[PATCH] D57925: [TTI] Add generic cost model for fixed point smul/umul

[Nikita Popov via Phabricator via llvm-commits]

nikic added a comment.

> The existing method to do this is to pass Value arguments to getArithmeticInstrCost, there are already some targets that use this to detect extend+add/mul style cases. The problem we have here is that we don't really want to create Values on the fly for the analysis, and adding a Type equivalent version would be a little messy and cause duplication (we already suffer with this with the 2 getIntrinsicInstrCost variants).

Another possibility might be to add an OperandValueProperties flag. Right now it's used only for OP_PowerOf2, but we could also have something like OP_ZExtHalf and OP_SExtHalf or similar.


Repository:
  rL LLVM

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  https://reviews.llvm.org/D57925/new/

https://reviews.llvm.org/D57925