[all-commits] [llvm/llvm-project] c40776: [InstCombine] (~(a | b) & c) | ~(c | (a ^ b)) -> ~...

[Stanislav Mekhanoshin via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: c407769f5e6c81d56de0b251aed5750a16a7651c
      https://github.com/llvm/llvm-project/commit/c407769f5e6c81d56de0b251aed5750a16a7651c
  Author: Stanislav Mekhanoshin <Stanislav.Mekhanoshin at amd.com>
  Date:   2021-11-22 (Mon, 22 Nov 2021)

  Changed paths:
    M llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
    M llvm/test/Transforms/InstCombine/and-xor-or.ll

  Log Message:
  -----------
  [InstCombine] (~(a | b) & c) | ~(c | (a ^ b)) -> ~((a | b) & (c | (b ^ a)))

Transform
```
(~(a | b) & c) | ~(c | (a ^ b)) -> ~((a | b) & (c | (b ^ a)))
```
And swapped case:
```
(a | ~(b & c)) & ~(a & (b ^ c)) --> ~(a | b) | (a ^ b ^ c)
```

```
----------------------------------------
define i3 @src(i3 %a, i3 %b, i3 %c) {
%0:
  %or1 = or i3 %b, %c
  %not1 = xor i3 %or1, 7
  %and1 = and i3 %a, %not1
  %xor1 = xor i3 %b, %c
  %or2 = or i3 %xor1, %a
  %not2 = xor i3 %or2, 7
  %or3 = or i3 %and1, %not2
  ret i3 %or3
}
=>
define i3 @tgt(i3 %a, i3 %b, i3 %c) {
%0:
  %obc = or i3 %b, %c
  %xbc = xor i3 %b, %c
  %o = or i3 %a, %xbc
  %and = and i3 %obc, %o
  %r = xor i3 %and, 7
  ret i3 %r
}
Transformation seems to be correct!
```
```
----------------------------------------
define i4 @src(i4 %a, i4 %b, i4 %c) {
%0:
  %and1 = and i4 %b, %c
  %not1 = xor i4 %and1, 15
  %or1 = or i4 %not1, %a
  %xor1 = xor i4 %b, %c
  %and2 = and i4 %xor1, %a
  %not2 = xor i4 %and2, 15
  %and3 = and i4 %or1, %not2
  ret i4 %and3
}
=>
define i4 @tgt(i4 %a, i4 %b, i4 %c) {
%0:
  %xor1 = xor i4 %b, %c
  %xor2 = xor i4 %xor1, %a
  %or1 = or i4 %a, %b
  %not1 = xor i4 %or1, 15
  %or2 = or i4 %xor2, %not1
  ret i4 %or2
}
Transformation seems to be correct!
```

Differential Revision: https://reviews.llvm.org/D112955