[PATCH] D22652: GVH-hoist: only clone GEPs (PR28606)

[Sebastian Pop via llvm-commits]

sebpop added inline comments.

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Comment at: llvm/lib/Transforms/Scalar/GVNHoist.cpp:586
@@ -585,3 +585,3 @@
       Gep = dyn_cast<GetElementPtrInst>(St->getPointerOperand());
       Val = dyn_cast<Instruction>(St->getValueOperand());
     }
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majnemer wrote:
> We could put the check here:
>   ...
>   GetElementPtrInst *Val = nullptr;
>   if (auto *St = dyn_cast<StoreInst>(Repl)) {
>     Gep = ...
>     Val = dyn_cast<GetElementPtrInst>(St->getValueOperand());
I think this is not possible: we need to check whether the stored value is available at HoistPt.
If we dyn_cast Val to GEP this early we would only hoist GEP stores. 


https://reviews.llvm.org/D22652