conservatively say that volatile stores read memory.

llvm-svn: 50872

1 files changed, 3 insertions, 2 deletions

diff --git a/llvm/lib/VMCore/Instruction.cpp b/llvm/lib/VMCore/Instruction.cpp
index a446cc20a93..2316b486898 100644
--- a/llvm/lib/VMCore/Instruction.cpp
+++ b/llvm/lib/VMCore/Instruction.cpp
@@ -226,13 +226,14 @@ bool Instruction::mayReadFromMemory() const {
   default: return false;
   case Instruction::Free:
   case Instruction::VAArg:
+  case Instruction::Load:
     return true;
   case Instruction::Call:
     return !cast<CallInst>(this)->doesNotAccessMemory();
   case Instruction::Invoke:
     return !cast<InvokeInst>(this)->doesNotAccessMemory();
-  case Instruction::Load:
-    return true;
+  case Instruction::Store:
+    return cast<StoreInst>(this)->isVolatile();
   }
 }