[llvm] c545d57 - [X86] combineConcatVectorOps - use ConcatSubOperand helper to concat VPERMV3 subvector operands together.

[Simon Pilgrim via llvm-commits]

Author: Simon Pilgrim
Date: 2025-03-03T10:27:17Z
New Revision: c545d571c596a2d59e1d164bc9dc5f40881c3ff1

URL: https://github.com/llvm/llvm-project/commit/c545d571c596a2d59e1d164bc9dc5f40881c3ff1
DIFF: https://github.com/llvm/llvm-project/commit/c545d571c596a2d59e1d164bc9dc5f40881c3ff1.diff

LOG: [X86] combineConcatVectorOps - use ConcatSubOperand helper to concat VPERMV3 subvector operands together.

Shouldn't affect existing test coverage, but aggressively peeking through bitcasts before concatenation will help in a future patch.

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 7fb5157c00d84..5b9db77a3330f 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -57974,7 +57974,7 @@ static SDValue combineConcatVectorOps(const SDLoc &DL, MVT VT,
               int Src = M < NumSrcElts ? 0 : 2;
               M += M < NumSrcElts ? 0 : NumSrcElts;
 
-              // Reference the lowest sub if they upper sub is the same.
+              // Reference the lowest sub if the upper sub is the same.
               if (Ops[0].getOperand(Src) != Ops[i].getOperand(Src))
                 M += i * NumSrcElts;
             }
@@ -57982,10 +57982,8 @@ static SDValue combineConcatVectorOps(const SDLoc &DL, MVT VT,
           }
         }
         if (ConcatMask.size() == (NumOps * NumSrcElts)) {
-          SDValue Src0 = concatSubVectors(Ops[0].getOperand(0),
-                                          Ops[1].getOperand(0), DAG, DL);
-          SDValue Src1 = concatSubVectors(Ops[0].getOperand(2),
-                                          Ops[1].getOperand(2), DAG, DL);
+          SDValue Src0 = ConcatSubOperand(VT, Ops, 0);
+          SDValue Src1 = ConcatSubOperand(VT, Ops, 2);
           MVT IntMaskSVT = MVT::getIntegerVT(EltSizeInBits);
           MVT IntMaskVT = MVT::getVectorVT(IntMaskSVT, NumOps * NumSrcElts);
           SDValue Mask = getConstVector(ConcatMask, IntMaskVT, DAG, DL, true);