3 files changed, 16 insertions, 8 deletions
diff --git a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
index 777065107dc..ff02b7d269b 100644
--- a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -2047,6 +2047,9 @@ static void WriteUseList(ValueEnumerator &VE, UseListOrder &&Order,
 
 static void WriteUseListBlock(const Function *F, ValueEnumerator &VE,
                               BitstreamWriter &Stream) {
+  assert(VE.shouldPreserveUseListOrder() &&
+         "Expected to be preserving use-list order");
+
   auto hasMore = [&]() {
     return !VE.UseListOrders.empty() && VE.UseListOrders.back().F == F;
   };
@@ -2127,7 +2130,7 @@ static void WriteFunction(const Function &F, ValueEnumerator &VE,
 
   if (NeedsMetadataAttachment)
     WriteMetadataAttachment(F, VE, Stream);
-  if (shouldPreserveBitcodeUseListOrder())
+  if (VE.shouldPreserveUseListOrder())
     WriteUseListBlock(&F, VE, Stream);
   VE.purgeFunction();
   Stream.ExitBlock();
@@ -2318,7 +2321,7 @@ static void WriteModule(const Module *M, BitstreamWriter &Stream) {
   Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
 
   // Analyze the module, enumerating globals, functions, etc.
-  ValueEnumerator VE(*M);
+  ValueEnumerator VE(*M, shouldPreserveBitcodeUseListOrder());
 
   // Emit blockinfo, which defines the standard abbreviations etc.
   WriteBlockInfo(VE, Stream);
@@ -2351,7 +2354,7 @@ static void WriteModule(const Module *M, BitstreamWriter &Stream) {
   WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream);
 
   // Emit module-level use-lists.
-  if (shouldPreserveBitcodeUseListOrder())
+  if (VE.shouldPreserveUseListOrder())
     WriteUseListBlock(nullptr, VE, Stream);
 
   // Emit function bodies.
diff --git a/llvm/lib/Bitcode/Writer/ValueEnumerator.cpp b/llvm/lib/Bitcode/Writer/ValueEnumerator.cpp
index a450f697f20..7f576d758bd 100644
--- a/llvm/lib/Bitcode/Writer/ValueEnumerator.cpp
+++ b/llvm/lib/Bitcode/Writer/ValueEnumerator.cpp
@@ -283,9 +283,11 @@ static bool isIntOrIntVectorValue(const std::pair<const Value*, unsigned> &V) {
   return V.first->getType()->isIntOrIntVectorTy();
 }
 
-ValueEnumerator::ValueEnumerator(const Module &M)
-    : HasMDString(false), HasMDLocation(false), HasGenericDebugNode(false) {
-  if (shouldPreserveBitcodeUseListOrder())
+ValueEnumerator::ValueEnumerator(const Module &M,
+                                 bool ShouldPreserveUseListOrder)
+    : HasMDString(false), HasMDLocation(false), HasGenericDebugNode(false),
+      ShouldPreserveUseListOrder(ShouldPreserveUseListOrder) {
+  if (ShouldPreserveUseListOrder)
     UseListOrders = predictUseListOrder(M);
 
   // Enumerate the global variables.
@@ -461,7 +463,7 @@ void ValueEnumerator::print(raw_ostream &OS, const MetadataMapType &Map,
 void ValueEnumerator::OptimizeConstants(unsigned CstStart, unsigned CstEnd) {
   if (CstStart == CstEnd || CstStart+1 == CstEnd) return;
 
-  if (shouldPreserveBitcodeUseListOrder())
+  if (ShouldPreserveUseListOrder)
     // Optimizing constants makes the use-list order difficult to predict.
     // Disable it for now when trying to preserve the order.
     return;
diff --git a/llvm/lib/Bitcode/Writer/ValueEnumerator.h b/llvm/lib/Bitcode/Writer/ValueEnumerator.h
index b94c37039ef..ba245a3de68 100644
--- a/llvm/lib/Bitcode/Writer/ValueEnumerator.h
+++ b/llvm/lib/Bitcode/Writer/ValueEnumerator.h
@@ -67,6 +67,7 @@ private:
   bool HasMDString;
   bool HasMDLocation;
   bool HasGenericDebugNode;
+  bool ShouldPreserveUseListOrder;
 
   typedef DenseMap<AttributeSet, unsigned> AttributeGroupMapType;
   AttributeGroupMapType AttributeGroupMap;
@@ -102,7 +103,7 @@ private:
   ValueEnumerator(const ValueEnumerator &) = delete;
   void operator=(const ValueEnumerator &) = delete;
 public:
-  ValueEnumerator(const Module &M);
+  ValueEnumerator(const Module &M, bool ShouldPreserveUseListOrder);
 
   void dump() const;
   void print(raw_ostream &OS, const ValueMapType &Map, const char *Name) const;
@@ -123,6 +124,8 @@ public:
   bool hasMDLocation() const { return HasMDLocation; }
   bool hasGenericDebugNode() const { return HasGenericDebugNode; }
 
+  bool shouldPreserveUseListOrder() const { return ShouldPreserveUseListOrder; }
+
   unsigned getTypeID(Type *T) const {
     TypeMapType::const_iterator I = TypeMap.find(T);
     assert(I != TypeMap.end() && "Type not in ValueEnumerator!");