[PATCH] D120439: [SLP] Fix for the min/max intrinsic cost.

[Vasileios Porpodas via Phabricator via llvm-commits]

vporpo added inline comments.


================
Comment at: llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp:5128
         if (IntrinsicAndUse.second)
-          IntrinsicCost -=
-              TTI->getCmpSelInstrCost(Instruction::ICmp, VecTy, MaskTy,
-                                      CmpInst::BAD_ICMP_PREDICATE, CostKind);
+          IntrinsicCost -= VecCost;
         VecCost = std::min(VecCost, IntrinsicCost);
----------------
vporpo wrote:
> ABataev wrote:
> > This is not correct, the original code is correct. Need to check more carefully the cause and probably fix the comment.
> Yeah you are right. This should subtract the cost of the vectorized compares, not the vectorized selects. Let me look into it again.
I think the issue was the BAD_ICMP_PREDICATE. If I understand correctly we should be using VecPred here instead.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D120439/new/

https://reviews.llvm.org/D120439