[all-commits] [llvm/llvm-project] aecad5: [SCEVExpander] Only create trunc when needed.

[Florian Hahn via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: aecad5828ee7c3cd6d7dea5ea9f552251e4362df
      https://github.com/llvm/llvm-project/commit/aecad5828ee7c3cd6d7dea5ea9f552251e4362df
  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/LoopVectorize/runtime-check-small-clamped-bounds.ll
    M llvm/test/Transforms/LoopVersioning/wrapping-pointer-versioning.ll

  Log Message:
  -----------
  [SCEVExpander] Only create trunc when needed.

9345ab3a4550 updated generateOverflowCheck to skip creating checks that
always evaluate to false. This in turn means that we only need to
create TruncTripCount if it is actually used.

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