From 0f1ef5a1549e861424a97d1283173492af0b42cc Mon Sep 17 00:00:00 2001
From: Billy Moses <wmoses@google.com>
Date: Thu, 21 May 2026 16:35:55 -0500
Subject: [PATCH] Add sparam

---
 src/llvm/attributes.jl |  4 ++++
 test/sparam.jl         | 17 +++++++++++++++++
 2 files changed, 21 insertions(+)
 create mode 100644 test/sparam.jl

diff --git a/src/llvm/attributes.jl b/src/llvm/attributes.jl
index 29e87aba17..eb96fb163f 100644
--- a/src/llvm/attributes.jl
+++ b/src/llvm/attributes.jl
@@ -1,4 +1,6 @@
 const nofreefns = Set{String}((
+    "jl_f__compute_sparams",
+    "ijl_f__compute_sparams",
     "jl_genericmemory_copyto",
     "jl_get_binding_value_seqcst",
     "ijl_get_binding_value_seqcst",
@@ -215,6 +217,8 @@ const nofreefns = Set{String}((
 ))
 
 const inactivefns = Set{String}((
+    "jl_f__compute_sparams",
+    "ijl_f__compute_sparams",
     
     # The binding lookup is asserted as inactive [e.g. globals are considered constant wrt differentiation]
     # If and when this changes, we need to change that here
diff --git a/test/sparam.jl b/test/sparam.jl
new file mode 100644
index 0000000000..b129c90c36
--- /dev/null
+++ b/test/sparam.jl
@@ -0,0 +1,17 @@
+using Enzyme, Test
+
+dual_type(c::NTuple{N, Float64}) where {N} = Val{N}
+
+function loss(x::Vector{Float64})
+    t = ntuple(_ -> 0.0, length(x))   # NTuple{_A, Float64} where _A — non-inferable N
+    return sum(x) + (dual_type(t) === Val{2} ? 0.0 : 1.0)
+end
+
+@testset "broadcast" begin
+    res = Enzyme.gradient(
+        Enzyme.set_runtime_activity(Enzyme.Reverse),
+        Enzyme.Const(loss),
+        [1.0, 2.0]
+    )[1]
+    @test res ≈ [1.0, 1.0]
+end
\ No newline at end of file