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;
+ };
+ static inline void *allocate(unsigned);
+};
+
class User : public Value {
User(const User &); // Do not implement
void *operator new(size_t); // Do not implement
+ template <unsigned>
+ friend struct HungoffOperandTraits;
protected:
- /// OperandList - This is a pointer to the array of Users for this operand.
+ /// 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
- /// embedded into the derived class. For nodes of variable arity
- /// (e.g. ConstantArrays, CallInst, PHINodes, ReturnInst etc), this memory
- /// will be dynamically allocated and should be destroyed by the classes
- /// virtual dtor.
+ /// 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;
/// NumOperands - The number of values used by this User.
///
unsigned NumOperands;
- void *operator new(size_t s, unsigned) {
- return ::operator new(s);
+ 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);
}
- User(const Type *Ty, unsigned vty, Use *OpList, unsigned NumOps)
- : Value(Ty, vty), OperandList(OpList), NumOperands(NumOps) {}
-
public:
Value *getOperand(unsigned i) const {
assert(i < NumOperands && "getOperand() out of range!");
}
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;
}
+ const Use &getOperandUse(unsigned i) const {
+ assert(i < NumOperands && "getOperand() out of range!");
+ return OperandList[i];
+ }
+ Use &getOperandUse(unsigned i) {
+ assert(i < NumOperands && "getOperand() out of range!");
+ return OperandList[i];
+ }
+
unsigned getNumOperands() const { return 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
+ // 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.
//
void dropAllReferences() {
- Use *OL = OperandList;
- for (unsigned i = 0, e = NumOperands; i != e; ++i)
- OL[i].set(0);
+ for (op_iterator i = op_begin(), e = op_end(); i != e; ++i)
+ i->set(0);
}
/// replaceUsesOfWith - Replaces all references to the "From" definition with
}
};
+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;