| Issue |
120089
|
| Summary |
[ConstraintElim] `icmp spred x, y` implies `icmp samesign upred x, y`
|
| Labels |
missed-optimization,
llvm:transforms
|
| Assignees |
dtcxzyw
|
| Reporter |
dtcxzyw
|
Alive2: https://alive2.llvm.org/ce/z/ZNNbj_
```
define i1 @src(i32 %x, i32 %y) {
entry:
%cond = icmp sgt i32 %x, %y
br i1 %cond, label %if.then, label %if.else
if.then:
%cmp = icmp samesign ugt i32 %x, %y
ret i1 %cmp
if.else:
ret i1 false
}
define i1 @tgt(i32 %x, i32 %y) {
entry:
%cond = icmp sgt i32 %x, %y
br i1 %cond, label %if.then, label %if.else
if.then:
ret i1 true
if.else:
ret i1 false
}
```
We already perform similar optimizations in https://github.com/llvm/llvm-project/pull/115893.
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