llvm-6502/include/llvm/IR/User.h
Rafael Espindola 7fe65d691d Cleanup the simplify_type implementation.
As far as simplify_type is concerned, there are 3 kinds of smart pointers:

* const correct: A 'const MyPtr<int> &' produces a 'const int*'. A
'MyPtr<int> &' produces a 'int *'.
* always const: Even a 'MyPtr<int> &' produces a 'const int*'.
* no const: Even a 'const MyPtr<int> &' produces a 'int*'.

This patch then does the following:

* Removes the unused specializations. Since they are unused, it is hard
to know which kind should be implemented.
* Make sure we don't drop const.
* Fix the default forwarding so that const correct pointer only need
one specialization.
* Simplifies the existing specializations.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178147 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-27 16:43:11 +00:00

206 lines
6.8 KiB
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 uses a Value must implement.
// Each instance of the Value class keeps track of what User's have handles
// to it.
//
// * Instructions are the largest class of Users.
// * Constants may be users of other constants (think arrays and stuff)
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_IR_USER_H
#define LLVM_IR_USER_H
#include "llvm/IR/Value.h"
#include "llvm/Support/ErrorHandling.h"
namespace llvm {
/// OperandTraits - Compile-time customization of
/// operand-related allocators and accessors
/// for use of the User class
template <class>
struct OperandTraits;
class User : public Value {
User(const User &) LLVM_DELETED_FUNCTION;
void *operator new(size_t) LLVM_DELETED_FUNCTION;
template <unsigned>
friend struct HungoffOperandTraits;
virtual void anchor();
protected:
/// 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;
/// NumOperands - The number of values used by this User.
///
unsigned NumOperands;
void *operator new(size_t s, unsigned Us);
User(Type *ty, unsigned vty, Use *OpList, unsigned NumOps)
: Value(ty, vty), OperandList(OpList), NumOperands(NumOps) {}
Use *allocHungoffUses(unsigned) const;
void dropHungoffUses() {
Use::zap(OperandList, OperandList + NumOperands, true);
OperandList = 0;
// Reset NumOperands so User::operator delete() does the right thing.
NumOperands = 0;
}
public:
~User() {
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) {
llvm_unreachable("Constructor throws?");
}
/// placement delete - required by std, but never called.
void operator delete(void*, unsigned, bool) {
llvm_unreachable("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;
}
const Use &getOperandUse(unsigned i) const {
assert(i < NumOperands && "getOperandUse() out of range!");
return OperandList[i];
}
Use &getOperandUse(unsigned i) {
assert(i < NumOperands && "getOperandUse() out of range!");
return OperandList[i];
}
unsigned getNumOperands() const { return NumOperands; }
// ---------------------------------------------------------------------------
// Operand Iterator interface...
//
typedef Use* op_iterator;
typedef const Use* const_op_iterator;
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; }
/// Convenience iterator for directly iterating over the Values in the
/// OperandList
class value_op_iterator : public std::iterator<std::forward_iterator_tag,
Value*> {
op_iterator OI;
public:
explicit value_op_iterator(Use *U) : OI(U) {}
bool operator==(const value_op_iterator &x) const {
return OI == x.OI;
}
bool operator!=(const value_op_iterator &x) const {
return !operator==(x);
}
/// Iterator traversal: forward iteration only
value_op_iterator &operator++() { // Preincrement
++OI;
return *this;
}
value_op_iterator operator++(int) { // Postincrement
value_op_iterator tmp = *this; ++*this; return tmp;
}
/// Retrieve a pointer to the current Value.
Value *operator*() const {
return *OI;
}
Value *operator->() const { return operator*(); }
};
inline value_op_iterator value_op_begin() {
return value_op_iterator(op_begin());
}
inline value_op_iterator value_op_end() {
return value_op_iterator(op_end());
}
// 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 deleted for real. Note that no operations are
// valid on an object that has "dropped all references", except operator
// delete.
//
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.
///
void replaceUsesOfWith(Value *From, Value *To);
// Methods for support type inquiry through isa, cast, and dyn_cast:
static inline bool classof(const Value *V) {
return isa<Instruction>(V) || isa<Constant>(V);
}
};
template<> struct simplify_type<User::op_iterator> {
typedef Value* SimpleType;
static SimpleType getSimplifiedValue(User::op_iterator &Val) {
return Val->get();
}
};
template<> struct simplify_type<User::const_op_iterator> {
typedef /*const*/ Value* SimpleType;
static SimpleType getSimplifiedValue(User::const_op_iterator &Val) {
return Val->get();
}
};
// 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