[PATCH] D93523: [DSE] Use correct memory location for read clobber check

[Nikita Popov via Phabricator via llvm-commits]

nikic added inline comments.


================
Comment at: llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp:1944
     // Find the next clobbering Mod access for DefLoc, starting at StartAccess.
+    Optional<MemoryLocation> CurrentLoc;
     do {
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fhahn wrote:
> nikic wrote:
> > fhahn wrote:
> > > Can this just be `MemoryLocation CurrentLoc`? We should skip the case when it would be `None` and it should always be `!= None` before after the loop.
> > This uses Optional<MemoryLocation> because getLocForWriteEx() returns it that way. Should I copy it into a separate non-Optional variable after the check that it is not None?
> I'd put the result of `getLocForWriteEx` into a new temprary and move the content to `CurrentLoc` after the check. Or have something like 
> 
> ```
> if (auto Loc = getLocForWriteEx(....)) {
>   CurrentLoc = *Loc;
> } else {
>   StepAgain = true;
>   ....
>   continue;
> }
> ```
I liked your second suggestion. Does the new version look fine?


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  https://reviews.llvm.org/D93523/new/

https://reviews.llvm.org/D93523