JumpThreading: when default destination is the destination of some cases in a
switch, make sure we include the value for the cases when calculating edge
value from switch to the default destination.
rdar://12241132
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163270 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/LazyValueInfo.cpp b/lib/Analysis/LazyValueInfo.cpp
index c2306b4..ec618fa 100644
--- a/lib/Analysis/LazyValueInfo.cpp
+++ b/lib/Analysis/LazyValueInfo.cpp
@@ -847,9 +847,12 @@
for (SwitchInst::CaseIt i = SI->case_begin(), e = SI->case_end();
i != e; ++i) {
ConstantRange EdgeVal(i.getCaseValue()->getValue());
- if (DefaultCase)
- EdgesVals = EdgesVals.difference(EdgeVal);
- else if (i.getCaseSuccessor() == BBTo)
+ if (DefaultCase) {
+ // It is possible that the default destination is the destination of
+ // some cases. There is no need to perform difference for those cases.
+ if (i.getCaseSuccessor() != BBTo)
+ EdgesVals = EdgesVals.difference(EdgeVal);
+ } else if (i.getCaseSuccessor() == BBTo)
EdgesVals = EdgesVals.unionWith(EdgeVal);
}
Result = LVILatticeVal::getRange(EdgesVals);