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[RISCV] Move volatile check to isCandidate in VL optimizer. NFC #154685

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Merged
lukel97 merged 1 commit into from
Aug 21, 2025
Merged

[RISCV] Move volatile check to isCandidate in VL optimizer. NFC #154685

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15 changes: 8 additions & 7 deletions llvm/lib/Target/RISCV/RISCVVLOptimizer.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -847,13 +847,7 @@ static bool isSupportedInstr(const MachineInstr &MI) {
case RISCV::VLUXEI32_V:
case RISCV::VLOXEI32_V:
case RISCV::VLUXEI64_V:
case RISCV::VLOXEI64_V: {
for (const MachineMemOperand *MMO : MI.memoperands())
if (MMO->isVolatile())
return false;
return true;
}

case RISCV::VLOXEI64_V:
// Vector Single-Width Integer Add and Subtract
case RISCV::VADD_VI:
case RISCV::VADD_VV:
Expand Down Expand Up @@ -1292,6 +1286,13 @@ bool RISCVVLOptimizer::isCandidate(const MachineInstr &MI) const {
return false;
}

for (const MachineMemOperand *MMO : MI.memoperands()) {
if (MMO->isVolatile()) {
LLVM_DEBUG(dbgs() << "Not a candidate because contains volatile MMO\n");
return false;
}
}

// Some instructions that produce vectors have semantics that make it more
// difficult to determine whether the VL can be reduced. For example, some
// instructions, such as reductions, may write lanes past VL to a scalar
Expand Down