| Issue |
167199
|
| Summary |
Missed Optimization: Fold ((x & (1<<y)) != 0) || ((x & (4<<y)) != 0) to (x & (5<<y)) != 0
|
| Labels |
new issue
|
| Assignees |
|
| Reporter |
Leo0506
|
```
define i1 @src(i64 %arg0, ptr %arg1) {
%v0 = load i8, ptr %arg1, align 1
%v1 = trunc nuw nsw i64 %arg0 to i32
%v2 = shl nuw nsw i32 1, %v1
%v3 = trunc nuw nsw i32 %v2 to i8
%v4 = and i8 %v0, %v3
%v5 = shl nuw nsw i32 4, %v1
%v6 = trunc nuw nsw i32 %v5 to i8
%v7 = and i8 %v0, %v6
%v8 = icmp ne i8 %v4, 0
%v9 = icmp ne i8 %v7, 0
%v10 = select i1 %v8, i1 true, i1 %v9
ret i1 %v10
}
define i1 @tgt(i64 %arg0, ptr %arg1) {
%v0 = load i8, ptr %arg1, align 1
%v1 = trunc nuw nsw i64 %arg0 to i8
%1 = shl i8 5, %v1
%2 = and i8 %v0, %1
%v8 = icmp ne i8 %2, 0
ret i1 %v8
}
```
alive2: https://alive2.llvm.org/ce/z/A8HQZ5
godbolt: https://godbolt.org/z/TxoE3qMYh
pattern found in: https://github.com/dtcxzyw/llvm-opt-benchmark/blob/main/bench/ffmpeg/optimized/vc1_loopfilter.ll
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