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[CHERI] Disable GlobalMerge for RISCV whenever CHERI is enabled in any form. #142

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Merged
merged 1 commit into from
Apr 30, 2025
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[CHERI] Disable GlobalMerge for RISCV whenever CHERI is enabled in any form. #142

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2 changes: 2 additions & 0 deletions llvm/include/llvm/Target/TargetMachine.h
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Original file line number Diff line number Diff line change
Expand Up @@ -203,6 +203,8 @@ class TargetMachine {
return DL.getPointerSize(DL.getAllocaAddrSpace());
}

bool hasCheriCapabilities() const { return DL.hasCheriCapabilities(); }

/// Reset the target options based on the function's attributes.
// FIXME: Remove TargetOptions that affect per-function code generation
// from TargetMachine.
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8 changes: 4 additions & 4 deletions llvm/lib/Target/RISCV/RISCVTargetMachine.cpp
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Expand Up @@ -510,10 +510,10 @@ bool RISCVPassConfig::addPreISel() {
addPass(createBarrierNoopPass());
}

bool isCheriot =
TM->getTargetTriple().getSubArch() == Triple::RISCV32SubArch_cheriot_v1;
if ((TM->getOptLevel() != CodeGenOptLevel::None && !isCheriot &&
EnableGlobalMerge == cl::BOU_UNSET) ||
// XXX: GlobalMerge is undesirable on CHERI, as it makes the bounds on globals
// excessively loose.
if ((TM->getOptLevel() != CodeGenOptLevel::None &&
!TM->hasCheriCapabilities() && EnableGlobalMerge == cl::BOU_UNSET) ||
EnableGlobalMerge == cl::BOU_TRUE) {
// FIXME: Like AArch64, we disable extern global merging by default due to
// concerns it might regress some workloads. Unlike AArch64, we don't
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