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fix(compiler): shrink merged live range after erasing coalesced COPYs #392

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Merged
zoowii merged 2 commits into from
Mar 13, 2026
Merged

fix(compiler): shrink merged live range after erasing coalesced COPYs #392

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fix(compiler): shrink merged live range after erasing coalesced COPYs…
cmgCr Mar 6, 2026
8d1c903
ci: remove auto-assign workflow
cmgCr Mar 13, 2026
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19 changes: 0 additions & 19 deletions .github/workflows/auto-assign.yml
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13 changes: 8 additions & 5 deletions src/compiler/cgir/pass/register_coalescer.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -2226,10 +2226,11 @@ class JoinVals {
/// Erase any machine instructions that have been coalesced away.
/// Add erased instructions to ErasedInstrs.
/// Add foreign virtual registers to ShrinkRegs if their live range ended at
/// the erased instrs.
/// the erased instrs. Set ShrinkMainRange when erasing a COPY whose source
/// is part of the coalesced pair, so the merged interval gets shrunk.
void eraseInstrs(SmallPtrSetImpl<CgInstruction *> &ErasedInstrs,
SmallVectorImpl<CgRegister> &ShrinkRegs,
CgLiveInterval *LI = nullptr);
bool &ShrinkMainRange, CgLiveInterval *LI = nullptr);

/// Remove liverange defs at places where implicit defs will be removed.
void removeImplicitDefs();
Expand Down Expand Up @@ -3019,7 +3020,7 @@ void JoinVals::removeImplicitDefs() {

void JoinVals::eraseInstrs(SmallPtrSetImpl<CgInstruction *> &ErasedInstrs,
SmallVectorImpl<CgRegister> &ShrinkRegs,
CgLiveInterval *LI) {
bool &ShrinkMainRange, CgLiveInterval *LI) {
for (unsigned i = 0, e = LR.getNumValNums(); i != e; ++i) {
// Get the def location before markUnused() below invalidates it.
CgVNInfo *VNI = LR.getValNumInfo(i);
Expand Down Expand Up @@ -3101,6 +3102,8 @@ void JoinVals::eraseInstrs(SmallPtrSetImpl<CgInstruction *> &ErasedInstrs,
if (Register::isVirtualRegister(Reg) && Reg != CP.getSrcReg() &&
Reg != CP.getDstReg())
ShrinkRegs.push_back(Reg);
else if (Register::isVirtualRegister(Reg) && MI->allDefsAreDead())
ShrinkMainRange = true;
}
ErasedInstrs.insert(MI);
LLVM_DEBUG(dbgs() << "\t\terased:\t" << Def << '\t' << *MI);
Expand Down Expand Up @@ -3294,8 +3297,8 @@ bool CgRegisterCoalescer::joinVirtRegs(CgCoalescerPair &CP) {
// Erase COPY and IMPLICIT_DEF instructions. This may cause some external
// registers to require trimming.
SmallVector<CgRegister, 8> ShrinkRegs;
LHSVals.eraseInstrs(ErasedInstrs, ShrinkRegs, &LHS);
RHSVals.eraseInstrs(ErasedInstrs, ShrinkRegs);
LHSVals.eraseInstrs(ErasedInstrs, ShrinkRegs, ShrinkMainRange, &LHS);
RHSVals.eraseInstrs(ErasedInstrs, ShrinkRegs, ShrinkMainRange);
while (!ShrinkRegs.empty())
shrinkToUses(&LIS->getInterval(ShrinkRegs.pop_back_val()));

Expand Down
21 changes: 21 additions & 0 deletions tests/wast/spec_extra/coalescer_if_local_tee.wast
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Original file line number Diff line number Diff line change
@@ -0,0 +1,21 @@
(module
(type (;0;) (func (result f64)))
(type (;1;) (func (result i64)))
(func (;0;) (type 0) (result f64)
(local f64)
i32.const 1
if ;; label = @1
end
call 1
local.get 0
local.set 0
drop
f64.const 0x0p+0 (;=0;)
local.tee 0
local.get 0
i32.trunc_f64_u
drop)
(func (;1;) (type 1) (result i64)
i64.const 1)
(export "to_test" (func 0)))
(assert_return (invoke "to_test") (f64.const 0))
16 changes: 16 additions & 0 deletions tests/wast/spec_extra/coalescer_memory_grow_local_tee.wast
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Original file line number Diff line number Diff line change
@@ -0,0 +1,16 @@
(module
(type (;0;) (func (param i32) (result i64)))
(type (;1;) (func (result i64)))
(func (;0;) (type 1) (result i64)
(local i32)
i32.const -1812402867
memory.grow
local.get 0
local.set 0
local.tee 0
drop
local.get 0
i64.load32_u offset=55218920 align=1)
(memory (;0;) 1)
(export "to_test" (func 0)))
(assert_trap (invoke "to_test") "out of bounds memory access")
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