1 files changed, 14 insertions, 4 deletions

diff --git a/llvm/lib/Transforms/InstCombine/InstCombinePHI.cpp b/llvm/lib/Transforms/InstCombine/InstCombinePHI.cpp
index 74e015a4f1d..6c2aead5a75 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombinePHI.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombinePHI.cpp
@@ -218,13 +218,21 @@ Instruction *InstCombiner::FoldIntegerTypedPHI(PHINode &PN) {
     return nullptr;
 
   // If any of the operand that requires casting is a terminator
-  // instruction, do not do it.
+  // instruction, do not do it. Similarly, do not do the transform if the value
+  // is PHI in a block with no insertion point, for example, a catchswitch
+  // block, since we will not be able to insert a cast after the PHI.
   if (any_of(AvailablePtrVals, [&](Value *V) {
         if (V->getType() == IntToPtr->getType())
           return false;
-
         auto *Inst = dyn_cast<Instruction>(V);
-        return Inst && Inst->isTerminator();
+        if (!Inst)
+          return false;
+        if (Inst->isTerminator())
+          return true;
+        auto *BB = Inst->getParent();
+        if (isa<PHINode>(Inst) && BB->getFirstInsertionPt() == BB->end())
+          return true;
+        return false;
       }))
     return nullptr;
 
@@ -264,8 +272,10 @@ Instruction *InstCombiner::FoldIntegerTypedPHI(PHINode &PN) {
       if (auto *IncomingI = dyn_cast<Instruction>(IncomingVal)) {
         BasicBlock::iterator InsertPos(IncomingI);
         InsertPos++;
+        BasicBlock *BB = IncomingI->getParent();
         if (isa<PHINode>(IncomingI))
-          InsertPos = IncomingI->getParent()->getFirstInsertionPt();
+          InsertPos = BB->getFirstInsertionPt();
+        assert(InsertPos != BB->end() && "should have checked above");
         InsertNewInstBefore(CI, *InsertPos);
       } else {
         auto *InsertBB = &IncomingBB->getParent()->getEntryBlock();