[llvm-branch-commits] [llvm] [LoopVectorizer] Bundle partial reductions with different extensions (PR #136997)

[Gaëtan Bossu via llvm-branch-commits]

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@@ -2526,13 +2523,14 @@ class VPMulAccumulateReductionRecipe : public VPReductionRecipe {
             R->getCondOp(), R->isOrdered(),
             WrapFlagsTy(Mul->hasNoUnsignedWrap(), Mul->hasNoSignedWrap()),
             R->getDebugLoc()),
-        ExtOp(Ext0->getOpcode()), IsNonNeg(Ext0->isNonNeg()),
         ResultTy(ResultTy),
         IsPartialReduction(isa<VPPartialReductionRecipe>(R)) {
     assert(RecurrenceDescriptor::getOpcode(getRecurrenceKind()) ==
                Instruction::Add &&
            "The reduction instruction in MulAccumulateteReductionRecipe must "
            "be Add");
+    VecOpInfo[0] = {Ext0->getOpcode(), Ext0->isNonNeg()};
+    VecOpInfo[1] = {Ext1->getOpcode(), Ext1->isNonNeg()};
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gbossu wrote:

Curious: From the description of the `VPMulAccumulateReductionRecipe` class, it seems that the extending operations are optional. Yet, this code seems to assume `Ext0` and `Ext1` aren't null. Does that mean that these widen recipes are always valid, but sometimes they represent an "identity" transformation?

https://github.com/llvm/llvm-project/pull/136997