[PATCH] D128917: [SCEVExpander] Use IRBuilder to create BinOp

[Nikita Popov via Phabricator via llvm-commits]

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This makes InsertBinOp in SCEVExpander go through the IRBuilder, which will fold the operation with InstSimplifyFolder. When doing this, it's important that the flags are directly passed to the builder, not fixed up after the fact, because it might have folded to some unrelated instruction. Expose a CreateNoWrapBinOp API for this purpose.

I am somewhat uncertain whether this change is actually desirable though. This does fold things as expected, but I'm not sure it's wanted in the LSR case, e.g. because it can shift a use from `iv.inc` to `iv`. Any thoughts on that?


https://reviews.llvm.org/D128917

Files:
  llvm/include/llvm/IR/IRBuilder.h
  llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp
  llvm/test/CodeGen/Thumb2/LowOverheadLoops/no-dec-le-simple.ll
  llvm/test/CodeGen/X86/break-false-dep.ll
  llvm/test/Transforms/LoopDeletion/pr53969.ll
  llvm/test/Transforms/LoopStrengthReduce/X86/2011-11-29-postincphi.ll
  llvm/test/Transforms/LoopStrengthReduce/X86/pr46943.ll
  llvm/test/Transforms/LoopStrengthReduce/depth-limit-overrun.ll
  llvm/test/Transforms/LoopStrengthReduce/wrong-hoisting-iv.ll

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