[PATCH] D112313: [DSE] Optimize defining access of defs while walking upwards.

[Nikita Popov via Phabricator via llvm-commits]

nikic added inline comments.


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Comment at: llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp:1486
+              (OR == OW_Complete || OR == OW_MaybePartial))
+            KillingDef->setOptimized(CurrentDef);
+
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I think this is incorrect if KillingDef accesses multiple locations. Say you have a memcpy, then KillingLoc will point to the write location only, and that's the only one for which we will check aliasing. This means that the optimized access might look past a clobber of the read location.


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  https://reviews.llvm.org/D112313/new/

https://reviews.llvm.org/D112313