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/StringSwitch.h" 12 #include "llvm/Config/llvm-config.h" 13 #include "llvm/MC/MCAsmBackend.h" 14 #include "llvm/MC/MCAsmInfo.h" 15 #include "llvm/MC/MCAsmLayout.h" 16 #include "llvm/MC/MCAssembler.h" 17 #include "llvm/MC/MCContext.h" 18 #include "llvm/MC/MCObjectWriter.h" 19 #include "llvm/MC/MCSymbol.h" 20 #include "llvm/MC/MCValue.h" 21 #include "llvm/Support/Casting.h" 22 #include "llvm/Support/Compiler.h" 23 #include "llvm/Support/Debug.h" 24 #include "llvm/Support/ErrorHandling.h" 25 #include "llvm/Support/raw_ostream.h" 26 #include <cassert> 27 #include <cstdint> 28 29 using namespace llvm; 30 31 #define DEBUG_TYPE "mcexpr" 32 33 namespace { 34 namespace stats { 35 36 STATISTIC(MCExprEvaluate, "Number of MCExpr evaluations"); 37 38 } // end namespace stats 39 } // end anonymous namespace 40 41 void MCExpr::print(raw_ostream &OS, const MCAsmInfo *MAI, bool InParens) const { 42 switch (getKind()) { 43 case MCExpr::Target: 44 return cast<MCTargetExpr>(this)->printImpl(OS, MAI); 45 case MCExpr::Constant: { 46 auto Value = cast<MCConstantExpr>(*this).getValue(); 47 auto PrintInHex = cast<MCConstantExpr>(*this).useHexFormat(); 48 auto SizeInBytes = cast<MCConstantExpr>(*this).getSizeInBytes(); 49 if (Value < 0 && MAI && !MAI->supportsSignedData()) 50 PrintInHex = true; 51 if (PrintInHex) 52 switch (SizeInBytes) { 53 default: 54 OS << "0x" << Twine::utohexstr(Value); 55 break; 56 case 1: 57 OS << format("0x%02" PRIx64, Value); 58 break; 59 case 2: 60 OS << format("0x%04" PRIx64, Value); 61 break; 62 case 4: 63 OS << format("0x%08" PRIx64, Value); 64 break; 65 case 8: 66 OS << format("0x%016" PRIx64, Value); 67 break; 68 } 69 else 70 OS << Value; 71 return; 72 } 73 case MCExpr::SymbolRef: { 74 const MCSymbolRefExpr &SRE = cast<MCSymbolRefExpr>(*this); 75 const MCSymbol &Sym = SRE.getSymbol(); 76 // Parenthesize names that start with $ so that they don't look like 77 // absolute names. 78 bool UseParens = MAI && MAI->useParensForDollarSignNames() && !InParens && 79 !Sym.getName().empty() && Sym.getName()[0] == '$'; 80 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) 175 LLVM_DUMP_METHOD void MCExpr::dump() const { 176 dbgs() << *this; 177 dbgs() << '\n'; 178 } 179 #endif 180 181 /* *** */ 182 183 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 } 188 189 const MCUnaryExpr *MCUnaryExpr::create(Opcode Opc, const MCExpr *Expr, 190 MCContext &Ctx, SMLoc Loc) { 191 return new (Ctx) MCUnaryExpr(Opc, Expr, Loc); 192 } 193 194 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 /* *** */ 201 202 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 } 209 210 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 } 215 216 const MCSymbolRefExpr *MCSymbolRefExpr::create(StringRef Name, VariantKind Kind, 217 MCContext &Ctx) { 218 return create(Ctx.getOrCreateSymbol(Name), Kind, Ctx); 219 } 220 221 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_GOTPCREL_NORELAX: return "GOTPCREL_NORELAX"; 234 case VK_GOTTPOFF: return "GOTTPOFF"; 235 case VK_INDNTPOFF: return "INDNTPOFF"; 236 case VK_NTPOFF: return "NTPOFF"; 237 case VK_GOTNTPOFF: return "GOTNTPOFF"; 238 case VK_PLT: return "PLT"; 239 case VK_TLSGD: return "TLSGD"; 240 case VK_TLSLD: return "TLSLD"; 241 case VK_TLSLDM: return "TLSLDM"; 242 case VK_TPOFF: return "TPOFF"; 243 case VK_TPREL: return "TPREL"; 244 case VK_TLSCALL: return "tlscall"; 245 case VK_TLSDESC: return "tlsdesc"; 246 case VK_TLVP: return "TLVP"; 247 case VK_TLVPPAGE: return "TLVPPAGE"; 248 case VK_TLVPPAGEOFF: return "TLVPPAGEOFF"; 249 case VK_PAGE: return "PAGE"; 250 case VK_PAGEOFF: return "PAGEOFF"; 251 case VK_GOTPAGE: return "GOTPAGE"; 252 case VK_GOTPAGEOFF: return "GOTPAGEOFF"; 253 case VK_SECREL: return "SECREL32"; 254 case VK_SIZE: return "SIZE"; 255 case VK_WEAKREF: return "WEAKREF"; 256 case VK_X86_ABS8: return "ABS8"; 257 case VK_X86_PLTOFF: return "PLTOFF"; 258 case VK_ARM_NONE: return "none"; 259 case VK_ARM_GOT_PREL: return "GOT_PREL"; 260 case VK_ARM_TARGET1: return "target1"; 261 case VK_ARM_TARGET2: return "target2"; 262 case VK_ARM_PREL31: return "prel31"; 263 case VK_ARM_SBREL: return "sbrel"; 264 case VK_ARM_TLSLDO: return "tlsldo"; 265 case VK_ARM_TLSDESCSEQ: return "tlsdescseq"; 266 case VK_AVR_NONE: return "none"; 267 case VK_AVR_LO8: return "lo8"; 268 case VK_AVR_HI8: return "hi8"; 269 case VK_AVR_HLO8: return "hlo8"; 270 case VK_AVR_DIFF8: return "diff8"; 271 case VK_AVR_DIFF16: return "diff16"; 272 case VK_AVR_DIFF32: return "diff32"; 273 case VK_AVR_PM: return "pm"; 274 case VK_PPC_LO: return "l"; 275 case VK_PPC_HI: return "h"; 276 case VK_PPC_HA: return "ha"; 277 case VK_PPC_HIGH: return "high"; 278 case VK_PPC_HIGHA: return "higha"; 279 case VK_PPC_HIGHER: return "higher"; 280 case VK_PPC_HIGHERA: return "highera"; 281 case VK_PPC_HIGHEST: return "highest"; 282 case VK_PPC_HIGHESTA: return "highesta"; 283 case VK_PPC_GOT_LO: return "got@l"; 284 case VK_PPC_GOT_HI: return "got@h"; 285 case VK_PPC_GOT_HA: return "got@ha"; 286 case VK_PPC_TOCBASE: return "tocbase"; 287 case VK_PPC_TOC: return "toc"; 288 case VK_PPC_TOC_LO: return "toc@l"; 289 case VK_PPC_TOC_HI: return "toc@h"; 290 case VK_PPC_TOC_HA: return "toc@ha"; 291 case VK_PPC_U: return "u"; 292 case VK_PPC_L: return "l"; 293 case VK_PPC_DTPMOD: return "dtpmod"; 294 case VK_PPC_TPREL_LO: return "tprel@l"; 295 case VK_PPC_TPREL_HI: return "tprel@h"; 296 case VK_PPC_TPREL_HA: return "tprel@ha"; 297 case VK_PPC_TPREL_HIGH: return "tprel@high"; 298 case VK_PPC_TPREL_HIGHA: return "tprel@higha"; 299 case VK_PPC_TPREL_HIGHER: return "tprel@higher"; 300 case VK_PPC_TPREL_HIGHERA: return "tprel@highera"; 301 case VK_PPC_TPREL_HIGHEST: return "tprel@highest"; 302 case VK_PPC_TPREL_HIGHESTA: return "tprel@highesta"; 303 case VK_PPC_DTPREL_LO: return "dtprel@l"; 304 case VK_PPC_DTPREL_HI: return "dtprel@h"; 305 case VK_PPC_DTPREL_HA: return "dtprel@ha"; 306 case VK_PPC_DTPREL_HIGH: return "dtprel@high"; 307 case VK_PPC_DTPREL_HIGHA: return "dtprel@higha"; 308 case VK_PPC_DTPREL_HIGHER: return "dtprel@higher"; 309 case VK_PPC_DTPREL_HIGHERA: return "dtprel@highera"; 310 case VK_PPC_DTPREL_HIGHEST: return "dtprel@highest"; 311 case VK_PPC_DTPREL_HIGHESTA: return "dtprel@highesta"; 312 case VK_PPC_GOT_TPREL: return "got@tprel"; 313 case VK_PPC_GOT_TPREL_LO: return "got@tprel@l"; 314 case VK_PPC_GOT_TPREL_HI: return "got@tprel@h"; 315 case VK_PPC_GOT_TPREL_HA: return "got@tprel@ha"; 316 case VK_PPC_GOT_DTPREL: return "got@dtprel"; 317 case VK_PPC_GOT_DTPREL_LO: return "got@dtprel@l"; 318 case VK_PPC_GOT_DTPREL_HI: return "got@dtprel@h"; 319 case VK_PPC_GOT_DTPREL_HA: return "got@dtprel@ha"; 320 case VK_PPC_TLS: return "tls"; 321 case VK_PPC_GOT_TLSGD: return "got@tlsgd"; 322 case VK_PPC_GOT_TLSGD_LO: return "got@tlsgd@l"; 323 case VK_PPC_GOT_TLSGD_HI: return "got@tlsgd@h"; 324 case VK_PPC_GOT_TLSGD_HA: return "got@tlsgd@ha"; 325 case VK_PPC_TLSGD: return "tlsgd"; 326 case VK_PPC_AIX_TLSGD: 327 return "gd"; 328 case VK_PPC_AIX_TLSGDM: 329 return "m"; 330 case VK_PPC_AIX_TLSIE: 331 return "ie"; 332 case VK_PPC_AIX_TLSLE: 333 return "le"; 334 case VK_PPC_GOT_TLSLD: return "got@tlsld"; 335 case VK_PPC_GOT_TLSLD_LO: return "got@tlsld@l"; 336 case VK_PPC_GOT_TLSLD_HI: return "got@tlsld@h"; 337 case VK_PPC_GOT_TLSLD_HA: return "got@tlsld@ha"; 338 case VK_PPC_GOT_PCREL: 339 return "got@pcrel"; 340 case VK_PPC_GOT_TLSGD_PCREL: 341 return "got@tlsgd@pcrel"; 342 case VK_PPC_GOT_TLSLD_PCREL: 343 return "got@tlsld@pcrel"; 344 case VK_PPC_GOT_TPREL_PCREL: 345 return "got@tprel@pcrel"; 346 case VK_PPC_TLS_PCREL: 347 return "tls@pcrel"; 348 case VK_PPC_TLSLD: return "tlsld"; 349 case VK_PPC_LOCAL: return "local"; 350 case VK_PPC_NOTOC: return "notoc"; 351 case VK_PPC_PCREL_OPT: return "<<invalid>>"; 352 case VK_COFF_IMGREL32: return "IMGREL"; 353 case VK_Hexagon_LO16: return "LO16"; 354 case VK_Hexagon_HI16: return "HI16"; 355 case VK_Hexagon_GPREL: return "GPREL"; 356 case VK_Hexagon_GD_GOT: return "GDGOT"; 357 case VK_Hexagon_LD_GOT: return "LDGOT"; 358 case VK_Hexagon_GD_PLT: return "GDPLT"; 359 case VK_Hexagon_LD_PLT: return "LDPLT"; 360 case VK_Hexagon_IE: return "IE"; 361 case VK_Hexagon_IE_GOT: return "IEGOT"; 362 case VK_WASM_TYPEINDEX: return "TYPEINDEX"; 363 case VK_WASM_MBREL: return "MBREL"; 364 case VK_WASM_TLSREL: return "TLSREL"; 365 case VK_WASM_TBREL: return "TBREL"; 366 case VK_WASM_GOT_TLS: return "GOT@TLS"; 367 case VK_WASM_FUNCINDEX: return "FUNCINDEX"; 368 case VK_AMDGPU_GOTPCREL32_LO: return "gotpcrel32@lo"; 369 case VK_AMDGPU_GOTPCREL32_HI: return "gotpcrel32@hi"; 370 case VK_AMDGPU_REL32_LO: return "rel32@lo"; 371 case VK_AMDGPU_REL32_HI: return "rel32@hi"; 372 case VK_AMDGPU_REL64: return "rel64"; 373 case VK_AMDGPU_ABS32_LO: return "abs32@lo"; 374 case VK_AMDGPU_ABS32_HI: return "abs32@hi"; 375 case VK_VE_HI32: return "hi"; 376 case VK_VE_LO32: return "lo"; 377 case VK_VE_PC_HI32: return "pc_hi"; 378 case VK_VE_PC_LO32: return "pc_lo"; 379 case VK_VE_GOT_HI32: return "got_hi"; 380 case VK_VE_GOT_LO32: return "got_lo"; 381 case VK_VE_GOTOFF_HI32: return "gotoff_hi"; 382 case VK_VE_GOTOFF_LO32: return "gotoff_lo"; 383 case VK_VE_PLT_HI32: return "plt_hi"; 384 case VK_VE_PLT_LO32: return "plt_lo"; 385 case VK_VE_TLS_GD_HI32: return "tls_gd_hi"; 386 case VK_VE_TLS_GD_LO32: return "tls_gd_lo"; 387 case VK_VE_TPOFF_HI32: return "tpoff_hi"; 388 case VK_VE_TPOFF_LO32: return "tpoff_lo"; 389 } 390 llvm_unreachable("Invalid variant kind"); 391 } 392 393 MCSymbolRefExpr::VariantKind 394 MCSymbolRefExpr::getVariantKindForName(StringRef Name) { 395 return StringSwitch<VariantKind>(Name.lower()) 396 .Case("dtprel", VK_DTPREL) 397 .Case("dtpoff", VK_DTPOFF) 398 .Case("got", VK_GOT) 399 .Case("gotoff", VK_GOTOFF) 400 .Case("gotrel", VK_GOTREL) 401 .Case("pcrel", VK_PCREL) 402 .Case("gotpcrel", VK_GOTPCREL) 403 .Case("gotpcrel_norelax", VK_GOTPCREL_NORELAX) 404 .Case("gottpoff", VK_GOTTPOFF) 405 .Case("indntpoff", VK_INDNTPOFF) 406 .Case("ntpoff", VK_NTPOFF) 407 .Case("gotntpoff", VK_GOTNTPOFF) 408 .Case("plt", VK_PLT) 409 .Case("tlscall", VK_TLSCALL) 410 .Case("tlsdesc", VK_TLSDESC) 411 .Case("tlsgd", VK_TLSGD) 412 .Case("tlsld", VK_TLSLD) 413 .Case("tlsldm", VK_TLSLDM) 414 .Case("tpoff", VK_TPOFF) 415 .Case("tprel", VK_TPREL) 416 .Case("tlvp", VK_TLVP) 417 .Case("tlvppage", VK_TLVPPAGE) 418 .Case("tlvppageoff", VK_TLVPPAGEOFF) 419 .Case("page", VK_PAGE) 420 .Case("pageoff", VK_PAGEOFF) 421 .Case("gotpage", VK_GOTPAGE) 422 .Case("gotpageoff", VK_GOTPAGEOFF) 423 .Case("imgrel", VK_COFF_IMGREL32) 424 .Case("secrel32", VK_SECREL) 425 .Case("size", VK_SIZE) 426 .Case("abs8", VK_X86_ABS8) 427 .Case("pltoff", VK_X86_PLTOFF) 428 .Case("l", VK_PPC_LO) 429 .Case("h", VK_PPC_HI) 430 .Case("ha", VK_PPC_HA) 431 .Case("high", VK_PPC_HIGH) 432 .Case("higha", VK_PPC_HIGHA) 433 .Case("higher", VK_PPC_HIGHER) 434 .Case("highera", VK_PPC_HIGHERA) 435 .Case("highest", VK_PPC_HIGHEST) 436 .Case("highesta", VK_PPC_HIGHESTA) 437 .Case("got@l", VK_PPC_GOT_LO) 438 .Case("got@h", VK_PPC_GOT_HI) 439 .Case("got@ha", VK_PPC_GOT_HA) 440 .Case("local", VK_PPC_LOCAL) 441 .Case("tocbase", VK_PPC_TOCBASE) 442 .Case("toc", VK_PPC_TOC) 443 .Case("toc@l", VK_PPC_TOC_LO) 444 .Case("toc@h", VK_PPC_TOC_HI) 445 .Case("toc@ha", VK_PPC_TOC_HA) 446 .Case("u", VK_PPC_U) 447 .Case("l", VK_PPC_L) 448 .Case("tls", VK_PPC_TLS) 449 .Case("dtpmod", VK_PPC_DTPMOD) 450 .Case("tprel@l", VK_PPC_TPREL_LO) 451 .Case("tprel@h", VK_PPC_TPREL_HI) 452 .Case("tprel@ha", VK_PPC_TPREL_HA) 453 .Case("tprel@high", VK_PPC_TPREL_HIGH) 454 .Case("tprel@higha", VK_PPC_TPREL_HIGHA) 455 .Case("tprel@higher", VK_PPC_TPREL_HIGHER) 456 .Case("tprel@highera", VK_PPC_TPREL_HIGHERA) 457 .Case("tprel@highest", VK_PPC_TPREL_HIGHEST) 458 .Case("tprel@highesta", VK_PPC_TPREL_HIGHESTA) 459 .Case("dtprel@l", VK_PPC_DTPREL_LO) 460 .Case("dtprel@h", VK_PPC_DTPREL_HI) 461 .Case("dtprel@ha", VK_PPC_DTPREL_HA) 462 .Case("dtprel@high", VK_PPC_DTPREL_HIGH) 463 .Case("dtprel@higha", VK_PPC_DTPREL_HIGHA) 464 .Case("dtprel@higher", VK_PPC_DTPREL_HIGHER) 465 .Case("dtprel@highera", VK_PPC_DTPREL_HIGHERA) 466 .Case("dtprel@highest", VK_PPC_DTPREL_HIGHEST) 467 .Case("dtprel@highesta", VK_PPC_DTPREL_HIGHESTA) 468 .Case("got@tprel", VK_PPC_GOT_TPREL) 469 .Case("got@tprel@l", VK_PPC_GOT_TPREL_LO) 470 .Case("got@tprel@h", VK_PPC_GOT_TPREL_HI) 471 .Case("got@tprel@ha", VK_PPC_GOT_TPREL_HA) 472 .Case("got@dtprel", VK_PPC_GOT_DTPREL) 473 .Case("got@dtprel@l", VK_PPC_GOT_DTPREL_LO) 474 .Case("got@dtprel@h", VK_PPC_GOT_DTPREL_HI) 475 .Case("got@dtprel@ha", VK_PPC_GOT_DTPREL_HA) 476 .Case("got@tlsgd", VK_PPC_GOT_TLSGD) 477 .Case("got@tlsgd@l", VK_PPC_GOT_TLSGD_LO) 478 .Case("got@tlsgd@h", VK_PPC_GOT_TLSGD_HI) 479 .Case("got@tlsgd@ha", VK_PPC_GOT_TLSGD_HA) 480 .Case("got@tlsld", VK_PPC_GOT_TLSLD) 481 .Case("got@tlsld@l", VK_PPC_GOT_TLSLD_LO) 482 .Case("got@tlsld@h", VK_PPC_GOT_TLSLD_HI) 483 .Case("got@tlsld@ha", VK_PPC_GOT_TLSLD_HA) 484 .Case("got@pcrel", VK_PPC_GOT_PCREL) 485 .Case("got@tlsgd@pcrel", VK_PPC_GOT_TLSGD_PCREL) 486 .Case("got@tlsld@pcrel", VK_PPC_GOT_TLSLD_PCREL) 487 .Case("got@tprel@pcrel", VK_PPC_GOT_TPREL_PCREL) 488 .Case("tls@pcrel", VK_PPC_TLS_PCREL) 489 .Case("notoc", VK_PPC_NOTOC) 490 .Case("gdgot", VK_Hexagon_GD_GOT) 491 .Case("gdplt", VK_Hexagon_GD_PLT) 492 .Case("iegot", VK_Hexagon_IE_GOT) 493 .Case("ie", VK_Hexagon_IE) 494 .Case("ldgot", VK_Hexagon_LD_GOT) 495 .Case("ldplt", VK_Hexagon_LD_PLT) 496 .Case("none", VK_ARM_NONE) 497 .Case("got_prel", VK_ARM_GOT_PREL) 498 .Case("target1", VK_ARM_TARGET1) 499 .Case("target2", VK_ARM_TARGET2) 500 .Case("prel31", VK_ARM_PREL31) 501 .Case("sbrel", VK_ARM_SBREL) 502 .Case("tlsldo", VK_ARM_TLSLDO) 503 .Case("lo8", VK_AVR_LO8) 504 .Case("hi8", VK_AVR_HI8) 505 .Case("hlo8", VK_AVR_HLO8) 506 .Case("typeindex", VK_WASM_TYPEINDEX) 507 .Case("tbrel", VK_WASM_TBREL) 508 .Case("mbrel", VK_WASM_MBREL) 509 .Case("tlsrel", VK_WASM_TLSREL) 510 .Case("got@tls", VK_WASM_GOT_TLS) 511 .Case("funcindex", VK_WASM_FUNCINDEX) 512 .Case("gotpcrel32@lo", VK_AMDGPU_GOTPCREL32_LO) 513 .Case("gotpcrel32@hi", VK_AMDGPU_GOTPCREL32_HI) 514 .Case("rel32@lo", VK_AMDGPU_REL32_LO) 515 .Case("rel32@hi", VK_AMDGPU_REL32_HI) 516 .Case("rel64", VK_AMDGPU_REL64) 517 .Case("abs32@lo", VK_AMDGPU_ABS32_LO) 518 .Case("abs32@hi", VK_AMDGPU_ABS32_HI) 519 .Case("hi", VK_VE_HI32) 520 .Case("lo", VK_VE_LO32) 521 .Case("pc_hi", VK_VE_PC_HI32) 522 .Case("pc_lo", VK_VE_PC_LO32) 523 .Case("got_hi", VK_VE_GOT_HI32) 524 .Case("got_lo", VK_VE_GOT_LO32) 525 .Case("gotoff_hi", VK_VE_GOTOFF_HI32) 526 .Case("gotoff_lo", VK_VE_GOTOFF_LO32) 527 .Case("plt_hi", VK_VE_PLT_HI32) 528 .Case("plt_lo", VK_VE_PLT_LO32) 529 .Case("tls_gd_hi", VK_VE_TLS_GD_HI32) 530 .Case("tls_gd_lo", VK_VE_TLS_GD_LO32) 531 .Case("tpoff_hi", VK_VE_TPOFF_HI32) 532 .Case("tpoff_lo", VK_VE_TPOFF_LO32) 533 .Default(VK_Invalid); 534 } 535 536 /* *** */ 537 538 void MCTargetExpr::anchor() {} 539 540 /* *** */ 541 542 bool MCExpr::evaluateAsAbsolute(int64_t &Res) const { 543 return evaluateAsAbsolute(Res, nullptr, nullptr, nullptr, false); 544 } 545 546 bool MCExpr::evaluateAsAbsolute(int64_t &Res, 547 const MCAsmLayout &Layout) const { 548 return evaluateAsAbsolute(Res, &Layout.getAssembler(), &Layout, nullptr, false); 549 } 550 551 bool MCExpr::evaluateAsAbsolute(int64_t &Res, 552 const MCAsmLayout &Layout, 553 const SectionAddrMap &Addrs) const { 554 // Setting InSet causes us to absolutize differences across sections and that 555 // is what the MachO writer uses Addrs for. 556 return evaluateAsAbsolute(Res, &Layout.getAssembler(), &Layout, &Addrs, true); 557 } 558 559 bool MCExpr::evaluateAsAbsolute(int64_t &Res, const MCAssembler &Asm) const { 560 return evaluateAsAbsolute(Res, &Asm, nullptr, nullptr, false); 561 } 562 563 bool MCExpr::evaluateAsAbsolute(int64_t &Res, const MCAssembler *Asm) const { 564 return evaluateAsAbsolute(Res, Asm, nullptr, nullptr, false); 565 } 566 567 bool MCExpr::evaluateKnownAbsolute(int64_t &Res, 568 const MCAsmLayout &Layout) const { 569 return evaluateAsAbsolute(Res, &Layout.getAssembler(), &Layout, nullptr, 570 true); 571 } 572 573 bool MCExpr::evaluateAsAbsolute(int64_t &Res, const MCAssembler *Asm, 574 const MCAsmLayout *Layout, 575 const SectionAddrMap *Addrs, bool InSet) const { 576 MCValue Value; 577 578 // Fast path constants. 579 if (const MCConstantExpr *CE = dyn_cast<MCConstantExpr>(this)) { 580 Res = CE->getValue(); 581 return true; 582 } 583 584 bool IsRelocatable = 585 evaluateAsRelocatableImpl(Value, Asm, Layout, nullptr, Addrs, InSet); 586 587 // Record the current value. 588 Res = Value.getConstant(); 589 590 return IsRelocatable && Value.isAbsolute(); 591 } 592 593 /// Helper method for \see EvaluateSymbolAdd(). 594 static void AttemptToFoldSymbolOffsetDifference( 595 const MCAssembler *Asm, const MCAsmLayout *Layout, 596 const SectionAddrMap *Addrs, bool InSet, const MCSymbolRefExpr *&A, 597 const MCSymbolRefExpr *&B, int64_t &Addend) { 598 if (!A || !B) 599 return; 600 601 const MCSymbol &SA = A->getSymbol(); 602 const MCSymbol &SB = B->getSymbol(); 603 604 if (SA.isUndefined() || SB.isUndefined()) 605 return; 606 607 if (!Asm->getWriter().isSymbolRefDifferenceFullyResolved(*Asm, A, B, InSet)) 608 return; 609 610 auto FinalizeFolding = [&]() { 611 // Pointers to Thumb symbols need to have their low-bit set to allow 612 // for interworking. 613 if (Asm->isThumbFunc(&SA)) 614 Addend |= 1; 615 616 // Clear the symbol expr pointers to indicate we have folded these 617 // operands. 618 A = B = nullptr; 619 }; 620 621 const MCFragment *FA = SA.getFragment(); 622 const MCFragment *FB = SB.getFragment(); 623 const MCSection &SecA = *FA->getParent(); 624 const MCSection &SecB = *FB->getParent(); 625 if ((&SecA != &SecB) && !Addrs) 626 return; 627 628 // When layout is available, we can generally compute the difference using the 629 // getSymbolOffset path, which also avoids the possible slow fragment walk. 630 // However, linker relaxation may cause incorrect fold of A-B if A and B are 631 // separated by a linker-relaxable instruction. If the section contains 632 // instructions and InSet is false (not expressions in directive like 633 // .size/.fill), disable the fast path. 634 if (Layout && (InSet || !SecA.hasInstructions() || 635 !Asm->getContext().getTargetTriple().isRISCV())) { 636 // If both symbols are in the same fragment, return the difference of their 637 // offsets. canGetFragmentOffset(FA) may be false. 638 if (FA == FB && !SA.isVariable() && !SB.isVariable()) { 639 Addend += SA.getOffset() - SB.getOffset(); 640 return FinalizeFolding(); 641 } 642 // One of the symbol involved is part of a fragment being laid out. Quit now 643 // to avoid a self loop. 644 if (!Layout->canGetFragmentOffset(FA) || !Layout->canGetFragmentOffset(FB)) 645 return; 646 647 // Eagerly evaluate when layout is finalized. 648 Addend += Layout->getSymbolOffset(A->getSymbol()) - 649 Layout->getSymbolOffset(B->getSymbol()); 650 if (Addrs && (&SecA != &SecB)) 651 Addend += (Addrs->lookup(&SecA) - Addrs->lookup(&SecB)); 652 653 FinalizeFolding(); 654 } else { 655 // When layout is not finalized, our ability to resolve differences between 656 // symbols is limited to specific cases where the fragments between two 657 // symbols (including the fragments the symbols are defined in) are 658 // fixed-size fragments so the difference can be calculated. For example, 659 // this is important when the Subtarget is changed and a new MCDataFragment 660 // is created in the case of foo: instr; .arch_extension ext; instr .if . - 661 // foo. 662 if (SA.isVariable() || SB.isVariable() || 663 FA->getSubsectionNumber() != FB->getSubsectionNumber()) 664 return; 665 666 // Try to find a constant displacement from FA to FB, add the displacement 667 // between the offset in FA of SA and the offset in FB of SB. 668 bool Reverse = false; 669 if (FA == FB) { 670 Reverse = SA.getOffset() < SB.getOffset(); 671 } else if (!isa<MCDummyFragment>(FA)) { 672 Reverse = std::find_if(std::next(FA->getIterator()), SecA.end(), 673 [&](auto &I) { return &I == FB; }) != SecA.end(); 674 } 675 676 uint64_t SAOffset = SA.getOffset(), SBOffset = SB.getOffset(); 677 int64_t Displacement = SA.getOffset() - SB.getOffset(); 678 if (Reverse) { 679 std::swap(FA, FB); 680 std::swap(SAOffset, SBOffset); 681 Displacement *= -1; 682 } 683 684 [[maybe_unused]] bool Found = false; 685 // Track whether B is before a relaxable instruction and whether A is after 686 // a relaxable instruction. If SA and SB are separated by a linker-relaxable 687 // instruction, the difference cannot be resolved as it may be changed by 688 // the linker. 689 bool BBeforeRelax = false, AAfterRelax = false; 690 for (auto FI = FB->getIterator(), FE = SecA.end(); FI != FE; ++FI) { 691 auto DF = dyn_cast<MCDataFragment>(FI); 692 if (DF && DF->isLinkerRelaxable()) { 693 if (&*FI != FB || SBOffset != DF->getContents().size()) 694 BBeforeRelax = true; 695 if (&*FI != FA || SAOffset == DF->getContents().size()) 696 AAfterRelax = true; 697 if (BBeforeRelax && AAfterRelax) 698 return; 699 } 700 if (&*FI == FA) { 701 Found = true; 702 break; 703 } 704 705 int64_t Num; 706 if (DF) { 707 Displacement += DF->getContents().size(); 708 } else if (auto *FF = dyn_cast<MCFillFragment>(FI); 709 FF && FF->getNumValues().evaluateAsAbsolute(Num)) { 710 Displacement += Num * FF->getValueSize(); 711 } else { 712 return; 713 } 714 } 715 // If the previous loop does not find FA, FA must be a dummy fragment not in 716 // the fragment list (which means SA is a pending label (see 717 // flushPendingLabels)). In either case, we can resolve the difference. 718 assert(Found || isa<MCDummyFragment>(FA)); 719 Addend += Reverse ? -Displacement : Displacement; 720 FinalizeFolding(); 721 } 722 } 723 724 /// Evaluate the result of an add between (conceptually) two MCValues. 725 /// 726 /// This routine conceptually attempts to construct an MCValue: 727 /// Result = (Result_A - Result_B + Result_Cst) 728 /// from two MCValue's LHS and RHS where 729 /// Result = LHS + RHS 730 /// and 731 /// Result = (LHS_A - LHS_B + LHS_Cst) + (RHS_A - RHS_B + RHS_Cst). 732 /// 733 /// This routine attempts to aggressively fold the operands such that the result 734 /// is representable in an MCValue, but may not always succeed. 735 /// 736 /// \returns True on success, false if the result is not representable in an 737 /// MCValue. 738 739 /// NOTE: It is really important to have both the Asm and Layout arguments. 740 /// They might look redundant, but this function can be used before layout 741 /// is done (see the object streamer for example) and having the Asm argument 742 /// lets us avoid relaxations early. 743 static bool EvaluateSymbolicAdd(const MCAssembler *Asm, 744 const MCAsmLayout *Layout, 745 const SectionAddrMap *Addrs, bool InSet, 746 const MCValue &LHS, const MCValue &RHS, 747 MCValue &Res) { 748 // FIXME: This routine (and other evaluation parts) are *incredibly* sloppy 749 // about dealing with modifiers. This will ultimately bite us, one day. 750 const MCSymbolRefExpr *LHS_A = LHS.getSymA(); 751 const MCSymbolRefExpr *LHS_B = LHS.getSymB(); 752 int64_t LHS_Cst = LHS.getConstant(); 753 754 const MCSymbolRefExpr *RHS_A = RHS.getSymA(); 755 const MCSymbolRefExpr *RHS_B = RHS.getSymB(); 756 int64_t RHS_Cst = RHS.getConstant(); 757 758 if (LHS.getRefKind() != RHS.getRefKind()) 759 return false; 760 761 // Fold the result constant immediately. 762 int64_t Result_Cst = LHS_Cst + RHS_Cst; 763 764 assert((!Layout || Asm) && 765 "Must have an assembler object if layout is given!"); 766 767 // If we have a layout, we can fold resolved differences. 768 if (Asm) { 769 // First, fold out any differences which are fully resolved. By 770 // reassociating terms in 771 // Result = (LHS_A - LHS_B + LHS_Cst) + (RHS_A - RHS_B + RHS_Cst). 772 // we have the four possible differences: 773 // (LHS_A - LHS_B), 774 // (LHS_A - RHS_B), 775 // (RHS_A - LHS_B), 776 // (RHS_A - RHS_B). 777 // Since we are attempting to be as aggressive as possible about folding, we 778 // attempt to evaluate each possible alternative. 779 AttemptToFoldSymbolOffsetDifference(Asm, Layout, Addrs, InSet, LHS_A, LHS_B, 780 Result_Cst); 781 AttemptToFoldSymbolOffsetDifference(Asm, Layout, Addrs, InSet, LHS_A, RHS_B, 782 Result_Cst); 783 AttemptToFoldSymbolOffsetDifference(Asm, Layout, Addrs, InSet, RHS_A, LHS_B, 784 Result_Cst); 785 AttemptToFoldSymbolOffsetDifference(Asm, Layout, Addrs, InSet, RHS_A, RHS_B, 786 Result_Cst); 787 } 788 789 // We can't represent the addition or subtraction of two symbols. 790 if ((LHS_A && RHS_A) || (LHS_B && RHS_B)) 791 return false; 792 793 // At this point, we have at most one additive symbol and one subtractive 794 // symbol -- find them. 795 const MCSymbolRefExpr *A = LHS_A ? LHS_A : RHS_A; 796 const MCSymbolRefExpr *B = LHS_B ? LHS_B : RHS_B; 797 798 Res = MCValue::get(A, B, Result_Cst); 799 return true; 800 } 801 802 bool MCExpr::evaluateAsRelocatable(MCValue &Res, 803 const MCAsmLayout *Layout, 804 const MCFixup *Fixup) const { 805 MCAssembler *Assembler = Layout ? &Layout->getAssembler() : nullptr; 806 return evaluateAsRelocatableImpl(Res, Assembler, Layout, Fixup, nullptr, 807 false); 808 } 809 810 bool MCExpr::evaluateAsValue(MCValue &Res, const MCAsmLayout &Layout) const { 811 MCAssembler *Assembler = &Layout.getAssembler(); 812 return evaluateAsRelocatableImpl(Res, Assembler, &Layout, nullptr, nullptr, 813 true); 814 } 815 816 static bool canExpand(const MCSymbol &Sym, bool InSet) { 817 if (Sym.isWeakExternal()) 818 return false; 819 820 const MCExpr *Expr = Sym.getVariableValue(); 821 const auto *Inner = dyn_cast<MCSymbolRefExpr>(Expr); 822 if (Inner) { 823 if (Inner->getKind() == MCSymbolRefExpr::VK_WEAKREF) 824 return false; 825 } 826 827 if (InSet) 828 return true; 829 return !Sym.isInSection(); 830 } 831 832 bool MCExpr::evaluateAsRelocatableImpl(MCValue &Res, const MCAssembler *Asm, 833 const MCAsmLayout *Layout, 834 const MCFixup *Fixup, 835 const SectionAddrMap *Addrs, 836 bool InSet) const { 837 ++stats::MCExprEvaluate; 838 839 switch (getKind()) { 840 case Target: 841 return cast<MCTargetExpr>(this)->evaluateAsRelocatableImpl(Res, Layout, 842 Fixup); 843 844 case Constant: 845 Res = MCValue::get(cast<MCConstantExpr>(this)->getValue()); 846 return true; 847 848 case SymbolRef: { 849 const MCSymbolRefExpr *SRE = cast<MCSymbolRefExpr>(this); 850 const MCSymbol &Sym = SRE->getSymbol(); 851 const auto Kind = SRE->getKind(); 852 853 // Evaluate recursively if this is a variable. 854 if (Sym.isVariable() && (Kind == MCSymbolRefExpr::VK_None || Layout) && 855 canExpand(Sym, InSet)) { 856 bool IsMachO = SRE->hasSubsectionsViaSymbols(); 857 if (Sym.getVariableValue()->evaluateAsRelocatableImpl( 858 Res, Asm, Layout, Fixup, Addrs, InSet || IsMachO)) { 859 if (Kind != MCSymbolRefExpr::VK_None) { 860 if (Res.isAbsolute()) { 861 Res = MCValue::get(SRE, nullptr, 0); 862 return true; 863 } 864 // If the reference has a variant kind, we can only handle expressions 865 // which evaluate exactly to a single unadorned symbol. Attach the 866 // original VariantKind to SymA of the result. 867 if (Res.getRefKind() != MCSymbolRefExpr::VK_None || !Res.getSymA() || 868 Res.getSymB() || Res.getConstant()) 869 return false; 870 Res = 871 MCValue::get(MCSymbolRefExpr::create(&Res.getSymA()->getSymbol(), 872 Kind, Asm->getContext()), 873 Res.getSymB(), Res.getConstant(), Res.getRefKind()); 874 } 875 if (!IsMachO) 876 return true; 877 878 const MCSymbolRefExpr *A = Res.getSymA(); 879 const MCSymbolRefExpr *B = Res.getSymB(); 880 // FIXME: This is small hack. Given 881 // a = b + 4 882 // .long a 883 // the OS X assembler will completely drop the 4. We should probably 884 // include it in the relocation or produce an error if that is not 885 // possible. 886 // Allow constant expressions. 887 if (!A && !B) 888 return true; 889 // Allows aliases with zero offset. 890 if (Res.getConstant() == 0 && (!A || !B)) 891 return true; 892 } 893 } 894 895 Res = MCValue::get(SRE, nullptr, 0); 896 return true; 897 } 898 899 case Unary: { 900 const MCUnaryExpr *AUE = cast<MCUnaryExpr>(this); 901 MCValue Value; 902 903 if (!AUE->getSubExpr()->evaluateAsRelocatableImpl(Value, Asm, Layout, Fixup, 904 Addrs, InSet)) 905 return false; 906 907 switch (AUE->getOpcode()) { 908 case MCUnaryExpr::LNot: 909 if (!Value.isAbsolute()) 910 return false; 911 Res = MCValue::get(!Value.getConstant()); 912 break; 913 case MCUnaryExpr::Minus: 914 /// -(a - b + const) ==> (b - a - const) 915 if (Value.getSymA() && !Value.getSymB()) 916 return false; 917 918 // The cast avoids undefined behavior if the constant is INT64_MIN. 919 Res = MCValue::get(Value.getSymB(), Value.getSymA(), 920 -(uint64_t)Value.getConstant()); 921 break; 922 case MCUnaryExpr::Not: 923 if (!Value.isAbsolute()) 924 return false; 925 Res = MCValue::get(~Value.getConstant()); 926 break; 927 case MCUnaryExpr::Plus: 928 Res = Value; 929 break; 930 } 931 932 return true; 933 } 934 935 case Binary: { 936 const MCBinaryExpr *ABE = cast<MCBinaryExpr>(this); 937 MCValue LHSValue, RHSValue; 938 939 if (!ABE->getLHS()->evaluateAsRelocatableImpl(LHSValue, Asm, Layout, Fixup, 940 Addrs, InSet) || 941 !ABE->getRHS()->evaluateAsRelocatableImpl(RHSValue, Asm, Layout, Fixup, 942 Addrs, InSet)) { 943 // Check if both are Target Expressions, see if we can compare them. 944 if (const MCTargetExpr *L = dyn_cast<MCTargetExpr>(ABE->getLHS())) { 945 const MCTargetExpr *R = cast<MCTargetExpr>(ABE->getRHS()); 946 switch (ABE->getOpcode()) { 947 case MCBinaryExpr::EQ: 948 Res = MCValue::get(L->isEqualTo(R) ? -1 : 0); 949 return true; 950 case MCBinaryExpr::NE: 951 Res = MCValue::get(L->isEqualTo(R) ? 0 : -1); 952 return true; 953 default: 954 break; 955 } 956 } 957 return false; 958 } 959 960 // We only support a few operations on non-constant expressions, handle 961 // those first. 962 if (!LHSValue.isAbsolute() || !RHSValue.isAbsolute()) { 963 switch (ABE->getOpcode()) { 964 default: 965 return false; 966 case MCBinaryExpr::Sub: 967 // Negate RHS and add. 968 // The cast avoids undefined behavior if the constant is INT64_MIN. 969 return EvaluateSymbolicAdd( 970 Asm, Layout, Addrs, InSet, LHSValue, 971 MCValue::get(RHSValue.getSymB(), RHSValue.getSymA(), 972 -(uint64_t)RHSValue.getConstant(), 973 RHSValue.getRefKind()), 974 Res); 975 976 case MCBinaryExpr::Add: 977 return EvaluateSymbolicAdd( 978 Asm, Layout, Addrs, InSet, LHSValue, 979 MCValue::get(RHSValue.getSymA(), RHSValue.getSymB(), 980 RHSValue.getConstant(), RHSValue.getRefKind()), 981 Res); 982 } 983 } 984 985 // FIXME: We need target hooks for the evaluation. It may be limited in 986 // width, and gas defines the result of comparisons differently from 987 // Apple as. 988 int64_t LHS = LHSValue.getConstant(), RHS = RHSValue.getConstant(); 989 int64_t Result = 0; 990 auto Op = ABE->getOpcode(); 991 switch (Op) { 992 case MCBinaryExpr::AShr: Result = LHS >> RHS; break; 993 case MCBinaryExpr::Add: Result = LHS + RHS; break; 994 case MCBinaryExpr::And: Result = LHS & RHS; break; 995 case MCBinaryExpr::Div: 996 case MCBinaryExpr::Mod: 997 // Handle division by zero. gas just emits a warning and keeps going, 998 // we try to be stricter. 999 // FIXME: Currently the caller of this function has no way to understand 1000 // we're bailing out because of 'division by zero'. Therefore, it will 1001 // emit a 'expected relocatable expression' error. It would be nice to 1002 // change this code to emit a better diagnostic. 1003 if (RHS == 0) 1004 return false; 1005 if (ABE->getOpcode() == MCBinaryExpr::Div) 1006 Result = LHS / RHS; 1007 else 1008 Result = LHS % RHS; 1009 break; 1010 case MCBinaryExpr::EQ: Result = LHS == RHS; break; 1011 case MCBinaryExpr::GT: Result = LHS > RHS; break; 1012 case MCBinaryExpr::GTE: Result = LHS >= RHS; break; 1013 case MCBinaryExpr::LAnd: Result = LHS && RHS; break; 1014 case MCBinaryExpr::LOr: Result = LHS || RHS; break; 1015 case MCBinaryExpr::LShr: Result = uint64_t(LHS) >> uint64_t(RHS); break; 1016 case MCBinaryExpr::LT: Result = LHS < RHS; break; 1017 case MCBinaryExpr::LTE: Result = LHS <= RHS; break; 1018 case MCBinaryExpr::Mul: Result = LHS * RHS; break; 1019 case MCBinaryExpr::NE: Result = LHS != RHS; break; 1020 case MCBinaryExpr::Or: Result = LHS | RHS; break; 1021 case MCBinaryExpr::OrNot: Result = LHS | ~RHS; break; 1022 case MCBinaryExpr::Shl: Result = uint64_t(LHS) << uint64_t(RHS); break; 1023 case MCBinaryExpr::Sub: Result = LHS - RHS; break; 1024 case MCBinaryExpr::Xor: Result = LHS ^ RHS; break; 1025 } 1026 1027 switch (Op) { 1028 default: 1029 Res = MCValue::get(Result); 1030 break; 1031 case MCBinaryExpr::EQ: 1032 case MCBinaryExpr::GT: 1033 case MCBinaryExpr::GTE: 1034 case MCBinaryExpr::LT: 1035 case MCBinaryExpr::LTE: 1036 case MCBinaryExpr::NE: 1037 // A comparison operator returns a -1 if true and 0 if false. 1038 Res = MCValue::get(Result ? -1 : 0); 1039 break; 1040 } 1041 1042 return true; 1043 } 1044 } 1045 1046 llvm_unreachable("Invalid assembly expression kind!"); 1047 } 1048 1049 MCFragment *MCExpr::findAssociatedFragment() const { 1050 switch (getKind()) { 1051 case Target: 1052 // We never look through target specific expressions. 1053 return cast<MCTargetExpr>(this)->findAssociatedFragment(); 1054 1055 case Constant: 1056 return MCSymbol::AbsolutePseudoFragment; 1057 1058 case SymbolRef: { 1059 const MCSymbolRefExpr *SRE = cast<MCSymbolRefExpr>(this); 1060 const MCSymbol &Sym = SRE->getSymbol(); 1061 return Sym.getFragment(); 1062 } 1063 1064 case Unary: 1065 return cast<MCUnaryExpr>(this)->getSubExpr()->findAssociatedFragment(); 1066 1067 case Binary: { 1068 const MCBinaryExpr *BE = cast<MCBinaryExpr>(this); 1069 MCFragment *LHS_F = BE->getLHS()->findAssociatedFragment(); 1070 MCFragment *RHS_F = BE->getRHS()->findAssociatedFragment(); 1071 1072 // If either is absolute, return the other. 1073 if (LHS_F == MCSymbol::AbsolutePseudoFragment) 1074 return RHS_F; 1075 if (RHS_F == MCSymbol::AbsolutePseudoFragment) 1076 return LHS_F; 1077 1078 // Not always correct, but probably the best we can do without more context. 1079 if (BE->getOpcode() == MCBinaryExpr::Sub) 1080 return MCSymbol::AbsolutePseudoFragment; 1081 1082 // Otherwise, return the first non-null fragment. 1083 return LHS_F ? LHS_F : RHS_F; 1084 } 1085 } 1086 1087 llvm_unreachable("Invalid assembly expression kind!"); 1088 } 1089