[PATCH] D155406: (WIP) [MemCpyOpt] implement multi BB stack-move optimization

[Nikita Popov via Phabricator via llvm-commits]

nikic added inline comments.


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Comment at: llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp:1631
+    if (PDom) {
+      Builder.SetInsertPoint(PDom->getParent(), ++PDom->getIterator());
+      Builder.CreateLifetimeEnd(SrcAlloca, AllocaSize);
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nikic wrote:
> A possible issue here is that `PDom` could be a terminator, e.g. an `invoke`. In that case `++` will go past the end of the block. I think it would be fine to treat this case as if there is no PDom, as it's unlikely to occur in practice (generally, the pdom use will be in a lifetime intrinsic, which can't be a terminator).
Heh, looks like exactly this issue got reported here: https://reviews.llvm.org/D153453#inline-1503870 I failed to realize that this can already be an issue with the initial patch, not just this extension...


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D155406/new/

https://reviews.llvm.org/D155406