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,
167 const MCSymbol &getSymbol() const { return *Symbol; }
169 VariantKind getKind() const { return Kind; }
172 /// @name Static Utility Functions
175 static StringRef getVariantKindName(VariantKind Kind);
177 static VariantKind getVariantKindForName(StringRef Name);
181 static bool classof(const MCExpr *E) {
182 return E->getKind() == MCExpr::SymbolRef;
184 static bool classof(const MCSymbolRefExpr *) { return true; }
187 /// MCUnaryExpr - Unary assembler expressions.
188 class MCUnaryExpr : public MCExpr {
191 LNot, ///< Logical negation.
192 Minus, ///< Unary minus.
193 Not, ///< Bitwise negation.
194 Plus ///< Unary plus.
201 MCUnaryExpr(Opcode _Op, const MCExpr *_Expr)
202 : MCExpr(MCExpr::Unary), Op(_Op), Expr(_Expr) {}
205 /// @name Construction
208 static const MCUnaryExpr *Create(Opcode Op, const MCExpr *Expr,
210 static const MCUnaryExpr *CreateLNot(const MCExpr *Expr, MCContext &Ctx) {
211 return Create(LNot, Expr, Ctx);
213 static const MCUnaryExpr *CreateMinus(const MCExpr *Expr, MCContext &Ctx) {
214 return Create(Minus, Expr, Ctx);
216 static const MCUnaryExpr *CreateNot(const MCExpr *Expr, MCContext &Ctx) {
217 return Create(Not, Expr, Ctx);
219 static const MCUnaryExpr *CreatePlus(const MCExpr *Expr, MCContext &Ctx) {
220 return Create(Plus, Expr, Ctx);
227 /// getOpcode - Get the kind of this unary expression.
228 Opcode getOpcode() const { return Op; }
230 /// getSubExpr - Get the child of this unary expression.
231 const MCExpr *getSubExpr() const { return Expr; }
235 static bool classof(const MCExpr *E) {
236 return E->getKind() == MCExpr::Unary;
238 static bool classof(const MCUnaryExpr *) { return true; }
241 /// MCBinaryExpr - Binary assembler expressions.
242 class MCBinaryExpr : public MCExpr {
246 And, ///< Bitwise and.
247 Div, ///< Signed division.
248 EQ, ///< Equality comparison.
249 GT, ///< Signed greater than comparison (result is either 0 or some
250 ///< target-specific non-zero value)
251 GTE, ///< Signed greater than or equal comparison (result is either 0 or
252 ///< some target-specific non-zero value).
253 LAnd, ///< Logical and.
254 LOr, ///< Logical or.
255 LT, ///< Signed less than comparison (result is either 0 or
256 ///< some target-specific non-zero value).
257 LTE, ///< Signed less than or equal comparison (result is either 0 or
258 ///< some target-specific non-zero value).
259 Mod, ///< Signed remainder.
260 Mul, ///< Multiplication.
261 NE, ///< Inequality comparison.
263 Shl, ///< Shift left.
264 Shr, ///< Shift right (arithmetic or logical, depending on target)
265 Sub, ///< Subtraction.
266 Xor ///< Bitwise exclusive or.
271 const MCExpr *LHS, *RHS;
273 MCBinaryExpr(Opcode _Op, const MCExpr *_LHS, const MCExpr *_RHS)
274 : MCExpr(MCExpr::Binary), Op(_Op), LHS(_LHS), RHS(_RHS) {}
277 /// @name Construction
280 static const MCBinaryExpr *Create(Opcode Op, const MCExpr *LHS,
281 const MCExpr *RHS, MCContext &Ctx);
282 static const MCBinaryExpr *CreateAdd(const MCExpr *LHS, const MCExpr *RHS,
284 return Create(Add, LHS, RHS, Ctx);
286 static const MCBinaryExpr *CreateAnd(const MCExpr *LHS, const MCExpr *RHS,
288 return Create(And, LHS, RHS, Ctx);
290 static const MCBinaryExpr *CreateDiv(const MCExpr *LHS, const MCExpr *RHS,
292 return Create(Div, LHS, RHS, Ctx);
294 static const MCBinaryExpr *CreateEQ(const MCExpr *LHS, const MCExpr *RHS,
296 return Create(EQ, LHS, RHS, Ctx);
298 static const MCBinaryExpr *CreateGT(const MCExpr *LHS, const MCExpr *RHS,
300 return Create(GT, LHS, RHS, Ctx);
302 static const MCBinaryExpr *CreateGTE(const MCExpr *LHS, const MCExpr *RHS,
304 return Create(GTE, LHS, RHS, Ctx);
306 static const MCBinaryExpr *CreateLAnd(const MCExpr *LHS, const MCExpr *RHS,
308 return Create(LAnd, LHS, RHS, Ctx);
310 static const MCBinaryExpr *CreateLOr(const MCExpr *LHS, const MCExpr *RHS,
312 return Create(LOr, LHS, RHS, Ctx);
314 static const MCBinaryExpr *CreateLT(const MCExpr *LHS, const MCExpr *RHS,
316 return Create(LT, LHS, RHS, Ctx);
318 static const MCBinaryExpr *CreateLTE(const MCExpr *LHS, const MCExpr *RHS,
320 return Create(LTE, LHS, RHS, Ctx);
322 static const MCBinaryExpr *CreateMod(const MCExpr *LHS, const MCExpr *RHS,
324 return Create(Mod, LHS, RHS, Ctx);
326 static const MCBinaryExpr *CreateMul(const MCExpr *LHS, const MCExpr *RHS,
328 return Create(Mul, LHS, RHS, Ctx);
330 static const MCBinaryExpr *CreateNE(const MCExpr *LHS, const MCExpr *RHS,
332 return Create(NE, LHS, RHS, Ctx);
334 static const MCBinaryExpr *CreateOr(const MCExpr *LHS, const MCExpr *RHS,
336 return Create(Or, LHS, RHS, Ctx);
338 static const MCBinaryExpr *CreateShl(const MCExpr *LHS, const MCExpr *RHS,
340 return Create(Shl, LHS, RHS, Ctx);
342 static const MCBinaryExpr *CreateShr(const MCExpr *LHS, const MCExpr *RHS,
344 return Create(Shr, LHS, RHS, Ctx);
346 static const MCBinaryExpr *CreateSub(const MCExpr *LHS, const MCExpr *RHS,
348 return Create(Sub, LHS, RHS, Ctx);
350 static const MCBinaryExpr *CreateXor(const MCExpr *LHS, const MCExpr *RHS,
352 return Create(Xor, LHS, RHS, Ctx);
359 /// getOpcode - Get the kind of this binary expression.
360 Opcode getOpcode() const { return Op; }
362 /// getLHS - Get the left-hand side expression of the binary operator.
363 const MCExpr *getLHS() const { return LHS; }
365 /// getRHS - Get the right-hand side expression of the binary operator.
366 const MCExpr *getRHS() const { return RHS; }
370 static bool classof(const MCExpr *E) {
371 return E->getKind() == MCExpr::Binary;
373 static bool classof(const MCBinaryExpr *) { return true; }
376 /// MCTargetExpr - This is an extension point for target-specific MCExpr
377 /// subclasses to implement.
379 /// NOTE: All subclasses are required to have trivial destructors because
380 /// MCExprs are bump pointer allocated and not destructed.
381 class MCTargetExpr : public MCExpr {
382 virtual void Anchor();
384 MCTargetExpr() : MCExpr(Target) {}
385 virtual ~MCTargetExpr() {}
388 virtual void PrintImpl(raw_ostream &OS) const = 0;
389 virtual bool EvaluateAsRelocatableImpl(MCValue &Res,
390 const MCAsmLayout *Layout) const = 0;
393 static bool classof(const MCExpr *E) {
394 return E->getKind() == MCExpr::Target;
396 static bool classof(const MCTargetExpr *) { return true; }
399 } // end namespace llvm