[PATCH] D132657: [DSE] Eliminate noop store even through has clobbering between LoadI and StoreI

[luxufan via Phabricator via llvm-commits]

StephenFan added a comment.

In D132657#3840493 <https://reviews.llvm.org/D132657#3840493>, @aeubanks wrote:

> reduced test case
>
>   define void @f(ptr %arg, ptr %arg1, i1 %arg2) {
>   bb:
>     %tmp = load ptr, ptr %arg, align 8
>     %tmp3 = load ptr, ptr %arg1, align 8
>     store ptr %tmp3, ptr %arg, align 8
>     store ptr %tmp, ptr %arg1, align 8
>     br i1 %arg2, label %bb5, label %bb6
>   
>   bb5:
>     store ptr %tmp, ptr %arg, align 8 ; this store is incorrectly removed
>     store ptr %tmp3, ptr %arg1, align 8
>     ret void
>   
>   bb6:
>     ret void
>   }
>
> we're first swapping the values `%arg` and `%arg1` point to, then conditionally swapping them back to their original values
>
> will revert

Thanks for providing a reduced test case!


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