Update various Loop optimization passes to cope with the possibility that
LoopSimplify form may not be available.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86175 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/LoopUnswitch.cpp b/lib/Transforms/Scalar/LoopUnswitch.cpp
index c7b00da..be8366d 100644
--- a/lib/Transforms/Scalar/LoopUnswitch.cpp
+++ b/lib/Transforms/Scalar/LoopUnswitch.cpp
@@ -407,6 +407,10 @@
initLoopData();
Function *F = loopHeader->getParent();
+ // If LoopSimplify was unable to form a preheader, don't do any unswitching.
+ if (!loopPreheader)
+ return false;
+
// If the condition is trivial, always unswitch. There is no code growth for
// this case.
if (!IsTrivialUnswitchCondition(LoopCond)) {