| Issue |
167173
|
| Summary |
Missed Optimization: Fold parity select (x&1 ? (x-1): (x|1) ) into x ^ 1
|
| Labels |
new issue
|
| Assignees |
|
| Reporter |
Leo0506
|
```
define i32 @src(i32 %arg0) {
%v0 = and i32 %arg0, 1
%v1 = icmp eq i32 %v0, 0
%v2 = or disjoint i32 %arg0, 1
%v3 = add nsw i32 %arg0, -1
%v4 = select i1 %v1, i32 %v2, i32 %v3
%v5 = srem i32 %v4, 6
ret i32 %v5
}
define i32 @tgt(i32 %arg0) {
%v4_opt = xor i32 %arg0, 1
%v5_opt = srem i32 %v4_opt, 6
ret i32 %v5_opt
}
```
alive2: https://alive2.llvm.org/ce/z/VGsqMZ
godbolt: https://godbolt.org/z/zETszvo4o
Pattern found in: https://github.com/dtcxzyw/llvm-opt-benchmark/blob/main/bench/linux/optimized/uncore_nhmex.ll
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