Make sure PRE doesn't split crit edges from indirectbr.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85692 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/GVN.cpp b/lib/Transforms/Scalar/GVN.cpp
index 33ad4e1..0e3f750 100644
--- a/lib/Transforms/Scalar/GVN.cpp
+++ b/lib/Transforms/Scalar/GVN.cpp
@@ -1810,7 +1810,7 @@
/// performPRE - Perform a purely local form of PRE that looks for diamond
/// control flow patterns and attempts to perform simple PRE at the join point.
-bool GVN::performPRE(Function& F) {
+bool GVN::performPRE(Function &F) {
bool Changed = false;
SmallVector<std::pair<TerminatorInst*, unsigned>, 4> toSplit;
DenseMap<BasicBlock*, Value*> predMap;
@@ -1875,6 +1875,10 @@
// we would need to insert instructions in more than one pred.
if (NumWithout != 1 || NumWith == 0)
continue;
+
+ // Don't do PRE across indirect branch.
+ if (isa<IndirectBrInst>(PREPred->getTerminator()))
+ continue;
// We can't do PRE safely on a critical edge, so instead we schedule
// the edge to be split and perform the PRE the next time we iterate