• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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 
21 namespace llvm {
22 
23 class GetElementPtrInst;
24 class BinaryOperator;
25 class ConstantExpr;
26 
27 /// Operator - This is a utility class that provides an abstraction for the
28 /// common functionality between Instructions and ConstantExprs.
29 ///
30 class Operator : public User {
31 private:
32   // Do not implement any of these. The Operator class is intended to be used
33   // as a utility, and is never itself instantiated.
34   void *operator new(size_t, unsigned);
35   void *operator new(size_t s);
36   Operator();
37   ~Operator();
38 
39 public:
40   /// getOpcode - Return the opcode for this Instruction or ConstantExpr.
41   ///
getOpcode()42   unsigned getOpcode() const {
43     if (const Instruction *I = dyn_cast<Instruction>(this))
44       return I->getOpcode();
45     return cast<ConstantExpr>(this)->getOpcode();
46   }
47 
48   /// getOpcode - If V is an Instruction or ConstantExpr, return its
49   /// opcode. Otherwise return UserOp1.
50   ///
getOpcode(const Value * V)51   static unsigned getOpcode(const Value *V) {
52     if (const Instruction *I = dyn_cast<Instruction>(V))
53       return I->getOpcode();
54     if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(V))
55       return CE->getOpcode();
56     return Instruction::UserOp1;
57   }
58 
classof(const Operator *)59   static inline bool classof(const Operator *) { return true; }
classof(const Instruction *)60   static inline bool classof(const Instruction *) { return true; }
classof(const ConstantExpr *)61   static inline bool classof(const ConstantExpr *) { return true; }
classof(const Value * V)62   static inline bool classof(const Value *V) {
63     return isa<Instruction>(V) || isa<ConstantExpr>(V);
64   }
65 };
66 
67 /// OverflowingBinaryOperator - Utility class for integer arithmetic operators
68 /// which may exhibit overflow - Add, Sub, and Mul. It does not include SDiv,
69 /// despite that operator having the potential for overflow.
70 ///
71 class OverflowingBinaryOperator : public Operator {
72 public:
73   enum {
74     NoUnsignedWrap = (1 << 0),
75     NoSignedWrap   = (1 << 1)
76   };
77 
78 private:
79   ~OverflowingBinaryOperator(); // do not implement
80 
81   friend class BinaryOperator;
82   friend class ConstantExpr;
setHasNoUnsignedWrap(bool B)83   void setHasNoUnsignedWrap(bool B) {
84     SubclassOptionalData =
85       (SubclassOptionalData & ~NoUnsignedWrap) | (B * NoUnsignedWrap);
86   }
setHasNoSignedWrap(bool B)87   void setHasNoSignedWrap(bool B) {
88     SubclassOptionalData =
89       (SubclassOptionalData & ~NoSignedWrap) | (B * NoSignedWrap);
90   }
91 
92 public:
93   /// hasNoUnsignedWrap - Test whether this operation is known to never
94   /// undergo unsigned overflow, aka the nuw property.
hasNoUnsignedWrap()95   bool hasNoUnsignedWrap() const {
96     return SubclassOptionalData & NoUnsignedWrap;
97   }
98 
99   /// hasNoSignedWrap - Test whether this operation is known to never
100   /// undergo signed overflow, aka the nsw property.
hasNoSignedWrap()101   bool hasNoSignedWrap() const {
102     return (SubclassOptionalData & NoSignedWrap) != 0;
103   }
104 
classof(const OverflowingBinaryOperator *)105   static inline bool classof(const OverflowingBinaryOperator *) { return true; }
classof(const Instruction * I)106   static inline bool classof(const Instruction *I) {
107     return I->getOpcode() == Instruction::Add ||
108            I->getOpcode() == Instruction::Sub ||
109            I->getOpcode() == Instruction::Mul ||
110            I->getOpcode() == Instruction::Shl;
111   }
classof(const ConstantExpr * CE)112   static inline bool classof(const ConstantExpr *CE) {
113     return CE->getOpcode() == Instruction::Add ||
114            CE->getOpcode() == Instruction::Sub ||
115            CE->getOpcode() == Instruction::Mul ||
116            CE->getOpcode() == Instruction::Shl;
117   }
classof(const Value * V)118   static inline bool classof(const Value *V) {
119     return (isa<Instruction>(V) && classof(cast<Instruction>(V))) ||
120            (isa<ConstantExpr>(V) && classof(cast<ConstantExpr>(V)));
121   }
122 };
123 
124 /// PossiblyExactOperator - A udiv or sdiv instruction, which can be marked as
125 /// "exact", indicating that no bits are destroyed.
126 class PossiblyExactOperator : public Operator {
127 public:
128   enum {
129     IsExact = (1 << 0)
130   };
131 
132   friend class BinaryOperator;
133   friend class ConstantExpr;
setIsExact(bool B)134   void setIsExact(bool B) {
135     SubclassOptionalData = (SubclassOptionalData & ~IsExact) | (B * IsExact);
136   }
137 
138 private:
139   ~PossiblyExactOperator(); // do not implement
140 public:
141   /// isExact - Test whether this division is known to be exact, with
142   /// zero remainder.
isExact()143   bool isExact() const {
144     return SubclassOptionalData & IsExact;
145   }
146 
isPossiblyExactOpcode(unsigned OpC)147   static bool isPossiblyExactOpcode(unsigned OpC) {
148     return OpC == Instruction::SDiv ||
149            OpC == Instruction::UDiv ||
150            OpC == Instruction::AShr ||
151            OpC == Instruction::LShr;
152   }
classof(const ConstantExpr * CE)153   static inline bool classof(const ConstantExpr *CE) {
154     return isPossiblyExactOpcode(CE->getOpcode());
155   }
classof(const Instruction * I)156   static inline bool classof(const Instruction *I) {
157     return isPossiblyExactOpcode(I->getOpcode());
158   }
classof(const Value * V)159   static inline bool classof(const Value *V) {
160     return (isa<Instruction>(V) && classof(cast<Instruction>(V))) ||
161            (isa<ConstantExpr>(V) && classof(cast<ConstantExpr>(V)));
162   }
163 };
164 
165 
166 
167 /// ConcreteOperator - A helper template for defining operators for individual
168 /// opcodes.
169 template<typename SuperClass, unsigned Opc>
170 class ConcreteOperator : public SuperClass {
171   ~ConcreteOperator(); // DO NOT IMPLEMENT
172 public:
classof(const ConcreteOperator<SuperClass,Opc> *)173   static inline bool classof(const ConcreteOperator<SuperClass, Opc> *) {
174     return true;
175   }
classof(const Instruction * I)176   static inline bool classof(const Instruction *I) {
177     return I->getOpcode() == Opc;
178   }
classof(const ConstantExpr * CE)179   static inline bool classof(const ConstantExpr *CE) {
180     return CE->getOpcode() == Opc;
181   }
classof(const Value * V)182   static inline bool classof(const Value *V) {
183     return (isa<Instruction>(V) && classof(cast<Instruction>(V))) ||
184            (isa<ConstantExpr>(V) && classof(cast<ConstantExpr>(V)));
185   }
186 };
187 
188 class AddOperator
189   : public ConcreteOperator<OverflowingBinaryOperator, Instruction::Add> {
190   ~AddOperator(); // DO NOT IMPLEMENT
191 };
192 class SubOperator
193   : public ConcreteOperator<OverflowingBinaryOperator, Instruction::Sub> {
194   ~SubOperator(); // DO NOT IMPLEMENT
195 };
196 class MulOperator
197   : public ConcreteOperator<OverflowingBinaryOperator, Instruction::Mul> {
198   ~MulOperator(); // DO NOT IMPLEMENT
199 };
200 class ShlOperator
201   : public ConcreteOperator<OverflowingBinaryOperator, Instruction::Shl> {
202   ~ShlOperator(); // DO NOT IMPLEMENT
203 };
204 
205 
206 class SDivOperator
207   : public ConcreteOperator<PossiblyExactOperator, Instruction::SDiv> {
208   ~SDivOperator(); // DO NOT IMPLEMENT
209 };
210 class UDivOperator
211   : public ConcreteOperator<PossiblyExactOperator, Instruction::UDiv> {
212   ~UDivOperator(); // DO NOT IMPLEMENT
213 };
214 class AShrOperator
215   : public ConcreteOperator<PossiblyExactOperator, Instruction::AShr> {
216   ~AShrOperator(); // DO NOT IMPLEMENT
217 };
218 class LShrOperator
219   : public ConcreteOperator<PossiblyExactOperator, Instruction::LShr> {
220   ~LShrOperator(); // DO NOT IMPLEMENT
221 };
222 
223 
224 
225 class GEPOperator
226   : public ConcreteOperator<Operator, Instruction::GetElementPtr> {
227   ~GEPOperator(); // DO NOT IMPLEMENT
228 
229   enum {
230     IsInBounds = (1 << 0)
231   };
232 
233   friend class GetElementPtrInst;
234   friend class ConstantExpr;
setIsInBounds(bool B)235   void setIsInBounds(bool B) {
236     SubclassOptionalData =
237       (SubclassOptionalData & ~IsInBounds) | (B * IsInBounds);
238   }
239 
240 public:
241   /// isInBounds - Test whether this is an inbounds GEP, as defined
242   /// by LangRef.html.
isInBounds()243   bool isInBounds() const {
244     return SubclassOptionalData & IsInBounds;
245   }
246 
idx_begin()247   inline op_iterator       idx_begin()       { return op_begin()+1; }
idx_begin()248   inline const_op_iterator idx_begin() const { return op_begin()+1; }
idx_end()249   inline op_iterator       idx_end()         { return op_end(); }
idx_end()250   inline const_op_iterator idx_end()   const { return op_end(); }
251 
getPointerOperand()252   Value *getPointerOperand() {
253     return getOperand(0);
254   }
getPointerOperand()255   const Value *getPointerOperand() const {
256     return getOperand(0);
257   }
getPointerOperandIndex()258   static unsigned getPointerOperandIndex() {
259     return 0U;                      // get index for modifying correct operand
260   }
261 
262   /// getPointerOperandType - Method to return the pointer operand as a
263   /// PointerType.
getPointerOperandType()264   PointerType *getPointerOperandType() const {
265     return reinterpret_cast<PointerType*>(getPointerOperand()->getType());
266   }
267 
getNumIndices()268   unsigned getNumIndices() const {  // Note: always non-negative
269     return getNumOperands() - 1;
270   }
271 
hasIndices()272   bool hasIndices() const {
273     return getNumOperands() > 1;
274   }
275 
276   /// hasAllZeroIndices - Return true if all of the indices of this GEP are
277   /// zeros.  If so, the result pointer and the first operand have the same
278   /// value, just potentially different types.
hasAllZeroIndices()279   bool hasAllZeroIndices() const {
280     for (const_op_iterator I = idx_begin(), E = idx_end(); I != E; ++I) {
281       if (ConstantInt *C = dyn_cast<ConstantInt>(I))
282         if (C->isZero())
283           continue;
284       return false;
285     }
286     return true;
287   }
288 
289   /// hasAllConstantIndices - Return true if all of the indices of this GEP are
290   /// constant integers.  If so, the result pointer and the first operand have
291   /// a constant offset between them.
hasAllConstantIndices()292   bool hasAllConstantIndices() const {
293     for (const_op_iterator I = idx_begin(), E = idx_end(); I != E; ++I) {
294       if (!isa<ConstantInt>(I))
295         return false;
296     }
297     return true;
298   }
299 };
300 
301 } // End llvm namespace
302 
303 #endif
304