OperandTraits.h revision 07252fd463d2378383ae035e45f6ed3c12959efe 
1//===-- llvm/OperandTraits.h - OperandTraits class definition ---------------------*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file defines the traits classes that are handy for enforcing the correct
11// layout of various User subclasses. It also provides the means for accessing
12// the operands in the most efficient manner.
13//
14
15#ifndef LLVM_OPERAND_TRAITS_H
16#define LLVM_OPERAND_TRAITS_H
17
18#include "llvm/User.h"
19
20namespace llvm {
21
22//===----------------------------------------------------------------------===//
23//                          FixedNumOperands Trait Class
24//===----------------------------------------------------------------------===//
25
26/// FixedNumOperandTraits - determine the allocation regime of the Use array
27/// when it is a prefix to the User object, and the number of Use objects is
28/// known at compile time.
29
30template <unsigned ARITY>
31struct FixedNumOperandTraits {
32  static Use *op_begin(User* U) {
33    return reinterpret_cast<Use*>(U) - ARITY;
34  }
35  static Use *op_end(User* U) {
36    return reinterpret_cast<Use*>(U);
37  }
38  static unsigned operands(const User*) {
39    return ARITY;
40  }
41  struct prefix {
42    Use Ops[ARITY];
43    prefix(); // DO NOT IMPLEMENT
44  };
45  template <class U>
46  struct Layout {
47    struct overlay : prefix, U {
48      overlay(); // DO NOT IMPLEMENT
49    };
50  };
51  static inline void *allocate(unsigned); // FIXME
52};
53
54//===----------------------------------------------------------------------===//
55//                          OptionalOperands Trait Class
56//===----------------------------------------------------------------------===//
57
58template <unsigned ARITY = 1>
59struct OptionalOperandTraits : FixedNumOperandTraits<ARITY> {
60  static unsigned operands(const User *U) {
61    return U->getNumOperands();
62  }
63};
64
65//===----------------------------------------------------------------------===//
66//                          VariadicOperand Trait Class
67//===----------------------------------------------------------------------===//
68
69/// VariadicOperandTraits - determine the allocation regime of the Use array
70/// when it is a prefix to the User object, and the number of Use objects is
71/// only known at allocation time.
72
73template <unsigned MINARITY = 0>
74struct VariadicOperandTraits {
75  static Use *op_begin(User* U) {
76    return reinterpret_cast<Use*>(U) - U->getNumOperands();
77  }
78  static Use *op_end(User* U) {
79    return reinterpret_cast<Use*>(U);
80  }
81  static unsigned operands(const User *U) {
82    return U->getNumOperands();
83  }
84  static inline void *allocate(unsigned); // FIXME
85};
86
87//===----------------------------------------------------------------------===//
88//                          HungoffOperand Trait Class
89//===----------------------------------------------------------------------===//
90
91/// HungoffOperandTraits - determine the allocation regime of the Use array
92/// when it is not a prefix to the User object, but allocated at an unrelated
93/// heap address.
94/// Assumes that the User subclass that is determined by this traits class
95/// has an OperandList member of type User::op_iterator. [Note: this is now
96/// trivially satisfied, because User has that member for historic reasons.]
97///
98/// This is the traits class that is needed when the Use array must be
99/// resizable.
100
101template <unsigned MINARITY = 1>
102struct HungoffOperandTraits {
103  static Use *op_begin(User* U) {
104    return U->OperandList;
105  }
106  static Use *op_end(User* U) {
107    return U->OperandList + U->getNumOperands();
108  }
109  static unsigned operands(const User *U) {
110    return U->getNumOperands();
111  }
112  static inline void *allocate(unsigned); // FIXME
113};
114
115/// Macro for generating in-class operand accessor declarations.
116/// It should only be called in the public section of the interface.
117///
118#define DECLARE_TRANSPARENT_OPERAND_ACCESSORS(VALUECLASS) \
119  public: \
120  inline VALUECLASS *getOperand(unsigned) const; \
121  inline void setOperand(unsigned, VALUECLASS*); \
122  protected: \
123  template <unsigned> inline Use &Op(); \
124  template <unsigned> inline const Use &Op() const; \
125  public: \
126  inline unsigned getNumOperands() const
127
128/// Macro for generating out-of-class operand accessor definitions
129#define DEFINE_TRANSPARENT_OPERAND_ACCESSORS(CLASS, VALUECLASS) \
130VALUECLASS *CLASS::getOperand(unsigned i_nocapture) const { \
131  assert(i_nocapture < OperandTraits<CLASS>::operands(this) \
132         && "getOperand() out of range!"); \
133  return static_cast<VALUECLASS*>( \
134    OperandTraits<CLASS>::op_begin(const_cast<CLASS*>(this))[i_nocapture]); \
135} \
136void CLASS::setOperand(unsigned i_nocapture, VALUECLASS *Val_nocapture) { \
137  assert(i_nocapture < OperandTraits<CLASS>::operands(this) \
138         && "setOperand() out of range!"); \
139  OperandTraits<CLASS>::op_begin(this)[i_nocapture] = Val_nocapture; \
140} \
141unsigned CLASS::getNumOperands() const { \
142  return OperandTraits<CLASS>::operands(this);  \
143} \
144template <unsigned Idx_nocapture> Use &CLASS::Op() { \
145  return OperandTraits<CLASS>::op_begin(this)[Idx_nocapture]; \
146} \
147template <unsigned Idx_nocapture> const Use &CLASS::Op() const { \
148  return OperandTraits<CLASS>::op_begin( \
149    const_cast<CLASS*>(this))[Idx_nocapture]; \
150}
151
152
153/// Macro for generating out-of-class operand accessor
154/// definitions with casted result
155#define DEFINE_TRANSPARENT_CASTED_OPERAND_ACCESSORS(CLASS, VALUECLASS) \
156VALUECLASS *CLASS::getOperand(unsigned i_nocapture) const { \
157  assert(i_nocapture < OperandTraits<CLASS>::operands(this) \
158         && "getOperand() out of range!"); \
159  return cast<VALUECLASS>( \
160    OperandTraits<CLASS>::op_begin(const_cast<CLASS*>(this))[i_nocapture]); \
161} \
162void CLASS::setOperand(unsigned i_nocapture, VALUECLASS *Val_nocapture) { \
163  assert(i_nocapture < OperandTraits<CLASS>::operands(this) \
164         && "setOperand() out of range!"); \
165  OperandTraits<CLASS>::op_begin(this)[i_nocapture] = Val_nocapture; \
166} \
167unsigned CLASS::getNumOperands() const { \
168  return OperandTraits<CLASS>::operands(this); \
169} \
170template <unsigned Idx_nocapture> Use &CLASS::Op() { \
171  return OperandTraits<CLASS>::op_begin(this)[Idx_nocapture]; \
172} \
173template <unsigned Idx_nocapture> const Use &CLASS::Op() const { \
174  return OperandTraits<CLASS>::op_begin( \
175    const_cast<CLASS*>(this))[Idx_nocapture]; \
176}
177
178
179} // End llvm namespace
180
181#endif
182