X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=include%2Fllvm%2FUser.h;h=f8277952ee4ba9fa7cd03e8ee116c4a4fbb9f5fa;hb=b095ba439ddc9199d2340e55b29a93050fae7639;hp=7cc4cfb036d6efba277ba66a2a22967541132fc9;hpb=fb3f24fd57312f7f9317eedfa7b85e0dde112a00;p=oota-llvm.git

diff --git a/include/llvm/User.h b/include/llvm/User.h
index 7cc4cfb036d..f8277952ee4 100644
--- a/include/llvm/User.h
+++ b/include/llvm/User.h
@@ -1,4 +1,11 @@
-//===-- llvm/User.h - User class definition ----------------------*- C++ -*--=//
+//===-- llvm/User.h - User class definition ---------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
 //
 // This class defines the interface that one who 'use's a Value must implement.
 // Each instance of the Value class keeps track of what User's have handles
@@ -13,67 +20,185 @@
 #define LLVM_USER_H
 
 #include "llvm/Value.h"
-#include <vector>
+
+namespace llvm {
+
+/// OperandTraits - Compile-time customization of
+/// operand-related allocators and accessors
+/// for use of the User class
+template <class>
+struct OperandTraits;
+
+class User;
+
+/// OperandTraits<User> - specialization to User
+template <>
+struct OperandTraits<User> {
+  static inline Use *op_begin(User*);
+  static inline Use *op_end(User*);
+  static inline unsigned operands(const User*);
+  template <class U>
+  struct Layout {
+    typedef U overlay;
+  };
+};
 
 class User : public Value {
   User(const User &);             // Do not implement
+  void *operator new(size_t);     // Do not implement
+  template <unsigned>
+  friend struct HungoffOperandTraits;
 protected:
-  vector<Use> Operands;
-public:
-  User(const Type *Ty, ValueTy vty, const string &name = "");
-  virtual ~User() { dropAllReferences(); }
+  /// OperandList - This is a pointer to the array of Uses for this User.
+  /// For nodes of fixed arity (e.g. a binary operator) this array will live
+  /// prefixed to some derived class instance.  For nodes of resizable variable
+  /// arity (e.g. PHINodes, SwitchInst etc.), this memory will be dynamically
+  /// allocated and should be destroyed by the classes' virtual dtor.
+  Use *OperandList;
 
-  inline Value *getOperand(unsigned i) { 
-    assert(i < Operands.size() && "getOperand() out of range!");
-    return Operands[i]; 
+  /// NumOperands - The number of values used by this User.
+  ///
+  unsigned NumOperands;
+
+  void *operator new(size_t s, unsigned Us);
+  void *operator new(size_t s, unsigned Us, bool Prefix);
+  User(const Type *ty, unsigned vty, Use *OpList, unsigned NumOps)
+    : Value(ty, vty), OperandList(OpList), NumOperands(NumOps) {}
+  Use *allocHungoffUses(unsigned) const;
+  void dropHungoffUses(Use *U) {
+    if (OperandList == U) {
+      OperandList = 0;
+      NumOperands = 0;
+    }
+    Use::zap(U, U->getImpliedUser(), true);
+  }
+public:
+  ~User() {
+    if ((intptr_t(OperandList) & 1) == 0)
+      Use::zap(OperandList, OperandList + NumOperands);
+  }
+  /// operator delete - free memory allocated for User and Use objects
+  void operator delete(void *Usr);
+  /// placement delete - required by std, but never called.
+  void operator delete(void*, unsigned) {
+    assert(0 && "Constructor throws?");
+  }
+  /// placement delete - required by std, but never called.
+  void operator delete(void*, unsigned, bool) {
+    assert(0 && "Constructor throws?");
+  }
+protected:
+  template <int Idx, typename U> static Use &OpFrom(const U *that) {
+    return Idx < 0
+      ? OperandTraits<U>::op_end(const_cast<U*>(that))[Idx]
+      : OperandTraits<U>::op_begin(const_cast<U*>(that))[Idx];
+  }
+  template <int Idx> Use &Op() {
+    return OpFrom<Idx>(this);
+  }
+  template <int Idx> const Use &Op() const {
+    return OpFrom<Idx>(this);
+  }
+public:
+  Value *getOperand(unsigned i) const {
+    assert(i < NumOperands && "getOperand() out of range!");
+    return OperandList[i];
+  }
+  void setOperand(unsigned i, Value *Val) {
+    assert(i < NumOperands && "setOperand() out of range!");
+    assert((!isa<Constant>((const Value*)this) ||
+            isa<GlobalValue>((const Value*)this)) &&
+           "Cannot mutate a constant with setOperand!");
+    OperandList[i] = Val;
   }
-  inline const Value *getOperand(unsigned i) const {
-    assert(i < Operands.size() && "getOperand() const out of range!");
-    return Operands[i]; 
+  const Use &getOperandUse(unsigned i) const {
+    assert(i < NumOperands && "getOperand() out of range!");
+    return OperandList[i];
   }
-  inline void setOperand(unsigned i, Value *Val) {
-    assert(i < Operands.size() && "setOperand() out of range!");
-    Operands[i] = Val;
+  Use &getOperandUse(unsigned i) {
+    assert(i < NumOperands && "getOperand() out of range!");
+    return OperandList[i];
   }
-  inline unsigned getNumOperands() const { return Operands.size(); }
+  
+  unsigned getNumOperands() const { return NumOperands; }
 
   // ---------------------------------------------------------------------------
   // Operand Iterator interface...
   //
-  typedef vector<Use>::iterator       op_iterator;
-  typedef vector<Use>::const_iterator op_const_iterator;
+  typedef Use*       op_iterator;
+  typedef const Use* const_op_iterator;
 
-  inline op_iterator       op_begin()       { return Operands.begin(); }
-  inline op_const_iterator op_begin() const { return Operands.begin(); }
-  inline op_iterator       op_end()         { return Operands.end(); }
-  inline op_const_iterator op_end()   const { return Operands.end(); }
+  inline op_iterator       op_begin()       { return OperandList; }
+  inline const_op_iterator op_begin() const { return OperandList; }
+  inline op_iterator       op_end()         { return OperandList+NumOperands; }
+  inline const_op_iterator op_end()   const { return OperandList+NumOperands; }
 
   // dropAllReferences() - This function is in charge of "letting go" of all
   // objects that this User refers to.  This allows one to
   // 'delete' a whole class at a time, even though there may be circular
-  // references... first all references are dropped, and all use counts go to
-  // zero.  Then everything is delete'd for real.  Note that no operations are
-  // valid on an object that has "dropped all references", except operator 
+  // references...  First all references are dropped, and all use counts go to
+  // zero.  Then everything is deleted for real.  Note that no operations are
+  // valid on an object that has "dropped all references", except operator
   // delete.
   //
-  inline void dropAllReferences() {
-    Operands.clear();
+  void dropAllReferences() {
+    for (op_iterator i = op_begin(), e = op_end(); i != e; ++i)
+      i->set(0);
   }
 
-  // replaceUsesOfWith - Replaces all references to the "From" definition with
-  // references to the "To" definition.  (defined in Value.cpp)
-  //
+  /// replaceUsesOfWith - Replaces all references to the "From" definition with
+  /// references to the "To" definition.
+  ///
   void replaceUsesOfWith(Value *From, Value *To);
 
-  // addOperand - This is a special purpose API that should not be used in most
-  // cases.  It adds an empty (null) operand to the instruction specified.  This
-  // is currently used by the back end as part of the "lowering" process... most
-  // optimizations will not handle instructions that are not in their normal
-  // form, so this method should be used with care.
-  //
-  void addOperand() {
-    Operands.push_back(Use(0, this));
+  // Methods for support type inquiry through isa, cast, and dyn_cast:
+  static inline bool classof(const User *) { return true; }
+  static inline bool classof(const Value *V) {
+    return isa<Instruction>(V) || isa<Constant>(V);
+  }
+};
+
+inline Use *OperandTraits<User>::op_begin(User *U) {
+  return U->op_begin();
+}
+
+inline Use *OperandTraits<User>::op_end(User *U) {
+  return U->op_end();
+}
+
+inline unsigned OperandTraits<User>::operands(const User *U) {
+  return U->getNumOperands();
+}
+
+template<> struct simplify_type<User::op_iterator> {
+  typedef Value* SimpleType;
+
+  static SimpleType getSimplifiedValue(const User::op_iterator &Val) {
+    return static_cast<SimpleType>(Val->get());
+  }
+};
+
+template<> struct simplify_type<const User::op_iterator>
+  : public simplify_type<User::op_iterator> {};
+
+template<> struct simplify_type<User::const_op_iterator> {
+  typedef Value* SimpleType;
+
+  static SimpleType getSimplifiedValue(const User::const_op_iterator &Val) {
+    return static_cast<SimpleType>(Val->get());
   }
 };
 
+template<> struct simplify_type<const User::const_op_iterator>
+  : public simplify_type<User::const_op_iterator> {};
+
+
+// value_use_iterator::getOperandNo - Requires the definition of the User class.
+template<typename UserTy>
+unsigned value_use_iterator<UserTy>::getOperandNo() const {
+  return U - U->getUser()->op_begin();
+}
+
+} // End llvm namespace
+
 #endif