[llvm] fa0aff6 - Revert "[X86][SSE] isHorizontalBinOp - use getTargetShuffleInputs helper"

[Nico Weber via llvm-commits]

Author: Nico Weber
Date: 2021-04-02T09:55:55-04:00
New Revision: fa0aff6d6960e3ca4640b0a64b675a768ab99bf0

URL: https://github.com/llvm/llvm-project/commit/fa0aff6d6960e3ca4640b0a64b675a768ab99bf0
DIFF: https://github.com/llvm/llvm-project/commit/fa0aff6d6960e3ca4640b0a64b675a768ab99bf0.diff

LOG: Revert "[X86][SSE] isHorizontalBinOp - use getTargetShuffleInputs helper"

This reverts commit 500969f1d0b1d92d7c4ccfb6bf8807de96b7e4a0.
Makes clang assert compiling avx2 code, see
https://bugs.chromium.org/p/chromium/issues/detail?id=1195353#c4
for a standalone repro.

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 563f38db86ae..f4f9812a4024 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -45984,8 +45984,18 @@ static bool isHorizontalBinOp(unsigned HOpcode, SDValue &LHS, SDValue &RHS,
          "Unsupported vector type for horizontal add/sub");
   unsigned NumElts = VT.getVectorNumElements();
 
+  // TODO - can we make a general helper method that does all of this for us?
   auto GetShuffle = [&](SDValue Op, SDValue &N0, SDValue &N1,
                         SmallVectorImpl<int> &ShuffleMask) {
+    if (Op.getOpcode() == ISD::VECTOR_SHUFFLE) {
+      if (!Op.getOperand(0).isUndef())
+        N0 = Op.getOperand(0);
+      if (!Op.getOperand(1).isUndef())
+        N1 = Op.getOperand(1);
+      ArrayRef<int> Mask = cast<ShuffleVectorSDNode>(Op)->getMask();
+      ShuffleMask.append(Mask.begin(), Mask.end());
+      return;
+    }
     bool UseSubVector = false;
     if (Op.getOpcode() == ISD::EXTRACT_SUBVECTOR &&
         Op.getOperand(0).getValueType().is256BitVector() &&
@@ -45994,25 +46004,23 @@ static bool isHorizontalBinOp(unsigned HOpcode, SDValue &LHS, SDValue &RHS,
       UseSubVector = true;
     }
     SmallVector<SDValue, 2> SrcOps;
-    SmallVector<int, 16> SrcMask, ScaledMask;
+    SmallVector<int, 16> SrcShuffleMask;
     SDValue BC = peekThroughBitcasts(Op);
-    if (getTargetShuffleInputs(BC, SrcOps, SrcMask, DAG) &&
-        !isAnyZero(SrcMask) && all_of(SrcOps, [BC](SDValue Op) {
-          return Op.getValueSizeInBits() == BC.getValueSizeInBits();
-        })) {
-      resolveTargetShuffleInputsAndMask(SrcOps, SrcMask);
-      if (!UseSubVector && SrcOps.size() <= 2 &&
-          scaleShuffleElements(SrcMask, NumElts, ScaledMask)) {
+    if (isTargetShuffle(BC.getOpcode()) &&
+        getTargetShuffleMask(BC.getNode(), BC.getSimpleValueType(), false,
+                             SrcOps, SrcShuffleMask)) {
+      if (!UseSubVector && SrcShuffleMask.size() == NumElts &&
+          SrcOps.size() <= 2) {
         N0 = SrcOps.size() > 0 ? SrcOps[0] : SDValue();
         N1 = SrcOps.size() > 1 ? SrcOps[1] : SDValue();
-        ShuffleMask.assign(ScaledMask.begin(), ScaledMask.end());
+        ShuffleMask.append(SrcShuffleMask.begin(), SrcShuffleMask.end());
       }
-      if (UseSubVector && SrcOps.size() == 1 &&
-          scaleShuffleElements(SrcMask, 2 * NumElts, ScaledMask)) {
+      if (UseSubVector && (SrcShuffleMask.size() == (NumElts * 2)) &&
+          SrcOps.size() == 1) {
         N0 = extract128BitVector(SrcOps[0], 0, DAG, SDLoc(Op));
         N1 = extract128BitVector(SrcOps[0], NumElts, DAG, SDLoc(Op));
-        ArrayRef<int> Mask = ArrayRef<int>(ScaledMask).slice(0, NumElts);
-        ShuffleMask.assign(Mask.begin(), Mask.end());
+        ArrayRef<int> Mask = ArrayRef<int>(SrcShuffleMask).slice(0, NumElts);
+        ShuffleMask.append(Mask.begin(), Mask.end());
       }
     }
   };