[llvm] 44badc9 - [X86] combineConcatVectorOps - use isSplatValue helper instead of matching specific VBROADCAST opcodes. (#129556)

[via llvm-commits]

Author: Simon Pilgrim
Date: 2025-03-03T17:59:15Z
New Revision: 44badc9810ede7843c65ac3e32e0820c13eaec85

URL: https://github.com/llvm/llvm-project/commit/44badc9810ede7843c65ac3e32e0820c13eaec85
DIFF: https://github.com/llvm/llvm-project/commit/44badc9810ede7843c65ac3e32e0820c13eaec85.diff

LOG: [X86] combineConcatVectorOps - use isSplatValue helper instead of matching specific VBROADCAST opcodes. (#129556)

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 fe170fe3ade08..6d883de66dea2 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -57798,19 +57798,18 @@ static SDValue combineConcatVectorOps(const SDLoc &DL, MVT VT,
         Op0.getOperand(0).getValueType() == VT.getScalarType())
       return DAG.getNode(X86ISD::VBROADCAST, DL, VT, Op0.getOperand(0));
 
-    // concat_vectors(extract_subvector(broadcast(x)),
-    //                extract_subvector(broadcast(x))) -> broadcast(x)
+    // concat_vectors(extract_subvector(splat(x)),
+    //                extract_subvector(splat(x))) -> splat(x)
     // concat_vectors(extract_subvector(subv_broadcast(x)),
     //                extract_subvector(subv_broadcast(x))) -> subv_broadcast(x)
     if (Op0.getOpcode() == ISD::EXTRACT_SUBVECTOR &&
         Op0.getOperand(0).getValueType() == VT) {
       SDValue SrcVec = Op0.getOperand(0);
-      if (SrcVec.getOpcode() == X86ISD::VBROADCAST ||
-          SrcVec.getOpcode() == X86ISD::VBROADCAST_LOAD)
-        return Op0.getOperand(0);
+      if (DAG.isSplatValue(SrcVec, /*AllowUndefs*/ false))
+        return SrcVec;
       if (SrcVec.getOpcode() == X86ISD::SUBV_BROADCAST_LOAD &&
           Op0.getValueType() == cast<MemSDNode>(SrcVec)->getMemoryVT())
-        return Op0.getOperand(0);
+        return SrcVec;
     }
 
     // concat_vectors(permq(x),permq(x)) -> permq(concat_vectors(x,x))