[PATCH] D130153: [DRAFT] Don't create new memory accesses for dbg intrinsics in MemorySSA

[Chuanqi Xu via Phabricator via llvm-commits]

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After we landed https://reviews.llvm.org/D127383, the compiler may crash at: https://github.com/llvm/llvm-project/blob/051738b08cf5e39fd274dd379147d1c19e2b5b20/llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp#L687-L691.

This is because the dbg intrinsics are readnone originally and the MemorySSA would refuse to create a new memory access at https://github.com/llvm/llvm-project/blob/051738b08cf5e39fd274dd379147d1c19e2b5b20/llvm/lib/Analysis/MemorySSA.cpp#L1830-L1831

But after D127383 <https://reviews.llvm.org/D127383>, it wouldn't be true for the dbg intrinsics in presplit coroutine. So here is the crash.


https://reviews.llvm.org/D130153

Files:
  llvm/lib/Analysis/MemorySSA.cpp


Index: llvm/lib/Analysis/MemorySSA.cpp
===================================================================
--- llvm/lib/Analysis/MemorySSA.cpp
+++ llvm/lib/Analysis/MemorySSA.cpp
@@ -1789,6 +1789,10 @@
     case Intrinsic::assume:
     case Intrinsic::experimental_noalias_scope_decl:
     case Intrinsic::pseudoprobe:
+    case Intrinsic::dbg_addr:
+    case Intrinsic::dbg_declare:
+    case Intrinsic::dbg_label:
+    case Intrinsic::dbg_value:
       return nullptr;
     }
   }


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