>
 		<levels>
 			<level>extended</level>
 		</levels>
diff --git a/test/functional/JIT_Test/playlist.xml b/test/functional/JIT_Test/playlist.xml
index 8a25b29267a..4fe5fb9f7a8 100644
--- a/test/functional/JIT_Test/playlist.xml
+++ b/test/functional/JIT_Test/playlist.xml
@@ -511,7 +511,7 @@
 		-cp $(Q)$(RESOURCES_DIR)$(P)$(TESTNG)$(P)$(TEST_RESROOT)$(D)jitt.jar$(Q) \
 		-DSERVER_EXE=$(Q)$(TEST_JDK_BIN)$(D)jitserver$(Q) \
 		-DCLIENT_EXE=$(JAVA_COMMAND) \
-		-DCLIENT_PROGRAM=$(SQ)$(JVM_OPTIONS) -cp $(RESOURCES_DIR)$(P)$(TESTNG)$(P)$(TEST_RESROOT)$(D)jitt.jar -DjarTesterArgs=$(TEST_RESROOT)$(D)jitt.jar org.testng.TestNG -d $(REPORTDIR)$(D)client $(TEST_RESROOT)$(D)testng.xml -testnames JarTesterTest -groups $(TEST_GROUP) -excludegroups $(DEFAULT_EXCLUDE)$(SQ) \
+		-DCLIENT_PROGRAM=$(SQ)$(JVM_OPTIONS) -cp $(RESOURCES_DIR)$(P)$(TESTNG)$(P)$(TEST_RESROOT)$(D)jitt.jar -DjarTesterArgs=$(Q)-loopforever $(TEST_RESROOT)$(D)jitt.jar$(Q) org.testng.TestNG -d $(REPORTDIR)$(D)client $(TEST_RESROOT)$(D)testng.xml -testnames JarTesterTest -groups $(TEST_GROUP) -excludegroups $(DEFAULT_EXCLUDE)$(SQ) \
 		org.testng.TestNG \
 		-d $(REPORTDIR) \
 		$(Q)$(TEST_RESROOT)$(D)testng.xml$(Q) \
@@ -523,7 +523,6 @@
 		echo $(Q)$(TEST_JDK_BIN)$(D)jitserver doesn't exist; assuming this JDK does not support JITServer and trivially passing the test.$(Q); \
 	fi; \
 	$(TEST_STATUS)</command>
-		<disabled>https://github.com/eclipse/openj9/issues/8806</disabled>
 		<platformRequirements>os.linux,arch.x86,bits.64</platformRequirements>
 		<levels>
 			<level>sanity</level>
diff --git a/test/functional/JIT_Test/src/jit/test/jar/ZipTester.java b/test/functional/JIT_Test/src/jit/test/jar/ZipTester.java
index 99ada9e786c..5049be8c8ee 100644
--- a/test/functional/JIT_Test/src/jit/test/jar/ZipTester.java
+++ b/test/functional/JIT_Test/src/jit/test/jar/ZipTester.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2001, 2018 IBM Corp. and others
+ * Copyright (c) 2001, 2020 IBM Corp. and others
  *
  * This program and the accompanying materials are made available under
  * the terms of the Eclipse Public License 2.0 which accompanies this
@@ -37,11 +37,16 @@
  */
 public class ZipTester {
 	private static Logger logger = Logger.getLogger(ZipTester.class);
-	public static final String CLASS_FILTER_TAG = "-class:";
+	public static final String TAG_PREFIX = "-";
+	public static final String LOOP_FOREVER_TAG = TAG_PREFIX + "loopforever";
+	public static final String CLASS_FILTER_TAG = TAG_PREFIX + "class:";
 	public static final String CLASS_FILTER_SUBSTRING = "substring";
 	public static final String CLASS_FILTER =
 		CLASS_FILTER_TAG + CLASS_FILTER_SUBSTRING;
 	public static final String ZIP_NAMES = "zip1 zip2 ...";
+	public static final String LOOP_FOREVER_HELPER =
+		LOOP_FOREVER_TAG
+			+ " --> loop forever (until the JVM is terminated)";
 	public static final String CLASS_FILTER_HELPER =
 		CLASS_FILTER
 			+ " --> load classes whose names contain "
@@ -53,23 +58,31 @@ public class ZipTester {
 	public static void main(String args[]) {
 		new ZipTester().run(args);
 	}
-	
+
 	public void run(String args[]) {
 		if (args.length < 1 || args[0].isEmpty()) {
 			printUsageText();
 			Assert.fail();
 		}
 
-		String classFilter = args[0];
+		String classFilter = "";
+		boolean loopForever = false;
 		int zipFilenameIndex = 0;
-		if (!classFilter.startsWith(CLASS_FILTER_TAG))
-			classFilter = "";
-		else {
-			classFilter = classFilter.substring(CLASS_FILTER_TAG.length());
-			zipFilenameIndex = 1;
+
+		while (args[zipFilenameIndex].startsWith(TAG_PREFIX)) {
+			if (args[zipFilenameIndex].startsWith(CLASS_FILTER_TAG))
+				classFilter = classFilter.substring(CLASS_FILTER_TAG.length());
+			else if (args[zipFilenameIndex].equals(LOOP_FOREVER_TAG))
+				loopForever = true;
+			zipFilenameIndex++;
 		}
 
-		process(classFilter, args, zipFilenameIndex);
+		if (loopForever)
+			logger.info(LOOP_FOREVER_TAG + " was specified; test will run continuously until the JVM is terminated.");
+
+		do {
+			process(classFilter, args, zipFilenameIndex);
+		} while (loopForever);
 	}
 
 	public String getClassName() {
@@ -123,6 +136,7 @@ protected String getGenericCommandline() {
 	}
 
 	protected void printGenericCommandlineExplanation() {
+		logger.debug("\t" + LOOP_FOREVER_HELPER);
 		logger.debug("\t" + CLASS_FILTER_HELPER);
 		logger.debug("\t" + JAR_NAMES_HELPER);
 	}
diff --git a/test/functional/JIT_Test/src/jit/test/jitserver/JITServerTest.java b/test/functional/JIT_Test/src/jit/test/jitserver/JITServerTest.java
index 32fdddfed20..650c9deef55 100644
--- a/test/functional/JIT_Test/src/jit/test/jitserver/JITServerTest.java
+++ b/test/functional/JIT_Test/src/jit/test/jitserver/JITServerTest.java
@@ -25,6 +25,7 @@
 import java.util.Random;
 import java.util.concurrent.TimeUnit;
 import java.util.Scanner;
+import java.util.ArrayList;
 import java.io.File;
 import java.io.IOException;
 import java.io.FileNotFoundException;
@@ -79,8 +80,15 @@ public class JITServerTest {
 			logger.info("Chose random port for server: " + randomPort + ", set " + SERVER_PORT_ENV_VAR_NAME + " in your env to override.");
 		}
 
-		clientBuilder = new ProcessBuilder(String.join(" ", CLIENT_EXE, "-XX:+UseJITServer", portOption, CLIENT_PROGRAM).split(" +"));
-		serverBuilder = new ProcessBuilder(String.join(" ", SERVER_EXE, portOption).split(" +"));
+		// This handy regex pattern uses positive lookahead to match a string containing either zero or an even number of " (double quote) characters.
+		// If a character is followed by this pattern it means that the character itself is not in a quoted string, otherwise it would be followed by
+		// an odd number of " characters. Note that this doesn't handle ' (single quote) characters.
+		final String QUOTES_LOOKAHEAD_PATTERN = "(?=([^\"]*\"[^\"]*\")*[^\"]*$)";
+		// We want to split the client program string on whitespace, unless the space appears in a quoted string.
+		final String SPLIT_ARGS_PATTERN = "\\s+" + QUOTES_LOOKAHEAD_PATTERN;
+		clientBuilder = new ProcessBuilder(stripQuotesFromEachArg(String.join(" ", CLIENT_EXE, "-XX:+UseJITServer", portOption, CLIENT_PROGRAM).split(SPLIT_ARGS_PATTERN)));
+		serverBuilder = new ProcessBuilder(stripQuotesFromEachArg(String.join(" ", SERVER_EXE, portOption).split(SPLIT_ARGS_PATTERN)));
+
 		// Redirect stderr to stdout, one log for each of the client and server is sufficient.
 		clientBuilder.redirectErrorStream(true);
 		serverBuilder.redirectErrorStream(true);
@@ -89,14 +97,23 @@ public class JITServerTest {
 		serverBuilder.environment().compute("TR_Options", (k, v) -> v != null && !v.isEmpty() ? String.join(",", v, JIT_LOG_ENV_OPTION) : JIT_LOG_ENV_OPTION);
 	}
 
+	private static String[] stripQuotesFromEachArg(String[] args) {
+		for (int i = 0; i < args.length; ++i) {
+			args[i] = args[i].replaceAll("\"", "");
+		}
+		return args;
+	}
+
 	private static void dumpProcessLog(final ProcessBuilder b) {
 		File log = b.redirectOutput().file();
 		try {
+			final String topAndBottom = "////////////////////////////////////////////////////////////////////////";
+			final String leftMargin = "//// ";
 			Scanner s = new Scanner(log);
-			System.err.println("Dumping the contents of log file: " + log.getAbsolutePath() + "\n");
+			System.err.println("Dumping the contents of log file: " + log.getAbsolutePath() + "\n" + topAndBottom);
 			while (s.hasNextLine())
-				System.err.println(s.nextLine());
-			System.err.println("");
+				System.err.println(leftMargin + s.nextLine());
+			System.err.println(topAndBottom);
 		}
 		catch (FileNotFoundException e) {
 			System.err.println("Attempted to dump the log file '" + log.getAbsolutePath() + "' but it was not found.\n" + e.getMessage());
@@ -117,21 +134,26 @@ private static void destroyAndCheckProcess(final Process p, final ProcessBuilder
 
 		// The process may exit normally before we can destroy it so we have to accept two possible return values.
 		if ((exitValue != SUCCESS_RETURN_VALUE) && (exitValue != SIGTERM_RETURN_VALUE)) {
-			System.err.println("Expected a return value of " + SUCCESS_RETURN_VALUE + " or " + SIGTERM_RETURN_VALUE + ", got " + exitValue + " instead.");
+			final String errorText = "Expected an exit value of " + SUCCESS_RETURN_VALUE + " or " + SIGTERM_RETURN_VALUE + ", got " + exitValue + " instead.";
+			System.err.println(errorText);
 			dumpProcessLog(builder);
-			AssertJUnit.fail();
+			AssertJUnit.fail(errorText);
 		}
 	}
 
 	private static Process startProcess(final ProcessBuilder builder, final String name) throws IOException, InterruptedException {
-		logger.info("Starting " + name + " with command line:\n" + String.join(" ", builder.command()));
+		// Wrap any arguments containing whitespace in quotes for display (we have to make a copy of ProcessBuilder.command() to avoid modifying our PB's commands).
+		ArrayList<String> command = new ArrayList<String>(builder.command());
+		command.replaceAll(s -> s.matches("\\S+") ? s : "\"" + s + "\"");
+		logger.info("Starting " + name + " with command line:\n" + String.join(" ", command));
 		logger.info("With stdout/stderr redirected to:\n" + builder.redirectOutput().file().getAbsolutePath());
 		final Process p = builder.start();
 		// We expect these processes to be fairly long running; if they exit almost immediately abort the test.
 		if (p.waitFor(PROCESS_START_WAIT_TIME_MS, TimeUnit.MILLISECONDS)) {
-			System.err.println("Failed to start " + name);
+			final String errorText = "Failed to properly start " + name + ", it terminated prematurely with exit value: " + p.exitValue();
+			System.err.println(errorText);
 			dumpProcessLog(builder);
-			AssertJUnit.fail();
+			AssertJUnit.fail(errorText);
 		}
 		return p;
 	}
diff --git a/test/functional/JLM_Tests/playlist.xml b/test/functional/JLM_Tests/playlist.xml
index 64780d3e681..0ec0cc86520 100644
--- a/test/functional/JLM_Tests/playlist.xml
+++ b/test/functional/JLM_Tests/playlist.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 
 <!--
-  Copyright (c) 2016, 2019 IBM Corp. and others
+  Copyright (c) 2016, 2020 IBM Corp. and others
 
   This program and the accompanying materials are made available under
   the terms of the Eclipse Public License 2.0 which accompanies this
@@ -1343,7 +1343,8 @@
 	-groups $(TEST_GROUP) \
 	-excludegroups $(DEFAULT_EXCLUDE); \
 	$(TEST_STATUS)</command>
-		<platformRequirements>^os.zos,bits.64</platformRequirements>
+		<!-- Temporarily disable this test on AArch64; github.com/eclipse/openj9/issues/8967 -->
+		<platformRequirements>^os.zos,bits.64,^arch.aarch64</platformRequirements>
 		<levels>
 			<level>extended</level>
 		</levels>
diff --git a/test/functional/Valhalla/src/org/openj9/test/lworld/ValueTypeTests.java b/test/functional/Valhalla/src/org/openj9/test/lworld/ValueTypeTests.java
index 1a218e7c9aa..b8bc0303457 100644
--- a/test/functional/Valhalla/src/org/openj9/test/lworld/ValueTypeTests.java
+++ b/test/functional/Valhalla/src/org/openj9/test/lworld/ValueTypeTests.java
@@ -569,41 +569,372 @@ static public void testWithFieldOnNonExistentClass() throws Throwable {
 		} catch (NoClassDefFoundError e) {}
 	}
 
-	/*
-	 * TODO: behaviour of the test between two valueTypes will depend on the new spec(not finalized)
-	 * 
-	 * Test ifacmp on value class
-	 * 
-	 * class TestIfacmpOnValueClass {}
-	 *
-	 *
-	 *	@Test(priority=2)
-	 *	static public void TestIfacmpOnValueClass() throws Throwable {
-	 *	int x = 0;
-	 *	int y = 0;
-	 *
-	 *	Object valueType = makePoint2D.invoke(x, y);
-	 *	Object refType = (Object) x;
-	 *
-	 *	Assert.assertFalse((valueType == refType), "An identity (==) comparison that contains a valueType should always return false");
-	 *
-	 *	Assert.assertFalse((refType == valueType), "An identity (==) comparison that contains a valueType should always return false");
-	 *
-	 *	Assert.assertFalse((valueType == valueType), "An identity (==) comparison that contains a valueType should always return false");
-	 *
-	 *	Assert.assertTrue((refType == refType), "An identity (==) comparison on the same refType should always return true");
-	 *
-	 *	Assert.assertTrue((valueType != refType), "An identity (!=) comparison that contains a valueType should always return true");
-	 *
-	 *	Assert.assertTrue((refType != valueType), "An identity (!=) comparison that contains a valueType should always return true");
-	 *
-	 *	Assert.assertTrue((valueType != valueType), "An identity (!=) comparison that contains a valueType should always return true");
-	 *
-	 *	Assert.assertFalse((refType != refType), "An identity (!=) comparison on the same refType should always return false");
-	 *	}
-	 */
+	
+	@Test(priority=2)
+	static public void testBasicACMPTestOnIdentityTypes() throws Throwable {
+		
+		Object identityType1 = new String();
+		Object identityType2 = new String();
+		Object nullPointer = null;
+		
+		/* sanity test on identity classes */
+		Assert.assertTrue((identityType1 == identityType1), "An identity (==) comparison on the same identityType should always return true");
+		
+		Assert.assertFalse((identityType2 == identityType1), "An identity (==) comparison on different identityTypes should always return false");
+		
+		Assert.assertFalse((identityType2 == nullPointer), "An identity (==) comparison on different identityTypes should always return false");
+		
+		Assert.assertTrue((nullPointer == nullPointer), "An identity (==) comparison on the same identityType should always return true");
+		
+		Assert.assertFalse((identityType1 != identityType1), "An identity (!=) comparison on the same identityType should always return false");
+		
+		Assert.assertTrue((identityType2 != identityType1), "An identity (!=) comparison on different identityTypes should always return true");
+		
+		Assert.assertTrue((identityType2 != nullPointer), "An identity (!=) comparison on different identityTypes should always return true");
+		
+		Assert.assertFalse((nullPointer != nullPointer), "An identity (!=) comparison on the same identityType should always return false");
+		
+	}
+	
+	@Test(priority=2)
+	static public void testBasicACMPTestOnValueTypes() throws Throwable {
+		Object valueType1 = makePoint2D.invoke(1, 2);
+		Object valueType2 = makePoint2D.invoke(1, 2);
+		Object newValueType = makePoint2D.invoke(2, 1);
+		Object identityType = new String();
+		Object nullPointer = null;
+		
+		Assert.assertTrue((valueType1 == valueType1), "A substitutability (==) test on the same value should always return true");
+		
+		Assert.assertTrue((valueType1 == valueType2), "A substitutability (==) test on different value the same contents should always return true");
+		
+		Assert.assertFalse((valueType1 == newValueType), "A substitutability (==) test on different value should always return false");
+		
+		Assert.assertFalse((valueType1 == identityType), "A substitutability (==) test on different value with identity type should always return false");
+		
+		Assert.assertFalse((valueType1 == nullPointer), "A substitutability (==) test on different value with null pointer should always return false");
+		
+		Assert.assertFalse((valueType1 != valueType1), "A substitutability (!=) test on the same value should always return false");
+		
+		Assert.assertFalse((valueType1 != valueType2), "A substitutability (!=) test on different value the same contents should always return false");
+		
+		Assert.assertTrue((valueType1 != newValueType), "A substitutability (!=) test on different value should always return true");
+		
+		Assert.assertTrue((valueType1 != identityType), "A substitutability (!=) test on different value with identity type should always return true");
+		
+		Assert.assertTrue((valueType1 != nullPointer), "A substitutability (!=) test on different value with null pointer should always return true");
+	}
+	
+	@Test(priority=4)
+	static public void testACMPTestOnFastSubstitutableValueTypes() throws Throwable {
+		Object valueType1 = createTriangle2D(defaultTrianglePositions);
+		Object valueType2 = createTriangle2D(defaultTrianglePositions);
+		Object newValueType = createTriangle2D(defaultTrianglePositionsNew);
+		Object identityType = new String();
+		Object nullPointer = null;
+		
+		Assert.assertTrue((valueType1 == valueType1), "A substitutability (==) test on the same value should always return true");
+		
+		Assert.assertTrue((valueType1 == valueType2), "A substitutability (==) test on different value the same contents should always return true");
+		
+		Assert.assertFalse((valueType1 == newValueType), "A substitutability (==) test on different value should always return false");
+		
+		Assert.assertFalse((valueType1 == identityType), "A substitutability (==) test on different value with identity type should always return false");
+		
+		Assert.assertFalse((valueType1 == nullPointer), "A substitutability (==) test on different value with null pointer should always return false");
+		
+		Assert.assertFalse((valueType1 != valueType1), "A substitutability (!=) test on the same value should always return false");
+		
+		Assert.assertFalse((valueType1 != valueType2), "A substitutability (!=) test on different value the same contents should always return false");
+		
+		Assert.assertTrue((valueType1 != newValueType), "A substitutability (!=) test on different value should always return true");
+		
+		Assert.assertTrue((valueType1 != identityType), "A substitutability (!=) test on different value with identity type should always return true");
+		
+		Assert.assertTrue((valueType1 != nullPointer), "A substitutability (!=) test on different value with null pointer should always return true");
+	}
+	
+	@Test(priority=3)
+	static public void testACMPTestOnFastSubstitutableValueTypesVer2() throws Throwable {
+		/* these VTs will have array refs */
+		String fields[] = {"x:I", "y:I", "z:I", "arr:[Ljava/lang/Object;"};
+		Class<?> fastSubVT = ValueTypeGenerator.generateValueClass("FastSubVT", fields);
+		
+		MethodHandle makeFastSubVT = lookup.findStatic(fastSubVT, "makeValue", MethodType.methodType(fastSubVT, int.class, int.class, int.class, Object[].class));
+		
+		Object[] arr = {"foo", "bar", "baz"};
+		Object[] arr2 = {"foozo", "barzo", "bazzo"};
+		Object valueType1 = makeFastSubVT.invoke(1, 2, 3, arr);
+		Object valueType2 = makeFastSubVT.invoke(1, 2, 3, arr);
+		Object newValueType = makeFastSubVT.invoke(3, 2, 1, arr2);
+		Object identityType = new String();
+		Object nullPointer = null;
+		
+		Assert.assertTrue((valueType1 == valueType1), "A substitutability (==) test on the same value should always return true");
+		
+		Assert.assertTrue((valueType1 == valueType2), "A substitutability (==) test on different value the same contents should always return true");
+		
+		Assert.assertFalse((valueType1 == newValueType), "A substitutability (==) test on different value should always return false");
+		
+		Assert.assertFalse((valueType1 == identityType), "A substitutability (==) test on different value with identity type should always return false");
+		
+		Assert.assertFalse((valueType1 == nullPointer), "A substitutability (==) test on different value with null pointer should always return false");
+		
+		Assert.assertFalse((valueType1 != valueType1), "A substitutability (!=) test on the same value should always return false");
+		
+		Assert.assertFalse((valueType1 != valueType2), "A substitutability (!=) test on different value the same contents should always return false");
+		
+		Assert.assertTrue((valueType1 != newValueType), "A substitutability (!=) test on different value should always return true");
+		
+		Assert.assertTrue((valueType1 != identityType), "A substitutability (!=) test on different value with identity type should always return true");
+		
+		Assert.assertTrue((valueType1 != nullPointer), "A substitutability (!=) test on different value with null pointer should always return true");
+	}
+	
+	@Test(priority=3)
+	static public void testACMPTestOnRecursiveValueTypes() throws Throwable {
+		String fields[] = {"l:J", "next:Ljava/lang/Object;", "i:I"};
+		Class<?> nodeClass = ValueTypeGenerator.generateValueClass("Node", fields);
+		MethodHandle makeNode = lookup.findStatic(nodeClass, "makeValue", MethodType.methodType(nodeClass, long.class, Object.class, int.class));
+		
+		Object list1 = makeNode.invoke(3, null, 3);
+		Object list2 = makeNode.invoke(3, null, 3);
+		Object list3sameAs1 = makeNode.invoke(3, null, 3);
+		Object list4 = makeNode.invoke(3, null, 3);
+		Object list5null = makeNode.invoke(3, null, 3);
+		Object list6null = makeNode.invoke(3, null, 3);
+		Object list7obj = makeNode.invoke(3, new Object(), 3);
+		Object list8str = makeNode.invoke(3, "foo", 3);
+		Object identityType = new String();
+		Object nullPointer = null;
+		
+		for (int i = 0; i < 100; i++) {
+			list1 = makeNode.invoke(3, list1, i);
+			list2 = makeNode.invoke(3, list2, i + 1);
+			list3sameAs1 = makeNode.invoke(3, list3sameAs1, i);
+		}
+		for (int i = 0; i < 50; i++) {
+			list4 = makeNode.invoke(3, list4, i);
+		}
+		
+		Assert.assertTrue((list1 == list1), "A substitutability (==) test on the same value should always return true");
+		
+		Assert.assertTrue((list5null == list5null), "A substitutability (==) test on the same value should always return true");
+		
+		Assert.assertTrue((list1 == list3sameAs1), "A substitutability (==) test on different value the same contents should always return true");
+		
+		Assert.assertTrue((list5null == list6null), "A substitutability (==) test on different value the same contents should always return true");
+		
+		Assert.assertFalse((list1 == list2), "A substitutability (==) test on different value should always return false");
+		
+		Assert.assertFalse((list1 == list4), "A substitutability (==) test on different value should always return false");
+		
+		Assert.assertFalse((list1 == list5null), "A substitutability (==) test on different value should always return false");
+		
+		Assert.assertFalse((list1 == list7obj), "A substitutability (==) test on different value should always return false");
+		
+		Assert.assertFalse((list1 == list8str), "A substitutability (==) test on different value should always return false");
+		
+		Assert.assertFalse((list7obj == list8str), "A substitutability (==) test on different value should always return false");
+		
+		Assert.assertFalse((list1 == identityType), "A substitutability (==) test on different value with identity type should always return false");
+		
+		Assert.assertFalse((list1 == nullPointer), "A substitutability (==) test on different value with null pointer should always return false");
+		
+		Assert.assertFalse((list1 != list1), "A substitutability (!=) test on the same value should always return false");
+		
+		Assert.assertFalse((list5null != list5null), "A substitutability (!=) test on the same value should always return false");
+		
+		Assert.assertFalse((list1 != list3sameAs1), "A substitutability (!=) test on different value the same contents should always return false");
+		
+		Assert.assertFalse((list5null != list6null), "A substitutability (!=) test on different value the same contents should always return false");
+		
+		Assert.assertTrue((list1 != list2), "A substitutability (!=) test on different value should always return true");
+		
+		Assert.assertTrue((list1 != list4), "A substitutability (!=) test on different value should always return true");
+		
+		Assert.assertTrue((list1 != list5null), "A substitutability (!=) test on different value should always return true");
+		
+		Assert.assertTrue((list1 != list7obj), "A substitutability (!=) test on different value should always return true");
+		
+		Assert.assertTrue((list1 != list8str), "A substitutability (!=) test on different value should always return true");
+		
+		Assert.assertTrue((list7obj != list8str), "A substitutability (!=) test on different value should always return true");
+		
+		Assert.assertTrue((list1 != identityType), "A substitutability (!=) test on different value with identity type should always return true");
+		
+		Assert.assertTrue((list1 != nullPointer), "A substitutability (!=) test on different value with null pointer should always return true");
+		
+	}
+	
+	@Test(priority=3)
+	static public void testACMPTestOnValueFloat() throws Throwable {
+		Object float1 = makeValueFloat.invoke(1.1f);
+		Object float2 = makeValueFloat.invoke(-1.1f);
+		Object float3 = makeValueFloat.invoke(12341.112341234f);
+		Object float4sameAs1 = makeValueFloat.invoke(1.1f);
+		Object nan = makeValueFloat.invoke(Float.NaN);
+		Object nan2 = makeValueFloat.invoke(Float.NaN);
+		Object positiveZero = makeValueFloat.invoke(0.0f);
+		Object negativeZero = makeValueFloat.invoke(-0.0f);
+		Object positiveInfinity = makeValueFloat.invoke(Float.POSITIVE_INFINITY);
+		Object negativeInfinity = makeValueFloat.invoke(Float.NEGATIVE_INFINITY);
+		
+		Assert.assertTrue((float1 == float1), "A substitutability (==) test on the same value should always return true");
+
+		Assert.assertTrue((float1 == float4sameAs1), "A substitutability (==) test on different value the same contents should always return true");
+
+		Assert.assertTrue((nan == nan2), "A substitutability (==) test on different value the same contents should always return true");
+
+		Assert.assertFalse((float1 == float2), "A substitutability (==) test on different value should always return false");
+
+		Assert.assertFalse((float1 == float3), "A substitutability (==) test on different value should always return false");
+
+		Assert.assertFalse((float1 == nan), "A substitutability (==) test on different value should always return false");
+
+		Assert.assertFalse((float1 == positiveZero), "A substitutability (==) test on different value should always return false");
+
+		Assert.assertFalse((float1 == negativeZero), "A substitutability (==) test on different value should always return false");
+
+		Assert.assertFalse((float1 == positiveInfinity), "A substitutability (==) test on different value should always return false");
+
+		Assert.assertFalse((float1 == negativeInfinity), "A substitutability (==) test on different value should always return false");
+
+		Assert.assertFalse((positiveInfinity == negativeInfinity), "A substitutability (==) test on different value should always return false");
+
+		Assert.assertFalse((positiveZero == negativeZero), "A substitutability (==) test on different value should always return false");
+
+		Assert.assertFalse((float1 != float1), "A substitutability (!=) test on the same value should always return false");
+				
+		Assert.assertFalse((float1 != float4sameAs1), "A substitutability (!=) test on different value the same contents should always return false");
+		
+		Assert.assertFalse((nan != nan2), "A substitutability (!=) test on different value the same contents should always return false");
+
+		Assert.assertTrue((float1 != float2), "A substitutability (!=) test on different value should always return true");
+		
+		Assert.assertTrue((float1 != float3), "A substitutability (!=) test on different value should always return true");
+
+		Assert.assertTrue((float1 != nan), "A substitutability (!=) test on different value should always return true");
+
+		Assert.assertTrue((float1 != positiveZero), "A substitutability (!=) test on different value should always return true");
+
+		Assert.assertTrue((float1 != negativeZero), "A substitutability (!=) test on different value should always return true");
+
+		Assert.assertTrue((float1 != positiveInfinity), "A substitutability (!=) test on different value should always return true");
+
+		Assert.assertTrue((float1 != negativeInfinity), "A substitutability (!=) test on different value should always return true");
+
+		Assert.assertTrue((positiveInfinity != negativeInfinity), "A substitutability (!=) test on different value should always return true");
+
+		Assert.assertTrue((positiveZero != negativeZero), "A substitutability (!=) test on different value should always return true");
+			
+	}
+
+	@Test(priority=3)
+	static public void testACMPTestOnValueDouble() throws Throwable {
+		Object double1 = makeValueDouble.invoke(1.1d);
+		Object double2 = makeValueDouble.invoke(-1.1d);
+		Object double3 = makeValueDouble.invoke(12341.112341234d);
+		Object double4sameAs1 = makeValueDouble.invoke(1.1d);
+		Object nan = makeValueDouble.invoke(Double.NaN);
+		Object nan2 = makeValueDouble.invoke(Double.NaN);
+		Object positiveZero = makeValueDouble.invoke(0.0f);
+		Object negativeZero = makeValueDouble.invoke(-0.0f);
+		Object positiveInfinity = makeValueDouble.invoke(Double.POSITIVE_INFINITY);
+		Object negativeInfinity = makeValueDouble.invoke(Double.NEGATIVE_INFINITY);
+		
+		Assert.assertTrue((double1 == double1), "A substitutability (==) test on the same value should always return true");
+
+		Assert.assertTrue((double1 == double4sameAs1), "A substitutability (==) test on different value the same contents should always return true");
 
-    /*    
+		Assert.assertTrue((nan == nan2), "A substitutability (==) test on different value the same contents should always return true");
+
+		Assert.assertFalse((double1 == double2), "A substitutability (==) test on different value should always return false");
+
+		Assert.assertFalse((double1 == double3), "A substitutability (==) test on different value should always return false");
+
+		Assert.assertFalse((double1 == nan), "A substitutability (==) test on different value should always return false");
+
+		Assert.assertFalse((double1 == positiveZero), "A substitutability (==) test on different value should always return false");
+
+		Assert.assertFalse((double1 == negativeZero), "A substitutability (==) test on different value should always return false");
+
+		Assert.assertFalse((double1 == positiveInfinity), "A substitutability (==) test on different value should always return false");
+
+		Assert.assertFalse((double1 == negativeInfinity), "A substitutability (==) test on different value should always return false");
+
+		Assert.assertFalse((positiveInfinity == negativeInfinity), "A substitutability (==) test on different value should always return false");
+
+		Assert.assertFalse((positiveZero == negativeZero), "A substitutability (==) test on different value should always return false");
+
+		Assert.assertFalse((double1 != double1), "A substitutability (!=) test on the same value should always return false");
+				
+		Assert.assertFalse((double1 != double4sameAs1), "A substitutability (!=) test on different value the same contents should always return false");
+		
+		Assert.assertFalse((nan != nan2), "A substitutability (!=) test on different value the same contents should always return false");
+
+		Assert.assertTrue((double1 != double2), "A substitutability (!=) test on different value should always return true");
+		
+		Assert.assertTrue((double1 != double3), "A substitutability (!=) test on different value should always return true");
+
+		Assert.assertTrue((double1 != nan), "A substitutability (!=) test on different value should always return true");
+
+		Assert.assertTrue((double1 != positiveZero), "A substitutability (!=) test on different value should always return true");
+
+		Assert.assertTrue((double1 != negativeZero), "A substitutability (!=) test on different value should always return true");
+
+		Assert.assertTrue((double1 != positiveInfinity), "A substitutability (!=) test on different value should always return true");
+
+		Assert.assertTrue((double1 != negativeInfinity), "A substitutability (!=) test on different value should always return true");
+
+		Assert.assertTrue((positiveInfinity != negativeInfinity), "A substitutability (!=) test on different value should always return true");
+
+		Assert.assertTrue((positiveZero != negativeZero), "A substitutability (!=) test on different value should always return true");
+	}
+	
+	@Test(priority=6)
+	static public void testACMPTestOnAssortedValues() throws Throwable {
+		Object assortedValueWithLongAlignment = createAssorted(makeAssortedValueWithLongAlignment, typeWithLongAlignmentFields);
+		Object assortedValueWithLongAlignment2 = createAssorted(makeAssortedValueWithLongAlignment, typeWithLongAlignmentFields);
+		Object assortedValueWithLongAlignment3 = createAssorted(makeAssortedValueWithLongAlignment, typeWithLongAlignmentFields);
+		assortedValueWithLongAlignment3 = checkFieldAccessMHOfAssortedType(assortedValueWithLongAlignmentGetterAndWither, assortedValueWithLongAlignment3, typeWithLongAlignmentFields, true);
+		
+		Object assortedValueWithObjectAlignment = createAssorted(makeAssortedValueWithObjectAlignment, typeWithObjectAlignmentFields);
+		Object assortedValueWithObjectAlignment2 = createAssorted(makeAssortedValueWithObjectAlignment, typeWithObjectAlignmentFields);
+		Object assortedValueWithObjectAlignment3 = createAssorted(makeAssortedValueWithObjectAlignment, typeWithObjectAlignmentFields);
+		assortedValueWithObjectAlignment3 = checkFieldAccessMHOfAssortedType(assortedValueWithObjectAlignmentGetterAndWither, assortedValueWithObjectAlignment3, typeWithObjectAlignmentFields, true);
+		
+		Assert.assertTrue((assortedValueWithLongAlignment == assortedValueWithLongAlignment), "A substitutability (==) test on the same value should always return true");
+
+		Assert.assertTrue((assortedValueWithObjectAlignment == assortedValueWithObjectAlignment), "A substitutability (==) test on the same value should always return true");
+		
+		Assert.assertTrue((assortedValueWithLongAlignment == assortedValueWithLongAlignment2), "A substitutability (==) test on different value the same contents should always return true");
+
+		Assert.assertTrue((assortedValueWithObjectAlignment == assortedValueWithObjectAlignment2), "A substitutability (==) test on different value the same contents should always return true");
+
+		Assert.assertFalse((assortedValueWithLongAlignment == assortedValueWithLongAlignment3), "A substitutability (==) test on different value should always return false");
+
+		Assert.assertFalse((assortedValueWithLongAlignment == assortedValueWithObjectAlignment), "A substitutability (==) test on different value should always return false");
+
+		Assert.assertFalse((assortedValueWithObjectAlignment == assortedValueWithObjectAlignment3), "A substitutability (==) test on different value should always return false");
+
+		Assert.assertFalse((assortedValueWithLongAlignment != assortedValueWithLongAlignment), "A substitutability (!=) test on the same value should always return false");
+		
+		Assert.assertFalse((assortedValueWithObjectAlignment != assortedValueWithObjectAlignment), "A substitutability (!=) test on the same value should always return false");
+				
+		Assert.assertFalse((assortedValueWithLongAlignment != assortedValueWithLongAlignment2), "A substitutability (!=) test on different value the same contents should always return false");
+		
+		Assert.assertFalse((assortedValueWithObjectAlignment != assortedValueWithObjectAlignment2), "A substitutability (!=) test on different value the same contents should always return false");
+
+		Assert.assertTrue((assortedValueWithLongAlignment != assortedValueWithLongAlignment3), "A substitutability (!=) test on different value the same contents should always return false");
+
+		Assert.assertTrue((assortedValueWithLongAlignment != assortedValueWithObjectAlignment), "A substitutability (!=) test on different value the same contents should always return false");
+
+		Assert.assertTrue((assortedValueWithObjectAlignment != assortedValueWithObjectAlignment3), "A substitutability (!=) test on different value the same contents should always return false");
+
+	}
+	
+	/*
 	 * Test monitorEnter on valueType
 	 * 
 	 * class TestMonitorEnterOnValueType {
@@ -1916,7 +2247,7 @@ static void initializeStaticFields(Class clazz, MethodHandle[][] getterAndSetter
 		}
 	}
 
-	static void checkFieldAccessMHOfAssortedType(MethodHandle[][] fieldAccessMHs, Object instance, String[] fields,
+	static Object checkFieldAccessMHOfAssortedType(MethodHandle[][] fieldAccessMHs, Object instance, String[] fields,
 			boolean ifValue)
 			throws Throwable {
 		for (int i = 0; i < fields.length; i++) {
@@ -2017,6 +2348,7 @@ static void checkFieldAccessMHOfAssortedType(MethodHandle[][] fieldAccessMHs, Ob
 				break;
 			}
 		}
+		return instance;
 	}
 
 	static void checkFieldAccessMHOfStaticType(MethodHandle[][] fieldAccessMHs, String[] fields)
diff --git a/test/functional/cmdLineTests/callsitedbgddrext/playlist.xml b/test/functional/cmdLineTests/callsitedbgddrext/playlist.xml
index 2559f32df9f..65ef9b74c04 100644
--- a/test/functional/cmdLineTests/callsitedbgddrext/playlist.xml
+++ b/test/functional/cmdLineTests/callsitedbgddrext/playlist.xml
@@ -92,7 +92,7 @@ SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0 WITH Classpath-excepti
 	-config $(Q)$(TEST_RESROOT)$(D)callsiteddrtests.xml$(Q) -plats all,$(PLATFORM),$(VARIATION) -nonZeroExitWhenError; \
 	${TEST_STATUS}</command>
 		<!-- temporarily disable this test on z/OS; github.com/eclipse/openj9/issues/1511 -->
-		<platformRequirements>^os.zos,^arch.aarch64</platformRequirements>
+		<platformRequirements>^os.zos</platformRequirements>
 		<levels>
 			<level>sanity</level>
 		</levels>
diff --git a/test/functional/cmdLineTests/classesdbgddrext/playlist.xml b/test/functional/cmdLineTests/classesdbgddrext/playlist.xml
index f032eca516a..14afc36b3af 100644
--- a/test/functional/cmdLineTests/classesdbgddrext/playlist.xml
+++ b/test/functional/cmdLineTests/classesdbgddrext/playlist.xml
@@ -64,7 +64,7 @@ SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0 WITH Classpath-excepti
 	-xlist $(Q)$(TEST_RESROOT)$(D)dbgextddrtests_excludes.xml$(Q) -nonZeroExitWhenError; \
 	${TEST_STATUS}</command>
 		<!-- j9ddr.jar is not supported on z/OS; OpenJ9 issue 1511 -->
-		<platformRequirements>^os.zos,^arch.aarch64</platformRequirements>
+		<platformRequirements>^os.zos</platformRequirements>
 		<levels>
 			<level>extended</level>
 		</levels>
diff --git a/test/functional/cmdLineTests/modularityddrtests/playlist.xml b/test/functional/cmdLineTests/modularityddrtests/playlist.xml
index ee27b92be9b..f56883a2867 100644
--- a/test/functional/cmdLineTests/modularityddrtests/playlist.xml
+++ b/test/functional/cmdLineTests/modularityddrtests/playlist.xml
@@ -39,7 +39,7 @@ SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0 WITH Classpath-excepti
 	-outputLimit 1000 -explainExcludes -nonZeroExitWhenError; \
 	${TEST_STATUS}</command>
 		<!-- Tests excluded on zos because it does not support DDR yet. Please see https://github.com/eclipse/openj9/issues/1511 for updates -->
-		<platformRequirements>^os.zos,^arch.aarch64</platformRequirements>
+		<platformRequirements>^os.zos</platformRequirements>
 		<levels>
 			<level>extended</level>
 		</levels>
diff --git a/test/functional/cmdLineTests/shrcdbgddrext/playlist.xml b/test/functional/cmdLineTests/shrcdbgddrext/playlist.xml
index 1fb1b81bd2b..7f39b3ec44d 100644
--- a/test/functional/cmdLineTests/shrcdbgddrext/playlist.xml
+++ b/test/functional/cmdLineTests/shrcdbgddrext/playlist.xml
@@ -40,7 +40,7 @@ SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0 WITH Classpath-excepti
 	-config $(Q)$(TEST_RESROOT)$(D)shrcdbgextddrtests.xml$(Q) -plats all,$(PLATFORM),$(VARIATION) -nonZeroExitWhenError; \
 	${TEST_STATUS}</command>
 		<!-- temporarily disable this test on z/OS; github.com/eclipse/openj9/issues/1511 -->
-		<platformRequirements>^os.zos,^arch.aarch64</platformRequirements>
+		<platformRequirements>^os.zos</platformRequirements>
 		<levels>
 			<level>extended</level>
 		</levels>