[all-commits] [llvm/llvm-project] 2ad42c: [ValueTracking] improve analysis for fdiv with sam...

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  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 2ad42c2653ce31ca93dd2c9fdbd561d1d846d983
      https://github.com/llvm/llvm-project/commit/2ad42c2653ce31ca93dd2c9fdbd561d1d846d983
  Author: Sanjay Patel <spatel at rotateright.com>
  Date:   2020-06-21 (Sun, 21 Jun 2020)

  Changed paths:
    M llvm/lib/Analysis/ValueTracking.cpp
    M llvm/test/Transforms/InstSimplify/floating-point-compare.ll

  Log Message:
  -----------
  [ValueTracking] improve analysis for fdiv with same operands

(The 'nnan' variant of this pattern is already tested to produce '1.0'.)

https://alive2.llvm.org/ce/z/D4hPBy

define i1 @src(float %x, i32 %y) {
%0:
  %d = fdiv float %x, %x
  %uge = fcmp uge float %d, 0.000000
  ret i1 %uge
}
=>
define i1 @tgt(float %x, i32 %y) {
%0:
  ret i1 1
}
Transformation seems to be correct!