[PATCH] D55966: Ensure coro split pass only spills variables dominated by CoroBegin

[Gor Nishanov via Phabricator via llvm-commits]

GorNishanov requested changes to this revision.
GorNishanov added inline comments.
This revision now requires changes to proceed.


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Comment at: lib/Transforms/Coroutines/CoroFrame.cpp:932
     for (User *U : A.users())
-      if (Checker.isDefinitionAcrossSuspend(A, U))
+      if (Checker.isDefinitionAcrossSuspend(A, U) && !A.getType()->isPointerTy())
         Spills.emplace_back(&A, U);
----------------
This does not look right. It states that we never spill arguments that are pointer types, whether we use them across suspend point or not.

Any access to those arguments after suspend point will be garbage.

To observe, add `i16* %x` argument that you will use after suspend (either on resume path or destroy path` and observe that in .resume or .destroy parts of the coroutine any access to %x will be replaced with `undef`


Repository:
  rL LLVM

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D55966/new/

https://reviews.llvm.org/D55966