[all-commits] [llvm/llvm-project] c45761: ValueTracking: ldexp cannot return denormals based...

[Matt Arsenault via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: c457619c5b2ed854c5277470c4313b337de91665
      https://github.com/llvm/llvm-project/commit/c457619c5b2ed854c5277470c4313b337de91665
  Author: Matt Arsenault <Matthew.Arsenault at amd.com>
  Date:   2023-07-11 (Tue, 11 Jul 2023)

  Changed paths:
    M llvm/lib/Analysis/ValueTracking.cpp
    M llvm/test/Transforms/Attributor/nofpclass-ldexp.ll

  Log Message:
  -----------
  ValueTracking: ldexp cannot return denormals based on range of exponent

The implementations of a number of math functions on amdgpu involve
pre and post-scaling the inputs out of the denormal range. If these
are chained together we can possibly fold them out.

computeConstantRange seems weaker than computeKnownBits, so this
regresses some of the older vector tests.