3 files changed, 9 insertions, 4 deletions
diff --git a/llvm/include/llvm/Transforms/Utils/Local.h b/llvm/include/llvm/Transforms/Utils/Local.h
index 81b376f0c21..911c6f14da0 100644
--- a/llvm/include/llvm/Transforms/Utils/Local.h
+++ b/llvm/include/llvm/Transforms/Utils/Local.h
@@ -42,6 +42,7 @@ class TargetLibraryInfo;
 class TargetTransformInfo;
 class DIBuilder;
 class DominatorTree;
+class LazyValueInfo;
 
 template<typename T> class SmallVectorImpl;
 
@@ -303,7 +304,7 @@ void removeUnwindEdge(BasicBlock *BB);
 /// \brief Remove all blocks that can not be reached from the function's entry.
 ///
 /// Returns true if any basic block was removed.
-bool removeUnreachableBlocks(Function &F);
+bool removeUnreachableBlocks(Function &F, LazyValueInfo *LVI = nullptr);
 
 /// \brief Combine the metadata of two instructions so that K can replace J
 ///
diff --git a/llvm/lib/Transforms/Scalar/JumpThreading.cpp b/llvm/lib/Transforms/Scalar/JumpThreading.cpp
index 35a10db3292..dcdcfed66e6 100644
--- a/llvm/lib/Transforms/Scalar/JumpThreading.cpp
+++ b/llvm/lib/Transforms/Scalar/JumpThreading.cpp
@@ -211,11 +211,12 @@ bool JumpThreading::runOnFunction(Function &F) {
   // we will loop forever. We take care of this issue by not jump threading for
   // back edges. This works for normal cases but not for unreachable blocks as
   // they may have cycle with no back edge.
-  removeUnreachableBlocks(F);
+  bool EverChanged = false;
+  EverChanged |= removeUnreachableBlocks(F, LVI);
 
   FindLoopHeaders(F);
 
-  bool Changed, EverChanged = false;
+  bool Changed;
   do {
     Changed = false;
     for (Function::iterator I = F.begin(), E = F.end(); I != E;) {
diff --git a/llvm/lib/Transforms/Utils/Local.cpp b/llvm/lib/Transforms/Utils/Local.cpp
index 0e386ac83e9..e4310c79736 100644
--- a/llvm/lib/Transforms/Utils/Local.cpp
+++ b/llvm/lib/Transforms/Utils/Local.cpp
@@ -23,6 +23,7 @@
 #include "llvm/Analysis/EHPersonalities.h"
 #include "llvm/Analysis/InstructionSimplify.h"
 #include "llvm/Analysis/MemoryBuiltins.h"
+#include "llvm/Analysis/LazyValueInfo.h"
 #include "llvm/Analysis/ValueTracking.h"
 #include "llvm/IR/CFG.h"
 #include "llvm/IR/Constants.h"
@@ -1407,7 +1408,7 @@ void llvm::removeUnwindEdge(BasicBlock *BB) {
 /// removeUnreachableBlocksFromFn - Remove blocks that are not reachable, even
 /// if they are in a dead cycle.  Return true if a change was made, false
 /// otherwise.
-bool llvm::removeUnreachableBlocks(Function &F) {
+bool llvm::removeUnreachableBlocks(Function &F, LazyValueInfo *LVI) {
   SmallPtrSet<BasicBlock*, 128> Reachable;
   bool Changed = markAliveBlocks(F, Reachable);
 
@@ -1428,6 +1429,8 @@ bool llvm::removeUnreachableBlocks(Function &F) {
          ++SI)
       if (Reachable.count(*SI))
         (*SI)->removePredecessor(&*BB);
+    if (LVI)
+      LVI->eraseBlock(&*BB);
     BB->dropAllReferences();
   }