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| author | Simon Pilgrim <llvm-dev@redking.me.uk> | 2019-01-12 16:38:56 +0000 |
|---|---|---|
| committer | Simon Pilgrim <llvm-dev@redking.me.uk> | 2019-01-12 16:38:56 +0000 |
| commit | a0069ba0dbe797ae18354cdd00d84e40f68fb97d (patch) | |
| tree | 030852d4727ccd7ae0995559513d330a9493cdd7 /llvm/lib/Target/X86/X86ISelLowering.cpp | |
| parent | 63a6f3acbd80c602647a2f37aabd2a5c2967094f (diff) | |
| download | bcm5719-llvm-a0069ba0dbe797ae18354cdd00d84e40f68fb97d.tar.gz bcm5719-llvm-a0069ba0dbe797ae18354cdd00d84e40f68fb97d.zip | |
[X86] More aggressive shuffle mask widening in combineExtractWithShuffle
Use demanded extract index to set most of the shuffle mask to undef, making it easier to widen and peek through.
llvm-svn: 351013
Diffstat (limited to 'llvm/lib/Target/X86/X86ISelLowering.cpp')
| -rw-r--r-- | llvm/lib/Target/X86/X86ISelLowering.cpp | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp index 06802aac81e..843d2875832 100644 --- a/llvm/lib/Target/X86/X86ISelLowering.cpp +++ b/llvm/lib/Target/X86/X86ISelLowering.cpp @@ -33691,6 +33691,15 @@ static SDValue combineExtractWithShuffle(SDNode *N, SelectionDAG &DAG, scaleShuffleMask<int>(Scale, Mask, ScaledMask); Mask = std::move(ScaledMask); } else if ((Mask.size() % NumSrcElts) == 0) { + // Simplify Mask based on demanded element. + int ExtractIdx = (int)N->getConstantOperandVal(1); + int Scale = Mask.size() / NumSrcElts; + int Lo = Scale * ExtractIdx; + int Hi = Scale * (ExtractIdx + 1); + for (int i = 0, e = (int)Mask.size(); i != e; ++i) + if (i < Lo || Hi <= i) + Mask[i] = SM_SentinelUndef; + SmallVector<int, 16> WidenedMask; while (Mask.size() > NumSrcElts && canWidenShuffleElements(Mask, WidenedMask)) |
