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| author | Igor Kirillov <igor.kirillov@arm.com> | 2024-12-10 16:29:20 +0000 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2024-12-10 16:29:20 +0000 |
| commit | 444e53f675ff490a3023d48e1b809486513e3fd3 (patch) | |
| tree | c0ef0fbe38a8accff4a8ca3cbc6f48ba27dff4d2 /llvm/lib/CodeGen/SelectOptimize.cpp | |
| parent | 4f933277a53d61f7df42e70ec8ec465652019f7f (diff) | |
| download | llvm-444e53f675ff490a3023d48e1b809486513e3fd3.zip llvm-444e53f675ff490a3023d48e1b809486513e3fd3.tar.gz llvm-444e53f675ff490a3023d48e1b809486513e3fd3.tar.bz2 | |
[SelectOpt] Fix incorrect IR for SUB when comparison dependent operand is first (#119362)
Diffstat (limited to 'llvm/lib/CodeGen/SelectOptimize.cpp')
| -rw-r--r-- | llvm/lib/CodeGen/SelectOptimize.cpp | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/llvm/lib/CodeGen/SelectOptimize.cpp b/llvm/lib/CodeGen/SelectOptimize.cpp index 484705ea..2ec5af2d 100644 --- a/llvm/lib/CodeGen/SelectOptimize.cpp +++ b/llvm/lib/CodeGen/SelectOptimize.cpp @@ -806,7 +806,12 @@ void SelectOptimizeImpl::collectSelectGroups(BasicBlock &BB, break; } - for (unsigned Idx = 0; Idx < 2; Idx++) { + // Iterate through operands and find dependant on recognised sign + // extending auxiliary select-like instructions. The operand index does + // not matter for Add and Or. However, for Sub, we can only safely + // transform when the operand is second. + unsigned Idx = BO->getOpcode() == Instruction::Sub ? 1 : 0; + for (; Idx < 2; Idx++) { auto *Op = BO->getOperand(Idx); auto It = SelectInfo.find(Op); if (It != SelectInfo.end() && It->second.IsAuxiliary) { |