Jessica Paquette a52e78012a [GlobalISel] Combine (xor (and x, y), y) -> (and (not x), y) ...

When we see this:

```
%and = G_AND %x, %y
%xor = G_XOR %and, %y
```

Produce this:

```
%not = G_XOR %x, -1
%new_and = G_AND %not, %y
```

as long as we are guaranteed to eliminate the original G_AND.

Also matches all commuted forms. E.g.

```
%and = G_AND %y, %x
%xor = G_XOR %y, %and
```

will be matched as well.

Differential Revision: https://reviews.llvm.org/D88104

2020-09-28 10:08:14 -07:00

99 KiB

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