Don't assume that two identical instructions that read from memory

will always return the same value. This isn't currently necessary,
since this code doesn't currently ever get called under circumstances
where it would matter, but it may some day.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@80017 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp
index 33d8a18412d0eee477f7d96de9d411493ac92289..d639aee70993d0b7b6fb42e3cbb3c1e8f4f79118 100644 (file)
--- a/lib/Analysis/ScalarEvolution.cpp
+++ b/lib/Analysis/ScalarEvolution.cpp
@@ -4349,7 +4349,7 @@ static bool HasSameValue(const SCEV *A, const SCEV *B) {
     if (const SCEVUnknown *BU = dyn_cast<SCEVUnknown>(B))
       if (const Instruction *AI = dyn_cast<Instruction>(AU->getValue()))
         if (const Instruction *BI = dyn_cast<Instruction>(BU->getValue()))
-          if (AI->isIdenticalTo(BI))
+          if (AI->isIdenticalTo(BI) && !AI->mayReadFromMemory())
             return true;
 
   // Otherwise assume they may have a different value.