[all-commits] [llvm/llvm-project] ad1b87: [SCEVExpander] Only create multiplication if needed.

[Florian Hahn via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: ad1b8772cf6b16c1162bb8ff425679f5ff046ae9
      https://github.com/llvm/llvm-project/commit/ad1b8772cf6b16c1162bb8ff425679f5ff046ae9
  Author: Florian Hahn <flo at fhahn.com>
  Date:   2022-01-10 (Mon, 10 Jan 2022)

  Changed paths:
    M llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp
    M llvm/test/Transforms/LoopDistribute/scev-inserted-runtime-check.ll
    M llvm/test/Transforms/LoopVersioning/wrapping-pointer-versioning.ll

  Log Message:
  -----------
  [SCEVExpander] Only create multiplication if needed.

9345ab3a4550 updated generateOverflowCheck to skip creating checks that
always evaluate to false. This in turn means that we only need to
compute |Step| * Trip count  if the result of the multiplication is
actually used.

Sink the multiplication into ComputeEndCheck, so it is only created
when there's an actual check.