xref: /llvm-project/llvm/include/llvm/MC/MCExpr.h (revision bd9145c8c21334e099d51b3e66f49d51d24931ee)
1 //===- MCExpr.h - Assembly Level Expressions --------------------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #ifndef LLVM_MC_MCEXPR_H
10 #define LLVM_MC_MCEXPR_H
11 
12 #include "llvm/ADT/DenseMap.h"
13 #include "llvm/Support/SMLoc.h"
14 #include <cstdint>
15 
16 namespace llvm {
17 
18 class MCAsmInfo;
19 class MCAssembler;
20 class MCContext;
21 class MCFixup;
22 class MCFragment;
23 class MCSection;
24 class MCStreamer;
25 class MCSymbol;
26 class MCValue;
27 class raw_ostream;
28 class StringRef;
29 
30 using SectionAddrMap = DenseMap<const MCSection *, uint64_t>;
31 
32 /// Base class for the full range of assembler expressions which are
33 /// needed for parsing.
34 class MCExpr {
35 public:
36   enum ExprKind : uint8_t {
37     Binary,    ///< Binary expressions.
38     Constant,  ///< Constant expressions.
39     SymbolRef, ///< References to labels and assigned expressions.
40     Unary,     ///< Unary expressions.
41     Target     ///< Target specific expression.
42   };
43 
44 private:
45   static const unsigned NumSubclassDataBits = 24;
46   static_assert(
47       NumSubclassDataBits == CHAR_BIT * (sizeof(unsigned) - sizeof(ExprKind)),
48       "ExprKind and SubclassData together should take up one word");
49 
50   ExprKind Kind;
51   /// Field reserved for use by MCExpr subclasses.
52   unsigned SubclassData : NumSubclassDataBits;
53   SMLoc Loc;
54 
55   bool evaluateAsAbsolute(int64_t &Res, const MCAssembler *Asm,
56                           const SectionAddrMap *Addrs, bool InSet) const;
57 
58 protected:
59   explicit MCExpr(ExprKind Kind, SMLoc Loc, unsigned SubclassData = 0)
60       : Kind(Kind), SubclassData(SubclassData), Loc(Loc) {
61     assert(SubclassData < (1 << NumSubclassDataBits) &&
62            "Subclass data too large");
63   }
64 
65   bool evaluateAsRelocatableImpl(MCValue &Res, const MCAssembler *Asm,
66                                  const MCFixup *Fixup,
67                                  const SectionAddrMap *Addrs, bool InSet) const;
68 
69   unsigned getSubclassData() const { return SubclassData; }
70 
71 public:
72   MCExpr(const MCExpr &) = delete;
73   MCExpr &operator=(const MCExpr &) = delete;
74 
75   /// \name Accessors
76   /// @{
77 
78   ExprKind getKind() const { return Kind; }
79   SMLoc getLoc() const { return Loc; }
80 
81   /// @}
82   /// \name Utility Methods
83   /// @{
84 
85   void print(raw_ostream &OS, const MCAsmInfo *MAI,
86              bool InParens = false) const;
87   void dump() const;
88 
89   /// Returns whether the given symbol is used anywhere in the expression or
90   /// subexpressions.
91   bool isSymbolUsedInExpression(const MCSymbol *Sym) const;
92 
93   /// @}
94   /// \name Expression Evaluation
95   /// @{
96 
97   /// Try to evaluate the expression to an absolute value.
98   ///
99   /// \param Res - The absolute value, if evaluation succeeds.
100   /// \return - True on success.
101   bool evaluateAsAbsolute(int64_t &Res, const MCAssembler &Asm,
102                           const SectionAddrMap &Addrs) const;
103   bool evaluateAsAbsolute(int64_t &Res) const;
104   bool evaluateAsAbsolute(int64_t &Res, const MCAssembler &Asm) const;
105   bool evaluateAsAbsolute(int64_t &Res, const MCAssembler *Asm) const;
106 
107   /// Aggressive variant of evaluateAsRelocatable when relocations are
108   /// unavailable (e.g. .fill). Expects callers to handle errors when true is
109   /// returned.
110   bool evaluateKnownAbsolute(int64_t &Res, const MCAssembler &Asm) const;
111 
112   /// Try to evaluate the expression to a relocatable value, i.e. an
113   /// expression of the fixed form (a - b + constant).
114   ///
115   /// \param Res - The relocatable value, if evaluation succeeds.
116   /// \param Asm - The assembler object to use for evaluating values.
117   /// \param Fixup - The Fixup object if available.
118   /// \return - True on success.
119   bool evaluateAsRelocatable(MCValue &Res, const MCAssembler *Asm,
120                              const MCFixup *Fixup) const;
121 
122   /// Try to evaluate the expression to the form (a - b + constant) where
123   /// neither a nor b are variables.
124   ///
125   /// This is a more aggressive variant of evaluateAsRelocatable. The intended
126   /// use is for when relocations are not available, like the .size directive.
127   bool evaluateAsValue(MCValue &Res, const MCAssembler &Asm) const;
128 
129   /// Find the "associated section" for this expression, which is
130   /// currently defined as the absolute section for constants, or
131   /// otherwise the section associated with the first defined symbol in the
132   /// expression.
133   MCFragment *findAssociatedFragment() const;
134 
135   /// @}
136 };
137 
138 inline raw_ostream &operator<<(raw_ostream &OS, const MCExpr &E) {
139   E.print(OS, nullptr);
140   return OS;
141 }
142 
143 ////  Represent a constant integer expression.
144 class MCConstantExpr : public MCExpr {
145   int64_t Value;
146 
147   // Subclass data stores SizeInBytes in bits 0..7 and PrintInHex in bit 8.
148   static const unsigned SizeInBytesBits = 8;
149   static const unsigned SizeInBytesMask = (1 << SizeInBytesBits) - 1;
150   static const unsigned PrintInHexBit = 1 << SizeInBytesBits;
151 
152   static unsigned encodeSubclassData(bool PrintInHex, unsigned SizeInBytes) {
153     assert(SizeInBytes <= sizeof(int64_t) && "Excessive size");
154     return SizeInBytes | (PrintInHex ? PrintInHexBit : 0);
155   }
156 
157   MCConstantExpr(int64_t Value, bool PrintInHex, unsigned SizeInBytes)
158       : MCExpr(MCExpr::Constant, SMLoc(),
159                encodeSubclassData(PrintInHex, SizeInBytes)), Value(Value) {}
160 
161 public:
162   /// \name Construction
163   /// @{
164 
165   static const MCConstantExpr *create(int64_t Value, MCContext &Ctx,
166                                       bool PrintInHex = false,
167                                       unsigned SizeInBytes = 0);
168 
169   /// @}
170   /// \name Accessors
171   /// @{
172 
173   int64_t getValue() const { return Value; }
174   unsigned getSizeInBytes() const {
175     return getSubclassData() & SizeInBytesMask;
176   }
177 
178   bool useHexFormat() const { return (getSubclassData() & PrintInHexBit) != 0; }
179 
180   /// @}
181 
182   static bool classof(const MCExpr *E) {
183     return E->getKind() == MCExpr::Constant;
184   }
185 };
186 
187 ///  Represent a reference to a symbol from inside an expression.
188 ///
189 /// A symbol reference in an expression may be a use of a label, a use of an
190 /// assembler variable (defined constant), or constitute an implicit definition
191 /// of the symbol as external.
192 class MCSymbolRefExpr : public MCExpr {
193 public:
194   enum VariantKind : uint16_t {
195     VK_None,
196     VK_Invalid,
197 
198     VK_GOT,
199     VK_GOTENT,
200     VK_GOTOFF,
201     VK_GOTREL,
202     VK_PCREL,
203     VK_GOTPCREL,
204     VK_GOTPCREL_NORELAX,
205     VK_GOTTPOFF,
206     VK_INDNTPOFF,
207     VK_NTPOFF,
208     VK_GOTNTPOFF,
209     VK_PLT,
210     VK_TLSGD,
211     VK_TLSLD,
212     VK_TLSLDM,
213     VK_TPOFF,
214     VK_DTPOFF,
215     VK_TLSCALL, // symbol(tlscall)
216     VK_TLSDESC, // symbol(tlsdesc)
217     VK_TLVP,    // Mach-O thread local variable relocations
218     VK_TLVPPAGE,
219     VK_TLVPPAGEOFF,
220     VK_PAGE,
221     VK_PAGEOFF,
222     VK_GOTPAGE,
223     VK_GOTPAGEOFF,
224     VK_SECREL,
225     VK_SIZE,    // symbol@SIZE
226     VK_WEAKREF, // The link between the symbols in .weakref foo, bar
227     VK_FUNCDESC,
228     VK_GOTFUNCDESC,
229     VK_GOTOFFFUNCDESC,
230     VK_TLSGD_FDPIC,
231     VK_TLSLDM_FDPIC,
232     VK_GOTTPOFF_FDPIC,
233 
234     VK_X86_ABS8,
235     VK_X86_PLTOFF,
236 
237     VK_ARM_NONE,
238     VK_ARM_GOT_PREL,
239     VK_ARM_TARGET1,
240     VK_ARM_TARGET2,
241     VK_ARM_PREL31,
242     VK_ARM_SBREL,  // symbol(sbrel)
243     VK_ARM_TLSLDO, // symbol(tlsldo)
244     VK_ARM_TLSDESCSEQ,
245 
246     VK_AVR_NONE,
247     VK_AVR_LO8,
248     VK_AVR_HI8,
249     VK_AVR_HLO8,
250     VK_AVR_DIFF8,
251     VK_AVR_DIFF16,
252     VK_AVR_DIFF32,
253     VK_AVR_PM,
254 
255     VK_PPC_LO,              // symbol@l
256     VK_PPC_HI,              // symbol@h
257     VK_PPC_HA,              // symbol@ha
258     VK_PPC_HIGH,            // symbol@high
259     VK_PPC_HIGHA,           // symbol@higha
260     VK_PPC_HIGHER,          // symbol@higher
261     VK_PPC_HIGHERA,         // symbol@highera
262     VK_PPC_HIGHEST,         // symbol@highest
263     VK_PPC_HIGHESTA,        // symbol@highesta
264     VK_PPC_GOT_LO,          // symbol@got@l
265     VK_PPC_GOT_HI,          // symbol@got@h
266     VK_PPC_GOT_HA,          // symbol@got@ha
267     VK_PPC_TOCBASE,         // symbol@tocbase
268     VK_PPC_TOC,             // symbol@toc
269     VK_PPC_TOC_LO,          // symbol@toc@l
270     VK_PPC_TOC_HI,          // symbol@toc@h
271     VK_PPC_TOC_HA,          // symbol@toc@ha
272     VK_PPC_U,               // symbol@u
273     VK_PPC_L,               // symbol@l
274     VK_PPC_DTPMOD,          // symbol@dtpmod
275     VK_PPC_TPREL_LO,        // symbol@tprel@l
276     VK_PPC_TPREL_HI,        // symbol@tprel@h
277     VK_PPC_TPREL_HA,        // symbol@tprel@ha
278     VK_PPC_TPREL_HIGH,      // symbol@tprel@high
279     VK_PPC_TPREL_HIGHA,     // symbol@tprel@higha
280     VK_PPC_TPREL_HIGHER,    // symbol@tprel@higher
281     VK_PPC_TPREL_HIGHERA,   // symbol@tprel@highera
282     VK_PPC_TPREL_HIGHEST,   // symbol@tprel@highest
283     VK_PPC_TPREL_HIGHESTA,  // symbol@tprel@highesta
284     VK_PPC_DTPREL_LO,       // symbol@dtprel@l
285     VK_PPC_DTPREL_HI,       // symbol@dtprel@h
286     VK_PPC_DTPREL_HA,       // symbol@dtprel@ha
287     VK_PPC_DTPREL_HIGH,     // symbol@dtprel@high
288     VK_PPC_DTPREL_HIGHA,    // symbol@dtprel@higha
289     VK_PPC_DTPREL_HIGHER,   // symbol@dtprel@higher
290     VK_PPC_DTPREL_HIGHERA,  // symbol@dtprel@highera
291     VK_PPC_DTPREL_HIGHEST,  // symbol@dtprel@highest
292     VK_PPC_DTPREL_HIGHESTA, // symbol@dtprel@highesta
293     VK_PPC_GOT_TPREL,       // symbol@got@tprel
294     VK_PPC_GOT_TPREL_LO,    // symbol@got@tprel@l
295     VK_PPC_GOT_TPREL_HI,    // symbol@got@tprel@h
296     VK_PPC_GOT_TPREL_HA,    // symbol@got@tprel@ha
297     VK_PPC_GOT_DTPREL,      // symbol@got@dtprel
298     VK_PPC_GOT_DTPREL_LO,   // symbol@got@dtprel@l
299     VK_PPC_GOT_DTPREL_HI,   // symbol@got@dtprel@h
300     VK_PPC_GOT_DTPREL_HA,   // symbol@got@dtprel@ha
301     VK_PPC_TLS,             // symbol@tls
302     VK_PPC_GOT_TLSGD,       // symbol@got@tlsgd
303     VK_PPC_GOT_TLSGD_LO,    // symbol@got@tlsgd@l
304     VK_PPC_GOT_TLSGD_HI,    // symbol@got@tlsgd@h
305     VK_PPC_GOT_TLSGD_HA,    // symbol@got@tlsgd@ha
306     VK_PPC_TLSGD,           // symbol@tlsgd
307     VK_PPC_AIX_TLSGD,       // symbol@gd
308     VK_PPC_AIX_TLSGDM,      // symbol@m
309     VK_PPC_AIX_TLSIE,       // symbol@ie
310     VK_PPC_AIX_TLSLE,       // symbol@le
311     VK_PPC_AIX_TLSLD,       // symbol@ld
312     VK_PPC_AIX_TLSML,       // symbol@ml
313     VK_PPC_GOT_TLSLD,       // symbol@got@tlsld
314     VK_PPC_GOT_TLSLD_LO,    // symbol@got@tlsld@l
315     VK_PPC_GOT_TLSLD_HI,    // symbol@got@tlsld@h
316     VK_PPC_GOT_TLSLD_HA,    // symbol@got@tlsld@ha
317     VK_PPC_GOT_PCREL,       // symbol@got@pcrel
318     VK_PPC_GOT_TLSGD_PCREL, // symbol@got@tlsgd@pcrel
319     VK_PPC_GOT_TLSLD_PCREL, // symbol@got@tlsld@pcrel
320     VK_PPC_GOT_TPREL_PCREL, // symbol@got@tprel@pcrel
321     VK_PPC_TLS_PCREL,       // symbol@tls@pcrel
322     VK_PPC_TLSLD,           // symbol@tlsld
323     VK_PPC_LOCAL,           // symbol@local
324     VK_PPC_NOTOC,           // symbol@notoc
325     VK_PPC_PCREL_OPT,       // .reloc expr, R_PPC64_PCREL_OPT, expr
326 
327     VK_COFF_IMGREL32, // symbol@imgrel (image-relative)
328 
329     VK_Hexagon_LO16,
330     VK_Hexagon_HI16,
331     VK_Hexagon_GPREL,
332     VK_Hexagon_GD_GOT,
333     VK_Hexagon_LD_GOT,
334     VK_Hexagon_GD_PLT,
335     VK_Hexagon_LD_PLT,
336     VK_Hexagon_IE,
337     VK_Hexagon_IE_GOT,
338 
339     VK_WASM_TYPEINDEX, // Reference to a symbol's type (signature)
340     VK_WASM_TLSREL,    // Memory address relative to __tls_base
341     VK_WASM_MBREL,     // Memory address relative to __memory_base
342     VK_WASM_TBREL,     // Table index relative to __table_base
343     VK_WASM_GOT_TLS,   // Wasm global index of TLS symbol.
344     VK_WASM_FUNCINDEX, // Wasm function index.
345 
346     VK_AMDGPU_GOTPCREL32_LO, // symbol@gotpcrel32@lo
347     VK_AMDGPU_GOTPCREL32_HI, // symbol@gotpcrel32@hi
348     VK_AMDGPU_REL32_LO,      // symbol@rel32@lo
349     VK_AMDGPU_REL32_HI,      // symbol@rel32@hi
350     VK_AMDGPU_REL64,         // symbol@rel64
351     VK_AMDGPU_ABS32_LO,      // symbol@abs32@lo
352     VK_AMDGPU_ABS32_HI,      // symbol@abs32@hi
353 
354     VK_VE_HI32,        // symbol@hi
355     VK_VE_LO32,        // symbol@lo
356     VK_VE_PC_HI32,     // symbol@pc_hi
357     VK_VE_PC_LO32,     // symbol@pc_lo
358     VK_VE_GOT_HI32,    // symbol@got_hi
359     VK_VE_GOT_LO32,    // symbol@got_lo
360     VK_VE_GOTOFF_HI32, // symbol@gotoff_hi
361     VK_VE_GOTOFF_LO32, // symbol@gotoff_lo
362     VK_VE_PLT_HI32,    // symbol@plt_hi
363     VK_VE_PLT_LO32,    // symbol@plt_lo
364     VK_VE_TLS_GD_HI32, // symbol@tls_gd_hi
365     VK_VE_TLS_GD_LO32, // symbol@tls_gd_lo
366     VK_VE_TPOFF_HI32,  // symbol@tpoff_hi
367     VK_VE_TPOFF_LO32,  // symbol@tpoff_lo
368 
369     VK_TPREL,
370     VK_DTPREL
371   };
372 
373 private:
374   /// The symbol being referenced.
375   const MCSymbol *Symbol;
376 
377   // Subclass data stores VariantKind in bits 0..15 and HasSubsectionsViaSymbols
378   // in bit 16.
379   static const unsigned VariantKindBits = 16;
380   static const unsigned VariantKindMask = (1 << VariantKindBits) - 1;
381 
382   // FIXME: Remove this bit.
383   static const unsigned HasSubsectionsViaSymbolsBit = 1 << VariantKindBits;
384 
385   static unsigned encodeSubclassData(VariantKind Kind,
386                                      bool HasSubsectionsViaSymbols) {
387     return (unsigned)Kind |
388            (HasSubsectionsViaSymbols ? HasSubsectionsViaSymbolsBit : 0);
389   }
390 
391   explicit MCSymbolRefExpr(const MCSymbol *Symbol, VariantKind Kind,
392                            const MCAsmInfo *MAI, SMLoc Loc = SMLoc());
393 
394 public:
395   /// \name Construction
396   /// @{
397 
398   static const MCSymbolRefExpr *create(const MCSymbol *Symbol, MCContext &Ctx) {
399     return MCSymbolRefExpr::create(Symbol, VK_None, Ctx);
400   }
401 
402   static const MCSymbolRefExpr *create(const MCSymbol *Symbol, VariantKind Kind,
403                                        MCContext &Ctx, SMLoc Loc = SMLoc());
404   static const MCSymbolRefExpr *create(StringRef Name, VariantKind Kind,
405                                        MCContext &Ctx);
406 
407   /// @}
408   /// \name Accessors
409   /// @{
410 
411   const MCSymbol &getSymbol() const { return *Symbol; }
412 
413   VariantKind getKind() const {
414     return (VariantKind)(getSubclassData() & VariantKindMask);
415   }
416 
417   bool hasSubsectionsViaSymbols() const {
418     return (getSubclassData() & HasSubsectionsViaSymbolsBit) != 0;
419   }
420 
421   /// @}
422   /// \name Static Utility Functions
423   /// @{
424 
425   static StringRef getVariantKindName(VariantKind Kind);
426 
427   static VariantKind getVariantKindForName(StringRef Name);
428 
429   /// @}
430 
431   static bool classof(const MCExpr *E) {
432     return E->getKind() == MCExpr::SymbolRef;
433   }
434 };
435 
436 /// Unary assembler expressions.
437 class MCUnaryExpr : public MCExpr {
438 public:
439   enum Opcode {
440     LNot,  ///< Logical negation.
441     Minus, ///< Unary minus.
442     Not,   ///< Bitwise negation.
443     Plus   ///< Unary plus.
444   };
445 
446 private:
447   const MCExpr *Expr;
448 
449   MCUnaryExpr(Opcode Op, const MCExpr *Expr, SMLoc Loc)
450       : MCExpr(MCExpr::Unary, Loc, Op), Expr(Expr) {}
451 
452 public:
453   /// \name Construction
454   /// @{
455 
456   static const MCUnaryExpr *create(Opcode Op, const MCExpr *Expr,
457                                    MCContext &Ctx, SMLoc Loc = SMLoc());
458 
459   static const MCUnaryExpr *createLNot(const MCExpr *Expr, MCContext &Ctx, SMLoc Loc = SMLoc()) {
460     return create(LNot, Expr, Ctx, Loc);
461   }
462 
463   static const MCUnaryExpr *createMinus(const MCExpr *Expr, MCContext &Ctx, SMLoc Loc = SMLoc()) {
464     return create(Minus, Expr, Ctx, Loc);
465   }
466 
467   static const MCUnaryExpr *createNot(const MCExpr *Expr, MCContext &Ctx, SMLoc Loc = SMLoc()) {
468     return create(Not, Expr, Ctx, Loc);
469   }
470 
471   static const MCUnaryExpr *createPlus(const MCExpr *Expr, MCContext &Ctx, SMLoc Loc = SMLoc()) {
472     return create(Plus, Expr, Ctx, Loc);
473   }
474 
475   /// @}
476   /// \name Accessors
477   /// @{
478 
479   /// Get the kind of this unary expression.
480   Opcode getOpcode() const { return (Opcode)getSubclassData(); }
481 
482   /// Get the child of this unary expression.
483   const MCExpr *getSubExpr() const { return Expr; }
484 
485   /// @}
486 
487   static bool classof(const MCExpr *E) {
488     return E->getKind() == MCExpr::Unary;
489   }
490 };
491 
492 /// Binary assembler expressions.
493 class MCBinaryExpr : public MCExpr {
494 public:
495   enum Opcode {
496     Add,  ///< Addition.
497     And,  ///< Bitwise and.
498     Div,  ///< Signed division.
499     EQ,   ///< Equality comparison.
500     GT,   ///< Signed greater than comparison (result is either 0 or some
501           ///< target-specific non-zero value)
502     GTE,  ///< Signed greater than or equal comparison (result is either 0 or
503           ///< some target-specific non-zero value).
504     LAnd, ///< Logical and.
505     LOr,  ///< Logical or.
506     LT,   ///< Signed less than comparison (result is either 0 or
507           ///< some target-specific non-zero value).
508     LTE,  ///< Signed less than or equal comparison (result is either 0 or
509           ///< some target-specific non-zero value).
510     Mod,  ///< Signed remainder.
511     Mul,  ///< Multiplication.
512     NE,   ///< Inequality comparison.
513     Or,   ///< Bitwise or.
514     OrNot, ///< Bitwise or not.
515     Shl,  ///< Shift left.
516     AShr, ///< Arithmetic shift right.
517     LShr, ///< Logical shift right.
518     Sub,  ///< Subtraction.
519     Xor   ///< Bitwise exclusive or.
520   };
521 
522 private:
523   const MCExpr *LHS, *RHS;
524 
525   MCBinaryExpr(Opcode Op, const MCExpr *LHS, const MCExpr *RHS,
526                SMLoc Loc = SMLoc())
527       : MCExpr(MCExpr::Binary, Loc, Op), LHS(LHS), RHS(RHS) {}
528 
529 public:
530   /// \name Construction
531   /// @{
532 
533   static const MCBinaryExpr *create(Opcode Op, const MCExpr *LHS,
534                                     const MCExpr *RHS, MCContext &Ctx,
535                                     SMLoc Loc = SMLoc());
536 
537   static const MCBinaryExpr *createAdd(const MCExpr *LHS, const MCExpr *RHS,
538                                        MCContext &Ctx) {
539     return create(Add, LHS, RHS, Ctx);
540   }
541 
542   static const MCBinaryExpr *createAnd(const MCExpr *LHS, const MCExpr *RHS,
543                                        MCContext &Ctx) {
544     return create(And, LHS, RHS, Ctx);
545   }
546 
547   static const MCBinaryExpr *createDiv(const MCExpr *LHS, const MCExpr *RHS,
548                                        MCContext &Ctx) {
549     return create(Div, LHS, RHS, Ctx);
550   }
551 
552   static const MCBinaryExpr *createEQ(const MCExpr *LHS, const MCExpr *RHS,
553                                       MCContext &Ctx) {
554     return create(EQ, LHS, RHS, Ctx);
555   }
556 
557   static const MCBinaryExpr *createGT(const MCExpr *LHS, const MCExpr *RHS,
558                                       MCContext &Ctx) {
559     return create(GT, LHS, RHS, Ctx);
560   }
561 
562   static const MCBinaryExpr *createGTE(const MCExpr *LHS, const MCExpr *RHS,
563                                        MCContext &Ctx) {
564     return create(GTE, LHS, RHS, Ctx);
565   }
566 
567   static const MCBinaryExpr *createLAnd(const MCExpr *LHS, const MCExpr *RHS,
568                                         MCContext &Ctx) {
569     return create(LAnd, LHS, RHS, Ctx);
570   }
571 
572   static const MCBinaryExpr *createLOr(const MCExpr *LHS, const MCExpr *RHS,
573                                        MCContext &Ctx) {
574     return create(LOr, LHS, RHS, Ctx);
575   }
576 
577   static const MCBinaryExpr *createLT(const MCExpr *LHS, const MCExpr *RHS,
578                                       MCContext &Ctx) {
579     return create(LT, LHS, RHS, Ctx);
580   }
581 
582   static const MCBinaryExpr *createLTE(const MCExpr *LHS, const MCExpr *RHS,
583                                        MCContext &Ctx) {
584     return create(LTE, LHS, RHS, Ctx);
585   }
586 
587   static const MCBinaryExpr *createMod(const MCExpr *LHS, const MCExpr *RHS,
588                                        MCContext &Ctx) {
589     return create(Mod, LHS, RHS, Ctx);
590   }
591 
592   static const MCBinaryExpr *createMul(const MCExpr *LHS, const MCExpr *RHS,
593                                        MCContext &Ctx) {
594     return create(Mul, LHS, RHS, Ctx);
595   }
596 
597   static const MCBinaryExpr *createNE(const MCExpr *LHS, const MCExpr *RHS,
598                                       MCContext &Ctx) {
599     return create(NE, LHS, RHS, Ctx);
600   }
601 
602   static const MCBinaryExpr *createOr(const MCExpr *LHS, const MCExpr *RHS,
603                                       MCContext &Ctx) {
604     return create(Or, LHS, RHS, Ctx);
605   }
606 
607   static const MCBinaryExpr *createShl(const MCExpr *LHS, const MCExpr *RHS,
608                                        MCContext &Ctx) {
609     return create(Shl, LHS, RHS, Ctx);
610   }
611 
612   static const MCBinaryExpr *createAShr(const MCExpr *LHS, const MCExpr *RHS,
613                                        MCContext &Ctx) {
614     return create(AShr, LHS, RHS, Ctx);
615   }
616 
617   static const MCBinaryExpr *createLShr(const MCExpr *LHS, const MCExpr *RHS,
618                                        MCContext &Ctx) {
619     return create(LShr, LHS, RHS, Ctx);
620   }
621 
622   static const MCBinaryExpr *createSub(const MCExpr *LHS, const MCExpr *RHS,
623                                        MCContext &Ctx) {
624     return create(Sub, LHS, RHS, Ctx);
625   }
626 
627   static const MCBinaryExpr *createXor(const MCExpr *LHS, const MCExpr *RHS,
628                                        MCContext &Ctx) {
629     return create(Xor, LHS, RHS, Ctx);
630   }
631 
632   /// @}
633   /// \name Accessors
634   /// @{
635 
636   /// Get the kind of this binary expression.
637   Opcode getOpcode() const { return (Opcode)getSubclassData(); }
638 
639   /// Get the left-hand side expression of the binary operator.
640   const MCExpr *getLHS() const { return LHS; }
641 
642   /// Get the right-hand side expression of the binary operator.
643   const MCExpr *getRHS() const { return RHS; }
644 
645   /// @}
646 
647   static bool classof(const MCExpr *E) {
648     return E->getKind() == MCExpr::Binary;
649   }
650 };
651 
652 /// This is an extension point for target-specific MCExpr subclasses to
653 /// implement.
654 ///
655 /// NOTE: All subclasses are required to have trivial destructors because
656 /// MCExprs are bump pointer allocated and not destructed.
657 class MCTargetExpr : public MCExpr {
658   virtual void anchor();
659 
660 protected:
661   MCTargetExpr() : MCExpr(Target, SMLoc()) {}
662   virtual ~MCTargetExpr() = default;
663 
664 public:
665   virtual void printImpl(raw_ostream &OS, const MCAsmInfo *MAI) const = 0;
666   virtual bool evaluateAsRelocatableImpl(MCValue &Res, const MCAssembler *Asm,
667                                          const MCFixup *Fixup) const = 0;
668   // allow Target Expressions to be checked for equality
669   virtual bool isEqualTo(const MCExpr *x) const { return false; }
670   virtual bool isSymbolUsedInExpression(const MCSymbol *Sym) const {
671     return false;
672   }
673   // This should be set when assigned expressions are not valid ".set"
674   // expressions, e.g. registers, and must be inlined.
675   virtual bool inlineAssignedExpr() const { return false; }
676   virtual void visitUsedExpr(MCStreamer& Streamer) const = 0;
677   virtual MCFragment *findAssociatedFragment() const = 0;
678 
679   virtual void fixELFSymbolsInTLSFixups(MCAssembler &) const = 0;
680 
681   static bool classof(const MCExpr *E) {
682     return E->getKind() == MCExpr::Target;
683   }
684 };
685 
686 } // end namespace llvm
687 
688 #endif // LLVM_MC_MCEXPR_H
689