[PATCH] D29996: [DeadStoreElimination] Check function modref behavior before considering memory clobbered

[Philip Reames via Phabricator via llvm-commits]

reames accepted this revision.
reames added a comment.
This revision is now accepted and ready to land.

The actual code change looks obviously correct.

LGTM once the AA change lands.



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Comment at: test/Transforms/DeadStoreElimination/operand-bundles.ll:48
+define void @test4() {
+; CHECK-LABEL: @test4
+  %local_obj = call i8* @calloc(i64 1, i64 4)
----------------
sanjoy wrote:
> Looks like today `-basicaa -dse` does not elide the second store in
> 
> ```
> declare void @foo()
> declare void @bar(i8*)
> 
> define void @test4(i8* %ptr) {
>   store i8 0, i8* %ptr, align 4
>   call void @foo() readonly
>   store i8 0, i8* %ptr, align 4
>   call void @bar(i8* nocapture %ptr)
>   ret void
> }
> ```
> 
> Will it be able to do that with your changes?  If so, adding that as a test case will be nice.
It doesn't look like we have the framework for this in DSE which is unfortunate.  Oddly enough earlycse probably will get this example.


https://reviews.llvm.org/D29996