[PATCH] D109271: [InstCombine] rotate(X,Z) eq/ne rotate(Y,Z) ---> X eq/ne Y (PR51565)

[Dávid Bolvanský via Phabricator via llvm-commits]

xbolva00 created this revision.
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  ----------------------------------------
  define i1 @src(i8 %x, i8 %y, i8 %z) {
  %0:
    %f = fshl i8 %x, i8 %x, i8 %z
    %f2 = fshl i8 %y, i8 %y, i8 %z
    %r = icmp eq i8 %f, %f2
    ret i1 %r
  }
  =>
  define i1 @tgt(i8 %x, i8 %y, i8 %z) {
  %0:
    %r = icmp eq i8 %x, %y
    ret i1 %r
  }
  Transformation seems to be correct!

https://alive2.llvm.org/ce/z/qAZp8f

Solves PR51565


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D109271

Files:
  llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
  llvm/test/Transforms/InstCombine/icmp-rotate.ll

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