[PATCH] D140392: [SLP][AArch64] Incorrectly estimated intrinsic as a function call

[Dinar Temirbulatov via Phabricator via llvm-commits]

dtemirbulatov added inline comments.


================
Comment at: llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp:7313-7318
+          InstructionCost IntrCost =
+              TTI->getIntrinsicInstrCost(ICA, TTI::TCK_RecipThroughput);
+          InstructionCost CallCost = TTI->getCallInstrCost(
+              nullptr, II->getType(), Tys, TTI::TCK_RecipThroughput);
+          if (IntrCost < CallCost)
+            NoCallIntrinsic = true;
----------------
ABataev wrote:
> Do we have a btter way to check if the intrinsic is lowered as an instruction rather than the call?
> ```
> NoCallIntrinsic = IntrCost < CallCost;
> ```
No, it looks to me the only way. We could duplicate the code from getTypeBasedIntrinsicInstrCost() and ask about legality of an operation from a target, but it would be too much to duplicate. Also, we could hardcode minimal call cost, for example 10, but it would look incorrect to me too.


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  https://reviews.llvm.org/D140392/new/

https://reviews.llvm.org/D140392