[PATCH] D112966: [InstCombine] (~a & b & c) | ~(a | b | c) -> ~(a | (b ^ c))

[Stanislav Mekhanoshin via Phabricator via llvm-commits]

rampitec created this revision.
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  ----------------------------------------
  define i4 @src(i4 %a, i4 %b, i4 %c) {
  %0:
    %or1 = or i4 %b, %a
    %or2 = or i4 %or1, %c
    %not1 = xor i4 %or2, 15
    %not2 = xor i4 %a, 15
    %and1 = and i4 %b, %not2
    %and2 = and i4 %and1, %c
    %or3 = or i4 %and2, %not1
    ret i4 %or3
  }
  =>
  define i4 @tgt(i4 %a, i4 %b, i4 %c) {
  %0:
    %1 = xor i4 %c, %b
    %2 = or i4 %1, %a
    %or3 = xor i4 %2, 15
    ret i4 %or3
  }
  Transformation seems to be correct!


https://reviews.llvm.org/D112966

Files:
  llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
  llvm/test/Transforms/InstCombine/and-xor-or.ll

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