[X86] getFauxShuffleMask - OR(BITCAST(SHUFFLE()),BITCAST(SHUFFLE())) patterns should return bitcasted source values #134993
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…patterns should return bitcasted source values Noticed while investigating llvm#133947 regressions - if we peek through bitcasts we can lose track of oneuse/combined nodes Same current codegen as combineX86ShufflesRecursively still peeks through the bitcasts itself, but we will soon handle this consistently as another part of llvm#133947
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@llvm/pr-subscribers-backend-x86 Author: Simon Pilgrim (RKSimon) ChangesNoticed while investigating #133947 regressions - if we peek through bitcasts we can lose track of oneuse/combined nodes in shuffle combining Currently the same codegen as combineX86ShufflesRecursively still peeks through the bitcasts itself, but we will soon handle this consistently as another part of #133947 Full diff: https://github.com/llvm/llvm-project/pull/134993.diff 1 Files Affected:
diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index 47ac1ee571269..53bed634c3cc6 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -6155,8 +6155,8 @@ static bool getFauxShuffleMask(SDValue N, const APInt &DemandedElts,
else
return false;
}
- Ops.push_back(N0);
- Ops.push_back(N1);
+ Ops.push_back(N.getOperand(0));
+ Ops.push_back(N.getOperand(1));
return true;
}
case ISD::CONCAT_VECTORS: {
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Apr 10, 2025
…patterns should return bitcasted source values (llvm#134993) Noticed while investigating llvm#133947 regressions - if we peek through bitcasts we can lose track of oneuse/combined nodes in shuffle combining Currently the same codegen as combineX86ShufflesRecursively still peeks through the bitcasts itself, but we will soon handle this consistently as another part of llvm#133947
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Noticed while investigating #133947 regressions - if we peek through bitcasts we can lose track of oneuse/combined nodes in shuffle combining
Currently the same codegen as combineX86ShufflesRecursively still peeks through the bitcasts itself, but we will soon handle this consistently as another part of #133947