1 files changed, 9 insertions, 4 deletions
diff --git a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
index 7c239cb19b7..60ac271bceb 100644
--- a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
+++ b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
@@ -4159,10 +4159,8 @@ static bool SwitchToLookupTable(SwitchInst *SI, IRBuilder<> &Builder,
 
   if (!DefaultIsReachable || GeneratingCoveredLookupTable) {
     Builder.CreateBr(LookupBB);
-    // We cached PHINodes in PHIs, to avoid accessing deleted PHINodes later,
-    // do not delete PHINodes here.
-    SI->getDefaultDest()->removePredecessor(SI->getParent(),
-                                            /*DontDeleteUselessPHIs=*/true);
+    // Note: We call removeProdecessor later since we need to be able to get the
+    // PHI value for the default case in case we're using a bit mask.
   } else {
     Value *Cmp = Builder.CreateICmpULT(TableIndex, ConstantInt::get(
                                        MinCaseVal->getType(), TableSize));
@@ -4214,6 +4212,13 @@ static bool SwitchToLookupTable(SwitchInst *SI, IRBuilder<> &Builder,
     AddPredecessorToBlock(SI->getDefaultDest(), MaskBB, SI->getParent());
   }
 
+  if (!DefaultIsReachable || GeneratingCoveredLookupTable) {
+    // We cached PHINodes in PHIs, to avoid accessing deleted PHINodes later,
+    // do not delete PHINodes here.
+    SI->getDefaultDest()->removePredecessor(SI->getParent(),
+                                            /*DontDeleteUselessPHIs=*/true);
+  }
+
   bool ReturnedEarly = false;
   for (size_t I = 0, E = PHIs.size(); I != E; ++I) {
     PHINode *PHI = PHIs[I];