[IndVarSimplify] Don't insert after a catchswitch

Widening a PHI requires us to insert a trunc.
The logical place for this trunc is in the same BB as the PHI.
This is not possible if the BB is terminated by a catchswitch.

This fixes PR27133.

llvm-svn: 264926

1 files changed, 6 insertions, 0 deletions

diff --git a/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp b/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp
index c9dec3b28dc..ecbb1481d62 100644
--- a/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp
+++ b/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp
@@ -1283,6 +1283,12 @@ Instruction *WidenIV::widenIVUse(NarrowIVDefUse DU, SCEVExpander &Rewriter) {
       if (UsePhi->getNumOperands() != 1)
         truncateIVUse(DU, DT, LI);
       else {
+        // Widening the PHI requires us to insert a trunc.  The logical place
+        // for this trunc is in the same BB as the PHI.  This is not possible if
+        // the BB is terminated by a catchswitch.
+        if (isa<CatchSwitchInst>(UsePhi->getParent()->getTerminator()))
+          return nullptr;
+
         PHINode *WidePhi =
           PHINode::Create(DU.WideDef->getType(), 1, UsePhi->getName() + ".wide",
                           UsePhi);