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"
25 #include "llvm/Support/ErrorHandling.h"
26 #include "llvm/Support/raw_ostream.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
print(raw_ostream & OS,const MCAsmInfo * MAI,bool InParens) const42 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 auto SizeInBytes = cast<MCConstantExpr>(*this).getSizeInBytes();
50 if (Value < 0 && MAI && !MAI->supportsSignedData())
51 PrintInHex = true;
52 if (PrintInHex)
53 switch (SizeInBytes) {
54 default:
55 OS << "0x" << Twine::utohexstr(Value);
56 break;
57 case 1:
58 OS << format("0x%02" PRIx64, Value);
59 break;
60 case 2:
61 OS << format("0x%04" PRIx64, Value);
62 break;
63 case 4:
64 OS << format("0x%08" PRIx64, Value);
65 break;
66 case 8:
67 OS << format("0x%016" PRIx64, Value);
68 break;
69 }
70 else
71 OS << Value;
72 return;
73 }
74 case MCExpr::SymbolRef: {
75 const MCSymbolRefExpr &SRE = cast<MCSymbolRefExpr>(*this);
76 const MCSymbol &Sym = SRE.getSymbol();
77 // Parenthesize names that start with $ so that they don't look like
78 // absolute names.
79 bool UseParens =
80 !InParens && !Sym.getName().empty() && Sym.getName()[0] == '$';
81 if (UseParens) {
82 OS << '(';
83 Sym.print(OS, MAI);
84 OS << ')';
85 } else
86 Sym.print(OS, MAI);
87
88 const MCSymbolRefExpr::VariantKind Kind = SRE.getKind();
89 if (Kind != MCSymbolRefExpr::VK_None) {
90 if (MAI && MAI->useParensForSymbolVariant()) // ARM
91 OS << '(' << MCSymbolRefExpr::getVariantKindName(Kind) << ')';
92 else
93 OS << '@' << MCSymbolRefExpr::getVariantKindName(Kind);
94 }
95
96 return;
97 }
98
99 case MCExpr::Unary: {
100 const MCUnaryExpr &UE = cast<MCUnaryExpr>(*this);
101 switch (UE.getOpcode()) {
102 case MCUnaryExpr::LNot: OS << '!'; break;
103 case MCUnaryExpr::Minus: OS << '-'; break;
104 case MCUnaryExpr::Not: OS << '~'; break;
105 case MCUnaryExpr::Plus: OS << '+'; break;
106 }
107 bool Binary = UE.getSubExpr()->getKind() == MCExpr::Binary;
108 if (Binary) OS << "(";
109 UE.getSubExpr()->print(OS, MAI);
110 if (Binary) OS << ")";
111 return;
112 }
113
114 case MCExpr::Binary: {
115 const MCBinaryExpr &BE = cast<MCBinaryExpr>(*this);
116
117 // Only print parens around the LHS if it is non-trivial.
118 if (isa<MCConstantExpr>(BE.getLHS()) || isa<MCSymbolRefExpr>(BE.getLHS())) {
119 BE.getLHS()->print(OS, MAI);
120 } else {
121 OS << '(';
122 BE.getLHS()->print(OS, MAI);
123 OS << ')';
124 }
125
126 switch (BE.getOpcode()) {
127 case MCBinaryExpr::Add:
128 // Print "X-42" instead of "X+-42".
129 if (const MCConstantExpr *RHSC = dyn_cast<MCConstantExpr>(BE.getRHS())) {
130 if (RHSC->getValue() < 0) {
131 OS << RHSC->getValue();
132 return;
133 }
134 }
135
136 OS << '+';
137 break;
138 case MCBinaryExpr::AShr: OS << ">>"; break;
139 case MCBinaryExpr::And: OS << '&'; break;
140 case MCBinaryExpr::Div: OS << '/'; break;
141 case MCBinaryExpr::EQ: OS << "=="; break;
142 case MCBinaryExpr::GT: OS << '>'; break;
143 case MCBinaryExpr::GTE: OS << ">="; break;
144 case MCBinaryExpr::LAnd: OS << "&&"; break;
145 case MCBinaryExpr::LOr: OS << "||"; break;
146 case MCBinaryExpr::LShr: OS << ">>"; break;
147 case MCBinaryExpr::LT: OS << '<'; break;
148 case MCBinaryExpr::LTE: OS << "<="; break;
149 case MCBinaryExpr::Mod: OS << '%'; break;
150 case MCBinaryExpr::Mul: OS << '*'; break;
151 case MCBinaryExpr::NE: OS << "!="; break;
152 case MCBinaryExpr::Or: OS << '|'; break;
153 case MCBinaryExpr::OrNot: OS << '!'; break;
154 case MCBinaryExpr::Shl: OS << "<<"; break;
155 case MCBinaryExpr::Sub: OS << '-'; break;
156 case MCBinaryExpr::Xor: OS << '^'; break;
157 }
158
159 // Only print parens around the LHS if it is non-trivial.
160 if (isa<MCConstantExpr>(BE.getRHS()) || isa<MCSymbolRefExpr>(BE.getRHS())) {
161 BE.getRHS()->print(OS, MAI);
162 } else {
163 OS << '(';
164 BE.getRHS()->print(OS, MAI);
165 OS << ')';
166 }
167 return;
168 }
169 }
170
171 llvm_unreachable("Invalid expression kind!");
172 }
173
174 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
dump() const175 LLVM_DUMP_METHOD void MCExpr::dump() const {
176 dbgs() << *this;
177 dbgs() << '\n';
178 }
179 #endif
180
181 /* *** */
182
create(Opcode Opc,const MCExpr * LHS,const MCExpr * RHS,MCContext & Ctx,SMLoc Loc)183 const MCBinaryExpr *MCBinaryExpr::create(Opcode Opc, const MCExpr *LHS,
184 const MCExpr *RHS, MCContext &Ctx,
185 SMLoc Loc) {
186 return new (Ctx) MCBinaryExpr(Opc, LHS, RHS, Loc);
187 }
188
create(Opcode Opc,const MCExpr * Expr,MCContext & Ctx,SMLoc Loc)189 const MCUnaryExpr *MCUnaryExpr::create(Opcode Opc, const MCExpr *Expr,
190 MCContext &Ctx, SMLoc Loc) {
191 return new (Ctx) MCUnaryExpr(Opc, Expr, Loc);
192 }
193
create(int64_t Value,MCContext & Ctx,bool PrintInHex,unsigned SizeInBytes)194 const MCConstantExpr *MCConstantExpr::create(int64_t Value, MCContext &Ctx,
195 bool PrintInHex,
196 unsigned SizeInBytes) {
197 return new (Ctx) MCConstantExpr(Value, PrintInHex, SizeInBytes);
198 }
199
200 /* *** */
201
MCSymbolRefExpr(const MCSymbol * Symbol,VariantKind Kind,const MCAsmInfo * MAI,SMLoc Loc)202 MCSymbolRefExpr::MCSymbolRefExpr(const MCSymbol *Symbol, VariantKind Kind,
203 const MCAsmInfo *MAI, SMLoc Loc)
204 : MCExpr(MCExpr::SymbolRef, Loc,
205 encodeSubclassData(Kind, MAI->hasSubsectionsViaSymbols())),
206 Symbol(Symbol) {
207 assert(Symbol);
208 }
209
create(const MCSymbol * Sym,VariantKind Kind,MCContext & Ctx,SMLoc Loc)210 const MCSymbolRefExpr *MCSymbolRefExpr::create(const MCSymbol *Sym,
211 VariantKind Kind,
212 MCContext &Ctx, SMLoc Loc) {
213 return new (Ctx) MCSymbolRefExpr(Sym, Kind, Ctx.getAsmInfo(), Loc);
214 }
215
create(StringRef Name,VariantKind Kind,MCContext & Ctx)216 const MCSymbolRefExpr *MCSymbolRefExpr::create(StringRef Name, VariantKind Kind,
217 MCContext &Ctx) {
218 return create(Ctx.getOrCreateSymbol(Name), Kind, Ctx);
219 }
220
getVariantKindName(VariantKind Kind)221 StringRef MCSymbolRefExpr::getVariantKindName(VariantKind Kind) {
222 switch (Kind) {
223 case VK_Invalid: return "<<invalid>>";
224 case VK_None: return "<<none>>";
225
226 case VK_DTPOFF: return "DTPOFF";
227 case VK_DTPREL: return "DTPREL";
228 case VK_GOT: return "GOT";
229 case VK_GOTOFF: return "GOTOFF";
230 case VK_GOTREL: return "GOTREL";
231 case VK_PCREL: return "PCREL";
232 case VK_GOTPCREL: return "GOTPCREL";
233 case VK_GOTTPOFF: return "GOTTPOFF";
234 case VK_INDNTPOFF: return "INDNTPOFF";
235 case VK_NTPOFF: return "NTPOFF";
236 case VK_GOTNTPOFF: return "GOTNTPOFF";
237 case VK_PLT: return "PLT";
238 case VK_TLSGD: return "TLSGD";
239 case VK_TLSLD: return "TLSLD";
240 case VK_TLSLDM: return "TLSLDM";
241 case VK_TPOFF: return "TPOFF";
242 case VK_TPREL: return "TPREL";
243 case VK_TLSCALL: return "tlscall";
244 case VK_TLSDESC: return "tlsdesc";
245 case VK_TLVP: return "TLVP";
246 case VK_TLVPPAGE: return "TLVPPAGE";
247 case VK_TLVPPAGEOFF: return "TLVPPAGEOFF";
248 case VK_PAGE: return "PAGE";
249 case VK_PAGEOFF: return "PAGEOFF";
250 case VK_GOTPAGE: return "GOTPAGE";
251 case VK_GOTPAGEOFF: return "GOTPAGEOFF";
252 case VK_SECREL: return "SECREL32";
253 case VK_SIZE: return "SIZE";
254 case VK_WEAKREF: return "WEAKREF";
255 case VK_X86_ABS8: return "ABS8";
256 case VK_X86_PLTOFF: return "PLTOFF";
257 case VK_ARM_NONE: return "none";
258 case VK_ARM_GOT_PREL: return "GOT_PREL";
259 case VK_ARM_TARGET1: return "target1";
260 case VK_ARM_TARGET2: return "target2";
261 case VK_ARM_PREL31: return "prel31";
262 case VK_ARM_SBREL: return "sbrel";
263 case VK_ARM_TLSLDO: return "tlsldo";
264 case VK_ARM_TLSDESCSEQ: return "tlsdescseq";
265 case VK_AVR_NONE: return "none";
266 case VK_AVR_LO8: return "lo8";
267 case VK_AVR_HI8: return "hi8";
268 case VK_AVR_HLO8: return "hlo8";
269 case VK_AVR_DIFF8: return "diff8";
270 case VK_AVR_DIFF16: return "diff16";
271 case VK_AVR_DIFF32: return "diff32";
272 case VK_PPC_LO: return "l";
273 case VK_PPC_HI: return "h";
274 case VK_PPC_HA: return "ha";
275 case VK_PPC_HIGH: return "high";
276 case VK_PPC_HIGHA: return "higha";
277 case VK_PPC_HIGHER: return "higher";
278 case VK_PPC_HIGHERA: return "highera";
279 case VK_PPC_HIGHEST: return "highest";
280 case VK_PPC_HIGHESTA: return "highesta";
281 case VK_PPC_GOT_LO: return "got@l";
282 case VK_PPC_GOT_HI: return "got@h";
283 case VK_PPC_GOT_HA: return "got@ha";
284 case VK_PPC_TOCBASE: return "tocbase";
285 case VK_PPC_TOC: return "toc";
286 case VK_PPC_TOC_LO: return "toc@l";
287 case VK_PPC_TOC_HI: return "toc@h";
288 case VK_PPC_TOC_HA: return "toc@ha";
289 case VK_PPC_U: return "u";
290 case VK_PPC_L: return "l";
291 case VK_PPC_DTPMOD: return "dtpmod";
292 case VK_PPC_TPREL_LO: return "tprel@l";
293 case VK_PPC_TPREL_HI: return "tprel@h";
294 case VK_PPC_TPREL_HA: return "tprel@ha";
295 case VK_PPC_TPREL_HIGH: return "tprel@high";
296 case VK_PPC_TPREL_HIGHA: return "tprel@higha";
297 case VK_PPC_TPREL_HIGHER: return "tprel@higher";
298 case VK_PPC_TPREL_HIGHERA: return "tprel@highera";
299 case VK_PPC_TPREL_HIGHEST: return "tprel@highest";
300 case VK_PPC_TPREL_HIGHESTA: return "tprel@highesta";
301 case VK_PPC_DTPREL_LO: return "dtprel@l";
302 case VK_PPC_DTPREL_HI: return "dtprel@h";
303 case VK_PPC_DTPREL_HA: return "dtprel@ha";
304 case VK_PPC_DTPREL_HIGH: return "dtprel@high";
305 case VK_PPC_DTPREL_HIGHA: return "dtprel@higha";
306 case VK_PPC_DTPREL_HIGHER: return "dtprel@higher";
307 case VK_PPC_DTPREL_HIGHERA: return "dtprel@highera";
308 case VK_PPC_DTPREL_HIGHEST: return "dtprel@highest";
309 case VK_PPC_DTPREL_HIGHESTA: return "dtprel@highesta";
310 case VK_PPC_GOT_TPREL: return "got@tprel";
311 case VK_PPC_GOT_TPREL_LO: return "got@tprel@l";
312 case VK_PPC_GOT_TPREL_HI: return "got@tprel@h";
313 case VK_PPC_GOT_TPREL_HA: return "got@tprel@ha";
314 case VK_PPC_GOT_DTPREL: return "got@dtprel";
315 case VK_PPC_GOT_DTPREL_LO: return "got@dtprel@l";
316 case VK_PPC_GOT_DTPREL_HI: return "got@dtprel@h";
317 case VK_PPC_GOT_DTPREL_HA: return "got@dtprel@ha";
318 case VK_PPC_TLS: return "tls";
319 case VK_PPC_GOT_TLSGD: return "got@tlsgd";
320 case VK_PPC_GOT_TLSGD_LO: return "got@tlsgd@l";
321 case VK_PPC_GOT_TLSGD_HI: return "got@tlsgd@h";
322 case VK_PPC_GOT_TLSGD_HA: return "got@tlsgd@ha";
323 case VK_PPC_TLSGD: return "tlsgd";
324 case VK_PPC_GOT_TLSLD: return "got@tlsld";
325 case VK_PPC_GOT_TLSLD_LO: return "got@tlsld@l";
326 case VK_PPC_GOT_TLSLD_HI: return "got@tlsld@h";
327 case VK_PPC_GOT_TLSLD_HA: return "got@tlsld@ha";
328 case VK_PPC_GOT_PCREL:
329 return "got@pcrel";
330 case VK_PPC_GOT_TLSGD_PCREL:
331 return "got@tlsgd@pcrel";
332 case VK_PPC_GOT_TLSLD_PCREL:
333 return "got@tlsld@pcrel";
334 case VK_PPC_GOT_TPREL_PCREL:
335 return "got@tprel@pcrel";
336 case VK_PPC_TLS_PCREL:
337 return "tls@pcrel";
338 case VK_PPC_TLSLD: return "tlsld";
339 case VK_PPC_LOCAL: return "local";
340 case VK_PPC_NOTOC: return "notoc";
341 case VK_PPC_PCREL_OPT: return "<<invalid>>";
342 case VK_COFF_IMGREL32: return "IMGREL";
343 case VK_Hexagon_LO16: return "LO16";
344 case VK_Hexagon_HI16: return "HI16";
345 case VK_Hexagon_GPREL: return "GPREL";
346 case VK_Hexagon_GD_GOT: return "GDGOT";
347 case VK_Hexagon_LD_GOT: return "LDGOT";
348 case VK_Hexagon_GD_PLT: return "GDPLT";
349 case VK_Hexagon_LD_PLT: return "LDPLT";
350 case VK_Hexagon_IE: return "IE";
351 case VK_Hexagon_IE_GOT: return "IEGOT";
352 case VK_WASM_TYPEINDEX: return "TYPEINDEX";
353 case VK_WASM_MBREL: return "MBREL";
354 case VK_WASM_TLSREL: return "TLSREL";
355 case VK_WASM_TBREL: return "TBREL";
356 case VK_AMDGPU_GOTPCREL32_LO: return "gotpcrel32@lo";
357 case VK_AMDGPU_GOTPCREL32_HI: return "gotpcrel32@hi";
358 case VK_AMDGPU_REL32_LO: return "rel32@lo";
359 case VK_AMDGPU_REL32_HI: return "rel32@hi";
360 case VK_AMDGPU_REL64: return "rel64";
361 case VK_AMDGPU_ABS32_LO: return "abs32@lo";
362 case VK_AMDGPU_ABS32_HI: return "abs32@hi";
363 case VK_VE_HI32: return "hi";
364 case VK_VE_LO32: return "lo";
365 case VK_VE_PC_HI32: return "pc_hi";
366 case VK_VE_PC_LO32: return "pc_lo";
367 case VK_VE_GOT_HI32: return "got_hi";
368 case VK_VE_GOT_LO32: return "got_lo";
369 case VK_VE_GOTOFF_HI32: return "gotoff_hi";
370 case VK_VE_GOTOFF_LO32: return "gotoff_lo";
371 case VK_VE_PLT_HI32: return "plt_hi";
372 case VK_VE_PLT_LO32: return "plt_lo";
373 case VK_VE_TLS_GD_HI32: return "tls_gd_hi";
374 case VK_VE_TLS_GD_LO32: return "tls_gd_lo";
375 case VK_VE_TPOFF_HI32: return "tpoff_hi";
376 case VK_VE_TPOFF_LO32: return "tpoff_lo";
377 }
378 llvm_unreachable("Invalid variant kind");
379 }
380
381 MCSymbolRefExpr::VariantKind
getVariantKindForName(StringRef Name)382 MCSymbolRefExpr::getVariantKindForName(StringRef Name) {
383 return StringSwitch<VariantKind>(Name.lower())
384 .Case("dtprel", VK_DTPREL)
385 .Case("dtpoff", VK_DTPOFF)
386 .Case("got", VK_GOT)
387 .Case("gotoff", VK_GOTOFF)
388 .Case("gotrel", VK_GOTREL)
389 .Case("pcrel", VK_PCREL)
390 .Case("gotpcrel", VK_GOTPCREL)
391 .Case("gottpoff", VK_GOTTPOFF)
392 .Case("indntpoff", VK_INDNTPOFF)
393 .Case("ntpoff", VK_NTPOFF)
394 .Case("gotntpoff", VK_GOTNTPOFF)
395 .Case("plt", VK_PLT)
396 .Case("tlscall", VK_TLSCALL)
397 .Case("tlsdesc", VK_TLSDESC)
398 .Case("tlsgd", VK_TLSGD)
399 .Case("tlsld", VK_TLSLD)
400 .Case("tlsldm", VK_TLSLDM)
401 .Case("tpoff", VK_TPOFF)
402 .Case("tprel", VK_TPREL)
403 .Case("tlvp", VK_TLVP)
404 .Case("tlvppage", VK_TLVPPAGE)
405 .Case("tlvppageoff", VK_TLVPPAGEOFF)
406 .Case("page", VK_PAGE)
407 .Case("pageoff", VK_PAGEOFF)
408 .Case("gotpage", VK_GOTPAGE)
409 .Case("gotpageoff", VK_GOTPAGEOFF)
410 .Case("imgrel", VK_COFF_IMGREL32)
411 .Case("secrel32", VK_SECREL)
412 .Case("size", VK_SIZE)
413 .Case("abs8", VK_X86_ABS8)
414 .Case("pltoff", VK_X86_PLTOFF)
415 .Case("l", VK_PPC_LO)
416 .Case("h", VK_PPC_HI)
417 .Case("ha", VK_PPC_HA)
418 .Case("high", VK_PPC_HIGH)
419 .Case("higha", VK_PPC_HIGHA)
420 .Case("higher", VK_PPC_HIGHER)
421 .Case("highera", VK_PPC_HIGHERA)
422 .Case("highest", VK_PPC_HIGHEST)
423 .Case("highesta", VK_PPC_HIGHESTA)
424 .Case("got@l", VK_PPC_GOT_LO)
425 .Case("got@h", VK_PPC_GOT_HI)
426 .Case("got@ha", VK_PPC_GOT_HA)
427 .Case("local", VK_PPC_LOCAL)
428 .Case("tocbase", VK_PPC_TOCBASE)
429 .Case("toc", VK_PPC_TOC)
430 .Case("toc@l", VK_PPC_TOC_LO)
431 .Case("toc@h", VK_PPC_TOC_HI)
432 .Case("toc@ha", VK_PPC_TOC_HA)
433 .Case("u", VK_PPC_U)
434 .Case("l", VK_PPC_L)
435 .Case("tls", VK_PPC_TLS)
436 .Case("dtpmod", VK_PPC_DTPMOD)
437 .Case("tprel@l", VK_PPC_TPREL_LO)
438 .Case("tprel@h", VK_PPC_TPREL_HI)
439 .Case("tprel@ha", VK_PPC_TPREL_HA)
440 .Case("tprel@high", VK_PPC_TPREL_HIGH)
441 .Case("tprel@higha", VK_PPC_TPREL_HIGHA)
442 .Case("tprel@higher", VK_PPC_TPREL_HIGHER)
443 .Case("tprel@highera", VK_PPC_TPREL_HIGHERA)
444 .Case("tprel@highest", VK_PPC_TPREL_HIGHEST)
445 .Case("tprel@highesta", VK_PPC_TPREL_HIGHESTA)
446 .Case("dtprel@l", VK_PPC_DTPREL_LO)
447 .Case("dtprel@h", VK_PPC_DTPREL_HI)
448 .Case("dtprel@ha", VK_PPC_DTPREL_HA)
449 .Case("dtprel@high", VK_PPC_DTPREL_HIGH)
450 .Case("dtprel@higha", VK_PPC_DTPREL_HIGHA)
451 .Case("dtprel@higher", VK_PPC_DTPREL_HIGHER)
452 .Case("dtprel@highera", VK_PPC_DTPREL_HIGHERA)
453 .Case("dtprel@highest", VK_PPC_DTPREL_HIGHEST)
454 .Case("dtprel@highesta", VK_PPC_DTPREL_HIGHESTA)
455 .Case("got@tprel", VK_PPC_GOT_TPREL)
456 .Case("got@tprel@l", VK_PPC_GOT_TPREL_LO)
457 .Case("got@tprel@h", VK_PPC_GOT_TPREL_HI)
458 .Case("got@tprel@ha", VK_PPC_GOT_TPREL_HA)
459 .Case("got@dtprel", VK_PPC_GOT_DTPREL)
460 .Case("got@dtprel@l", VK_PPC_GOT_DTPREL_LO)
461 .Case("got@dtprel@h", VK_PPC_GOT_DTPREL_HI)
462 .Case("got@dtprel@ha", VK_PPC_GOT_DTPREL_HA)
463 .Case("got@tlsgd", VK_PPC_GOT_TLSGD)
464 .Case("got@tlsgd@l", VK_PPC_GOT_TLSGD_LO)
465 .Case("got@tlsgd@h", VK_PPC_GOT_TLSGD_HI)
466 .Case("got@tlsgd@ha", VK_PPC_GOT_TLSGD_HA)
467 .Case("got@tlsld", VK_PPC_GOT_TLSLD)
468 .Case("got@tlsld@l", VK_PPC_GOT_TLSLD_LO)
469 .Case("got@tlsld@h", VK_PPC_GOT_TLSLD_HI)
470 .Case("got@tlsld@ha", VK_PPC_GOT_TLSLD_HA)
471 .Case("got@pcrel", VK_PPC_GOT_PCREL)
472 .Case("got@tlsgd@pcrel", VK_PPC_GOT_TLSGD_PCREL)
473 .Case("got@tlsld@pcrel", VK_PPC_GOT_TLSLD_PCREL)
474 .Case("got@tprel@pcrel", VK_PPC_GOT_TPREL_PCREL)
475 .Case("tls@pcrel", VK_PPC_TLS_PCREL)
476 .Case("notoc", VK_PPC_NOTOC)
477 .Case("gdgot", VK_Hexagon_GD_GOT)
478 .Case("gdplt", VK_Hexagon_GD_PLT)
479 .Case("iegot", VK_Hexagon_IE_GOT)
480 .Case("ie", VK_Hexagon_IE)
481 .Case("ldgot", VK_Hexagon_LD_GOT)
482 .Case("ldplt", VK_Hexagon_LD_PLT)
483 .Case("none", VK_ARM_NONE)
484 .Case("got_prel", VK_ARM_GOT_PREL)
485 .Case("target1", VK_ARM_TARGET1)
486 .Case("target2", VK_ARM_TARGET2)
487 .Case("prel31", VK_ARM_PREL31)
488 .Case("sbrel", VK_ARM_SBREL)
489 .Case("tlsldo", VK_ARM_TLSLDO)
490 .Case("lo8", VK_AVR_LO8)
491 .Case("hi8", VK_AVR_HI8)
492 .Case("hlo8", VK_AVR_HLO8)
493 .Case("typeindex", VK_WASM_TYPEINDEX)
494 .Case("tbrel", VK_WASM_TBREL)
495 .Case("mbrel", VK_WASM_MBREL)
496 .Case("tlsrel", VK_WASM_TLSREL)
497 .Case("gotpcrel32@lo", VK_AMDGPU_GOTPCREL32_LO)
498 .Case("gotpcrel32@hi", VK_AMDGPU_GOTPCREL32_HI)
499 .Case("rel32@lo", VK_AMDGPU_REL32_LO)
500 .Case("rel32@hi", VK_AMDGPU_REL32_HI)
501 .Case("rel64", VK_AMDGPU_REL64)
502 .Case("abs32@lo", VK_AMDGPU_ABS32_LO)
503 .Case("abs32@hi", VK_AMDGPU_ABS32_HI)
504 .Case("hi", VK_VE_HI32)
505 .Case("lo", VK_VE_LO32)
506 .Case("pc_hi", VK_VE_PC_HI32)
507 .Case("pc_lo", VK_VE_PC_LO32)
508 .Case("got_hi", VK_VE_GOT_HI32)
509 .Case("got_lo", VK_VE_GOT_LO32)
510 .Case("gotoff_hi", VK_VE_GOTOFF_HI32)
511 .Case("gotoff_lo", VK_VE_GOTOFF_LO32)
512 .Case("plt_hi", VK_VE_PLT_HI32)
513 .Case("plt_lo", VK_VE_PLT_LO32)
514 .Case("tls_gd_hi", VK_VE_TLS_GD_HI32)
515 .Case("tls_gd_lo", VK_VE_TLS_GD_LO32)
516 .Case("tpoff_hi", VK_VE_TPOFF_HI32)
517 .Case("tpoff_lo", VK_VE_TPOFF_LO32)
518 .Default(VK_Invalid);
519 }
520
521 /* *** */
522
anchor()523 void MCTargetExpr::anchor() {}
524
525 /* *** */
526
evaluateAsAbsolute(int64_t & Res) const527 bool MCExpr::evaluateAsAbsolute(int64_t &Res) const {
528 return evaluateAsAbsolute(Res, nullptr, nullptr, nullptr, false);
529 }
530
evaluateAsAbsolute(int64_t & Res,const MCAsmLayout & Layout) const531 bool MCExpr::evaluateAsAbsolute(int64_t &Res,
532 const MCAsmLayout &Layout) const {
533 return evaluateAsAbsolute(Res, &Layout.getAssembler(), &Layout, nullptr, false);
534 }
535
evaluateAsAbsolute(int64_t & Res,const MCAsmLayout & Layout,const SectionAddrMap & Addrs) const536 bool MCExpr::evaluateAsAbsolute(int64_t &Res,
537 const MCAsmLayout &Layout,
538 const SectionAddrMap &Addrs) const {
539 // Setting InSet causes us to absolutize differences across sections and that
540 // is what the MachO writer uses Addrs for.
541 return evaluateAsAbsolute(Res, &Layout.getAssembler(), &Layout, &Addrs, true);
542 }
543
evaluateAsAbsolute(int64_t & Res,const MCAssembler & Asm) const544 bool MCExpr::evaluateAsAbsolute(int64_t &Res, const MCAssembler &Asm) const {
545 return evaluateAsAbsolute(Res, &Asm, nullptr, nullptr, false);
546 }
547
evaluateAsAbsolute(int64_t & Res,const MCAssembler * Asm) const548 bool MCExpr::evaluateAsAbsolute(int64_t &Res, const MCAssembler *Asm) const {
549 return evaluateAsAbsolute(Res, Asm, nullptr, nullptr, false);
550 }
551
evaluateKnownAbsolute(int64_t & Res,const MCAsmLayout & Layout) const552 bool MCExpr::evaluateKnownAbsolute(int64_t &Res,
553 const MCAsmLayout &Layout) const {
554 return evaluateAsAbsolute(Res, &Layout.getAssembler(), &Layout, nullptr,
555 true);
556 }
557
evaluateAsAbsolute(int64_t & Res,const MCAssembler * Asm,const MCAsmLayout * Layout,const SectionAddrMap * Addrs,bool InSet) const558 bool MCExpr::evaluateAsAbsolute(int64_t &Res, const MCAssembler *Asm,
559 const MCAsmLayout *Layout,
560 const SectionAddrMap *Addrs, bool InSet) const {
561 MCValue Value;
562
563 // Fast path constants.
564 if (const MCConstantExpr *CE = dyn_cast<MCConstantExpr>(this)) {
565 Res = CE->getValue();
566 return true;
567 }
568
569 bool IsRelocatable =
570 evaluateAsRelocatableImpl(Value, Asm, Layout, nullptr, Addrs, InSet);
571
572 // Record the current value.
573 Res = Value.getConstant();
574
575 return IsRelocatable && Value.isAbsolute();
576 }
577
578 /// Helper method for \see EvaluateSymbolAdd().
AttemptToFoldSymbolOffsetDifference(const MCAssembler * Asm,const MCAsmLayout * Layout,const SectionAddrMap * Addrs,bool InSet,const MCSymbolRefExpr * & A,const MCSymbolRefExpr * & B,int64_t & Addend)579 static void AttemptToFoldSymbolOffsetDifference(
580 const MCAssembler *Asm, const MCAsmLayout *Layout,
581 const SectionAddrMap *Addrs, bool InSet, const MCSymbolRefExpr *&A,
582 const MCSymbolRefExpr *&B, int64_t &Addend) {
583 if (!A || !B)
584 return;
585
586 const MCSymbol &SA = A->getSymbol();
587 const MCSymbol &SB = B->getSymbol();
588
589 if (SA.isUndefined() || SB.isUndefined())
590 return;
591
592 if (!Asm->getWriter().isSymbolRefDifferenceFullyResolved(*Asm, A, B, InSet))
593 return;
594
595 auto FinalizeFolding = [&]() {
596 // Pointers to Thumb symbols need to have their low-bit set to allow
597 // for interworking.
598 if (Asm->isThumbFunc(&SA))
599 Addend |= 1;
600
601 // If symbol is labeled as micromips, we set low-bit to ensure
602 // correct offset in .gcc_except_table
603 if (Asm->getBackend().isMicroMips(&SA))
604 Addend |= 1;
605
606 // Clear the symbol expr pointers to indicate we have folded these
607 // operands.
608 A = B = nullptr;
609 };
610
611 const MCFragment *FA = SA.getFragment();
612 const MCFragment *FB = SB.getFragment();
613 // If both symbols are in the same fragment, return the difference of their
614 // offsets
615 if (FA == FB && !SA.isVariable() && !SA.isUnset() && !SB.isVariable() &&
616 !SB.isUnset()) {
617 Addend += SA.getOffset() - SB.getOffset();
618 return FinalizeFolding();
619 }
620
621 const MCSection &SecA = *FA->getParent();
622 const MCSection &SecB = *FB->getParent();
623
624 if ((&SecA != &SecB) && !Addrs)
625 return;
626
627 if (Layout) {
628 // One of the symbol involved is part of a fragment being laid out. Quit now
629 // to avoid a self loop.
630 if (!Layout->canGetFragmentOffset(FA) || !Layout->canGetFragmentOffset(FB))
631 return;
632
633 // Eagerly evaluate when layout is finalized.
634 Addend += Layout->getSymbolOffset(A->getSymbol()) -
635 Layout->getSymbolOffset(B->getSymbol());
636 if (Addrs && (&SecA != &SecB))
637 Addend += (Addrs->lookup(&SecA) - Addrs->lookup(&SecB));
638
639 FinalizeFolding();
640 } else {
641 // When layout is not finalized, our ability to resolve differences between
642 // symbols is limited to specific cases where the fragments between two
643 // symbols (including the fragments the symbols are defined in) are
644 // fixed-size fragments so the difference can be calculated. For example,
645 // this is important when the Subtarget is changed and a new MCDataFragment
646 // is created in the case of foo: instr; .arch_extension ext; instr .if . -
647 // foo.
648 if (SA.isVariable() || SA.isUnset() || SB.isVariable() || SB.isUnset() ||
649 FA->getKind() != MCFragment::FT_Data ||
650 FB->getKind() != MCFragment::FT_Data ||
651 FA->getSubsectionNumber() != FB->getSubsectionNumber())
652 return;
653 // Try to find a constant displacement from FA to FB, add the displacement
654 // between the offset in FA of SA and the offset in FB of SB.
655 int64_t Displacement = SA.getOffset() - SB.getOffset();
656 for (auto FI = FB->getIterator(), FE = SecA.end(); FI != FE; ++FI) {
657 if (&*FI == FA) {
658 Addend += Displacement;
659 return FinalizeFolding();
660 }
661
662 if (FI->getKind() != MCFragment::FT_Data)
663 return;
664 Displacement += cast<MCDataFragment>(FI)->getContents().size();
665 }
666 }
667 }
668
canFold(const MCAssembler * Asm,const MCSymbolRefExpr * A,const MCSymbolRefExpr * B,bool InSet)669 static bool canFold(const MCAssembler *Asm, const MCSymbolRefExpr *A,
670 const MCSymbolRefExpr *B, bool InSet) {
671 if (InSet)
672 return true;
673
674 if (!Asm->getBackend().requiresDiffExpressionRelocations())
675 return true;
676
677 const MCSymbol &CheckSym = A ? A->getSymbol() : B->getSymbol();
678 if (!CheckSym.isInSection())
679 return true;
680
681 if (!CheckSym.getSection().hasInstructions())
682 return true;
683
684 return false;
685 }
686
687 /// Evaluate the result of an add between (conceptually) two MCValues.
688 ///
689 /// This routine conceptually attempts to construct an MCValue:
690 /// Result = (Result_A - Result_B + Result_Cst)
691 /// from two MCValue's LHS and RHS where
692 /// Result = LHS + RHS
693 /// and
694 /// Result = (LHS_A - LHS_B + LHS_Cst) + (RHS_A - RHS_B + RHS_Cst).
695 ///
696 /// This routine attempts to aggressively fold the operands such that the result
697 /// is representable in an MCValue, but may not always succeed.
698 ///
699 /// \returns True on success, false if the result is not representable in an
700 /// MCValue.
701
702 /// NOTE: It is really important to have both the Asm and Layout arguments.
703 /// They might look redundant, but this function can be used before layout
704 /// is done (see the object streamer for example) and having the Asm argument
705 /// lets us avoid relaxations early.
706 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)707 EvaluateSymbolicAdd(const MCAssembler *Asm, const MCAsmLayout *Layout,
708 const SectionAddrMap *Addrs, bool InSet, const MCValue &LHS,
709 const MCSymbolRefExpr *RHS_A, const MCSymbolRefExpr *RHS_B,
710 int64_t RHS_Cst, MCValue &Res) {
711 // FIXME: This routine (and other evaluation parts) are *incredibly* sloppy
712 // about dealing with modifiers. This will ultimately bite us, one day.
713 const MCSymbolRefExpr *LHS_A = LHS.getSymA();
714 const MCSymbolRefExpr *LHS_B = LHS.getSymB();
715 int64_t LHS_Cst = LHS.getConstant();
716
717 // Fold the result constant immediately.
718 int64_t Result_Cst = LHS_Cst + RHS_Cst;
719
720 assert((!Layout || Asm) &&
721 "Must have an assembler object if layout is given!");
722
723 // If we have a layout, we can fold resolved differences. Do not do this if
724 // the backend requires this to be emitted as individual relocations, unless
725 // the InSet flag is set to get the current difference anyway (used for
726 // example to calculate symbol sizes).
727 if (Asm && canFold(Asm, LHS_A, LHS_B, InSet)) {
728 // First, fold out any differences which are fully resolved. By
729 // reassociating terms in
730 // Result = (LHS_A - LHS_B + LHS_Cst) + (RHS_A - RHS_B + RHS_Cst).
731 // we have the four possible differences:
732 // (LHS_A - LHS_B),
733 // (LHS_A - RHS_B),
734 // (RHS_A - LHS_B),
735 // (RHS_A - RHS_B).
736 // Since we are attempting to be as aggressive as possible about folding, we
737 // attempt to evaluate each possible alternative.
738 AttemptToFoldSymbolOffsetDifference(Asm, Layout, Addrs, InSet, LHS_A, LHS_B,
739 Result_Cst);
740 AttemptToFoldSymbolOffsetDifference(Asm, Layout, Addrs, InSet, LHS_A, RHS_B,
741 Result_Cst);
742 AttemptToFoldSymbolOffsetDifference(Asm, Layout, Addrs, InSet, RHS_A, LHS_B,
743 Result_Cst);
744 AttemptToFoldSymbolOffsetDifference(Asm, Layout, Addrs, InSet, RHS_A, RHS_B,
745 Result_Cst);
746 }
747
748 // We can't represent the addition or subtraction of two symbols.
749 if ((LHS_A && RHS_A) || (LHS_B && RHS_B))
750 return false;
751
752 // At this point, we have at most one additive symbol and one subtractive
753 // symbol -- find them.
754 const MCSymbolRefExpr *A = LHS_A ? LHS_A : RHS_A;
755 const MCSymbolRefExpr *B = LHS_B ? LHS_B : RHS_B;
756
757 Res = MCValue::get(A, B, Result_Cst);
758 return true;
759 }
760
evaluateAsRelocatable(MCValue & Res,const MCAsmLayout * Layout,const MCFixup * Fixup) const761 bool MCExpr::evaluateAsRelocatable(MCValue &Res,
762 const MCAsmLayout *Layout,
763 const MCFixup *Fixup) const {
764 MCAssembler *Assembler = Layout ? &Layout->getAssembler() : nullptr;
765 return evaluateAsRelocatableImpl(Res, Assembler, Layout, Fixup, nullptr,
766 false);
767 }
768
evaluateAsValue(MCValue & Res,const MCAsmLayout & Layout) const769 bool MCExpr::evaluateAsValue(MCValue &Res, const MCAsmLayout &Layout) const {
770 MCAssembler *Assembler = &Layout.getAssembler();
771 return evaluateAsRelocatableImpl(Res, Assembler, &Layout, nullptr, nullptr,
772 true);
773 }
774
canExpand(const MCSymbol & Sym,bool InSet)775 static bool canExpand(const MCSymbol &Sym, bool InSet) {
776 const MCExpr *Expr = Sym.getVariableValue();
777 const auto *Inner = dyn_cast<MCSymbolRefExpr>(Expr);
778 if (Inner) {
779 if (Inner->getKind() == MCSymbolRefExpr::VK_WEAKREF)
780 return false;
781 }
782
783 if (InSet)
784 return true;
785 return !Sym.isInSection();
786 }
787
evaluateAsRelocatableImpl(MCValue & Res,const MCAssembler * Asm,const MCAsmLayout * Layout,const MCFixup * Fixup,const SectionAddrMap * Addrs,bool InSet) const788 bool MCExpr::evaluateAsRelocatableImpl(MCValue &Res, const MCAssembler *Asm,
789 const MCAsmLayout *Layout,
790 const MCFixup *Fixup,
791 const SectionAddrMap *Addrs,
792 bool InSet) const {
793 ++stats::MCExprEvaluate;
794
795 switch (getKind()) {
796 case Target:
797 return cast<MCTargetExpr>(this)->evaluateAsRelocatableImpl(Res, Layout,
798 Fixup);
799
800 case Constant:
801 Res = MCValue::get(cast<MCConstantExpr>(this)->getValue());
802 return true;
803
804 case SymbolRef: {
805 const MCSymbolRefExpr *SRE = cast<MCSymbolRefExpr>(this);
806 const MCSymbol &Sym = SRE->getSymbol();
807 const auto Kind = SRE->getKind();
808
809 // Evaluate recursively if this is a variable.
810 if (Sym.isVariable() && (Kind == MCSymbolRefExpr::VK_None || Layout) &&
811 canExpand(Sym, InSet)) {
812 bool IsMachO = SRE->hasSubsectionsViaSymbols();
813 if (Sym.getVariableValue()->evaluateAsRelocatableImpl(
814 Res, Asm, Layout, Fixup, Addrs, InSet || IsMachO)) {
815 if (Kind != MCSymbolRefExpr::VK_None) {
816 if (Res.isAbsolute()) {
817 Res = MCValue::get(SRE, nullptr, 0);
818 return true;
819 }
820 // If the reference has a variant kind, we can only handle expressions
821 // which evaluate exactly to a single unadorned symbol. Attach the
822 // original VariantKind to SymA of the result.
823 if (Res.getRefKind() != MCSymbolRefExpr::VK_None || !Res.getSymA() ||
824 Res.getSymB() || Res.getConstant())
825 return false;
826 Res =
827 MCValue::get(MCSymbolRefExpr::create(&Res.getSymA()->getSymbol(),
828 Kind, Asm->getContext()),
829 Res.getSymB(), Res.getConstant(), Res.getRefKind());
830 }
831 if (!IsMachO)
832 return true;
833
834 const MCSymbolRefExpr *A = Res.getSymA();
835 const MCSymbolRefExpr *B = Res.getSymB();
836 // FIXME: This is small hack. Given
837 // a = b + 4
838 // .long a
839 // the OS X assembler will completely drop the 4. We should probably
840 // include it in the relocation or produce an error if that is not
841 // possible.
842 // Allow constant expressions.
843 if (!A && !B)
844 return true;
845 // Allows aliases with zero offset.
846 if (Res.getConstant() == 0 && (!A || !B))
847 return true;
848 }
849 }
850
851 Res = MCValue::get(SRE, nullptr, 0);
852 return true;
853 }
854
855 case Unary: {
856 const MCUnaryExpr *AUE = cast<MCUnaryExpr>(this);
857 MCValue Value;
858
859 if (!AUE->getSubExpr()->evaluateAsRelocatableImpl(Value, Asm, Layout, Fixup,
860 Addrs, InSet))
861 return false;
862
863 switch (AUE->getOpcode()) {
864 case MCUnaryExpr::LNot:
865 if (!Value.isAbsolute())
866 return false;
867 Res = MCValue::get(!Value.getConstant());
868 break;
869 case MCUnaryExpr::Minus:
870 /// -(a - b + const) ==> (b - a - const)
871 if (Value.getSymA() && !Value.getSymB())
872 return false;
873
874 // The cast avoids undefined behavior if the constant is INT64_MIN.
875 Res = MCValue::get(Value.getSymB(), Value.getSymA(),
876 -(uint64_t)Value.getConstant());
877 break;
878 case MCUnaryExpr::Not:
879 if (!Value.isAbsolute())
880 return false;
881 Res = MCValue::get(~Value.getConstant());
882 break;
883 case MCUnaryExpr::Plus:
884 Res = Value;
885 break;
886 }
887
888 return true;
889 }
890
891 case Binary: {
892 const MCBinaryExpr *ABE = cast<MCBinaryExpr>(this);
893 MCValue LHSValue, RHSValue;
894
895 if (!ABE->getLHS()->evaluateAsRelocatableImpl(LHSValue, Asm, Layout, Fixup,
896 Addrs, InSet) ||
897 !ABE->getRHS()->evaluateAsRelocatableImpl(RHSValue, Asm, Layout, Fixup,
898 Addrs, InSet)) {
899 // Check if both are Target Expressions, see if we can compare them.
900 if (const MCTargetExpr *L = dyn_cast<MCTargetExpr>(ABE->getLHS()))
901 if (const MCTargetExpr *R = cast<MCTargetExpr>(ABE->getRHS())) {
902 switch (ABE->getOpcode()) {
903 case MCBinaryExpr::EQ:
904 Res = MCValue::get((L->isEqualTo(R)) ? -1 : 0);
905 return true;
906 case MCBinaryExpr::NE:
907 Res = MCValue::get((R->isEqualTo(R)) ? 0 : -1);
908 return true;
909 default: break;
910 }
911 }
912 return false;
913 }
914
915 // We only support a few operations on non-constant expressions, handle
916 // those first.
917 if (!LHSValue.isAbsolute() || !RHSValue.isAbsolute()) {
918 switch (ABE->getOpcode()) {
919 default:
920 return false;
921 case MCBinaryExpr::Sub:
922 // Negate RHS and add.
923 // The cast avoids undefined behavior if the constant is INT64_MIN.
924 return EvaluateSymbolicAdd(Asm, Layout, Addrs, InSet, LHSValue,
925 RHSValue.getSymB(), RHSValue.getSymA(),
926 -(uint64_t)RHSValue.getConstant(), Res);
927
928 case MCBinaryExpr::Add:
929 return EvaluateSymbolicAdd(Asm, Layout, Addrs, InSet, LHSValue,
930 RHSValue.getSymA(), RHSValue.getSymB(),
931 RHSValue.getConstant(), Res);
932 }
933 }
934
935 // FIXME: We need target hooks for the evaluation. It may be limited in
936 // width, and gas defines the result of comparisons differently from
937 // Apple as.
938 int64_t LHS = LHSValue.getConstant(), RHS = RHSValue.getConstant();
939 int64_t Result = 0;
940 auto Op = ABE->getOpcode();
941 switch (Op) {
942 case MCBinaryExpr::AShr: Result = LHS >> RHS; break;
943 case MCBinaryExpr::Add: Result = LHS + RHS; break;
944 case MCBinaryExpr::And: Result = LHS & RHS; break;
945 case MCBinaryExpr::Div:
946 case MCBinaryExpr::Mod:
947 // Handle division by zero. gas just emits a warning and keeps going,
948 // we try to be stricter.
949 // FIXME: Currently the caller of this function has no way to understand
950 // we're bailing out because of 'division by zero'. Therefore, it will
951 // emit a 'expected relocatable expression' error. It would be nice to
952 // change this code to emit a better diagnostic.
953 if (RHS == 0)
954 return false;
955 if (ABE->getOpcode() == MCBinaryExpr::Div)
956 Result = LHS / RHS;
957 else
958 Result = LHS % RHS;
959 break;
960 case MCBinaryExpr::EQ: Result = LHS == RHS; break;
961 case MCBinaryExpr::GT: Result = LHS > RHS; break;
962 case MCBinaryExpr::GTE: Result = LHS >= RHS; break;
963 case MCBinaryExpr::LAnd: Result = LHS && RHS; break;
964 case MCBinaryExpr::LOr: Result = LHS || RHS; break;
965 case MCBinaryExpr::LShr: Result = uint64_t(LHS) >> uint64_t(RHS); break;
966 case MCBinaryExpr::LT: Result = LHS < RHS; break;
967 case MCBinaryExpr::LTE: Result = LHS <= RHS; break;
968 case MCBinaryExpr::Mul: Result = LHS * RHS; break;
969 case MCBinaryExpr::NE: Result = LHS != RHS; break;
970 case MCBinaryExpr::Or: Result = LHS | RHS; break;
971 case MCBinaryExpr::OrNot: Result = LHS | ~RHS; break;
972 case MCBinaryExpr::Shl: Result = uint64_t(LHS) << uint64_t(RHS); break;
973 case MCBinaryExpr::Sub: Result = LHS - RHS; break;
974 case MCBinaryExpr::Xor: Result = LHS ^ RHS; break;
975 }
976
977 switch (Op) {
978 default:
979 Res = MCValue::get(Result);
980 break;
981 case MCBinaryExpr::EQ:
982 case MCBinaryExpr::GT:
983 case MCBinaryExpr::GTE:
984 case MCBinaryExpr::LT:
985 case MCBinaryExpr::LTE:
986 case MCBinaryExpr::NE:
987 // A comparison operator returns a -1 if true and 0 if false.
988 Res = MCValue::get(Result ? -1 : 0);
989 break;
990 }
991
992 return true;
993 }
994 }
995
996 llvm_unreachable("Invalid assembly expression kind!");
997 }
998
findAssociatedFragment() const999 MCFragment *MCExpr::findAssociatedFragment() const {
1000 switch (getKind()) {
1001 case Target:
1002 // We never look through target specific expressions.
1003 return cast<MCTargetExpr>(this)->findAssociatedFragment();
1004
1005 case Constant:
1006 return MCSymbol::AbsolutePseudoFragment;
1007
1008 case SymbolRef: {
1009 const MCSymbolRefExpr *SRE = cast<MCSymbolRefExpr>(this);
1010 const MCSymbol &Sym = SRE->getSymbol();
1011 return Sym.getFragment();
1012 }
1013
1014 case Unary:
1015 return cast<MCUnaryExpr>(this)->getSubExpr()->findAssociatedFragment();
1016
1017 case Binary: {
1018 const MCBinaryExpr *BE = cast<MCBinaryExpr>(this);
1019 MCFragment *LHS_F = BE->getLHS()->findAssociatedFragment();
1020 MCFragment *RHS_F = BE->getRHS()->findAssociatedFragment();
1021
1022 // If either is absolute, return the other.
1023 if (LHS_F == MCSymbol::AbsolutePseudoFragment)
1024 return RHS_F;
1025 if (RHS_F == MCSymbol::AbsolutePseudoFragment)
1026 return LHS_F;
1027
1028 // Not always correct, but probably the best we can do without more context.
1029 if (BE->getOpcode() == MCBinaryExpr::Sub)
1030 return MCSymbol::AbsolutePseudoFragment;
1031
1032 // Otherwise, return the first non-null fragment.
1033 return LHS_F ? LHS_F : RHS_F;
1034 }
1035 }
1036
1037 llvm_unreachable("Invalid assembly expression kind!");
1038 }
1039