| Issue |
185244
|
| Summary |
[InstCombine] Missed optimization: `trunc(smax(zext(a) - zext(b), 0)) -> usub.sat(a, b)`
|
| Labels |
llvm:instcombine,
missed-optimization
|
| Assignees |
|
| Reporter |
sweiglbosker
|
Possible folds
- `trunc(smax(zext(a) - zext(b), 0)) -> usub.sat(a, b)`
- `trunc(umin(zext(a) + zext(b), MAX)) -> uadd.sat(a, b)`
where a and b have the same type as the trunc result, the zext is to any wider type, and MAX is wrt the narrow type
https://llvm.godbolt.org/z/hnfnf5EK3
https://alive2.llvm.org/ce/z/vEhHH- (noundef on vector case to avoid timeout on ce, but it validates quickly locally with i4)
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