[PATCH] D149237: [Mem2Reg] !nonnull and !noundef are enough for creating assume

[luxufan via Phabricator via llvm-commits]

StephenFan created this revision.
StephenFan added reviewers: nikic, goldstein.w.n.
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The behavior of violating !nonnull and !noundef is immediate undefined
behavior, that's enough to create a non-null assumption.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D149237

Files:
  llvm/lib/Transforms/Utils/PromoteMemoryToRegister.cpp


Index: llvm/lib/Transforms/Utils/PromoteMemoryToRegister.cpp
===================================================================
--- llvm/lib/Transforms/Utils/PromoteMemoryToRegister.cpp
+++ llvm/lib/Transforms/Utils/PromoteMemoryToRegister.cpp
@@ -410,8 +410,7 @@
   // returns poison while assume violations are immediate undefined behavior,
   // we can only do this if the value is known non-poison.
   if (AC && LI->getMetadata(LLVMContext::MD_nonnull) &&
-      LI->getMetadata(LLVMContext::MD_noundef) &&
-      !isKnownNonZero(Val, DL, 0, AC, LI, DT))
+      LI->getMetadata(LLVMContext::MD_noundef))
     addAssumeNonNull(AC, LI);
 }
 


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