[llvm] 2804587 - [X86] combineConcatVectorOps - pull out repeated constant vector matching. NFC. (#172884)

[via llvm-commits]

Author: Simon Pilgrim
Date: 2025-12-18T18:23:47Z
New Revision: 28045875777d1c5b1ca33317256517ff41d4ea69

URL: https://github.com/llvm/llvm-project/commit/28045875777d1c5b1ca33317256517ff41d4ea69
DIFF: https://github.com/llvm/llvm-project/commit/28045875777d1c5b1ca33317256517ff41d4ea69.diff

LOG: [X86] combineConcatVectorOps - pull out repeated constant vector matching. NFC. (#172884)

Hopefully improve this in the future to handle constant pool loads.

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 2711d2cd5f8ff..081038701b585 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -59103,7 +59103,11 @@ static SDValue combineConcatVectorOps(const SDLoc &DL, MVT VT,
       }
       return DAG.getNode(ISD::CONCAT_VECTORS, DL, VT, Subs);
     };
-    auto IsConcatFree = [](MVT VT, ArrayRef<SDValue> SubOps, unsigned Op) {
+    auto IsOpConstant = [](SDValue Op) -> bool {
+      return ISD::isBuildVectorOfConstantSDNodes(Op.getNode()) ||
+             ISD::isBuildVectorOfConstantFPSDNodes(Op.getNode());
+    };
+    auto IsConcatFree = [&](MVT VT, ArrayRef<SDValue> SubOps, unsigned Op) {
       bool AllConstants = true;
       bool AllSubs = true;
       unsigned VecSize = VT.getSizeInBits();
@@ -59116,8 +59120,7 @@ static SDValue combineConcatVectorOps(const SDLoc &DL, MVT VT,
         SDValue BC = peekThroughBitcasts(SubOps[I].getOperand(Op));
         unsigned SubSize = BC.getValueSizeInBits();
         unsigned EltSize = BC.getScalarValueSizeInBits();
-        AllConstants &= ISD::isBuildVectorOfConstantSDNodes(BC.getNode()) ||
-                        ISD::isBuildVectorOfConstantFPSDNodes(BC.getNode());
+        AllConstants &= IsOpConstant(BC);
         AllSubs &= BC.getOpcode() == ISD::EXTRACT_SUBVECTOR &&
                    BC.getOperand(0).getValueSizeInBits() == VecSize &&
                    (BC.getConstantOperandVal(1) * EltSize) == (I * SubSize);
@@ -59128,9 +59131,7 @@ static SDValue combineConcatVectorOps(const SDLoc &DL, MVT VT,
       bool AllConstants = true;
       SmallVector<SDValue> Subs;
       for (SDValue SubOp : SubOps) {
-        SDValue BC = peekThroughBitcasts(SubOp.getOperand(I));
-        AllConstants &= ISD::isBuildVectorOfConstantSDNodes(BC.getNode()) ||
-                        ISD::isBuildVectorOfConstantFPSDNodes(BC.getNode());
+        AllConstants &= IsOpConstant(peekThroughBitcasts(SubOp.getOperand(I)));
         Subs.push_back(SubOp.getOperand(I));
       }
       if (AllConstants)