[PATCH] D153453: [MemCpyOpt] implement single BB stack-move optimization which unify the static unescaped allocas

[Kohei Asano via Phabricator via llvm-commits]

khei4 added inline comments.


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Comment at: llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp:1627
+      auto *EndMA = MSSAU->createMemoryAccessAfter(
+          End, LastMA->getDefiningAccess(), LastMA);
+      MSSAU->insertDef(cast<MemoryDef>(EndMA), /*RenameUses=*/true);
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nikic wrote:
> I think for the lifetime.start using getDefiningAccess() is right, as we're inserting it before the access (the new defining access of FirstMA will become the newly inserted MemoryDef). However, I think that for the lifetime.end we need to pass `LastMA` rather than `LastMA->getDefiningAccess()` as the defining access.
Thanks! 
> However, I think that for the lifetime.end we need to pass LastMA rather than LastMA->getDefiningAccess() as the defining access.

Hmm, I see all use of `createMemoryAccessAfter` on MemCpyOpt is so, TBH, I didn't get the meaning of defining access, anyway I can try it!


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  https://reviews.llvm.org/D153453/new/

https://reviews.llvm.org/D153453