Fix a subtle bug when removing instructions from memdep. In very specific
circumstances we could end up remapping a dependee to the same instruction
that we're trying to remove. Handle this properly by just falling back to
a conservative solution.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54132 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/MemoryDependenceAnalysis.cpp b/lib/Analysis/MemoryDependenceAnalysis.cpp
index 2012ab4..c93a680 100644
--- a/lib/Analysis/MemoryDependenceAnalysis.cpp
+++ b/lib/Analysis/MemoryDependenceAnalysis.cpp
@@ -528,6 +528,10 @@
// If we have dep info for rem, set them to it
BasicBlock::iterator RI = depGraphEntry->second.first;
RI++;
+
+ // If RI is rem, then we use rem's immediate successor.
+ if (RI == (BasicBlock::iterator)rem) RI++;
+
newDep = RI;
} else if ( (depGraphEntry->second.first == NonLocal ||
depGraphEntry->second.first == None ) &&