[PATCH] D106589: [GlobalOpt] support ConstantExpr use of global address for OptimizeGlobalAddressOfMalloc

[Shimin Cui via Phabricator via llvm-commits]

scui added inline comments.


================
Comment at: llvm/lib/Transforms/IPO/GlobalOpt.cpp:735
+        // Ignore stores to the global.
+        if (SI->getPointerOperand() != P)
+          return false;
----------------
efriedma wrote:
> scui wrote:
> > efriedma wrote:
> > > Instead of `SI->getPointerOperand() != P`, should be `SI->getValueOperand() == P`?
> > SI->getPointerOperand() != P is alright. It's ok to store into global (actually the StoredOnce).
> My concern is that with opaque pointers, it will become possible to write something like `store ptr @g, ptr @g`, at which point the difference between `SI->getPointerOperand() != P` and `SI->getValueOperand() == P` will start to matter.
When this function is called, we know there is only one store to the global, and it is from malloc. There are no other stores to the global. So we don't need to worry about "store @g @g". 


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  https://reviews.llvm.org/D106589/new/

https://reviews.llvm.org/D106589