[PATCH] D112955: [InstCombine] (a & ~(b | c)) | ~(a | (b ^ c)) -> (~a & b & c) | ~(b | c)

[Stanislav Mekhanoshin via Phabricator via llvm-commits]

rampitec created this revision.
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define i2 @src(i2 %a, i2 %b, i2 %c) {
%0:

  %or1 = or i2 %b, %c
  %not1 = xor i2 %or1, 3
  %and1 = and i2 %a, %not1
  %xor1 = xor i2 %b, %c
  %or2 = or i2 %xor1, %a
  %not2 = xor i2 %or2, 3
  %or3 = or i2 %and1, %not2
  ret i2 %or3

}

>
=

define i2 @tgt(i2 %a, i2 %b, i2 %c) {
%0:

  %1 = or i2 %b, %c
  %2 = xor i2 %1, 3
  %3 = and i2 %b, %c
  %4 = xor i2 %a, 3
  %5 = and i2 %3, %4
  %or3 = or i2 %5, %2
  ret i2 %or3

}
Transformation seems to be correct!


https://reviews.llvm.org/D112955

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

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