[all-commits] [llvm/llvm-project] f395a4: [SCEVExpand] Only create required predicate checks.

[Florian Hahn via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: f395a4f8d5dca005c951b5a881b74ec0a96d0c4c
      https://github.com/llvm/llvm-project/commit/f395a4f8d5dca005c951b5a881b74ec0a96d0c4c
  Author: Florian Hahn <flo at fhahn.com>
  Date:   2022-01-07 (Fri, 07 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/PowerPC/optimal-epilog-vectorization.ll
    M llvm/test/Transforms/LoopVectorize/X86/illegal-parallel-loop-uniform-write.ll
    M llvm/test/Transforms/LoopVectorize/X86/pr35432.ll
    M llvm/test/Transforms/LoopVectorize/first-order-recurrence-complex.ll
    M llvm/test/Transforms/LoopVectorize/induction.ll
    M llvm/test/Transforms/LoopVectorize/optimal-epilog-vectorization.ll
    M llvm/test/Transforms/LoopVectorize/pr30654-phiscev-sext-trunc.ll
    M llvm/test/Transforms/LoopVectorize/pr45259.ll
    M llvm/test/Transforms/LoopVectorize/runtime-check-small-clamped-bounds.ll
    M llvm/test/Transforms/LoopVersioning/wrapping-pointer-non-integral-addrspace.ll
    M llvm/test/Transforms/LoopVersioning/wrapping-pointer-versioning.ll

  Log Message:
  -----------
  [SCEVExpand] Only create required predicate checks.

Currently generateOverflowCheck always creates code for Step being
negative and positive, followed by a select at the end depending on
Step's sign.

This patch updates the code to only create either the checks for step
being positive or negative, if the sign is known.

Follow-up to D116696.

Reviewed By: reames

Differential Revision: https://reviews.llvm.org/D116747