[PATCH] D115167: [DSE] Use precise loc for memset_chk writing to local objects.

[Nikita Popov via Phabricator via llvm-commits]

nikic added inline comments.


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Comment at: llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp:1041
+        // executes. So it either writes exactly the number of specified bytes
+        // or the program gets aborted.
+        if (const auto *Len = dyn_cast<ConstantInt>(CB->getArgOperand(2))) {
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fhahn wrote:
> nikic wrote:
> > This hold for AA results in general though (they are only valid under the assumption of execution), so maybe it's okay to return a precise result directly in MemoryLocation?
> Hm, I am not sure. For AA it should be fine for the same reasons it's fine for DSE, but I am not sure about some of the other users? Grepping surfaces a couple of additional ones.
Looking through other `MemoryLocation::getForDest()` users, all of them seem to be limited to handling intrinsics, not libcalls, so I don't expect issues with existing callers.


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  https://reviews.llvm.org/D115167/new/

https://reviews.llvm.org/D115167