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

[Kohei Asano via Phabricator via llvm-commits]

khei4 marked 2 inline comments as done.
khei4 added a comment.

@vitalybuka Thank you for the review!



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Comment at: llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp:72
 STATISTIC(NumCallSlot,    "Number of call slot optimizations performed");
+STATISTIC(NumStackMove, "Number of stack-move optimizations performed");
 
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vitalybuka wrote:
> misaligned, clang-format please?
I aligned! Thanks!


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Comment at: llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp:1532
+            int64_t Size = cast<ConstantInt>(UI->getOperand(0))->getSExtValue();
+            if (Size < 0 || Size == DestSize) {
+              LifetimeMarkers.push_back(UI);
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vitalybuka wrote:
> why do we need this condition?
This transformation currently sees the full-sized (and not variable) lifetime intrinsics as an ignorable mod, because removing them doesn't change the semantics(but as you say, stack coloring might be affected), same as https://reviews.llvm.org/D140089, but the former patch does have more meaning to the full-sized lifetime intrinsics for liveness analysis. 


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https://reviews.llvm.org/D153453