[all-commits] [llvm/llvm-project] 036a13: [GlobalISel] Combine (X op Y) == X --> Y == 0

[Jessica Paquette via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 036a13065b7a744efcc48cdc0bca3b878ed906fd
      https://github.com/llvm/llvm-project/commit/036a13065b7a744efcc48cdc0bca3b878ed906fd
  Author: Jessica Paquette <jpaquette at apple.com>
  Date:   2022-10-11 (Tue, 11 Oct 2022)

  Changed paths:
    M llvm/include/llvm/CodeGen/GlobalISel/CombinerHelper.h
    M llvm/include/llvm/Target/GlobalISel/Combine.td
    M llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp
    A llvm/test/CodeGen/AArch64/GlobalISel/combine-icmp-of-binop-to-icmp-of-0.mir

  Log Message:
  -----------
  [GlobalISel] Combine (X op Y) == X --> Y == 0

This matches patterns of the form

```
(X op Y) == X
```

And transforms them to

```
Y == 0
```

where appropriate.

Example: https://godbolt.org/z/hfW811c7W

Differential Revision: https://reviews.llvm.org/D135380