[llvm] 59d8d13 - [X86] getTargetShuffleInputs - check that the source inputs are all the right size.

[Simon Pilgrim via llvm-commits]

Author: Simon Pilgrim
Date: 2020-02-24T16:26:10Z
New Revision: 59d8d13c7ba3e7bc06afcb20ed535523c1ed47ce

URL: https://github.com/llvm/llvm-project/commit/59d8d13c7ba3e7bc06afcb20ed535523c1ed47ce
DIFF: https://github.com/llvm/llvm-project/commit/59d8d13c7ba3e7bc06afcb20ed535523c1ed47ce.diff

LOG: [X86] getTargetShuffleInputs - check that the source inputs are all the right size.

I'm hoping to begin improving shuffle combining across different vector sizes, but before that we must ensure that all existing getTargetShuffleInputs calls must bail if the inputs aren't the same size.

Added: 
    

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

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index 859bc97b6210..8e2d60f3bcd0 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -7239,6 +7239,17 @@ static bool getFauxShuffleMask(SDValue N, const APInt &DemandedElts,
         !getTargetShuffleInputs(N1, SrcInputs1, SrcMask1, DAG, Depth + 1,
                                 true))
       return false;
+
+    // Shuffle inputs must be the same size as the result.
+    if (llvm::any_of(SrcInputs0, [VT](SDValue Op) {
+          return VT.getSizeInBits() != Op.getValueSizeInBits();
+        }))
+      return false;
+    if (llvm::any_of(SrcInputs1, [VT](SDValue Op) {
+          return VT.getSizeInBits() != Op.getValueSizeInBits();
+        }))
+      return false;
+
     size_t MaskSize = std::max(SrcMask0.size(), SrcMask1.size());
     SmallVector<int, 64> Mask0, Mask1;
     scaleShuffleMask<int>(MaskSize / SrcMask0.size(), SrcMask0, Mask0);
@@ -7287,6 +7298,13 @@ static bool getFauxShuffleMask(SDValue N, const APInt &DemandedElts,
     if (!getTargetShuffleInputs(peekThroughOneUseBitcasts(Sub), SubInputs,
                                 SubMask, DAG, Depth + 1, ResolveKnownElts))
       return false;
+
+    // Shuffle inputs must be the same size as the subvector.
+    if (llvm::any_of(SubInputs, [SubVT](SDValue Op) {
+          return SubVT.getSizeInBits() != Op.getValueSizeInBits();
+        }))
+      return false;
+
     if (SubMask.size() != NumSubElts) {
       assert(((SubMask.size() % NumSubElts) == 0 ||
               (NumSubElts % SubMask.size()) == 0) && "Illegal submask scale");
@@ -34530,6 +34548,12 @@ static SDValue combineX86ShufflesRecursively(
                               OpZero, DAG, Depth, false))
     return SDValue();
 
+  // Shuffle inputs must be the same size as the result.
+  if (llvm::any_of(OpInputs, [VT](SDValue Op) {
+        return VT.getSizeInBits() != Op.getValueSizeInBits();
+      }))
+    return SDValue();
+
   SmallVector<int, 64> Mask;
   SmallVector<SDValue, 16> Ops;
 
@@ -37687,6 +37711,12 @@ static SDValue combineExtractWithShuffle(SDNode *N, SelectionDAG &DAG,
   if (!getTargetShuffleInputs(SrcBC, Ops, Mask, DAG))
     return SDValue();
 
+  // Shuffle inputs must be the same size as the result.
+  if (llvm::any_of(Ops, [SrcVT](SDValue Op) {
+        return SrcVT.getSizeInBits() != Op.getValueSizeInBits();
+      }))
+    return SDValue();
+
   // Attempt to narrow/widen the shuffle mask to the correct size.
   if (Mask.size() != NumSrcElts) {
     if ((NumSrcElts % Mask.size()) == 0) {