Don't skip over instructions other than loads that might read memory
when trying to sink stores.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52259 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp
index 8dbca0f..8a7128b 100644
--- a/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -10417,18 +10417,19 @@
return false;
break;
}
- // If we find something that may be using the stored value, or if we run
- // out of instructions, we can't do the xform.
- if (isa<LoadInst>(BBI) || BBI->mayWriteToMemory() ||
+ // If we find something that may be using or overwriting the stored
+ // value, or if we run out of instructions, we can't do the xform.
+ if (BBI->mayReadFromMemory() || BBI->mayWriteToMemory() ||
BBI == OtherBB->begin())
return false;
}
// In order to eliminate the store in OtherBr, we have to
- // make sure nothing reads the stored value in StoreBB.
+ // make sure nothing reads or overwrites the stored value in
+ // StoreBB.
for (BasicBlock::iterator I = StoreBB->begin(); &*I != &SI; ++I) {
// FIXME: This should really be AA driven.
- if (isa<LoadInst>(I) || I->mayWriteToMemory())
+ if (I->mayReadFromMemory() || I->mayWriteToMemory())
return false;
}
}