1 //===- MCExpr.h - Assembly Level Expressions --------------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 #ifndef LLVM_MC_MCEXPR_H
11 #define LLVM_MC_MCEXPR_H
13 #include "llvm/Support/Casting.h"
14 #include "llvm/System/DataTypes.h"
25 /// MCExpr - Base class for the full range of assembler expressions which are
26 /// needed for parsing.
30 Binary, ///< Binary expressions.
31 Constant, ///< Constant expressions.
32 SymbolRef, ///< References to labels and assigned expressions.
33 Unary, ///< Unary expressions.
34 Target ///< Target specific expression.
40 MCExpr(const MCExpr&); // DO NOT IMPLEMENT
41 void operator=(const MCExpr&); // DO NOT IMPLEMENT
44 explicit MCExpr(ExprKind _Kind) : Kind(_Kind) {}
50 ExprKind getKind() const { return Kind; }
53 /// @name Utility Methods
56 void print(raw_ostream &OS) const;
60 /// @name Expression Evaluation
63 /// EvaluateAsAbsolute - Try to evaluate the expression to an absolute value.
65 /// @param Res - The absolute value, if evaluation succeeds.
66 /// @param Layout - The assembler layout object to use for evaluating symbol
67 /// values. If not given, then only non-symbolic expressions will be
69 /// @result - True on success.
70 bool EvaluateAsAbsolute(int64_t &Res, const MCAsmLayout *Layout = 0) const;
72 /// EvaluateAsRelocatable - Try to evaluate the expression to a relocatable
73 /// value, i.e. an expression of the fixed form (a - b + constant).
75 /// @param Res - The relocatable value, if evaluation succeeds.
76 /// @param Layout - The assembler layout object to use for evaluating values.
77 /// @result - True on success.
78 bool EvaluateAsRelocatable(MCValue &Res, const MCAsmLayout *Layout = 0) const;
82 static bool classof(const MCExpr *) { return true; }
85 inline raw_ostream &operator<<(raw_ostream &OS, const MCExpr &E) {
90 //// MCConstantExpr - Represent a constant integer expression.
91 class MCConstantExpr : public MCExpr {
94 explicit MCConstantExpr(int64_t _Value)
95 : MCExpr(MCExpr::Constant), Value(_Value) {}
98 /// @name Construction
101 static const MCConstantExpr *Create(int64_t Value, MCContext &Ctx);
107 int64_t getValue() const { return Value; }
111 static bool classof(const MCExpr *E) {
112 return E->getKind() == MCExpr::Constant;
114 static bool classof(const MCConstantExpr *) { return true; }
117 /// MCSymbolRefExpr - Represent a reference to a symbol from inside an
120 /// A symbol reference in an expression may be a use of a label, a use of an
121 /// assembler variable (defined constant), or constitute an implicit definition
122 /// of the symbol as external.
123 class MCSymbolRefExpr : public MCExpr {
124 const MCSymbol *Symbol;
126 explicit MCSymbolRefExpr(const MCSymbol *_Symbol)
127 : MCExpr(MCExpr::SymbolRef), Symbol(_Symbol) {}
130 /// @name Construction
133 static const MCSymbolRefExpr *Create(const MCSymbol *Symbol, MCContext &Ctx);
134 static const MCSymbolRefExpr *Create(StringRef Name, MCContext &Ctx);
136 /// CreateTemp - Create a reference to an assembler temporary label with the
138 static const MCSymbolRefExpr *CreateTemp(StringRef Name, MCContext &Ctx);
144 const MCSymbol &getSymbol() const { return *Symbol; }
148 static bool classof(const MCExpr *E) {
149 return E->getKind() == MCExpr::SymbolRef;
151 static bool classof(const MCSymbolRefExpr *) { return true; }
154 /// MCUnaryExpr - Unary assembler expressions.
155 class MCUnaryExpr : public MCExpr {
158 LNot, ///< Logical negation.
159 Minus, ///< Unary minus.
160 Not, ///< Bitwise negation.
161 Plus ///< Unary plus.
168 MCUnaryExpr(Opcode _Op, const MCExpr *_Expr)
169 : MCExpr(MCExpr::Unary), Op(_Op), Expr(_Expr) {}
172 /// @name Construction
175 static const MCUnaryExpr *Create(Opcode Op, const MCExpr *Expr,
177 static const MCUnaryExpr *CreateLNot(const MCExpr *Expr, MCContext &Ctx) {
178 return Create(LNot, Expr, Ctx);
180 static const MCUnaryExpr *CreateMinus(const MCExpr *Expr, MCContext &Ctx) {
181 return Create(Minus, Expr, Ctx);
183 static const MCUnaryExpr *CreateNot(const MCExpr *Expr, MCContext &Ctx) {
184 return Create(Not, Expr, Ctx);
186 static const MCUnaryExpr *CreatePlus(const MCExpr *Expr, MCContext &Ctx) {
187 return Create(Plus, Expr, Ctx);
194 /// getOpcode - Get the kind of this unary expression.
195 Opcode getOpcode() const { return Op; }
197 /// getSubExpr - Get the child of this unary expression.
198 const MCExpr *getSubExpr() const { return Expr; }
202 static bool classof(const MCExpr *E) {
203 return E->getKind() == MCExpr::Unary;
205 static bool classof(const MCUnaryExpr *) { return true; }
208 /// MCBinaryExpr - Binary assembler expressions.
209 class MCBinaryExpr : public MCExpr {
213 And, ///< Bitwise and.
214 Div, ///< Signed division.
215 EQ, ///< Equality comparison.
216 GT, ///< Signed greater than comparison (result is either 0 or some
217 ///< target-specific non-zero value)
218 GTE, ///< Signed greater than or equal comparison (result is either 0 or
219 ///< some target-specific non-zero value).
220 LAnd, ///< Logical and.
221 LOr, ///< Logical or.
222 LT, ///< Signed less than comparison (result is either 0 or
223 ///< some target-specific non-zero value).
224 LTE, ///< Signed less than or equal comparison (result is either 0 or
225 ///< some target-specific non-zero value).
226 Mod, ///< Signed remainder.
227 Mul, ///< Multiplication.
228 NE, ///< Inequality comparison.
230 Shl, ///< Shift left.
231 Shr, ///< Shift right (arithmetic or logical, depending on target)
232 Sub, ///< Subtraction.
233 Xor ///< Bitwise exclusive or.
238 const MCExpr *LHS, *RHS;
240 MCBinaryExpr(Opcode _Op, const MCExpr *_LHS, const MCExpr *_RHS)
241 : MCExpr(MCExpr::Binary), Op(_Op), LHS(_LHS), RHS(_RHS) {}
244 /// @name Construction
247 static const MCBinaryExpr *Create(Opcode Op, const MCExpr *LHS,
248 const MCExpr *RHS, MCContext &Ctx);
249 static const MCBinaryExpr *CreateAdd(const MCExpr *LHS, const MCExpr *RHS,
251 return Create(Add, LHS, RHS, Ctx);
253 static const MCBinaryExpr *CreateAnd(const MCExpr *LHS, const MCExpr *RHS,
255 return Create(And, LHS, RHS, Ctx);
257 static const MCBinaryExpr *CreateDiv(const MCExpr *LHS, const MCExpr *RHS,
259 return Create(Div, LHS, RHS, Ctx);
261 static const MCBinaryExpr *CreateEQ(const MCExpr *LHS, const MCExpr *RHS,
263 return Create(EQ, LHS, RHS, Ctx);
265 static const MCBinaryExpr *CreateGT(const MCExpr *LHS, const MCExpr *RHS,
267 return Create(GT, LHS, RHS, Ctx);
269 static const MCBinaryExpr *CreateGTE(const MCExpr *LHS, const MCExpr *RHS,
271 return Create(GTE, LHS, RHS, Ctx);
273 static const MCBinaryExpr *CreateLAnd(const MCExpr *LHS, const MCExpr *RHS,
275 return Create(LAnd, LHS, RHS, Ctx);
277 static const MCBinaryExpr *CreateLOr(const MCExpr *LHS, const MCExpr *RHS,
279 return Create(LOr, LHS, RHS, Ctx);
281 static const MCBinaryExpr *CreateLT(const MCExpr *LHS, const MCExpr *RHS,
283 return Create(LT, LHS, RHS, Ctx);
285 static const MCBinaryExpr *CreateLTE(const MCExpr *LHS, const MCExpr *RHS,
287 return Create(LTE, LHS, RHS, Ctx);
289 static const MCBinaryExpr *CreateMod(const MCExpr *LHS, const MCExpr *RHS,
291 return Create(Mod, LHS, RHS, Ctx);
293 static const MCBinaryExpr *CreateMul(const MCExpr *LHS, const MCExpr *RHS,
295 return Create(Mul, LHS, RHS, Ctx);
297 static const MCBinaryExpr *CreateNE(const MCExpr *LHS, const MCExpr *RHS,
299 return Create(NE, LHS, RHS, Ctx);
301 static const MCBinaryExpr *CreateOr(const MCExpr *LHS, const MCExpr *RHS,
303 return Create(Or, LHS, RHS, Ctx);
305 static const MCBinaryExpr *CreateShl(const MCExpr *LHS, const MCExpr *RHS,
307 return Create(Shl, LHS, RHS, Ctx);
309 static const MCBinaryExpr *CreateShr(const MCExpr *LHS, const MCExpr *RHS,
311 return Create(Shr, LHS, RHS, Ctx);
313 static const MCBinaryExpr *CreateSub(const MCExpr *LHS, const MCExpr *RHS,
315 return Create(Sub, LHS, RHS, Ctx);
317 static const MCBinaryExpr *CreateXor(const MCExpr *LHS, const MCExpr *RHS,
319 return Create(Xor, LHS, RHS, Ctx);
326 /// getOpcode - Get the kind of this binary expression.
327 Opcode getOpcode() const { return Op; }
329 /// getLHS - Get the left-hand side expression of the binary operator.
330 const MCExpr *getLHS() const { return LHS; }
332 /// getRHS - Get the right-hand side expression of the binary operator.
333 const MCExpr *getRHS() const { return RHS; }
337 static bool classof(const MCExpr *E) {
338 return E->getKind() == MCExpr::Binary;
340 static bool classof(const MCBinaryExpr *) { return true; }
343 /// MCTargetExpr - This is an extension point for target-specific MCExpr
344 /// subclasses to implement.
346 /// NOTE: All subclasses are required to have trivial destructors because
347 /// MCExprs are bump pointer allocated and not destructed.
348 class MCTargetExpr : public MCExpr {
349 virtual void Anchor();
351 MCTargetExpr() : MCExpr(Target) {}
352 virtual ~MCTargetExpr() {}
355 virtual void PrintImpl(raw_ostream &OS) const = 0;
356 virtual bool EvaluateAsRelocatableImpl(MCValue &Res,
357 const MCAsmLayout *Layout) const = 0;
360 static bool classof(const MCExpr *E) {
361 return E->getKind() == MCExpr::Target;
363 static bool classof(const MCTargetExpr *) { return true; }
366 } // end namespace llvm