[PATCH] D117794: [ISEL] Canonicalise constant splats to RHS.

[Sander de Smalen via Phabricator via llvm-commits]

sdesmalen added inline comments.


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Comment at: llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp:5613
          "Operand is DELETED_NODE!");
   ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
   ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N2);
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craig.topper wrote:
> We could move the dyn_casts below the isCommutative block and fully rely on isConstantIntBuildVectorOrConstantInt inside the if. That would remove the need to swap the N1C/N2C.
Good point.


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Comment at: llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp:5618
   if (TLI->isCommutativeBinOp(Opcode)) {
-    if (N1C && !N2C) {
-      std::swap(N1C, N2C);
-      std::swap(N1, N2);
-    } else if (N1CFP && !N2CFP) {
-      std::swap(N1CFP, N2CFP);
+    bool IsN1C = N1C || isConstantIntBuildVectorOrConstantInt(N1);
+    bool IsN2C = N2C || isConstantIntBuildVectorOrConstantInt(N2);
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craig.topper wrote:
> Just to confirm, This will also handle SPLAT_VECTOR despite its name. Right?
Yes, that's correct.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D117794/new/

https://reviews.llvm.org/D117794