LLVM  10.0.0svn
MCExpr.cpp
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1 //===- MCExpr.cpp - Assembly Level Expression Implementation --------------===//
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 #include "llvm/MC/MCExpr.h"
10 #include "llvm/ADT/Statistic.h"
11 #include "llvm/ADT/StringExtras.h"
12 #include "llvm/ADT/StringSwitch.h"
13 #include "llvm/Config/llvm-config.h"
14 #include "llvm/MC/MCAsmBackend.h"
15 #include "llvm/MC/MCAsmInfo.h"
16 #include "llvm/MC/MCAsmLayout.h"
17 #include "llvm/MC/MCAssembler.h"
18 #include "llvm/MC/MCContext.h"
19 #include "llvm/MC/MCObjectWriter.h"
20 #include "llvm/MC/MCSymbol.h"
21 #include "llvm/MC/MCValue.h"
22 #include "llvm/Support/Casting.h"
23 #include "llvm/Support/Compiler.h"
24 #include "llvm/Support/Debug.h"
27 #include <cassert>
28 #include <cstdint>
29 
30 using namespace llvm;
31 
32 #define DEBUG_TYPE "mcexpr"
33 
34 namespace {
35 namespace stats {
36 
37 STATISTIC(MCExprEvaluate, "Number of MCExpr evaluations");
38 
39 } // end namespace stats
40 } // end anonymous namespace
41 
42 void MCExpr::print(raw_ostream &OS, const MCAsmInfo *MAI, bool InParens) const {
43  switch (getKind()) {
44  case MCExpr::Target:
45  return cast<MCTargetExpr>(this)->printImpl(OS, MAI);
46  case MCExpr::Constant: {
47  auto Value = cast<MCConstantExpr>(*this).getValue();
48  auto PrintInHex = cast<MCConstantExpr>(*this).useHexFormat();
49  if (PrintInHex)
50  OS << "0x" << Twine::utohexstr(Value);
51  else
52  OS << Value;
53  return;
54  }
55  case MCExpr::SymbolRef: {
56  const MCSymbolRefExpr &SRE = cast<MCSymbolRefExpr>(*this);
57  const MCSymbol &Sym = SRE.getSymbol();
58  // Parenthesize names that start with $ so that they don't look like
59  // absolute names.
60  bool UseParens =
61  !InParens && !Sym.getName().empty() && Sym.getName()[0] == '$';
62  if (UseParens) {
63  OS << '(';
64  Sym.print(OS, MAI);
65  OS << ')';
66  } else
67  Sym.print(OS, MAI);
68 
69  if (SRE.getKind() != MCSymbolRefExpr::VK_None)
70  SRE.printVariantKind(OS);
71 
72  return;
73  }
74 
75  case MCExpr::Unary: {
76  const MCUnaryExpr &UE = cast<MCUnaryExpr>(*this);
77  switch (UE.getOpcode()) {
78  case MCUnaryExpr::LNot: OS << '!'; break;
79  case MCUnaryExpr::Minus: OS << '-'; break;
80  case MCUnaryExpr::Not: OS << '~'; break;
81  case MCUnaryExpr::Plus: OS << '+'; break;
82  }
83  bool Binary = UE.getSubExpr()->getKind() == MCExpr::Binary;
84  if (Binary) OS << "(";
85  UE.getSubExpr()->print(OS, MAI);
86  if (Binary) OS << ")";
87  return;
88  }
89 
90  case MCExpr::Binary: {
91  const MCBinaryExpr &BE = cast<MCBinaryExpr>(*this);
92 
93  // Only print parens around the LHS if it is non-trivial.
94  if (isa<MCConstantExpr>(BE.getLHS()) || isa<MCSymbolRefExpr>(BE.getLHS())) {
95  BE.getLHS()->print(OS, MAI);
96  } else {
97  OS << '(';
98  BE.getLHS()->print(OS, MAI);
99  OS << ')';
100  }
101 
102  switch (BE.getOpcode()) {
103  case MCBinaryExpr::Add:
104  // Print "X-42" instead of "X+-42".
105  if (const MCConstantExpr *RHSC = dyn_cast<MCConstantExpr>(BE.getRHS())) {
106  if (RHSC->getValue() < 0) {
107  OS << RHSC->getValue();
108  return;
109  }
110  }
111 
112  OS << '+';
113  break;
114  case MCBinaryExpr::AShr: OS << ">>"; break;
115  case MCBinaryExpr::And: OS << '&'; break;
116  case MCBinaryExpr::Div: OS << '/'; break;
117  case MCBinaryExpr::EQ: OS << "=="; break;
118  case MCBinaryExpr::GT: OS << '>'; break;
119  case MCBinaryExpr::GTE: OS << ">="; break;
120  case MCBinaryExpr::LAnd: OS << "&&"; break;
121  case MCBinaryExpr::LOr: OS << "||"; break;
122  case MCBinaryExpr::LShr: OS << ">>"; break;
123  case MCBinaryExpr::LT: OS << '<'; break;
124  case MCBinaryExpr::LTE: OS << "<="; break;
125  case MCBinaryExpr::Mod: OS << '%'; break;
126  case MCBinaryExpr::Mul: OS << '*'; break;
127  case MCBinaryExpr::NE: OS << "!="; break;
128  case MCBinaryExpr::Or: OS << '|'; break;
129  case MCBinaryExpr::Shl: OS << "<<"; break;
130  case MCBinaryExpr::Sub: OS << '-'; break;
131  case MCBinaryExpr::Xor: OS << '^'; break;
132  }
133 
134  // Only print parens around the LHS if it is non-trivial.
135  if (isa<MCConstantExpr>(BE.getRHS()) || isa<MCSymbolRefExpr>(BE.getRHS())) {
136  BE.getRHS()->print(OS, MAI);
137  } else {
138  OS << '(';
139  BE.getRHS()->print(OS, MAI);
140  OS << ')';
141  }
142  return;
143  }
144  }
145 
146  llvm_unreachable("Invalid expression kind!");
147 }
148 
149 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
150 LLVM_DUMP_METHOD void MCExpr::dump() const {
151  dbgs() << *this;
152  dbgs() << '\n';
153 }
154 #endif
155 
156 /* *** */
157 
158 const MCBinaryExpr *MCBinaryExpr::create(Opcode Opc, const MCExpr *LHS,
159  const MCExpr *RHS, MCContext &Ctx,
160  SMLoc Loc) {
161  return new (Ctx) MCBinaryExpr(Opc, LHS, RHS, Loc);
162 }
163 
164 const MCUnaryExpr *MCUnaryExpr::create(Opcode Opc, const MCExpr *Expr,
165  MCContext &Ctx, SMLoc Loc) {
166  return new (Ctx) MCUnaryExpr(Opc, Expr, Loc);
167 }
168 
169 const MCConstantExpr *MCConstantExpr::create(int64_t Value, MCContext &Ctx,
170  bool PrintInHex) {
171  return new (Ctx) MCConstantExpr(Value, PrintInHex);
172 }
173 
174 /* *** */
175 
176 MCSymbolRefExpr::MCSymbolRefExpr(const MCSymbol *Symbol, VariantKind Kind,
177  const MCAsmInfo *MAI, SMLoc Loc)
178  : MCExpr(MCExpr::SymbolRef, Loc), Kind(Kind),
179  UseParensForSymbolVariant(MAI->useParensForSymbolVariant()),
180  HasSubsectionsViaSymbols(MAI->hasSubsectionsViaSymbols()),
181  Symbol(Symbol) {
182  assert(Symbol);
183 }
184 
185 const MCSymbolRefExpr *MCSymbolRefExpr::create(const MCSymbol *Sym,
186  VariantKind Kind,
187  MCContext &Ctx, SMLoc Loc) {
188  return new (Ctx) MCSymbolRefExpr(Sym, Kind, Ctx.getAsmInfo(), Loc);
189 }
190 
191 const MCSymbolRefExpr *MCSymbolRefExpr::create(StringRef Name, VariantKind Kind,
192  MCContext &Ctx) {
193  return create(Ctx.getOrCreateSymbol(Name), Kind, Ctx);
194 }
195 
196 StringRef MCSymbolRefExpr::getVariantKindName(VariantKind Kind) {
197  switch (Kind) {
198  case VK_Invalid: return "<<invalid>>";
199  case VK_None: return "<<none>>";
200 
201  case VK_DTPOFF: return "DTPOFF";
202  case VK_DTPREL: return "DTPREL";
203  case VK_GOT: return "GOT";
204  case VK_GOTOFF: return "GOTOFF";
205  case VK_GOTREL: return "GOTREL";
206  case VK_GOTPCREL: return "GOTPCREL";
207  case VK_GOTTPOFF: return "GOTTPOFF";
208  case VK_INDNTPOFF: return "INDNTPOFF";
209  case VK_NTPOFF: return "NTPOFF";
210  case VK_GOTNTPOFF: return "GOTNTPOFF";
211  case VK_PLT: return "PLT";
212  case VK_TLSGD: return "TLSGD";
213  case VK_TLSLD: return "TLSLD";
214  case VK_TLSLDM: return "TLSLDM";
215  case VK_TPOFF: return "TPOFF";
216  case VK_TPREL: return "TPREL";
217  case VK_TLSCALL: return "tlscall";
218  case VK_TLSDESC: return "tlsdesc";
219  case VK_TLVP: return "TLVP";
220  case VK_TLVPPAGE: return "TLVPPAGE";
221  case VK_TLVPPAGEOFF: return "TLVPPAGEOFF";
222  case VK_PAGE: return "PAGE";
223  case VK_PAGEOFF: return "PAGEOFF";
224  case VK_GOTPAGE: return "GOTPAGE";
225  case VK_GOTPAGEOFF: return "GOTPAGEOFF";
226  case VK_SECREL: return "SECREL32";
227  case VK_SIZE: return "SIZE";
228  case VK_WEAKREF: return "WEAKREF";
229  case VK_X86_ABS8: return "ABS8";
230  case VK_ARM_NONE: return "none";
231  case VK_ARM_GOT_PREL: return "GOT_PREL";
232  case VK_ARM_TARGET1: return "target1";
233  case VK_ARM_TARGET2: return "target2";
234  case VK_ARM_PREL31: return "prel31";
235  case VK_ARM_SBREL: return "sbrel";
236  case VK_ARM_TLSLDO: return "tlsldo";
237  case VK_ARM_TLSDESCSEQ: return "tlsdescseq";
238  case VK_AVR_NONE: return "none";
239  case VK_AVR_LO8: return "lo8";
240  case VK_AVR_HI8: return "hi8";
241  case VK_AVR_HLO8: return "hlo8";
242  case VK_AVR_DIFF8: return "diff8";
243  case VK_AVR_DIFF16: return "diff16";
244  case VK_AVR_DIFF32: return "diff32";
245  case VK_PPC_LO: return "l";
246  case VK_PPC_HI: return "h";
247  case VK_PPC_HA: return "ha";
248  case VK_PPC_HIGH: return "high";
249  case VK_PPC_HIGHA: return "higha";
250  case VK_PPC_HIGHER: return "higher";
251  case VK_PPC_HIGHERA: return "highera";
252  case VK_PPC_HIGHEST: return "highest";
253  case VK_PPC_HIGHESTA: return "highesta";
254  case VK_PPC_GOT_LO: return "got@l";
255  case VK_PPC_GOT_HI: return "got@h";
256  case VK_PPC_GOT_HA: return "got@ha";
257  case VK_PPC_TOCBASE: return "tocbase";
258  case VK_PPC_TOC: return "toc";
259  case VK_PPC_TOC_LO: return "toc@l";
260  case VK_PPC_TOC_HI: return "toc@h";
261  case VK_PPC_TOC_HA: return "toc@ha";
262  case VK_PPC_U: return "u";
263  case VK_PPC_L: return "l";
264  case VK_PPC_DTPMOD: return "dtpmod";
265  case VK_PPC_TPREL_LO: return "tprel@l";
266  case VK_PPC_TPREL_HI: return "tprel@h";
267  case VK_PPC_TPREL_HA: return "tprel@ha";
268  case VK_PPC_TPREL_HIGH: return "tprel@high";
269  case VK_PPC_TPREL_HIGHA: return "tprel@higha";
270  case VK_PPC_TPREL_HIGHER: return "tprel@higher";
271  case VK_PPC_TPREL_HIGHERA: return "tprel@highera";
272  case VK_PPC_TPREL_HIGHEST: return "tprel@highest";
273  case VK_PPC_TPREL_HIGHESTA: return "tprel@highesta";
274  case VK_PPC_DTPREL_LO: return "dtprel@l";
275  case VK_PPC_DTPREL_HI: return "dtprel@h";
276  case VK_PPC_DTPREL_HA: return "dtprel@ha";
277  case VK_PPC_DTPREL_HIGH: return "dtprel@high";
278  case VK_PPC_DTPREL_HIGHA: return "dtprel@higha";
279  case VK_PPC_DTPREL_HIGHER: return "dtprel@higher";
280  case VK_PPC_DTPREL_HIGHERA: return "dtprel@highera";
281  case VK_PPC_DTPREL_HIGHEST: return "dtprel@highest";
282  case VK_PPC_DTPREL_HIGHESTA: return "dtprel@highesta";
283  case VK_PPC_GOT_TPREL: return "got@tprel";
284  case VK_PPC_GOT_TPREL_LO: return "got@tprel@l";
285  case VK_PPC_GOT_TPREL_HI: return "got@tprel@h";
286  case VK_PPC_GOT_TPREL_HA: return "got@tprel@ha";
287  case VK_PPC_GOT_DTPREL: return "got@dtprel";
288  case VK_PPC_GOT_DTPREL_LO: return "got@dtprel@l";
289  case VK_PPC_GOT_DTPREL_HI: return "got@dtprel@h";
290  case VK_PPC_GOT_DTPREL_HA: return "got@dtprel@ha";
291  case VK_PPC_TLS: return "tls";
292  case VK_PPC_GOT_TLSGD: return "got@tlsgd";
293  case VK_PPC_GOT_TLSGD_LO: return "got@tlsgd@l";
294  case VK_PPC_GOT_TLSGD_HI: return "got@tlsgd@h";
295  case VK_PPC_GOT_TLSGD_HA: return "got@tlsgd@ha";
296  case VK_PPC_TLSGD: return "tlsgd";
297  case VK_PPC_GOT_TLSLD: return "got@tlsld";
298  case VK_PPC_GOT_TLSLD_LO: return "got@tlsld@l";
299  case VK_PPC_GOT_TLSLD_HI: return "got@tlsld@h";
300  case VK_PPC_GOT_TLSLD_HA: return "got@tlsld@ha";
301  case VK_PPC_TLSLD: return "tlsld";
302  case VK_PPC_LOCAL: return "local";
303  case VK_COFF_IMGREL32: return "IMGREL";
304  case VK_Hexagon_PCREL: return "PCREL";
305  case VK_Hexagon_LO16: return "LO16";
306  case VK_Hexagon_HI16: return "HI16";
307  case VK_Hexagon_GPREL: return "GPREL";
308  case VK_Hexagon_GD_GOT: return "GDGOT";
309  case VK_Hexagon_LD_GOT: return "LDGOT";
310  case VK_Hexagon_GD_PLT: return "GDPLT";
311  case VK_Hexagon_LD_PLT: return "LDPLT";
312  case VK_Hexagon_IE: return "IE";
313  case VK_Hexagon_IE_GOT: return "IEGOT";
314  case VK_WASM_TYPEINDEX: return "TYPEINDEX";
315  case VK_WASM_MBREL: return "MBREL";
316  case VK_WASM_TBREL: return "TBREL";
317  case VK_AMDGPU_GOTPCREL32_LO: return "gotpcrel32@lo";
318  case VK_AMDGPU_GOTPCREL32_HI: return "gotpcrel32@hi";
319  case VK_AMDGPU_REL32_LO: return "rel32@lo";
320  case VK_AMDGPU_REL32_HI: return "rel32@hi";
321  case VK_AMDGPU_REL64: return "rel64";
322  case VK_AMDGPU_ABS32_LO: return "abs32@lo";
323  case VK_AMDGPU_ABS32_HI: return "abs32@hi";
324  }
325  llvm_unreachable("Invalid variant kind");
326 }
327 
328 MCSymbolRefExpr::VariantKind
329 MCSymbolRefExpr::getVariantKindForName(StringRef Name) {
330  return StringSwitch<VariantKind>(Name.lower())
331  .Case("dtprel", VK_DTPREL)
332  .Case("dtpoff", VK_DTPOFF)
333  .Case("got", VK_GOT)
334  .Case("gotoff", VK_GOTOFF)
335  .Case("gotrel", VK_GOTREL)
336  .Case("gotpcrel", VK_GOTPCREL)
337  .Case("gottpoff", VK_GOTTPOFF)
338  .Case("indntpoff", VK_INDNTPOFF)
339  .Case("ntpoff", VK_NTPOFF)
340  .Case("gotntpoff", VK_GOTNTPOFF)
341  .Case("plt", VK_PLT)
342  .Case("tlscall", VK_TLSCALL)
343  .Case("tlsdesc", VK_TLSDESC)
344  .Case("tlsgd", VK_TLSGD)
345  .Case("tlsld", VK_TLSLD)
346  .Case("tlsldm", VK_TLSLDM)
347  .Case("tpoff", VK_TPOFF)
348  .Case("tprel", VK_TPREL)
349  .Case("tlvp", VK_TLVP)
350  .Case("tlvppage", VK_TLVPPAGE)
351  .Case("tlvppageoff", VK_TLVPPAGEOFF)
352  .Case("page", VK_PAGE)
353  .Case("pageoff", VK_PAGEOFF)
354  .Case("gotpage", VK_GOTPAGE)
355  .Case("gotpageoff", VK_GOTPAGEOFF)
356  .Case("imgrel", VK_COFF_IMGREL32)
357  .Case("secrel32", VK_SECREL)
358  .Case("size", VK_SIZE)
359  .Case("abs8", VK_X86_ABS8)
360  .Case("l", VK_PPC_LO)
361  .Case("h", VK_PPC_HI)
362  .Case("ha", VK_PPC_HA)
363  .Case("high", VK_PPC_HIGH)
364  .Case("higha", VK_PPC_HIGHA)
365  .Case("higher", VK_PPC_HIGHER)
366  .Case("highera", VK_PPC_HIGHERA)
367  .Case("highest", VK_PPC_HIGHEST)
368  .Case("highesta", VK_PPC_HIGHESTA)
369  .Case("got@l", VK_PPC_GOT_LO)
370  .Case("got@h", VK_PPC_GOT_HI)
371  .Case("got@ha", VK_PPC_GOT_HA)
372  .Case("local", VK_PPC_LOCAL)
373  .Case("tocbase", VK_PPC_TOCBASE)
374  .Case("toc", VK_PPC_TOC)
375  .Case("toc@l", VK_PPC_TOC_LO)
376  .Case("toc@h", VK_PPC_TOC_HI)
377  .Case("toc@ha", VK_PPC_TOC_HA)
378  .Case("u", VK_PPC_U)
379  .Case("l", VK_PPC_L)
380  .Case("tls", VK_PPC_TLS)
381  .Case("dtpmod", VK_PPC_DTPMOD)
382  .Case("tprel@l", VK_PPC_TPREL_LO)
383  .Case("tprel@h", VK_PPC_TPREL_HI)
384  .Case("tprel@ha", VK_PPC_TPREL_HA)
385  .Case("tprel@high", VK_PPC_TPREL_HIGH)
386  .Case("tprel@higha", VK_PPC_TPREL_HIGHA)
387  .Case("tprel@higher", VK_PPC_TPREL_HIGHER)
388  .Case("tprel@highera", VK_PPC_TPREL_HIGHERA)
389  .Case("tprel@highest", VK_PPC_TPREL_HIGHEST)
390  .Case("tprel@highesta", VK_PPC_TPREL_HIGHESTA)
391  .Case("dtprel@l", VK_PPC_DTPREL_LO)
392  .Case("dtprel@h", VK_PPC_DTPREL_HI)
393  .Case("dtprel@ha", VK_PPC_DTPREL_HA)
394  .Case("dtprel@high", VK_PPC_DTPREL_HIGH)
395  .Case("dtprel@higha", VK_PPC_DTPREL_HIGHA)
396  .Case("dtprel@higher", VK_PPC_DTPREL_HIGHER)
397  .Case("dtprel@highera", VK_PPC_DTPREL_HIGHERA)
398  .Case("dtprel@highest", VK_PPC_DTPREL_HIGHEST)
399  .Case("dtprel@highesta", VK_PPC_DTPREL_HIGHESTA)
400  .Case("got@tprel", VK_PPC_GOT_TPREL)
401  .Case("got@tprel@l", VK_PPC_GOT_TPREL_LO)
402  .Case("got@tprel@h", VK_PPC_GOT_TPREL_HI)
403  .Case("got@tprel@ha", VK_PPC_GOT_TPREL_HA)
404  .Case("got@dtprel", VK_PPC_GOT_DTPREL)
405  .Case("got@dtprel@l", VK_PPC_GOT_DTPREL_LO)
406  .Case("got@dtprel@h", VK_PPC_GOT_DTPREL_HI)
407  .Case("got@dtprel@ha", VK_PPC_GOT_DTPREL_HA)
408  .Case("got@tlsgd", VK_PPC_GOT_TLSGD)
409  .Case("got@tlsgd@l", VK_PPC_GOT_TLSGD_LO)
410  .Case("got@tlsgd@h", VK_PPC_GOT_TLSGD_HI)
411  .Case("got@tlsgd@ha", VK_PPC_GOT_TLSGD_HA)
412  .Case("got@tlsld", VK_PPC_GOT_TLSLD)
413  .Case("got@tlsld@l", VK_PPC_GOT_TLSLD_LO)
414  .Case("got@tlsld@h", VK_PPC_GOT_TLSLD_HI)
415  .Case("got@tlsld@ha", VK_PPC_GOT_TLSLD_HA)
416  .Case("gdgot", VK_Hexagon_GD_GOT)
417  .Case("gdplt", VK_Hexagon_GD_PLT)
418  .Case("iegot", VK_Hexagon_IE_GOT)
419  .Case("ie", VK_Hexagon_IE)
420  .Case("ldgot", VK_Hexagon_LD_GOT)
421  .Case("ldplt", VK_Hexagon_LD_PLT)
422  .Case("pcrel", VK_Hexagon_PCREL)
423  .Case("none", VK_ARM_NONE)
424  .Case("got_prel", VK_ARM_GOT_PREL)
425  .Case("target1", VK_ARM_TARGET1)
426  .Case("target2", VK_ARM_TARGET2)
427  .Case("prel31", VK_ARM_PREL31)
428  .Case("sbrel", VK_ARM_SBREL)
429  .Case("tlsldo", VK_ARM_TLSLDO)
430  .Case("lo8", VK_AVR_LO8)
431  .Case("hi8", VK_AVR_HI8)
432  .Case("hlo8", VK_AVR_HLO8)
433  .Case("typeindex", VK_WASM_TYPEINDEX)
434  .Case("tbrel", VK_WASM_TBREL)
435  .Case("mbrel", VK_WASM_MBREL)
436  .Case("gotpcrel32@lo", VK_AMDGPU_GOTPCREL32_LO)
437  .Case("gotpcrel32@hi", VK_AMDGPU_GOTPCREL32_HI)
438  .Case("rel32@lo", VK_AMDGPU_REL32_LO)
439  .Case("rel32@hi", VK_AMDGPU_REL32_HI)
440  .Case("rel64", VK_AMDGPU_REL64)
441  .Case("abs32@lo", VK_AMDGPU_ABS32_LO)
442  .Case("abs32@hi", VK_AMDGPU_ABS32_HI)
443  .Default(VK_Invalid);
444 }
445 
446 void MCSymbolRefExpr::printVariantKind(raw_ostream &OS) const {
447  if (UseParensForSymbolVariant)
448  OS << '(' << MCSymbolRefExpr::getVariantKindName(getKind()) << ')';
449  else
450  OS << '@' << MCSymbolRefExpr::getVariantKindName(getKind());
451 }
452 
453 /* *** */
454 
455 void MCTargetExpr::anchor() {}
456 
457 /* *** */
458 
459 bool MCExpr::evaluateAsAbsolute(int64_t &Res) const {
460  return evaluateAsAbsolute(Res, nullptr, nullptr, nullptr, false);
461 }
462 
463 bool MCExpr::evaluateAsAbsolute(int64_t &Res,
464  const MCAsmLayout &Layout) const {
465  return evaluateAsAbsolute(Res, &Layout.getAssembler(), &Layout, nullptr, false);
466 }
467 
468 bool MCExpr::evaluateAsAbsolute(int64_t &Res,
469  const MCAsmLayout &Layout,
470  const SectionAddrMap &Addrs) const {
471  // Setting InSet causes us to absolutize differences across sections and that
472  // is what the MachO writer uses Addrs for.
473  return evaluateAsAbsolute(Res, &Layout.getAssembler(), &Layout, &Addrs, true);
474 }
475 
476 bool MCExpr::evaluateAsAbsolute(int64_t &Res, const MCAssembler &Asm) const {
477  return evaluateAsAbsolute(Res, &Asm, nullptr, nullptr, false);
478 }
479 
480 bool MCExpr::evaluateAsAbsolute(int64_t &Res, const MCAssembler *Asm) const {
481  return evaluateAsAbsolute(Res, Asm, nullptr, nullptr, false);
482 }
483 
484 bool MCExpr::evaluateKnownAbsolute(int64_t &Res,
485  const MCAsmLayout &Layout) const {
486  return evaluateAsAbsolute(Res, &Layout.getAssembler(), &Layout, nullptr,
487  true);
488 }
489 
490 bool MCExpr::evaluateAsAbsolute(int64_t &Res, const MCAssembler *Asm,
491  const MCAsmLayout *Layout,
492  const SectionAddrMap *Addrs, bool InSet) const {
493  MCValue Value;
494 
495  // Fast path constants.
496  if (const MCConstantExpr *CE = dyn_cast<MCConstantExpr>(this)) {
497  Res = CE->getValue();
498  return true;
499  }
500 
501  bool IsRelocatable =
502  evaluateAsRelocatableImpl(Value, Asm, Layout, nullptr, Addrs, InSet);
503 
504  // Record the current value.
505  Res = Value.getConstant();
506 
507  return IsRelocatable && Value.isAbsolute();
508 }
509 
510 /// Helper method for \see EvaluateSymbolAdd().
511 static void AttemptToFoldSymbolOffsetDifference(
512  const MCAssembler *Asm, const MCAsmLayout *Layout,
513  const SectionAddrMap *Addrs, bool InSet, const MCSymbolRefExpr *&A,
514  const MCSymbolRefExpr *&B, int64_t &Addend) {
515  if (!A || !B)
516  return;
517 
518  const MCSymbol &SA = A->getSymbol();
519  const MCSymbol &SB = B->getSymbol();
520 
521  if (SA.isUndefined() || SB.isUndefined())
522  return;
523 
524  if (!Asm->getWriter().isSymbolRefDifferenceFullyResolved(*Asm, A, B, InSet))
525  return;
526 
527  if (SA.getFragment() == SB.getFragment() && !SA.isVariable() &&
528  !SA.isUnset() && !SB.isVariable() && !SB.isUnset()) {
529  Addend += (SA.getOffset() - SB.getOffset());
530 
531  // Pointers to Thumb symbols need to have their low-bit set to allow
532  // for interworking.
533  if (Asm->isThumbFunc(&SA))
534  Addend |= 1;
535 
536  // If symbol is labeled as micromips, we set low-bit to ensure
537  // correct offset in .gcc_except_table
538  if (Asm->getBackend().isMicroMips(&SA))
539  Addend |= 1;
540 
541  // Clear the symbol expr pointers to indicate we have folded these
542  // operands.
543  A = B = nullptr;
544  return;
545  }
546 
547  if (!Layout)
548  return;
549 
550  const MCSection &SecA = *SA.getFragment()->getParent();
551  const MCSection &SecB = *SB.getFragment()->getParent();
552 
553  if ((&SecA != &SecB) && !Addrs)
554  return;
555 
556  // Eagerly evaluate.
557  Addend += Layout->getSymbolOffset(A->getSymbol()) -
558  Layout->getSymbolOffset(B->getSymbol());
559  if (Addrs && (&SecA != &SecB))
560  Addend += (Addrs->lookup(&SecA) - Addrs->lookup(&SecB));
561 
562  // Pointers to Thumb symbols need to have their low-bit set to allow
563  // for interworking.
564  if (Asm->isThumbFunc(&SA))
565  Addend |= 1;
566 
567  // If symbol is labeled as micromips, we set low-bit to ensure
568  // correct offset in .gcc_except_table
569  if (Asm->getBackend().isMicroMips(&SA))
570  Addend |= 1;
571 
572  // Clear the symbol expr pointers to indicate we have folded these
573  // operands.
574  A = B = nullptr;
575 }
576 
577 static bool canFold(const MCAssembler *Asm, const MCSymbolRefExpr *A,
578  const MCSymbolRefExpr *B, bool InSet) {
579  if (InSet)
580  return true;
581 
582  if (!Asm->getBackend().requiresDiffExpressionRelocations())
583  return true;
584 
585  const MCSymbol &CheckSym = A ? A->getSymbol() : B->getSymbol();
586  if (!CheckSym.isInSection())
587  return true;
588 
589  if (!CheckSym.getSection().hasInstructions())
590  return true;
591 
592  return false;
593 }
594 
595 /// Evaluate the result of an add between (conceptually) two MCValues.
596 ///
597 /// This routine conceptually attempts to construct an MCValue:
598 /// Result = (Result_A - Result_B + Result_Cst)
599 /// from two MCValue's LHS and RHS where
600 /// Result = LHS + RHS
601 /// and
602 /// Result = (LHS_A - LHS_B + LHS_Cst) + (RHS_A - RHS_B + RHS_Cst).
603 ///
604 /// This routine attempts to aggresively fold the operands such that the result
605 /// is representable in an MCValue, but may not always succeed.
606 ///
607 /// \returns True on success, false if the result is not representable in an
608 /// MCValue.
609 
610 /// NOTE: It is really important to have both the Asm and Layout arguments.
611 /// They might look redundant, but this function can be used before layout
612 /// is done (see the object streamer for example) and having the Asm argument
613 /// lets us avoid relaxations early.
614 static bool
615 EvaluateSymbolicAdd(const MCAssembler *Asm, const MCAsmLayout *Layout,
616  const SectionAddrMap *Addrs, bool InSet, const MCValue &LHS,
617  const MCSymbolRefExpr *RHS_A, const MCSymbolRefExpr *RHS_B,
618  int64_t RHS_Cst, MCValue &Res) {
619  // FIXME: This routine (and other evaluation parts) are *incredibly* sloppy
620  // about dealing with modifiers. This will ultimately bite us, one day.
621  const MCSymbolRefExpr *LHS_A = LHS.getSymA();
622  const MCSymbolRefExpr *LHS_B = LHS.getSymB();
623  int64_t LHS_Cst = LHS.getConstant();
624 
625  // Fold the result constant immediately.
626  int64_t Result_Cst = LHS_Cst + RHS_Cst;
627 
628  assert((!Layout || Asm) &&
629  "Must have an assembler object if layout is given!");
630 
631  // If we have a layout, we can fold resolved differences. Do not do this if
632  // the backend requires this to be emitted as individual relocations, unless
633  // the InSet flag is set to get the current difference anyway (used for
634  // example to calculate symbol sizes).
635  if (Asm && canFold(Asm, LHS_A, LHS_B, InSet)) {
636  // First, fold out any differences which are fully resolved. By
637  // reassociating terms in
638  // Result = (LHS_A - LHS_B + LHS_Cst) + (RHS_A - RHS_B + RHS_Cst).
639  // we have the four possible differences:
640  // (LHS_A - LHS_B),
641  // (LHS_A - RHS_B),
642  // (RHS_A - LHS_B),
643  // (RHS_A - RHS_B).
644  // Since we are attempting to be as aggressive as possible about folding, we
645  // attempt to evaluate each possible alternative.
646  AttemptToFoldSymbolOffsetDifference(Asm, Layout, Addrs, InSet, LHS_A, LHS_B,
647  Result_Cst);
648  AttemptToFoldSymbolOffsetDifference(Asm, Layout, Addrs, InSet, LHS_A, RHS_B,
649  Result_Cst);
650  AttemptToFoldSymbolOffsetDifference(Asm, Layout, Addrs, InSet, RHS_A, LHS_B,
651  Result_Cst);
652  AttemptToFoldSymbolOffsetDifference(Asm, Layout, Addrs, InSet, RHS_A, RHS_B,
653  Result_Cst);
654  }
655 
656  // We can't represent the addition or subtraction of two symbols.
657  if ((LHS_A && RHS_A) || (LHS_B && RHS_B))
658  return false;
659 
660  // At this point, we have at most one additive symbol and one subtractive
661  // symbol -- find them.
662  const MCSymbolRefExpr *A = LHS_A ? LHS_A : RHS_A;
663  const MCSymbolRefExpr *B = LHS_B ? LHS_B : RHS_B;
664 
665  Res = MCValue::get(A, B, Result_Cst);
666  return true;
667 }
668 
670  const MCAsmLayout *Layout,
671  const MCFixup *Fixup) const {
672  MCAssembler *Assembler = Layout ? &Layout->getAssembler() : nullptr;
673  return evaluateAsRelocatableImpl(Res, Assembler, Layout, Fixup, nullptr,
674  false);
675 }
676 
677 bool MCExpr::evaluateAsValue(MCValue &Res, const MCAsmLayout &Layout) const {
678  MCAssembler *Assembler = &Layout.getAssembler();
679  return evaluateAsRelocatableImpl(Res, Assembler, &Layout, nullptr, nullptr,
680  true);
681 }
682 
683 static bool canExpand(const MCSymbol &Sym, bool InSet) {
684  const MCExpr *Expr = Sym.getVariableValue();
685  const auto *Inner = dyn_cast<MCSymbolRefExpr>(Expr);
686  if (Inner) {
687  if (Inner->getKind() == MCSymbolRefExpr::VK_WEAKREF)
688  return false;
689  }
690 
691  if (InSet)
692  return true;
693  return !Sym.isInSection();
694 }
695 
697  const MCAsmLayout *Layout,
698  const MCFixup *Fixup,
699  const SectionAddrMap *Addrs,
700  bool InSet) const {
701  ++stats::MCExprEvaluate;
702 
703  switch (getKind()) {
704  case Target:
705  return cast<MCTargetExpr>(this)->evaluateAsRelocatableImpl(Res, Layout,
706  Fixup);
707 
708  case Constant:
709  Res = MCValue::get(cast<MCConstantExpr>(this)->getValue());
710  return true;
711 
712  case SymbolRef: {
713  const MCSymbolRefExpr *SRE = cast<MCSymbolRefExpr>(this);
714  const MCSymbol &Sym = SRE->getSymbol();
715 
716  // Evaluate recursively if this is a variable.
717  if (Sym.isVariable() && SRE->getKind() == MCSymbolRefExpr::VK_None &&
718  canExpand(Sym, InSet)) {
719  bool IsMachO = SRE->hasSubsectionsViaSymbols();
720  if (Sym.getVariableValue()->evaluateAsRelocatableImpl(
721  Res, Asm, Layout, Fixup, Addrs, InSet || IsMachO)) {
722  if (!IsMachO)
723  return true;
724 
725  const MCSymbolRefExpr *A = Res.getSymA();
726  const MCSymbolRefExpr *B = Res.getSymB();
727  // FIXME: This is small hack. Given
728  // a = b + 4
729  // .long a
730  // the OS X assembler will completely drop the 4. We should probably
731  // include it in the relocation or produce an error if that is not
732  // possible.
733  // Allow constant expressions.
734  if (!A && !B)
735  return true;
736  // Allows aliases with zero offset.
737  if (Res.getConstant() == 0 && (!A || !B))
738  return true;
739  }
740  }
741 
742  Res = MCValue::get(SRE, nullptr, 0);
743  return true;
744  }
745 
746  case Unary: {
747  const MCUnaryExpr *AUE = cast<MCUnaryExpr>(this);
748  MCValue Value;
749 
750  if (!AUE->getSubExpr()->evaluateAsRelocatableImpl(Value, Asm, Layout, Fixup,
751  Addrs, InSet))
752  return false;
753 
754  switch (AUE->getOpcode()) {
755  case MCUnaryExpr::LNot:
756  if (!Value.isAbsolute())
757  return false;
758  Res = MCValue::get(!Value.getConstant());
759  break;
760  case MCUnaryExpr::Minus:
761  /// -(a - b + const) ==> (b - a - const)
762  if (Value.getSymA() && !Value.getSymB())
763  return false;
764 
765  // The cast avoids undefined behavior if the constant is INT64_MIN.
766  Res = MCValue::get(Value.getSymB(), Value.getSymA(),
767  -(uint64_t)Value.getConstant());
768  break;
769  case MCUnaryExpr::Not:
770  if (!Value.isAbsolute())
771  return false;
772  Res = MCValue::get(~Value.getConstant());
773  break;
774  case MCUnaryExpr::Plus:
775  Res = Value;
776  break;
777  }
778 
779  return true;
780  }
781 
782  case Binary: {
783  const MCBinaryExpr *ABE = cast<MCBinaryExpr>(this);
784  MCValue LHSValue, RHSValue;
785 
786  if (!ABE->getLHS()->evaluateAsRelocatableImpl(LHSValue, Asm, Layout, Fixup,
787  Addrs, InSet) ||
788  !ABE->getRHS()->evaluateAsRelocatableImpl(RHSValue, Asm, Layout, Fixup,
789  Addrs, InSet)) {
790  // Check if both are Target Expressions, see if we can compare them.
791  if (const MCTargetExpr *L = dyn_cast<MCTargetExpr>(ABE->getLHS()))
792  if (const MCTargetExpr *R = cast<MCTargetExpr>(ABE->getRHS())) {
793  switch (ABE->getOpcode()) {
794  case MCBinaryExpr::EQ:
795  Res = MCValue::get((L->isEqualTo(R)) ? -1 : 0);
796  return true;
797  case MCBinaryExpr::NE:
798  Res = MCValue::get((R->isEqualTo(R)) ? 0 : -1);
799  return true;
800  default: break;
801  }
802  }
803  return false;
804  }
805 
806  // We only support a few operations on non-constant expressions, handle
807  // those first.
808  if (!LHSValue.isAbsolute() || !RHSValue.isAbsolute()) {
809  switch (ABE->getOpcode()) {
810  default:
811  return false;
812  case MCBinaryExpr::Sub:
813  // Negate RHS and add.
814  // The cast avoids undefined behavior if the constant is INT64_MIN.
815  return EvaluateSymbolicAdd(Asm, Layout, Addrs, InSet, LHSValue,
816  RHSValue.getSymB(), RHSValue.getSymA(),
817  -(uint64_t)RHSValue.getConstant(), Res);
818 
819  case MCBinaryExpr::Add:
820  return EvaluateSymbolicAdd(Asm, Layout, Addrs, InSet, LHSValue,
821  RHSValue.getSymA(), RHSValue.getSymB(),
822  RHSValue.getConstant(), Res);
823  }
824  }
825 
826  // FIXME: We need target hooks for the evaluation. It may be limited in
827  // width, and gas defines the result of comparisons differently from
828  // Apple as.
829  int64_t LHS = LHSValue.getConstant(), RHS = RHSValue.getConstant();
830  int64_t Result = 0;
831  auto Op = ABE->getOpcode();
832  switch (Op) {
833  case MCBinaryExpr::AShr: Result = LHS >> RHS; break;
834  case MCBinaryExpr::Add: Result = LHS + RHS; break;
835  case MCBinaryExpr::And: Result = LHS & RHS; break;
836  case MCBinaryExpr::Div:
837  case MCBinaryExpr::Mod:
838  // Handle division by zero. gas just emits a warning and keeps going,
839  // we try to be stricter.
840  // FIXME: Currently the caller of this function has no way to understand
841  // we're bailing out because of 'division by zero'. Therefore, it will
842  // emit a 'expected relocatable expression' error. It would be nice to
843  // change this code to emit a better diagnostic.
844  if (RHS == 0)
845  return false;
846  if (ABE->getOpcode() == MCBinaryExpr::Div)
847  Result = LHS / RHS;
848  else
849  Result = LHS % RHS;
850  break;
851  case MCBinaryExpr::EQ: Result = LHS == RHS; break;
852  case MCBinaryExpr::GT: Result = LHS > RHS; break;
853  case MCBinaryExpr::GTE: Result = LHS >= RHS; break;
854  case MCBinaryExpr::LAnd: Result = LHS && RHS; break;
855  case MCBinaryExpr::LOr: Result = LHS || RHS; break;
856  case MCBinaryExpr::LShr: Result = uint64_t(LHS) >> uint64_t(RHS); break;
857  case MCBinaryExpr::LT: Result = LHS < RHS; break;
858  case MCBinaryExpr::LTE: Result = LHS <= RHS; break;
859  case MCBinaryExpr::Mul: Result = LHS * RHS; break;
860  case MCBinaryExpr::NE: Result = LHS != RHS; break;
861  case MCBinaryExpr::Or: Result = LHS | RHS; break;
862  case MCBinaryExpr::Shl: Result = uint64_t(LHS) << uint64_t(RHS); break;
863  case MCBinaryExpr::Sub: Result = LHS - RHS; break;
864  case MCBinaryExpr::Xor: Result = LHS ^ RHS; break;
865  }
866 
867  switch (Op) {
868  default:
869  Res = MCValue::get(Result);
870  break;
871  case MCBinaryExpr::EQ:
872  case MCBinaryExpr::GT:
873  case MCBinaryExpr::GTE:
874  case MCBinaryExpr::LT:
875  case MCBinaryExpr::LTE:
876  case MCBinaryExpr::NE:
877  // A comparison operator returns a -1 if true and 0 if false.
878  Res = MCValue::get(Result ? -1 : 0);
879  break;
880  }
881 
882  return true;
883  }
884  }
885 
886  llvm_unreachable("Invalid assembly expression kind!");
887 }
888 
890  switch (getKind()) {
891  case Target:
892  // We never look through target specific expressions.
893  return cast<MCTargetExpr>(this)->findAssociatedFragment();
894 
895  case Constant:
897 
898  case SymbolRef: {
899  const MCSymbolRefExpr *SRE = cast<MCSymbolRefExpr>(this);
900  const MCSymbol &Sym = SRE->getSymbol();
901  return Sym.getFragment();
902  }
903 
904  case Unary:
905  return cast<MCUnaryExpr>(this)->getSubExpr()->findAssociatedFragment();
906 
907  case Binary: {
908  const MCBinaryExpr *BE = cast<MCBinaryExpr>(this);
909  MCFragment *LHS_F = BE->getLHS()->findAssociatedFragment();
910  MCFragment *RHS_F = BE->getRHS()->findAssociatedFragment();
911 
912  // If either is absolute, return the other.
914  return RHS_F;
916  return LHS_F;
917 
918  // Not always correct, but probably the best we can do without more context.
919  if (BE->getOpcode() == MCBinaryExpr::Sub)
921 
922  // Otherwise, return the first non-null fragment.
923  return LHS_F ? LHS_F : RHS_F;
924  }
925  }
926 
927  llvm_unreachable("Invalid assembly expression kind!");
928 }
Signed less than comparison (result is either 0 or some target-specific non-zero value).
Definition: MCExpr.h:436
Bitwise negation.
Definition: MCExpr.h:371
This class represents lattice values for constants.
Definition: AllocatorList.h:23
Signed less than or equal comparison (result is either 0 or some target-specific non-zero value)...
Definition: MCExpr.h:438
This represents an "assembler immediate".
Definition: MCValue.h:39
MCSymbol - Instances of this class represent a symbol name in the MC file, and MCSymbols are created ...
Definition: MCSymbol.h:41
VariantKind getKind() const
Definition: MCExpr.h:344
Bitwise and.
Definition: MCExpr.h:427
Multiplication.
Definition: MCExpr.h:441
Opcode getOpcode() const
Get the kind of this unary expression.
Definition: MCExpr.h:410
const MCExpr * getLHS() const
Get the left-hand side expression of the binary operator.
Definition: MCExpr.h:570
Unary plus.
Definition: MCExpr.h:372
STATISTIC(NumFunctions, "Total number of functions")
Equality comparison.
Definition: MCExpr.h:429
Bitwise or.
Definition: MCExpr.h:443
Encode information on a single operation to perform on a byte sequence (e.g., an encoded instruction)...
Definition: MCFixup.h:77
int64_t getConstant() const
Definition: MCValue.h:46
const MCSymbolRefExpr * getSymB() const
Definition: MCValue.h:48
Encapsulates the layout of an assembly file at a particular point in time.
Definition: MCAsmLayout.h:28
Base class for the full range of assembler expressions which are needed for parsing.
Definition: MCExpr.h:35
This is an extension point for target-specific MCExpr subclasses to implement.
Definition: MCExpr.h:587
bool isInSection() const
isInSection - Check if this symbol is defined in some section (i.e., it is defined but not absolute)...
Definition: MCSymbol.h:253
Represent a reference to a symbol from inside an expression.
Definition: MCExpr.h:169
LLVM_NODISCARD bool empty() const
empty - Check if the string is empty.
Definition: StringRef.h:140
Arithmetic shift right.
Definition: MCExpr.h:445
bool evaluateAsRelocatable(MCValue &Res, const MCAsmLayout *Layout, const MCFixup *Fixup) const
Try to evaluate the expression to a relocatable value, i.e.
Definition: MCExpr.cpp:669
const MCExpr * getRHS() const
Get the right-hand side expression of the binary operator.
Definition: MCExpr.h:573
Logical or.
Definition: MCExpr.h:435
Signed remainder.
Definition: MCExpr.h:440
Unary assembler expressions.
Definition: MCExpr.h:366
static bool canExpand(const MCSymbol &Sym, bool InSet)
Definition: MCExpr.cpp:683
Signed division.
Definition: MCExpr.h:428
MCAssembler & getAssembler() const
Get the assembler object this is a layout for.
Definition: MCAsmLayout.h:50
Unary expressions.
Definition: MCExpr.h:41
Shift left.
Definition: MCExpr.h:444
This class is intended to be used as a base class for asm properties and features specific to the tar...
Definition: MCAsmInfo.h:56
static GCRegistry::Add< OcamlGC > B("ocaml", "ocaml 3.10-compatible GC")
void print(raw_ostream &OS, const MCAsmInfo *MAI, bool InParens=false) const
Definition: MCExpr.cpp:42
This is an important base class in LLVM.
Definition: Constant.h:41
static bool EvaluateSymbolicAdd(const MCAssembler *Asm, const MCAsmLayout *Layout, const SectionAddrMap *Addrs, bool InSet, const MCValue &LHS, const MCSymbolRefExpr *RHS_A, const MCSymbolRefExpr *RHS_B, int64_t RHS_Cst, MCValue &Res)
Evaluate the result of an add between (conceptually) two MCValues.
Definition: MCExpr.cpp:615
const MCSymbolRefExpr * getSymA() const
Definition: MCValue.h:47
Logical negation.
Definition: MCExpr.h:369
Logical and.
Definition: MCExpr.h:434
Binary assembler expressions.
Definition: MCExpr.h:423
bool hasSubsectionsViaSymbols() const
Definition: MCExpr.h:348
#define llvm_unreachable(msg)
Marks that the current location is not supposed to be reachable.
static MCFragment * AbsolutePseudoFragment
Definition: MCSymbol.h:65
void printVariantKind(raw_ostream &OS) const
Definition: MCExpr.cpp:446
const MCSymbol & getSymbol() const
Definition: MCExpr.h:342
ExprKind getKind() const
Definition: MCExpr.h:68
MCFragment * getFragment(bool SetUsed=true) const
Definition: MCSymbol.h:396
bool evaluateAsRelocatableImpl(MCValue &Res, const MCAssembler *Asm, const MCAsmLayout *Layout, const MCFixup *Fixup, const SectionAddrMap *Addrs, bool InSet) const
Definition: MCExpr.cpp:696
Inequality comparison.
Definition: MCExpr.h:442
static Twine utohexstr(const uint64_t &Val)
Definition: Twine.h:387
Signed greater than comparison (result is either 0 or some target-specific non-zero value) ...
Definition: MCExpr.h:430
MCFragment * findAssociatedFragment() const
Find the "associated section" for this expression, which is currently defined as the absolute section...
Definition: MCExpr.cpp:889
Signed greater than or equal comparison (result is either 0 or some target-specific non-zero value)...
Definition: MCExpr.h:432
Target - Wrapper for Target specific information.
Bitwise exclusive or.
Definition: MCExpr.h:448
Logical shift right.
Definition: MCExpr.h:446
static MCValue get(const MCSymbolRefExpr *SymA, const MCSymbolRefExpr *SymB=nullptr, int64_t Val=0, uint32_t RefKind=0)
Definition: MCValue.h:62
LLVM_NODISCARD std::enable_if<!is_simple_type< Y >::value, typename cast_retty< X, const Y >::ret_type >::type dyn_cast(const Y &Val)
Definition: Casting.h:332
References to labels and assigned expressions.
Definition: MCExpr.h:40
Unary minus.
Definition: MCExpr.h:370
bool evaluateAsValue(MCValue &Res, const MCAsmLayout &Layout) const
Try to evaluate the expression to the form (a - b + constant) where neither a nor b are variables...
Definition: MCExpr.cpp:677
Opcode getOpcode() const
Get the kind of this binary expression.
Definition: MCExpr.h:567
StringRef getName() const
getName - Get the symbol name.
Definition: MCSymbol.h:204
const MCExpr * getVariableValue(bool SetUsed=true) const
getVariableValue - Get the value for variable symbols.
Definition: MCSymbol.h:302
const MCExpr * getSubExpr() const
Get the child of this unary expression.
Definition: MCExpr.h:413
LLVM Value Representation.
Definition: Value.h:74
Constant expressions.
Definition: MCExpr.h:39
Binary expressions.
Definition: MCExpr.h:38
This class implements an extremely fast bulk output stream that can only output to a stream...
Definition: raw_ostream.h:45
Subtraction.
Definition: MCExpr.h:447
Target specific expression.
Definition: MCExpr.h:42
void print(raw_ostream &OS, const MCAsmInfo *MAI) const
print - Print the value to the stream OS.
Definition: MCSymbol.cpp:59