Operator.h revision d30658c3ffd1e33e98b82750202a9375bf5963ed 
1//===-- llvm/Operator.h - Operator utility subclass -------------*- 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 various classes for working with Instructions and
11// ConstantExprs.
12//
13//===----------------------------------------------------------------------===//
14
15#ifndef LLVM_OPERATOR_H
16#define LLVM_OPERATOR_H
17
18#include "llvm/Instruction.h"
19#include "llvm/Constants.h"
20
21namespace llvm {
22
23class GetElementPtrInst;
24
25/// Operator - This is a utility class that provides an abstraction for the
26/// common functionality between Instructions and ConstantExprs.
27///
28class Operator : public User {
29private:
30  // Do not implement any of these. The Operator class is intended to be used
31  // as a utility, and is never itself instantiated.
32  void *operator new(size_t, unsigned);
33  void *operator new(size_t s);
34  Operator();
35  ~Operator();
36
37public:
38  /// getOpcode - Return the opcode for this Instruction or ConstantExpr.
39  ///
40  unsigned getOpcode() const {
41    if (const Instruction *I = dyn_cast<Instruction>(this))
42      return I->getOpcode();
43    return cast<ConstantExpr>(this)->getOpcode();
44  }
45
46  /// getOpcode - If V is an Instruction or ConstantExpr, return its
47  /// opcode. Otherwise return UserOp1.
48  ///
49  static unsigned getOpcode(const Value *V) {
50    if (const Instruction *I = dyn_cast<Instruction>(V))
51      return I->getOpcode();
52    if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(V))
53      return CE->getOpcode();
54    return Instruction::UserOp1;
55  }
56
57  static inline bool classof(const Operator *) { return true; }
58  static inline bool classof(const Instruction *I) { return true; }
59  static inline bool classof(const ConstantExpr *I) { return true; }
60  static inline bool classof(const Value *V) {
61    return isa<Instruction>(V) || isa<ConstantExpr>(V);
62  }
63};
64
65/// OverflowingBinaryOperator - Utility class for integer arithmetic operators
66/// which may exhibit overflow - Add, Sub, and Mul. It does not include SDiv,
67/// despite that operator having the potential for overflow.
68///
69class OverflowingBinaryOperator : public Operator {
70public:
71  /// hasNoUnsignedOverflow - Test whether this operation is known to never
72  /// undergo unsigned overflow.
73  bool hasNoUnsignedOverflow() const {
74    return SubclassOptionalData & (1 << 0);
75  }
76  void setHasNoUnsignedOverflow(bool B) {
77    SubclassOptionalData = (SubclassOptionalData & ~(1 << 0)) | (B << 0);
78  }
79
80  /// hasNoSignedOverflow - Test whether this operation is known to never
81  /// undergo signed overflow.
82  bool hasNoSignedOverflow() const {
83    return SubclassOptionalData & (1 << 1);
84  }
85  void setHasNoSignedOverflow(bool B) {
86    SubclassOptionalData = (SubclassOptionalData & ~(1 << 1)) | (B << 1);
87  }
88
89  static inline bool classof(const OverflowingBinaryOperator *) { return true; }
90  static inline bool classof(const Instruction *I) {
91    return I->getOpcode() == Instruction::Add ||
92           I->getOpcode() == Instruction::Sub ||
93           I->getOpcode() == Instruction::Mul;
94  }
95  static inline bool classof(const ConstantExpr *CE) {
96    return CE->getOpcode() == Instruction::Add ||
97           CE->getOpcode() == Instruction::Sub ||
98           CE->getOpcode() == Instruction::Mul;
99  }
100  static inline bool classof(const Value *V) {
101    return (isa<Instruction>(V) && classof(cast<Instruction>(V))) ||
102           (isa<ConstantExpr>(V) && classof(cast<ConstantExpr>(V)));
103  }
104};
105
106/// AddOperator - Utility class for integer addition operators.
107///
108class AddOperator : public OverflowingBinaryOperator {
109public:
110  static inline bool classof(const AddOperator *) { return true; }
111  static inline bool classof(const Instruction *I) {
112    return I->getOpcode() == Instruction::Add;
113  }
114  static inline bool classof(const ConstantExpr *CE) {
115    return CE->getOpcode() == Instruction::Add;
116  }
117  static inline bool classof(const Value *V) {
118    return (isa<Instruction>(V) && classof(cast<Instruction>(V))) ||
119           (isa<ConstantExpr>(V) && classof(cast<ConstantExpr>(V)));
120  }
121};
122
123/// SubOperator - Utility class for integer subtraction operators.
124///
125class SubOperator : public OverflowingBinaryOperator {
126public:
127  static inline bool classof(const SubOperator *) { return true; }
128  static inline bool classof(const Instruction *I) {
129    return I->getOpcode() == Instruction::Sub;
130  }
131  static inline bool classof(const ConstantExpr *CE) {
132    return CE->getOpcode() == Instruction::Sub;
133  }
134  static inline bool classof(const Value *V) {
135    return (isa<Instruction>(V) && classof(cast<Instruction>(V))) ||
136           (isa<ConstantExpr>(V) && classof(cast<ConstantExpr>(V)));
137  }
138};
139
140/// MulOperator - Utility class for integer multiplication operators.
141///
142class MulOperator : public OverflowingBinaryOperator {
143public:
144  static inline bool classof(const MulOperator *) { return true; }
145  static inline bool classof(const Instruction *I) {
146    return I->getOpcode() == Instruction::Mul;
147  }
148  static inline bool classof(const ConstantExpr *CE) {
149    return CE->getOpcode() == Instruction::Mul;
150  }
151  static inline bool classof(const Value *V) {
152    return (isa<Instruction>(V) && classof(cast<Instruction>(V))) ||
153           (isa<ConstantExpr>(V) && classof(cast<ConstantExpr>(V)));
154  }
155};
156
157/// SDivOperator - An Operator with opcode Instruction::SDiv.
158///
159class SDivOperator : public Operator {
160public:
161  /// isExact - Test whether this division is known to be exact, with
162  /// zero remainder.
163  bool isExact() const {
164    return SubclassOptionalData & (1 << 0);
165  }
166  void setIsExact(bool B) {
167    SubclassOptionalData = (SubclassOptionalData & ~(1 << 0)) | (B << 0);
168  }
169
170  // Methods for support type inquiry through isa, cast, and dyn_cast:
171  static inline bool classof(const SDivOperator *) { return true; }
172  static inline bool classof(const ConstantExpr *CE) {
173    return CE->getOpcode() == Instruction::SDiv;
174  }
175  static inline bool classof(const Instruction *I) {
176    return I->getOpcode() == Instruction::SDiv;
177  }
178  static inline bool classof(const Value *V) {
179    return (isa<Instruction>(V) && classof(cast<Instruction>(V))) ||
180           (isa<ConstantExpr>(V) && classof(cast<ConstantExpr>(V)));
181  }
182};
183
184class GEPOperator : public Operator {
185public:
186  /// isInBounds - Test whether this is an inbounds GEP, as defined
187  /// by LangRef.html.
188  bool isInBounds() const {
189    return SubclassOptionalData & (1 << 0);
190  }
191  void setIsInBounds(bool B) {
192    SubclassOptionalData = (SubclassOptionalData & ~(1 << 0)) | (B << 0);
193  }
194
195  inline op_iterator       idx_begin()       { return op_begin()+1; }
196  inline const_op_iterator idx_begin() const { return op_begin()+1; }
197  inline op_iterator       idx_end()         { return op_end(); }
198  inline const_op_iterator idx_end()   const { return op_end(); }
199
200  Value *getPointerOperand() {
201    return getOperand(0);
202  }
203  const Value *getPointerOperand() const {
204    return getOperand(0);
205  }
206  static unsigned getPointerOperandIndex() {
207    return 0U;                      // get index for modifying correct operand
208  }
209
210  /// getPointerOperandType - Method to return the pointer operand as a
211  /// PointerType.
212  const PointerType *getPointerOperandType() const {
213    return reinterpret_cast<const PointerType*>(getPointerOperand()->getType());
214  }
215
216  unsigned getNumIndices() const {  // Note: always non-negative
217    return getNumOperands() - 1;
218  }
219
220  bool hasIndices() const {
221    return getNumOperands() > 1;
222  }
223
224  /// hasAllZeroIndices - Return true if all of the indices of this GEP are
225  /// zeros.  If so, the result pointer and the first operand have the same
226  /// value, just potentially different types.
227  bool hasAllZeroIndices() const {
228    for (const_op_iterator I = idx_begin(), E = idx_end(); I != E; ++I) {
229      if (Constant *C = dyn_cast<Constant>(I))
230        if (C->isNullValue())
231          continue;
232      return false;
233    }
234    return true;
235  }
236
237  // Methods for support type inquiry through isa, cast, and dyn_cast:
238  static inline bool classof(const GEPOperator *) { return true; }
239  static inline bool classof(const GetElementPtrInst *) { return true; }
240  static inline bool classof(const ConstantExpr *CE) {
241    return CE->getOpcode() == Instruction::GetElementPtr;
242  }
243  static inline bool classof(const Instruction *I) {
244    return I->getOpcode() == Instruction::GetElementPtr;
245  }
246  static inline bool classof(const Value *V) {
247    return (isa<Instruction>(V) && classof(cast<Instruction>(V))) ||
248           (isa<ConstantExpr>(V) && classof(cast<ConstantExpr>(V)));
249  }
250};
251
252} // End llvm namespace
253
254#endif
255