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 {
141 /// The symbol being referenced.
142 const MCSymbol *Symbol;
144 /// The symbol reference modifier.
145 const VariantKind Kind;
147 explicit MCSymbolRefExpr(const MCSymbol *_Symbol, VariantKind _Kind)
148 : MCExpr(MCExpr::SymbolRef), Symbol(_Symbol), Kind(_Kind) {}
151 /// @name Construction
154 static const MCSymbolRefExpr *Create(const MCSymbol *Symbol, MCContext &Ctx) {
155 return MCSymbolRefExpr::Create(Symbol, VK_None, Ctx);
158 static const MCSymbolRefExpr *Create(const MCSymbol *Symbol, VariantKind Kind,
160 static const MCSymbolRefExpr *Create(StringRef Name, VariantKind Kind,
163 /// CreateTemp - Create a reference to an assembler temporary label with the
165 static const MCSymbolRefExpr *CreateTemp(StringRef Name, VariantKind Kind,
172 const MCSymbol &getSymbol() const { return *Symbol; }
174 VariantKind getKind() const { return Kind; }
177 /// @name Static Utility Functions
180 static StringRef getVariantKindName(VariantKind Kind);
182 static VariantKind getVariantKindForName(StringRef Name);
186 static bool classof(const MCExpr *E) {
187 return E->getKind() == MCExpr::SymbolRef;
189 static bool classof(const MCSymbolRefExpr *) { return true; }
192 /// MCUnaryExpr - Unary assembler expressions.
193 class MCUnaryExpr : public MCExpr {
196 LNot, ///< Logical negation.
197 Minus, ///< Unary minus.
198 Not, ///< Bitwise negation.
199 Plus ///< Unary plus.
206 MCUnaryExpr(Opcode _Op, const MCExpr *_Expr)
207 : MCExpr(MCExpr::Unary), Op(_Op), Expr(_Expr) {}
210 /// @name Construction
213 static const MCUnaryExpr *Create(Opcode Op, const MCExpr *Expr,
215 static const MCUnaryExpr *CreateLNot(const MCExpr *Expr, MCContext &Ctx) {
216 return Create(LNot, Expr, Ctx);
218 static const MCUnaryExpr *CreateMinus(const MCExpr *Expr, MCContext &Ctx) {
219 return Create(Minus, Expr, Ctx);
221 static const MCUnaryExpr *CreateNot(const MCExpr *Expr, MCContext &Ctx) {
222 return Create(Not, Expr, Ctx);
224 static const MCUnaryExpr *CreatePlus(const MCExpr *Expr, MCContext &Ctx) {
225 return Create(Plus, Expr, Ctx);
232 /// getOpcode - Get the kind of this unary expression.
233 Opcode getOpcode() const { return Op; }
235 /// getSubExpr - Get the child of this unary expression.
236 const MCExpr *getSubExpr() const { return Expr; }
240 static bool classof(const MCExpr *E) {
241 return E->getKind() == MCExpr::Unary;
243 static bool classof(const MCUnaryExpr *) { return true; }
246 /// MCBinaryExpr - Binary assembler expressions.
247 class MCBinaryExpr : public MCExpr {
251 And, ///< Bitwise and.
252 Div, ///< Signed division.
253 EQ, ///< Equality comparison.
254 GT, ///< Signed greater than comparison (result is either 0 or some
255 ///< target-specific non-zero value)
256 GTE, ///< Signed greater than or equal comparison (result is either 0 or
257 ///< some target-specific non-zero value).
258 LAnd, ///< Logical and.
259 LOr, ///< Logical or.
260 LT, ///< Signed less than comparison (result is either 0 or
261 ///< some target-specific non-zero value).
262 LTE, ///< Signed less than or equal comparison (result is either 0 or
263 ///< some target-specific non-zero value).
264 Mod, ///< Signed remainder.
265 Mul, ///< Multiplication.
266 NE, ///< Inequality comparison.
268 Shl, ///< Shift left.
269 Shr, ///< Shift right (arithmetic or logical, depending on target)
270 Sub, ///< Subtraction.
271 Xor ///< Bitwise exclusive or.
276 const MCExpr *LHS, *RHS;
278 MCBinaryExpr(Opcode _Op, const MCExpr *_LHS, const MCExpr *_RHS)
279 : MCExpr(MCExpr::Binary), Op(_Op), LHS(_LHS), RHS(_RHS) {}
282 /// @name Construction
285 static const MCBinaryExpr *Create(Opcode Op, const MCExpr *LHS,
286 const MCExpr *RHS, MCContext &Ctx);
287 static const MCBinaryExpr *CreateAdd(const MCExpr *LHS, const MCExpr *RHS,
289 return Create(Add, LHS, RHS, Ctx);
291 static const MCBinaryExpr *CreateAnd(const MCExpr *LHS, const MCExpr *RHS,
293 return Create(And, LHS, RHS, Ctx);
295 static const MCBinaryExpr *CreateDiv(const MCExpr *LHS, const MCExpr *RHS,
297 return Create(Div, LHS, RHS, Ctx);
299 static const MCBinaryExpr *CreateEQ(const MCExpr *LHS, const MCExpr *RHS,
301 return Create(EQ, LHS, RHS, Ctx);
303 static const MCBinaryExpr *CreateGT(const MCExpr *LHS, const MCExpr *RHS,
305 return Create(GT, LHS, RHS, Ctx);
307 static const MCBinaryExpr *CreateGTE(const MCExpr *LHS, const MCExpr *RHS,
309 return Create(GTE, LHS, RHS, Ctx);
311 static const MCBinaryExpr *CreateLAnd(const MCExpr *LHS, const MCExpr *RHS,
313 return Create(LAnd, LHS, RHS, Ctx);
315 static const MCBinaryExpr *CreateLOr(const MCExpr *LHS, const MCExpr *RHS,
317 return Create(LOr, LHS, RHS, Ctx);
319 static const MCBinaryExpr *CreateLT(const MCExpr *LHS, const MCExpr *RHS,
321 return Create(LT, LHS, RHS, Ctx);
323 static const MCBinaryExpr *CreateLTE(const MCExpr *LHS, const MCExpr *RHS,
325 return Create(LTE, LHS, RHS, Ctx);
327 static const MCBinaryExpr *CreateMod(const MCExpr *LHS, const MCExpr *RHS,
329 return Create(Mod, LHS, RHS, Ctx);
331 static const MCBinaryExpr *CreateMul(const MCExpr *LHS, const MCExpr *RHS,
333 return Create(Mul, LHS, RHS, Ctx);
335 static const MCBinaryExpr *CreateNE(const MCExpr *LHS, const MCExpr *RHS,
337 return Create(NE, LHS, RHS, Ctx);
339 static const MCBinaryExpr *CreateOr(const MCExpr *LHS, const MCExpr *RHS,
341 return Create(Or, LHS, RHS, Ctx);
343 static const MCBinaryExpr *CreateShl(const MCExpr *LHS, const MCExpr *RHS,
345 return Create(Shl, LHS, RHS, Ctx);
347 static const MCBinaryExpr *CreateShr(const MCExpr *LHS, const MCExpr *RHS,
349 return Create(Shr, LHS, RHS, Ctx);
351 static const MCBinaryExpr *CreateSub(const MCExpr *LHS, const MCExpr *RHS,
353 return Create(Sub, LHS, RHS, Ctx);
355 static const MCBinaryExpr *CreateXor(const MCExpr *LHS, const MCExpr *RHS,
357 return Create(Xor, LHS, RHS, Ctx);
364 /// getOpcode - Get the kind of this binary expression.
365 Opcode getOpcode() const { return Op; }
367 /// getLHS - Get the left-hand side expression of the binary operator.
368 const MCExpr *getLHS() const { return LHS; }
370 /// getRHS - Get the right-hand side expression of the binary operator.
371 const MCExpr *getRHS() const { return RHS; }
375 static bool classof(const MCExpr *E) {
376 return E->getKind() == MCExpr::Binary;
378 static bool classof(const MCBinaryExpr *) { return true; }
381 /// MCTargetExpr - This is an extension point for target-specific MCExpr
382 /// subclasses to implement.
384 /// NOTE: All subclasses are required to have trivial destructors because
385 /// MCExprs are bump pointer allocated and not destructed.
386 class MCTargetExpr : public MCExpr {
387 virtual void Anchor();
389 MCTargetExpr() : MCExpr(Target) {}
390 virtual ~MCTargetExpr() {}
393 virtual void PrintImpl(raw_ostream &OS) const = 0;
394 virtual bool EvaluateAsRelocatableImpl(MCValue &Res,
395 const MCAsmLayout *Layout) const = 0;
398 static bool classof(const MCExpr *E) {
399 return E->getKind() == MCExpr::Target;
401 static bool classof(const MCTargetExpr *) { return true; }
404 } // end namespace llvm