allow a virtual register to be associated with live-in values.

[oota-llvm.git] / include / llvm / GlobalVariable.h

diff --git a/include/llvm/GlobalVariable.h b/include/llvm/GlobalVariable.h
index fd5e3a692411f7bbeb5b681224fc456a7a19a228..db7a5200e2cd23fb6696de18369372021a3a10c0 100644 (file)
--- a/include/llvm/GlobalVariable.h
+++ b/include/llvm/GlobalVariable.h
@@ -1,4 +1,11 @@
-//===-- llvm/Global.h - Class to represent a global variable -----*- C++ -*--=//
+//===-- llvm/GlobalVariable.h - GlobalVariable class ------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
 //
 // This file contains the declaration of the GlobalVariable class, which
 // represents a single global variable (or constant) in the VM.
@@ -14,6 +21,9 @@
 #define LLVM_GLOBAL_VARIABLE_H
 
 #include "llvm/GlobalValue.h"
+
+namespace llvm {
+
 class Module;
 class Constant;
 class PointerType;
@@ -31,50 +41,80 @@ class GlobalVariable : public GlobalValue {
   void setPrev(GlobalVariable *N) { Prev = N; }
 
   bool isConstantGlobal;               // Is this a global constant?
+  Use Initializer;
+
 public:
   /// GlobalVariable ctor - If a parent module is specified, the global is
   /// automatically inserted into the end of the specified modules global list.
   ///
-  GlobalVariable(const Type *Ty, bool isConstant, bool isInternal,
-                Constant *Initializer = 0, const std::string &Name = "",
+  GlobalVariable(const Type *Ty, bool isConstant, LinkageTypes Linkage,
+                 Constant *Initializer = 0, const std::string &Name = "",
                  Module *Parent = 0);
 
-  // Specialize setName to handle symbol table majik...
-  virtual void setName(const std::string &name, SymbolTable *ST = 0);
+  /// isExternal - Is this global variable lacking an initializer?  If so, the
+  /// global variable is defined in some other translation unit, and is thus
+  /// externally defined here.
+  ///
+  virtual bool isExternal() const { return getNumOperands() == 0; }
+
+  /// hasInitializer - Unless a global variable isExternal(), it has an
+  /// initializer.  The initializer for the global variable/constant is held by
+  /// Initializer if an initializer is specified.
+  ///
+  inline bool hasInitializer() const { return !isExternal(); }
 
-  // The initializer for the global variable/constant is held by Operands[0] if
-  // an initializer is specified.
-  //
-  inline bool hasInitializer() const { return !Operands.empty(); }
+  /// getInitializer - Return the initializer for this global variable.  It is
+  /// illegal to call this method if the global is external, because we cannot
+  /// tell what the value is initialized to!
+  ///
   inline Constant *getInitializer() const {
     assert(hasInitializer() && "GV doesn't have initializer!");
-    return (Constant*)Operands[0].get();
+    return reinterpret_cast<Constant*>(Initializer.get());
   }
   inline Constant *getInitializer() {
     assert(hasInitializer() && "GV doesn't have initializer!");
-    return (Constant*)Operands[0].get();
+    return reinterpret_cast<Constant*>(Initializer.get());
   }
   inline void setInitializer(Constant *CPV) {
     if (CPV == 0) {
-      if (hasInitializer()) Operands.pop_back();
+      if (hasInitializer()) {
+        Initializer.set(0);
+        NumOperands = 0;
+      }
     } else {
-      if (!hasInitializer()) Operands.push_back(Use(0, this));
-      Operands[0] = (Value*)CPV;
+      if (!hasInitializer())
+        NumOperands = 1;
+      Initializer.set(CPV);
     }
   }
 
-  // getNext/Prev - Return the next or previous instruction in the list.  The
-  // last node in the list is a terminator instruction.
+  // getNext/Prev - Return the next or previous global variable in the list.
         GlobalVariable *getNext()       { return Next; }
   const GlobalVariable *getNext() const { return Next; }
         GlobalVariable *getPrev()       { return Prev; }
   const GlobalVariable *getPrev() const { return Prev; }
 
-  // If the value is a global constant, its value is immutable throughout the
-  // runtime execution of the program.  Assigning a value into the constant
-  // leads to undefined behavior.
-  //
-  inline bool isConstant() const { return isConstantGlobal; }
+  /// If the value is a global constant, its value is immutable throughout the
+  /// runtime execution of the program.  Assigning a value into the constant
+  /// leads to undefined behavior.
+  ///
+  bool isConstant() const { return isConstantGlobal; }
+  void setConstant(bool Value) { isConstantGlobal = Value; }
+
+  /// removeFromParent - This method unlinks 'this' from the containing module,
+  /// but does not delete it.
+  ///
+  void removeFromParent();
+
+  /// eraseFromParent - This method unlinks 'this' from the containing module
+  /// and deletes it.
+  ///
+  void eraseFromParent();
+
+  /// Override Constant's implementation of this method so we can
+  /// replace constant initializers.
+  virtual void replaceUsesOfWithOnConstant(Value *From, Value *To,
+                                           bool DisableChecking = false);
 
   virtual void print(std::ostream &OS) const;
 
@@ -85,4 +125,6 @@ public:
   }
 };
 
+} // End llvm namespace
+
 #endif