[llvm] 2ceb129 - [X86] Add canScaleShuffleElements helper. NFC.

[Simon Pilgrim via llvm-commits]

Author: Simon Pilgrim
Date: 2024-05-08T17:01:43+01:00
New Revision: 2ceb1291ef3ddb87cb58030cd61d965f4030338f

URL: https://github.com/llvm/llvm-project/commit/2ceb1291ef3ddb87cb58030cd61d965f4030338f
DIFF: https://github.com/llvm/llvm-project/commit/2ceb1291ef3ddb87cb58030cd61d965f4030338f.diff

LOG: [X86] Add canScaleShuffleElements helper. NFC.

Returns true if the shuffle mask can be rescaled to the requested number of elements.

Added: 
    

Modified: 
    llvm/lib/Target/X86/X86ISelLowering.cpp

Removed: 
    


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diff  --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index 3ae68c438aa7..126577a4d59e 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -3738,6 +3738,11 @@ static bool scaleShuffleElements(ArrayRef<int> Mask, unsigned NumDstElts,
   return false;
 }
 
+static bool canScaleShuffleElements(ArrayRef<int> Mask, unsigned NumDstElts) {
+  SmallVector<int, 32> ScaledMask;
+  return scaleShuffleElements(Mask, NumDstElts, ScaledMask);
+}
+
 /// Returns true if Elt is a constant zero or a floating point constant +0.0.
 bool X86::isZeroNode(SDValue Elt) {
   return isNullConstant(Elt) || isNullFPConstant(Elt);
@@ -46684,14 +46689,14 @@ static SDValue combineSetCCMOVMSK(SDValue EFLAGS, X86::CondCode &CC,
   // To address this, we check that we can scale the shuffle mask to MOVMSK
   // element width (this will ensure "high" elements match). Its slightly overly
   // conservative, but fine for an edge case fold.
-  SmallVector<int, 32> ShuffleMask, ScaledMaskUnused;
+  SmallVector<int, 32> ShuffleMask;
   SmallVector<SDValue, 2> ShuffleInputs;
   if (NumElts <= CmpBits &&
       getTargetShuffleInputs(peekThroughBitcasts(Vec), ShuffleInputs,
                              ShuffleMask, DAG) &&
       ShuffleInputs.size() == 1 && isCompletePermute(ShuffleMask) &&
       ShuffleInputs[0].getValueSizeInBits() == VecVT.getSizeInBits() &&
-      scaleShuffleElements(ShuffleMask, NumElts, ScaledMaskUnused)) {
+      canScaleShuffleElements(ShuffleMask, NumElts)) {
     SDLoc DL(EFLAGS);
     SDValue Result = DAG.getBitcast(VecVT, ShuffleInputs[0]);
     Result = DAG.getNode(X86ISD::MOVMSK, DL, MVT::i32, Result);