[PATCH] D86859: [Coroutine] Make dealing with alloca spills more robust

[Hongtao Yu via Phabricator via llvm-commits]

hoy added inline comments.


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Comment at: llvm/lib/Transforms/Coroutines/CoroFrame.cpp:628
 // the value from the alloca into the coroutine frame spill slot corresponding
-// to that alloca.
+// to that alloca. We also collect any alias poiting to the alloca created
+// before CoroBegin but used after CoroBegin. These alias will be recreated
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typo : pointing


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Comment at: llvm/lib/Transforms/Coroutines/CoroFrame.cpp:634-638
+// TODO: If the pointer is really escaped, we are in big trouble because we
+// will be escaping a pointer to a stack address that would no longer exist
+// soon. However most escape analysis isn't good enough to precisely tell,
+// so we are assuming that if a pointer is escaped that it's written into.
+// TODO: Another potential issue is if we are creating an alias through
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This does sound fragile. I'm wondering if this is a defined behavior in the language standard. For a local variable first allocated on the local frame and later on copied into the coroutine frame, all subsequent accesses to it should be redirected to the coroutine frame? If so, can the coroutine frame be allocated ealier? 


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  https://reviews.llvm.org/D86859/new/

https://reviews.llvm.org/D86859