[PATCH] D149889: [TTI] Use users of GEP to guess access type in getGEPCost

[Alexey Bataev via Phabricator via llvm-commits]

ABataev added inline comments.


================
Comment at: llvm/include/llvm/Analysis/TargetTransformInfoImpl.h:1057
+
+    return IsFoldable ? TTI::TCC_Free : TTI::TCC_Basic;
   }
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luke wrote:
> ABataev wrote:
> > Same question, cost of int add instead of basic?
> I agree we should use getArithmeticInstrCost here, but I have some ideas about adding a new target hook to control this and was wondering if I could defer it to that patch?
> On RISC-V if `Scale != 1` then we will need an extra `mul` instruction, as opposed to aarch64 which can perform both an add and multiply in one. I think this would make sense to expose the address calculation cost as a hook since it's target dependent, and we already have all the information available here to pass onto TTI.
> 
Add FIXME/TODOs here then


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  https://reviews.llvm.org/D149889/new/

https://reviews.llvm.org/D149889