| Issue |
184088
|
| Summary |
[DSE] Pointer provenance to be taken into account in `dominatingConditionImpliesValue`
|
| Labels |
new issue
|
| Assignees |
|
| Reporter |
antoniofrighetto
|
Alive2: https://alive2.llvm.org/ce/z/e6pCvy.
```llvm
; RUN: ./bin/opt -S -passes=dse < %s
define void @src(ptr %x, ptr %y) {
entry:
%val = load ptr, ptr %x, align 8
%cmp = icmp eq ptr %val, %y
br i1 %cmp, label %then, label %end
then:
store ptr %y, ptr %x, align 8
br label %end
end:
ret void
}
define void @tgt(ptr %x, ptr %y) {
entry:
%val = load ptr, ptr %x, align 8
%cmp = icmp eq ptr %val, %y
br i1 %cmp, label %then, label %end
then:
br label %end
end:
ret void
}
```
Stores whose value being written may be implied by a dominating condition of kind `icmp eq ptr` may not be eliminated straightforwardly, as `icmp eq` compare their integral values only, not pointers' provenance. (From: https://github.com/llvm/llvm-project/pull/181709#discussion_r2868739673, similarly already tracked in SCCP, LVI).
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