IR: Split Metadata from Value

[oota-llvm.git] / include / llvm / IR / Value.h

diff --git a/include/llvm/IR/Value.h b/include/llvm/IR/Value.h
index 02630d8c6664ae405511e8ef85328a6658815e6c..92070210f2c405558d6b17f4387490fecf7e7bff 100644 (file)
--- a/include/llvm/IR/Value.h
+++ b/include/llvm/IR/Value.h
@@ -37,7 +37,6 @@ class GlobalVariable;
 class InlineAsm;
 class Instruction;
 class LLVMContext;
-class MDNode;
 class Module;
 class StringRef;
 class Twine;
@@ -70,9 +69,9 @@ class Value {
   Type *VTy;
   Use *UseList;
 
-  friend class ValueSymbolTable; // Allow ValueSymbolTable to directly mod Name.
+  friend class ValueAsMetadata; // Allow access to NameAndIsUsedByMD.
   friend class ValueHandleBase;
-  ValueName *Name;
+  PointerIntPair<ValueName *, 1> NameAndIsUsedByMD;
 
   const unsigned char SubclassID;   // Subclass identifier (for isa/dyn_cast)
   unsigned char HasValueHandle : 1; // Has a ValueHandle pointing to this?
@@ -92,6 +91,19 @@ private:
   /// field is initialized to zero by the ctor.
   unsigned short SubclassData;
 
+protected:
+  /// \brief The number of operands in the subclass.
+  ///
+  /// This member is defined by this class, but not used for anything.
+  /// Subclasses can use it to store their number of operands, if they have
+  /// any.
+  ///
+  /// This is stored here to save space in User on 64-bit hosts.  Since most
+  /// instances of Value have operands, 32-bit hosts aren't significantly
+  /// affected.
+  unsigned NumOperands;
+
+private:
   template <typename UseT> // UseT == 'Use' or 'const Use'
   class use_iterator_impl
       : public std::iterator<std::forward_iterator_tag, UseT *, ptrdiff_t> {
@@ -213,10 +225,14 @@ public:
   LLVMContext &getContext() const;
 
   // \brief All values can potentially be named.
-  bool hasName() const { return Name != nullptr && SubclassID != MDStringVal; }
-  ValueName *getValueName() const { return Name; }
-  void setValueName(ValueName *VN) { Name = VN; }
+  bool hasName() const { return getValueName() != nullptr; }
+  ValueName *getValueName() const { return NameAndIsUsedByMD.getPointer(); }
+  void setValueName(ValueName *VN) { NameAndIsUsedByMD.setPointer(VN); }
+
+private:
+  void destroyValueName();
 
+public:
   /// \brief Return a constant reference to the value's name.
   ///
   /// This is cheap and guaranteed to return the same reference as long as the
@@ -245,6 +261,13 @@ public:
   /// guaranteed to be empty.
   void replaceAllUsesWith(Value *V);
 
+  /// replaceUsesOutsideBlock - Go through the uses list for this definition and
+  /// make each use point to "V" instead of "this" when the use is outside the
+  /// block. 'This's use list is expected to have at least one element.
+  /// Unlike replaceAllUsesWith this function does not support basic block
+  /// values or constant users.
+  void replaceUsesOutsideBlock(Value *V, BasicBlock *BB);
+
   //----------------------------------------------------------------------
   // Methods for handling the chain of uses of this Value.
   //
@@ -332,8 +355,7 @@ public:
     ConstantStructVal,        // This is an instance of ConstantStruct
     ConstantVectorVal,        // This is an instance of ConstantVector
     ConstantPointerNullVal,   // This is an instance of ConstantPointerNull
-    MDNodeVal,                // This is an instance of MDNode
-    MDStringVal,              // This is an instance of MDString
+    MetadataAsValueVal,       // This is an instance of MetadataAsValue
     InlineAsmVal,             // This is an instance of InlineAsm
     InstructionVal,           // This is an instance of Instruction
     // Enum values starting at InstructionVal are used for Instructions;
@@ -383,6 +405,9 @@ public:
   /// \brief Return true if there is a value handle associated with this value.
   bool hasValueHandle() const { return HasValueHandle; }
 
+  /// \brief Return true if there is metadata referencing this value.
+  bool isUsedByMetadata() const { return NameAndIsUsedByMD.getInt(); }
+
   /// \brief Strip off pointer casts, all-zero GEPs, and aliases.
   ///
   /// Returns the original uncasted value.  If this is called on a non-pointer
@@ -666,12 +691,6 @@ template <> struct isa_impl<GlobalObject, Value> {
   }
 };
 
-template <> struct isa_impl<MDNode, Value> {
-  static inline bool doit(const Value &Val) {
-    return Val.getValueID() == Value::MDNodeVal;
-  }
-};
-
 // Value* is only 4-byte aligned.
 template<>
 class PointerLikeTypeTraits<Value*> {