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_IR_OPERANDTRAITS_H
16#define LLVM_IR_OPERANDTRAITS_H
17
18#include "llvm/IR/User.h"
19
20namespace llvm {
21
22//===----------------------------------------------------------------------===//
23//                          FixedNumOperand 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 <typename SubClass, unsigned ARITY>
31struct FixedNumOperandTraits {
32  static Use *op_begin(SubClass* U) {
33    static_assert(
34        !std::is_polymorphic<SubClass>::value,
35        "adding virtual methods to subclasses of User breaks use lists");
36    return reinterpret_cast<Use*>(U) - ARITY;
37  }
38  static Use *op_end(SubClass* U) {
39    return reinterpret_cast<Use*>(U);
40  }
41  static unsigned operands(const User*) {
42    return ARITY;
43  }
44};
45
46//===----------------------------------------------------------------------===//
47//                          OptionalOperand Trait Class
48//===----------------------------------------------------------------------===//
49
50/// OptionalOperandTraits - when the number of operands may change at runtime.
51/// Naturally it may only decrease, because the allocations may not change.
52
53template <typename SubClass, unsigned ARITY = 1>
54struct OptionalOperandTraits : public FixedNumOperandTraits<SubClass, ARITY> {
55  static unsigned operands(const User *U) {
56    return U->getNumOperands();
57  }
58};
59
60//===----------------------------------------------------------------------===//
61//                          VariadicOperand Trait Class
62//===----------------------------------------------------------------------===//
63
64/// VariadicOperandTraits - determine the allocation regime of the Use array
65/// when it is a prefix to the User object, and the number of Use objects is
66/// only known at allocation time.
67
68template <typename SubClass, unsigned MINARITY = 0>
69struct VariadicOperandTraits {
70  static Use *op_begin(SubClass* U) {
71    static_assert(
72        !std::is_polymorphic<SubClass>::value,
73        "adding virtual methods to subclasses of User breaks use lists");
74    return reinterpret_cast<Use*>(U) - static_cast<User*>(U)->getNumOperands();
75  }
76  static Use *op_end(SubClass* U) {
77    return reinterpret_cast<Use*>(U);
78  }
79  static unsigned operands(const User *U) {
80    return U->getNumOperands();
81  }
82};
83
84//===----------------------------------------------------------------------===//
85//                          HungoffOperand Trait Class
86//===----------------------------------------------------------------------===//
87
88/// HungoffOperandTraits - determine the allocation regime of the Use array
89/// when it is not a prefix to the User object, but allocated at an unrelated
90/// heap address.
91///
92/// This is the traits class that is needed when the Use array must be
93/// resizable.
94
95template <unsigned MINARITY = 1>
96struct HungoffOperandTraits {
97  static Use *op_begin(User* U) {
98    return U->getOperandList();
99  }
100  static Use *op_end(User* U) {
101    return U->getOperandList() + U->getNumOperands();
102  }
103  static unsigned operands(const User *U) {
104    return U->getNumOperands();
105  }
106};
107
108/// Macro for generating in-class operand accessor declarations.
109/// It should only be called in the public section of the interface.
110///
111#define DECLARE_TRANSPARENT_OPERAND_ACCESSORS(VALUECLASS) \
112  public: \
113  inline VALUECLASS *getOperand(unsigned) const; \
114  inline void setOperand(unsigned, VALUECLASS*); \
115  inline op_iterator op_begin(); \
116  inline const_op_iterator op_begin() const; \
117  inline op_iterator op_end(); \
118  inline const_op_iterator op_end() const; \
119  protected: \
120  template <int> inline Use &Op(); \
121  template <int> inline const Use &Op() const; \
122  public: \
123  inline unsigned getNumOperands() const
124
125/// Macro for generating out-of-class operand accessor definitions
126#define DEFINE_TRANSPARENT_OPERAND_ACCESSORS(CLASS, VALUECLASS) \
127CLASS::op_iterator CLASS::op_begin() { \
128  return OperandTraits<CLASS>::op_begin(this); \
129} \
130CLASS::const_op_iterator CLASS::op_begin() const { \
131  return OperandTraits<CLASS>::op_begin(const_cast<CLASS*>(this)); \
132} \
133CLASS::op_iterator CLASS::op_end() { \
134  return OperandTraits<CLASS>::op_end(this); \
135} \
136CLASS::const_op_iterator CLASS::op_end() const { \
137  return OperandTraits<CLASS>::op_end(const_cast<CLASS*>(this)); \
138} \
139VALUECLASS *CLASS::getOperand(unsigned i_nocapture) const { \
140  assert(i_nocapture < OperandTraits<CLASS>::operands(this) \
141         && "getOperand() out of range!"); \
142  return cast_or_null<VALUECLASS>( \
143    OperandTraits<CLASS>::op_begin(const_cast<CLASS*>(this))[i_nocapture].get()); \
144} \
145void CLASS::setOperand(unsigned i_nocapture, VALUECLASS *Val_nocapture) { \
146  assert(i_nocapture < OperandTraits<CLASS>::operands(this) \
147         && "setOperand() out of range!"); \
148  OperandTraits<CLASS>::op_begin(this)[i_nocapture] = Val_nocapture; \
149} \
150unsigned CLASS::getNumOperands() const { \
151  return OperandTraits<CLASS>::operands(this); \
152} \
153template <int Idx_nocapture> Use &CLASS::Op() { \
154  return this->OpFrom<Idx_nocapture>(this); \
155} \
156template <int Idx_nocapture> const Use &CLASS::Op() const { \
157  return this->OpFrom<Idx_nocapture>(this); \
158}
159
160
161} // End llvm namespace
162
163#endif
164