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/MCAssembler.h"
16#include "llvm/MC/MCContext.h"
17#include "llvm/MC/MCObjectWriter.h"
18#include "llvm/MC/MCSymbol.h"
19#include "llvm/MC/MCValue.h"
20#include "llvm/Support/Casting.h"
21#include "llvm/Support/Compiler.h"
22#include "llvm/Support/Debug.h"
23#include "llvm/Support/ErrorHandling.h"
24#include "llvm/Support/raw_ostream.h"
25#include <cassert>
26#include <cstdint>
27
28using namespace llvm;
29
30#define DEBUG_TYPE "mcexpr"
31
32namespace {
33namespace stats {
34
35STATISTIC(MCExprEvaluate, "Number of MCExpr evaluations");
36
37} // end namespace stats
38} // end anonymous namespace
39
40void MCExpr::print(raw_ostream &OS, const MCAsmInfo *MAI, bool InParens) const {
41 switch (getKind()) {
42 case MCExpr::Target:
43 return cast<MCTargetExpr>(Val: this)->printImpl(OS, MAI);
44 case MCExpr::Constant: {
45 auto Value = cast<MCConstantExpr>(Val: *this).getValue();
46 auto PrintInHex = cast<MCConstantExpr>(Val: *this).useHexFormat();
47 auto SizeInBytes = cast<MCConstantExpr>(Val: *this).getSizeInBytes();
48 if (Value < 0 && MAI && !MAI->supportsSignedData())
49 PrintInHex = true;
50 if (PrintInHex)
51 switch (SizeInBytes) {
52 default:
53 OS << "0x" << Twine::utohexstr(Val: Value);
54 break;
55 case 1:
56 OS << format(Fmt: "0x%02" PRIx64, Vals: Value);
57 break;
58 case 2:
59 OS << format(Fmt: "0x%04" PRIx64, Vals: Value);
60 break;
61 case 4:
62 OS << format(Fmt: "0x%08" PRIx64, Vals: Value);
63 break;
64 case 8:
65 OS << format(Fmt: "0x%016" PRIx64, Vals: Value);
66 break;
67 }
68 else
69 OS << Value;
70 return;
71 }
72 case MCExpr::SymbolRef: {
73 const MCSymbolRefExpr &SRE = cast<MCSymbolRefExpr>(Val: *this);
74 const MCSymbol &Sym = SRE.getSymbol();
75 // Parenthesize names that start with $ so that they don't look like
76 // absolute names.
77 bool UseParens = MAI && MAI->useParensForDollarSignNames() && !InParens &&
78 Sym.getName().starts_with(Prefix: '$');
79
80 if (UseParens) {
81 OS << '(';
82 Sym.print(OS, MAI);
83 OS << ')';
84 } else
85 Sym.print(OS, MAI);
86
87 const MCSymbolRefExpr::VariantKind Kind = SRE.getKind();
88 if (Kind != MCSymbolRefExpr::VK_None) {
89 if (MAI && MAI->useParensForSymbolVariant()) // ARM
90 OS << '(' << MCSymbolRefExpr::getVariantKindName(Kind) << ')';
91 else
92 OS << '@' << MCSymbolRefExpr::getVariantKindName(Kind);
93 }
94
95 return;
96 }
97
98 case MCExpr::Unary: {
99 const MCUnaryExpr &UE = cast<MCUnaryExpr>(Val: *this);
100 switch (UE.getOpcode()) {
101 case MCUnaryExpr::LNot: OS << '!'; break;
102 case MCUnaryExpr::Minus: OS << '-'; break;
103 case MCUnaryExpr::Not: OS << '~'; break;
104 case MCUnaryExpr::Plus: OS << '+'; break;
105 }
106 bool Binary = UE.getSubExpr()->getKind() == MCExpr::Binary;
107 if (Binary) OS << "(";
108 UE.getSubExpr()->print(OS, MAI);
109 if (Binary) OS << ")";
110 return;
111 }
112
113 case MCExpr::Binary: {
114 const MCBinaryExpr &BE = cast<MCBinaryExpr>(Val: *this);
115
116 // Only print parens around the LHS if it is non-trivial.
117 if (isa<MCConstantExpr>(Val: BE.getLHS()) || isa<MCSymbolRefExpr>(Val: BE.getLHS())) {
118 BE.getLHS()->print(OS, MAI);
119 } else {
120 OS << '(';
121 BE.getLHS()->print(OS, MAI);
122 OS << ')';
123 }
124
125 switch (BE.getOpcode()) {
126 case MCBinaryExpr::Add:
127 // Print "X-42" instead of "X+-42".
128 if (const MCConstantExpr *RHSC = dyn_cast<MCConstantExpr>(Val: BE.getRHS())) {
129 if (RHSC->getValue() < 0) {
130 OS << RHSC->getValue();
131 return;
132 }
133 }
134
135 OS << '+';
136 break;
137 case MCBinaryExpr::AShr: OS << ">>"; break;
138 case MCBinaryExpr::And: OS << '&'; break;
139 case MCBinaryExpr::Div: OS << '/'; break;
140 case MCBinaryExpr::EQ: OS << "=="; break;
141 case MCBinaryExpr::GT: OS << '>'; break;
142 case MCBinaryExpr::GTE: OS << ">="; break;
143 case MCBinaryExpr::LAnd: OS << "&&"; break;
144 case MCBinaryExpr::LOr: OS << "||"; break;
145 case MCBinaryExpr::LShr: OS << ">>"; break;
146 case MCBinaryExpr::LT: OS << '<'; break;
147 case MCBinaryExpr::LTE: OS << "<="; break;
148 case MCBinaryExpr::Mod: OS << '%'; break;
149 case MCBinaryExpr::Mul: OS << '*'; break;
150 case MCBinaryExpr::NE: OS << "!="; break;
151 case MCBinaryExpr::Or: OS << '|'; break;
152 case MCBinaryExpr::OrNot: OS << '!'; break;
153 case MCBinaryExpr::Shl: OS << "<<"; break;
154 case MCBinaryExpr::Sub: OS << '-'; break;
155 case MCBinaryExpr::Xor: OS << '^'; break;
156 }
157
158 // Only print parens around the LHS if it is non-trivial.
159 if (isa<MCConstantExpr>(Val: BE.getRHS()) || isa<MCSymbolRefExpr>(Val: BE.getRHS())) {
160 BE.getRHS()->print(OS, MAI);
161 } else {
162 OS << '(';
163 BE.getRHS()->print(OS, MAI);
164 OS << ')';
165 }
166 return;
167 }
168 }
169
170 llvm_unreachable("Invalid expression kind!");
171}
172
173#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
174LLVM_DUMP_METHOD void MCExpr::dump() const {
175 dbgs() << *this;
176 dbgs() << '\n';
177}
178#endif
179
180/* *** */
181
182const MCBinaryExpr *MCBinaryExpr::create(Opcode Opc, const MCExpr *LHS,
183 const MCExpr *RHS, MCContext &Ctx,
184 SMLoc Loc) {
185 return new (Ctx) MCBinaryExpr(Opc, LHS, RHS, Loc);
186}
187
188const MCUnaryExpr *MCUnaryExpr::create(Opcode Opc, const MCExpr *Expr,
189 MCContext &Ctx, SMLoc Loc) {
190 return new (Ctx) MCUnaryExpr(Opc, Expr, Loc);
191}
192
193const MCConstantExpr *MCConstantExpr::create(int64_t Value, MCContext &Ctx,
194 bool PrintInHex,
195 unsigned SizeInBytes) {
196 return new (Ctx) MCConstantExpr(Value, PrintInHex, SizeInBytes);
197}
198
199/* *** */
200
201MCSymbolRefExpr::MCSymbolRefExpr(const MCSymbol *Symbol, VariantKind Kind,
202 const MCAsmInfo *MAI, SMLoc Loc)
203 : MCExpr(MCExpr::SymbolRef, Loc,
204 encodeSubclassData(Kind, HasSubsectionsViaSymbols: MAI->hasSubsectionsViaSymbols())),
205 Symbol(Symbol) {
206 assert(Symbol);
207}
208
209const MCSymbolRefExpr *MCSymbolRefExpr::create(const MCSymbol *Sym,
210 VariantKind Kind,
211 MCContext &Ctx, SMLoc Loc) {
212 return new (Ctx) MCSymbolRefExpr(Sym, Kind, Ctx.getAsmInfo(), Loc);
213}
214
215const MCSymbolRefExpr *MCSymbolRefExpr::create(StringRef Name, VariantKind Kind,
216 MCContext &Ctx) {
217 return create(Sym: Ctx.getOrCreateSymbol(Name), Kind, Ctx);
218}
219
220StringRef MCSymbolRefExpr::getVariantKindName(VariantKind Kind) {
221 switch (Kind) {
222 // clang-format off
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_GOTTPOFF_FDPIC: return "gottpoff_fdpic";
236 case VK_INDNTPOFF: return "INDNTPOFF";
237 case VK_NTPOFF: return "NTPOFF";
238 case VK_GOTNTPOFF: return "GOTNTPOFF";
239 case VK_PLT: return "PLT";
240 case VK_TLSGD: return "TLSGD";
241 case VK_TLSGD_FDPIC: return "tlsgd_fdpic";
242 case VK_TLSLD: return "TLSLD";
243 case VK_TLSLDM: return "TLSLDM";
244 case VK_TLSLDM_FDPIC: return "tlsldm_fdpic";
245 case VK_TPOFF: return "TPOFF";
246 case VK_TPREL: return "TPREL";
247 case VK_TLSCALL: return "tlscall";
248 case VK_TLSDESC: return "tlsdesc";
249 case VK_TLVP: return "TLVP";
250 case VK_TLVPPAGE: return "TLVPPAGE";
251 case VK_TLVPPAGEOFF: return "TLVPPAGEOFF";
252 case VK_PAGE: return "PAGE";
253 case VK_PAGEOFF: return "PAGEOFF";
254 case VK_GOTPAGE: return "GOTPAGE";
255 case VK_GOTPAGEOFF: return "GOTPAGEOFF";
256 case VK_SECREL: return "SECREL32";
257 case VK_SIZE: return "SIZE";
258 case VK_WEAKREF: return "WEAKREF";
259 case VK_FUNCDESC: return "FUNCDESC";
260 case VK_GOTFUNCDESC: return "GOTFUNCDESC";
261 case VK_GOTOFFFUNCDESC: return "GOTOFFFUNCDESC";
262 case VK_X86_ABS8: return "ABS8";
263 case VK_X86_PLTOFF: return "PLTOFF";
264 case VK_ARM_NONE: return "none";
265 case VK_ARM_GOT_PREL: return "GOT_PREL";
266 case VK_ARM_TARGET1: return "target1";
267 case VK_ARM_TARGET2: return "target2";
268 case VK_ARM_PREL31: return "prel31";
269 case VK_ARM_SBREL: return "sbrel";
270 case VK_ARM_TLSLDO: return "tlsldo";
271 case VK_ARM_TLSDESCSEQ: return "tlsdescseq";
272 case VK_AVR_NONE: return "none";
273 case VK_AVR_LO8: return "lo8";
274 case VK_AVR_HI8: return "hi8";
275 case VK_AVR_HLO8: return "hlo8";
276 case VK_AVR_DIFF8: return "diff8";
277 case VK_AVR_DIFF16: return "diff16";
278 case VK_AVR_DIFF32: return "diff32";
279 case VK_AVR_PM: return "pm";
280 case VK_PPC_LO: return "l";
281 case VK_PPC_HI: return "h";
282 case VK_PPC_HA: return "ha";
283 case VK_PPC_HIGH: return "high";
284 case VK_PPC_HIGHA: return "higha";
285 case VK_PPC_HIGHER: return "higher";
286 case VK_PPC_HIGHERA: return "highera";
287 case VK_PPC_HIGHEST: return "highest";
288 case VK_PPC_HIGHESTA: return "highesta";
289 case VK_PPC_GOT_LO: return "got@l";
290 case VK_PPC_GOT_HI: return "got@h";
291 case VK_PPC_GOT_HA: return "got@ha";
292 case VK_PPC_TOCBASE: return "tocbase";
293 case VK_PPC_TOC: return "toc";
294 case VK_PPC_TOC_LO: return "toc@l";
295 case VK_PPC_TOC_HI: return "toc@h";
296 case VK_PPC_TOC_HA: return "toc@ha";
297 case VK_PPC_U: return "u";
298 case VK_PPC_L: return "l";
299 case VK_PPC_DTPMOD: return "dtpmod";
300 case VK_PPC_TPREL_LO: return "tprel@l";
301 case VK_PPC_TPREL_HI: return "tprel@h";
302 case VK_PPC_TPREL_HA: return "tprel@ha";
303 case VK_PPC_TPREL_HIGH: return "tprel@high";
304 case VK_PPC_TPREL_HIGHA: return "tprel@higha";
305 case VK_PPC_TPREL_HIGHER: return "tprel@higher";
306 case VK_PPC_TPREL_HIGHERA: return "tprel@highera";
307 case VK_PPC_TPREL_HIGHEST: return "tprel@highest";
308 case VK_PPC_TPREL_HIGHESTA: return "tprel@highesta";
309 case VK_PPC_DTPREL_LO: return "dtprel@l";
310 case VK_PPC_DTPREL_HI: return "dtprel@h";
311 case VK_PPC_DTPREL_HA: return "dtprel@ha";
312 case VK_PPC_DTPREL_HIGH: return "dtprel@high";
313 case VK_PPC_DTPREL_HIGHA: return "dtprel@higha";
314 case VK_PPC_DTPREL_HIGHER: return "dtprel@higher";
315 case VK_PPC_DTPREL_HIGHERA: return "dtprel@highera";
316 case VK_PPC_DTPREL_HIGHEST: return "dtprel@highest";
317 case VK_PPC_DTPREL_HIGHESTA: return "dtprel@highesta";
318 case VK_PPC_GOT_TPREL: return "got@tprel";
319 case VK_PPC_GOT_TPREL_LO: return "got@tprel@l";
320 case VK_PPC_GOT_TPREL_HI: return "got@tprel@h";
321 case VK_PPC_GOT_TPREL_HA: return "got@tprel@ha";
322 case VK_PPC_GOT_DTPREL: return "got@dtprel";
323 case VK_PPC_GOT_DTPREL_LO: return "got@dtprel@l";
324 case VK_PPC_GOT_DTPREL_HI: return "got@dtprel@h";
325 case VK_PPC_GOT_DTPREL_HA: return "got@dtprel@ha";
326 case VK_PPC_TLS: return "tls";
327 case VK_PPC_GOT_TLSGD: return "got@tlsgd";
328 case VK_PPC_GOT_TLSGD_LO: return "got@tlsgd@l";
329 case VK_PPC_GOT_TLSGD_HI: return "got@tlsgd@h";
330 case VK_PPC_GOT_TLSGD_HA: return "got@tlsgd@ha";
331 case VK_PPC_TLSGD: return "tlsgd";
332 case VK_PPC_AIX_TLSGD:
333 return "gd";
334 case VK_PPC_AIX_TLSGDM:
335 return "m";
336 case VK_PPC_AIX_TLSIE:
337 return "ie";
338 case VK_PPC_AIX_TLSLE:
339 return "le";
340 case VK_PPC_AIX_TLSLD:
341 return "ld";
342 case VK_PPC_AIX_TLSML:
343 return "ml";
344 case VK_PPC_GOT_TLSLD: return "got@tlsld";
345 case VK_PPC_GOT_TLSLD_LO: return "got@tlsld@l";
346 case VK_PPC_GOT_TLSLD_HI: return "got@tlsld@h";
347 case VK_PPC_GOT_TLSLD_HA: return "got@tlsld@ha";
348 case VK_PPC_GOT_PCREL:
349 return "got@pcrel";
350 case VK_PPC_GOT_TLSGD_PCREL:
351 return "got@tlsgd@pcrel";
352 case VK_PPC_GOT_TLSLD_PCREL:
353 return "got@tlsld@pcrel";
354 case VK_PPC_GOT_TPREL_PCREL:
355 return "got@tprel@pcrel";
356 case VK_PPC_TLS_PCREL:
357 return "tls@pcrel";
358 case VK_PPC_TLSLD: return "tlsld";
359 case VK_PPC_LOCAL: return "local";
360 case VK_PPC_NOTOC: return "notoc";
361 case VK_PPC_PCREL_OPT: return "<<invalid>>";
362 case VK_COFF_IMGREL32: return "IMGREL";
363 case VK_Hexagon_LO16: return "LO16";
364 case VK_Hexagon_HI16: return "HI16";
365 case VK_Hexagon_GPREL: return "GPREL";
366 case VK_Hexagon_GD_GOT: return "GDGOT";
367 case VK_Hexagon_LD_GOT: return "LDGOT";
368 case VK_Hexagon_GD_PLT: return "GDPLT";
369 case VK_Hexagon_LD_PLT: return "LDPLT";
370 case VK_Hexagon_IE: return "IE";
371 case VK_Hexagon_IE_GOT: return "IEGOT";
372 case VK_WASM_TYPEINDEX: return "TYPEINDEX";
373 case VK_WASM_MBREL: return "MBREL";
374 case VK_WASM_TLSREL: return "TLSREL";
375 case VK_WASM_TBREL: return "TBREL";
376 case VK_WASM_GOT_TLS: return "GOT@TLS";
377 case VK_WASM_FUNCINDEX: return "FUNCINDEX";
378 case VK_AMDGPU_GOTPCREL32_LO: return "gotpcrel32@lo";
379 case VK_AMDGPU_GOTPCREL32_HI: return "gotpcrel32@hi";
380 case VK_AMDGPU_REL32_LO: return "rel32@lo";
381 case VK_AMDGPU_REL32_HI: return "rel32@hi";
382 case VK_AMDGPU_REL64: return "rel64";
383 case VK_AMDGPU_ABS32_LO: return "abs32@lo";
384 case VK_AMDGPU_ABS32_HI: return "abs32@hi";
385 case VK_VE_HI32: return "hi";
386 case VK_VE_LO32: return "lo";
387 case VK_VE_PC_HI32: return "pc_hi";
388 case VK_VE_PC_LO32: return "pc_lo";
389 case VK_VE_GOT_HI32: return "got_hi";
390 case VK_VE_GOT_LO32: return "got_lo";
391 case VK_VE_GOTOFF_HI32: return "gotoff_hi";
392 case VK_VE_GOTOFF_LO32: return "gotoff_lo";
393 case VK_VE_PLT_HI32: return "plt_hi";
394 case VK_VE_PLT_LO32: return "plt_lo";
395 case VK_VE_TLS_GD_HI32: return "tls_gd_hi";
396 case VK_VE_TLS_GD_LO32: return "tls_gd_lo";
397 case VK_VE_TPOFF_HI32: return "tpoff_hi";
398 case VK_VE_TPOFF_LO32: return "tpoff_lo";
399 // clang-format on
400 }
401 llvm_unreachable("Invalid variant kind");
402}
403
404MCSymbolRefExpr::VariantKind
405MCSymbolRefExpr::getVariantKindForName(StringRef Name) {
406 return StringSwitch<VariantKind>(Name.lower())
407 .Case(S: "dtprel", Value: VK_DTPREL)
408 .Case(S: "dtpoff", Value: VK_DTPOFF)
409 .Case(S: "got", Value: VK_GOT)
410 .Case(S: "gotoff", Value: VK_GOTOFF)
411 .Case(S: "gotrel", Value: VK_GOTREL)
412 .Case(S: "pcrel", Value: VK_PCREL)
413 .Case(S: "gotpcrel", Value: VK_GOTPCREL)
414 .Case(S: "gotpcrel_norelax", Value: VK_GOTPCREL_NORELAX)
415 .Case(S: "gottpoff", Value: VK_GOTTPOFF)
416 .Case(S: "indntpoff", Value: VK_INDNTPOFF)
417 .Case(S: "ntpoff", Value: VK_NTPOFF)
418 .Case(S: "gotntpoff", Value: VK_GOTNTPOFF)
419 .Case(S: "plt", Value: VK_PLT)
420 .Case(S: "tlscall", Value: VK_TLSCALL)
421 .Case(S: "tlsdesc", Value: VK_TLSDESC)
422 .Case(S: "tlsgd", Value: VK_TLSGD)
423 .Case(S: "tlsld", Value: VK_TLSLD)
424 .Case(S: "tlsldm", Value: VK_TLSLDM)
425 .Case(S: "tpoff", Value: VK_TPOFF)
426 .Case(S: "tprel", Value: VK_TPREL)
427 .Case(S: "tlvp", Value: VK_TLVP)
428 .Case(S: "tlvppage", Value: VK_TLVPPAGE)
429 .Case(S: "tlvppageoff", Value: VK_TLVPPAGEOFF)
430 .Case(S: "page", Value: VK_PAGE)
431 .Case(S: "pageoff", Value: VK_PAGEOFF)
432 .Case(S: "gotpage", Value: VK_GOTPAGE)
433 .Case(S: "gotpageoff", Value: VK_GOTPAGEOFF)
434 .Case(S: "imgrel", Value: VK_COFF_IMGREL32)
435 .Case(S: "secrel32", Value: VK_SECREL)
436 .Case(S: "size", Value: VK_SIZE)
437 .Case(S: "abs8", Value: VK_X86_ABS8)
438 .Case(S: "pltoff", Value: VK_X86_PLTOFF)
439 .Case(S: "l", Value: VK_PPC_LO)
440 .Case(S: "h", Value: VK_PPC_HI)
441 .Case(S: "ha", Value: VK_PPC_HA)
442 .Case(S: "high", Value: VK_PPC_HIGH)
443 .Case(S: "higha", Value: VK_PPC_HIGHA)
444 .Case(S: "higher", Value: VK_PPC_HIGHER)
445 .Case(S: "highera", Value: VK_PPC_HIGHERA)
446 .Case(S: "highest", Value: VK_PPC_HIGHEST)
447 .Case(S: "highesta", Value: VK_PPC_HIGHESTA)
448 .Case(S: "got@l", Value: VK_PPC_GOT_LO)
449 .Case(S: "got@h", Value: VK_PPC_GOT_HI)
450 .Case(S: "got@ha", Value: VK_PPC_GOT_HA)
451 .Case(S: "local", Value: VK_PPC_LOCAL)
452 .Case(S: "tocbase", Value: VK_PPC_TOCBASE)
453 .Case(S: "toc", Value: VK_PPC_TOC)
454 .Case(S: "toc@l", Value: VK_PPC_TOC_LO)
455 .Case(S: "toc@h", Value: VK_PPC_TOC_HI)
456 .Case(S: "toc@ha", Value: VK_PPC_TOC_HA)
457 .Case(S: "u", Value: VK_PPC_U)
458 .Case(S: "l", Value: VK_PPC_L)
459 .Case(S: "tls", Value: VK_PPC_TLS)
460 .Case(S: "dtpmod", Value: VK_PPC_DTPMOD)
461 .Case(S: "tprel@l", Value: VK_PPC_TPREL_LO)
462 .Case(S: "tprel@h", Value: VK_PPC_TPREL_HI)
463 .Case(S: "tprel@ha", Value: VK_PPC_TPREL_HA)
464 .Case(S: "tprel@high", Value: VK_PPC_TPREL_HIGH)
465 .Case(S: "tprel@higha", Value: VK_PPC_TPREL_HIGHA)
466 .Case(S: "tprel@higher", Value: VK_PPC_TPREL_HIGHER)
467 .Case(S: "tprel@highera", Value: VK_PPC_TPREL_HIGHERA)
468 .Case(S: "tprel@highest", Value: VK_PPC_TPREL_HIGHEST)
469 .Case(S: "tprel@highesta", Value: VK_PPC_TPREL_HIGHESTA)
470 .Case(S: "dtprel@l", Value: VK_PPC_DTPREL_LO)
471 .Case(S: "dtprel@h", Value: VK_PPC_DTPREL_HI)
472 .Case(S: "dtprel@ha", Value: VK_PPC_DTPREL_HA)
473 .Case(S: "dtprel@high", Value: VK_PPC_DTPREL_HIGH)
474 .Case(S: "dtprel@higha", Value: VK_PPC_DTPREL_HIGHA)
475 .Case(S: "dtprel@higher", Value: VK_PPC_DTPREL_HIGHER)
476 .Case(S: "dtprel@highera", Value: VK_PPC_DTPREL_HIGHERA)
477 .Case(S: "dtprel@highest", Value: VK_PPC_DTPREL_HIGHEST)
478 .Case(S: "dtprel@highesta", Value: VK_PPC_DTPREL_HIGHESTA)
479 .Case(S: "got@tprel", Value: VK_PPC_GOT_TPREL)
480 .Case(S: "got@tprel@l", Value: VK_PPC_GOT_TPREL_LO)
481 .Case(S: "got@tprel@h", Value: VK_PPC_GOT_TPREL_HI)
482 .Case(S: "got@tprel@ha", Value: VK_PPC_GOT_TPREL_HA)
483 .Case(S: "got@dtprel", Value: VK_PPC_GOT_DTPREL)
484 .Case(S: "got@dtprel@l", Value: VK_PPC_GOT_DTPREL_LO)
485 .Case(S: "got@dtprel@h", Value: VK_PPC_GOT_DTPREL_HI)
486 .Case(S: "got@dtprel@ha", Value: VK_PPC_GOT_DTPREL_HA)
487 .Case(S: "got@tlsgd", Value: VK_PPC_GOT_TLSGD)
488 .Case(S: "got@tlsgd@l", Value: VK_PPC_GOT_TLSGD_LO)
489 .Case(S: "got@tlsgd@h", Value: VK_PPC_GOT_TLSGD_HI)
490 .Case(S: "got@tlsgd@ha", Value: VK_PPC_GOT_TLSGD_HA)
491 .Case(S: "got@tlsld", Value: VK_PPC_GOT_TLSLD)
492 .Case(S: "got@tlsld@l", Value: VK_PPC_GOT_TLSLD_LO)
493 .Case(S: "got@tlsld@h", Value: VK_PPC_GOT_TLSLD_HI)
494 .Case(S: "got@tlsld@ha", Value: VK_PPC_GOT_TLSLD_HA)
495 .Case(S: "got@pcrel", Value: VK_PPC_GOT_PCREL)
496 .Case(S: "got@tlsgd@pcrel", Value: VK_PPC_GOT_TLSGD_PCREL)
497 .Case(S: "got@tlsld@pcrel", Value: VK_PPC_GOT_TLSLD_PCREL)
498 .Case(S: "got@tprel@pcrel", Value: VK_PPC_GOT_TPREL_PCREL)
499 .Case(S: "tls@pcrel", Value: VK_PPC_TLS_PCREL)
500 .Case(S: "notoc", Value: VK_PPC_NOTOC)
501 .Case(S: "gdgot", Value: VK_Hexagon_GD_GOT)
502 .Case(S: "gdplt", Value: VK_Hexagon_GD_PLT)
503 .Case(S: "iegot", Value: VK_Hexagon_IE_GOT)
504 .Case(S: "ie", Value: VK_Hexagon_IE)
505 .Case(S: "ldgot", Value: VK_Hexagon_LD_GOT)
506 .Case(S: "ldplt", Value: VK_Hexagon_LD_PLT)
507 .Case(S: "lo8", Value: VK_AVR_LO8)
508 .Case(S: "hi8", Value: VK_AVR_HI8)
509 .Case(S: "hlo8", Value: VK_AVR_HLO8)
510 .Case(S: "typeindex", Value: VK_WASM_TYPEINDEX)
511 .Case(S: "tbrel", Value: VK_WASM_TBREL)
512 .Case(S: "mbrel", Value: VK_WASM_MBREL)
513 .Case(S: "tlsrel", Value: VK_WASM_TLSREL)
514 .Case(S: "got@tls", Value: VK_WASM_GOT_TLS)
515 .Case(S: "funcindex", Value: VK_WASM_FUNCINDEX)
516 .Case(S: "gotpcrel32@lo", Value: VK_AMDGPU_GOTPCREL32_LO)
517 .Case(S: "gotpcrel32@hi", Value: VK_AMDGPU_GOTPCREL32_HI)
518 .Case(S: "rel32@lo", Value: VK_AMDGPU_REL32_LO)
519 .Case(S: "rel32@hi", Value: VK_AMDGPU_REL32_HI)
520 .Case(S: "rel64", Value: VK_AMDGPU_REL64)
521 .Case(S: "abs32@lo", Value: VK_AMDGPU_ABS32_LO)
522 .Case(S: "abs32@hi", Value: VK_AMDGPU_ABS32_HI)
523 .Case(S: "hi", Value: VK_VE_HI32)
524 .Case(S: "lo", Value: VK_VE_LO32)
525 .Case(S: "pc_hi", Value: VK_VE_PC_HI32)
526 .Case(S: "pc_lo", Value: VK_VE_PC_LO32)
527 .Case(S: "got_hi", Value: VK_VE_GOT_HI32)
528 .Case(S: "got_lo", Value: VK_VE_GOT_LO32)
529 .Case(S: "gotoff_hi", Value: VK_VE_GOTOFF_HI32)
530 .Case(S: "gotoff_lo", Value: VK_VE_GOTOFF_LO32)
531 .Case(S: "plt_hi", Value: VK_VE_PLT_HI32)
532 .Case(S: "plt_lo", Value: VK_VE_PLT_LO32)
533 .Case(S: "tls_gd_hi", Value: VK_VE_TLS_GD_HI32)
534 .Case(S: "tls_gd_lo", Value: VK_VE_TLS_GD_LO32)
535 .Case(S: "tpoff_hi", Value: VK_VE_TPOFF_HI32)
536 .Case(S: "tpoff_lo", Value: VK_VE_TPOFF_LO32)
537 .Default(Value: VK_Invalid);
538}
539
540/* *** */
541
542void MCTargetExpr::anchor() {}
543
544/* *** */
545
546bool MCExpr::evaluateAsAbsolute(int64_t &Res) const {
547 return evaluateAsAbsolute(Res, Asm: nullptr, Addrs: nullptr, InSet: false);
548}
549
550bool MCExpr::evaluateAsAbsolute(int64_t &Res, const MCAssembler &Asm,
551 const SectionAddrMap &Addrs) const {
552 // Setting InSet causes us to absolutize differences across sections and that
553 // is what the MachO writer uses Addrs for.
554 return evaluateAsAbsolute(Res, Asm: &Asm, Addrs: &Addrs, InSet: true);
555}
556
557bool MCExpr::evaluateAsAbsolute(int64_t &Res, const MCAssembler &Asm) const {
558 return evaluateAsAbsolute(Res, Asm: &Asm, Addrs: nullptr, InSet: false);
559}
560
561bool MCExpr::evaluateAsAbsolute(int64_t &Res, const MCAssembler *Asm) const {
562 return evaluateAsAbsolute(Res, Asm, Addrs: nullptr, InSet: false);
563}
564
565bool MCExpr::evaluateKnownAbsolute(int64_t &Res, const MCAssembler &Asm) const {
566 return evaluateAsAbsolute(Res, Asm: &Asm, Addrs: nullptr, InSet: true);
567}
568
569bool MCExpr::evaluateAsAbsolute(int64_t &Res, const MCAssembler *Asm,
570 const SectionAddrMap *Addrs, bool InSet) const {
571 MCValue Value;
572
573 // Fast path constants.
574 if (const MCConstantExpr *CE = dyn_cast<MCConstantExpr>(Val: this)) {
575 Res = CE->getValue();
576 return true;
577 }
578
579 bool IsRelocatable =
580 evaluateAsRelocatableImpl(Res&: Value, Asm, Fixup: nullptr, Addrs, InSet);
581
582 // Record the current value.
583 Res = Value.getConstant();
584
585 return IsRelocatable && Value.isAbsolute();
586}
587
588/// Helper method for \see EvaluateSymbolAdd().
589static void AttemptToFoldSymbolOffsetDifference(
590 const MCAssembler *Asm, const SectionAddrMap *Addrs, bool InSet,
591 const MCSymbolRefExpr *&A, const MCSymbolRefExpr *&B, int64_t &Addend) {
592 if (!A || !B)
593 return;
594
595 const MCSymbol &SA = A->getSymbol();
596 const MCSymbol &SB = B->getSymbol();
597
598 if (SA.isUndefined() || SB.isUndefined())
599 return;
600
601 if (!Asm->getWriter().isSymbolRefDifferenceFullyResolved(Asm: *Asm, A, B, InSet))
602 return;
603
604 auto FinalizeFolding = [&]() {
605 // Pointers to Thumb symbols need to have their low-bit set to allow
606 // for interworking.
607 if (Asm->isThumbFunc(Func: &SA))
608 Addend |= 1;
609
610 // Clear the symbol expr pointers to indicate we have folded these
611 // operands.
612 A = B = nullptr;
613 };
614
615 const MCFragment *FA = SA.getFragment();
616 const MCFragment *FB = SB.getFragment();
617 const MCSection &SecA = *FA->getParent();
618 const MCSection &SecB = *FB->getParent();
619 if ((&SecA != &SecB) && !Addrs)
620 return;
621
622 // When layout is available, we can generally compute the difference using the
623 // getSymbolOffset path, which also avoids the possible slow fragment walk.
624 // However, linker relaxation may cause incorrect fold of A-B if A and B are
625 // separated by a linker-relaxable instruction. If the section contains
626 // instructions and InSet is false (not expressions in directive like
627 // .size/.fill), disable the fast path.
628 bool Layout = Asm->hasLayout();
629 if (Layout && (InSet || !SecA.hasInstructions() ||
630 !(Asm->getContext().getTargetTriple().isRISCV() ||
631 Asm->getContext().getTargetTriple().isLoongArch()))) {
632 // If both symbols are in the same fragment, return the difference of their
633 // offsets. canGetFragmentOffset(FA) may be false.
634 if (FA == FB && !SA.isVariable() && !SB.isVariable()) {
635 Addend += SA.getOffset() - SB.getOffset();
636 return FinalizeFolding();
637 }
638
639 // Eagerly evaluate when layout is finalized.
640 Addend += Asm->getSymbolOffset(S: A->getSymbol()) -
641 Asm->getSymbolOffset(S: B->getSymbol());
642 if (Addrs && (&SecA != &SecB))
643 Addend += (Addrs->lookup(Val: &SecA) - Addrs->lookup(Val: &SecB));
644
645 FinalizeFolding();
646 } else {
647 // When layout is not finalized, our ability to resolve differences between
648 // symbols is limited to specific cases where the fragments between two
649 // symbols (including the fragments the symbols are defined in) are
650 // fixed-size fragments so the difference can be calculated. For example,
651 // this is important when the Subtarget is changed and a new MCDataFragment
652 // is created in the case of foo: instr; .arch_extension ext; instr .if . -
653 // foo.
654 if (SA.isVariable() || SB.isVariable())
655 return;
656
657 // Try to find a constant displacement from FA to FB, add the displacement
658 // between the offset in FA of SA and the offset in FB of SB.
659 bool Reverse = false;
660 if (FA == FB)
661 Reverse = SA.getOffset() < SB.getOffset();
662 else
663 Reverse = FA->getLayoutOrder() < FB->getLayoutOrder();
664
665 uint64_t SAOffset = SA.getOffset(), SBOffset = SB.getOffset();
666 int64_t Displacement = SA.getOffset() - SB.getOffset();
667 if (Reverse) {
668 std::swap(a&: FA, b&: FB);
669 std::swap(a&: SAOffset, b&: SBOffset);
670 Displacement *= -1;
671 }
672
673 // Track whether B is before a relaxable instruction and whether A is after
674 // a relaxable instruction. If SA and SB are separated by a linker-relaxable
675 // instruction, the difference cannot be resolved as it may be changed by
676 // the linker.
677 bool BBeforeRelax = false, AAfterRelax = false;
678 for (auto FI = FB; FI; FI = FI->getNext()) {
679 auto DF = dyn_cast<MCDataFragment>(Val: FI);
680 if (DF && DF->isLinkerRelaxable()) {
681 if (&*FI != FB || SBOffset != DF->getContents().size())
682 BBeforeRelax = true;
683 if (&*FI != FA || SAOffset == DF->getContents().size())
684 AAfterRelax = true;
685 if (BBeforeRelax && AAfterRelax)
686 return;
687 }
688 if (&*FI == FA) {
689 // If FA and FB belong to the same subsection, the loop will find FA and
690 // we can resolve the difference.
691 Addend += Reverse ? -Displacement : Displacement;
692 FinalizeFolding();
693 return;
694 }
695
696 int64_t Num;
697 unsigned Count;
698 if (DF) {
699 Displacement += DF->getContents().size();
700 } else if (auto *AF = dyn_cast<MCAlignFragment>(Val: FI);
701 AF && Layout && AF->hasEmitNops() &&
702 !Asm->getBackend().shouldInsertExtraNopBytesForCodeAlign(
703 AF: *AF, Size&: Count)) {
704 Displacement += Asm->computeFragmentSize(F: *AF);
705 } else if (auto *FF = dyn_cast<MCFillFragment>(Val: FI);
706 FF && FF->getNumValues().evaluateAsAbsolute(Res&: Num)) {
707 Displacement += Num * FF->getValueSize();
708 } else {
709 return;
710 }
711 }
712 }
713}
714
715/// Evaluate the result of an add between (conceptually) two MCValues.
716///
717/// This routine conceptually attempts to construct an MCValue:
718/// Result = (Result_A - Result_B + Result_Cst)
719/// from two MCValue's LHS and RHS where
720/// Result = LHS + RHS
721/// and
722/// Result = (LHS_A - LHS_B + LHS_Cst) + (RHS_A - RHS_B + RHS_Cst).
723///
724/// This routine attempts to aggressively fold the operands such that the result
725/// is representable in an MCValue, but may not always succeed.
726///
727/// \returns True on success, false if the result is not representable in an
728/// MCValue.
729
730/// NOTE: It is really important to have both the Asm and Layout arguments.
731/// They might look redundant, but this function can be used before layout
732/// is done (see the object streamer for example) and having the Asm argument
733/// lets us avoid relaxations early.
734static bool evaluateSymbolicAdd(const MCAssembler *Asm,
735 const SectionAddrMap *Addrs, bool InSet,
736 const MCValue &LHS, const MCValue &RHS,
737 MCValue &Res) {
738 // FIXME: This routine (and other evaluation parts) are *incredibly* sloppy
739 // about dealing with modifiers. This will ultimately bite us, one day.
740 const MCSymbolRefExpr *LHS_A = LHS.getSymA();
741 const MCSymbolRefExpr *LHS_B = LHS.getSymB();
742 int64_t LHS_Cst = LHS.getConstant();
743
744 const MCSymbolRefExpr *RHS_A = RHS.getSymA();
745 const MCSymbolRefExpr *RHS_B = RHS.getSymB();
746 int64_t RHS_Cst = RHS.getConstant();
747
748 if (LHS.getRefKind() != RHS.getRefKind())
749 return false;
750
751 // Fold the result constant immediately.
752 int64_t Result_Cst = LHS_Cst + RHS_Cst;
753
754 // If we have a layout, we can fold resolved differences.
755 if (Asm) {
756 // First, fold out any differences which are fully resolved. By
757 // reassociating terms in
758 // Result = (LHS_A - LHS_B + LHS_Cst) + (RHS_A - RHS_B + RHS_Cst).
759 // we have the four possible differences:
760 // (LHS_A - LHS_B),
761 // (LHS_A - RHS_B),
762 // (RHS_A - LHS_B),
763 // (RHS_A - RHS_B).
764 // Since we are attempting to be as aggressive as possible about folding, we
765 // attempt to evaluate each possible alternative.
766 AttemptToFoldSymbolOffsetDifference(Asm, Addrs, InSet, A&: LHS_A, B&: LHS_B,
767 Addend&: Result_Cst);
768 AttemptToFoldSymbolOffsetDifference(Asm, Addrs, InSet, A&: LHS_A, B&: RHS_B,
769 Addend&: Result_Cst);
770 AttemptToFoldSymbolOffsetDifference(Asm, Addrs, InSet, A&: RHS_A, B&: LHS_B,
771 Addend&: Result_Cst);
772 AttemptToFoldSymbolOffsetDifference(Asm, Addrs, InSet, A&: RHS_A, B&: RHS_B,
773 Addend&: Result_Cst);
774 }
775
776 // We can't represent the addition or subtraction of two symbols.
777 if ((LHS_A && RHS_A) || (LHS_B && RHS_B))
778 return false;
779
780 // At this point, we have at most one additive symbol and one subtractive
781 // symbol -- find them.
782 const MCSymbolRefExpr *A = LHS_A ? LHS_A : RHS_A;
783 const MCSymbolRefExpr *B = LHS_B ? LHS_B : RHS_B;
784
785 Res = MCValue::get(SymA: A, SymB: B, Val: Result_Cst);
786 return true;
787}
788
789bool MCExpr::evaluateAsRelocatable(MCValue &Res, const MCAssembler *Asm,
790 const MCFixup *Fixup) const {
791 return evaluateAsRelocatableImpl(Res, Asm, Fixup, Addrs: nullptr, InSet: false);
792}
793
794bool MCExpr::evaluateAsValue(MCValue &Res, const MCAssembler &Asm) const {
795 return evaluateAsRelocatableImpl(Res, Asm: &Asm, Fixup: nullptr, Addrs: nullptr, InSet: true);
796}
797
798static bool canExpand(const MCSymbol &Sym, bool InSet) {
799 if (Sym.isWeakExternal())
800 return false;
801
802 const MCExpr *Expr = Sym.getVariableValue();
803 const auto *Inner = dyn_cast<MCSymbolRefExpr>(Val: Expr);
804 if (Inner) {
805 if (Inner->getKind() == MCSymbolRefExpr::VK_WEAKREF)
806 return false;
807 }
808
809 if (InSet)
810 return true;
811 return !Sym.isInSection();
812}
813
814bool MCExpr::evaluateAsRelocatableImpl(MCValue &Res, const MCAssembler *Asm,
815 const MCFixup *Fixup,
816 const SectionAddrMap *Addrs,
817 bool InSet) const {
818 ++stats::MCExprEvaluate;
819 switch (getKind()) {
820 case Target:
821 return cast<MCTargetExpr>(Val: this)->evaluateAsRelocatableImpl(Res, Asm, Fixup);
822
823 case Constant:
824 Res = MCValue::get(Val: cast<MCConstantExpr>(Val: this)->getValue());
825 return true;
826
827 case SymbolRef: {
828 const MCSymbolRefExpr *SRE = cast<MCSymbolRefExpr>(Val: this);
829 const MCSymbol &Sym = SRE->getSymbol();
830 const auto Kind = SRE->getKind();
831 bool Layout = Asm && Asm->hasLayout();
832
833 // Evaluate recursively if this is a variable.
834 if (Sym.isVariable() && (Kind == MCSymbolRefExpr::VK_None || Layout) &&
835 canExpand(Sym, InSet)) {
836 bool IsMachO = SRE->hasSubsectionsViaSymbols();
837 if (Sym.getVariableValue()->evaluateAsRelocatableImpl(
838 Res, Asm, Fixup, Addrs, InSet: InSet || IsMachO)) {
839 if (Kind != MCSymbolRefExpr::VK_None) {
840 if (Res.isAbsolute()) {
841 Res = MCValue::get(SymA: SRE, SymB: nullptr, Val: 0);
842 return true;
843 }
844 // If the reference has a variant kind, we can only handle expressions
845 // which evaluate exactly to a single unadorned symbol. Attach the
846 // original VariantKind to SymA of the result.
847 if (Res.getRefKind() != MCSymbolRefExpr::VK_None || !Res.getSymA() ||
848 Res.getSymB() || Res.getConstant())
849 return false;
850 Res =
851 MCValue::get(SymA: MCSymbolRefExpr::create(Sym: &Res.getSymA()->getSymbol(),
852 Kind, Ctx&: Asm->getContext()),
853 SymB: Res.getSymB(), Val: Res.getConstant(), RefKind: Res.getRefKind());
854 }
855 if (!IsMachO)
856 return true;
857
858 const MCSymbolRefExpr *A = Res.getSymA();
859 const MCSymbolRefExpr *B = Res.getSymB();
860 // FIXME: This is small hack. Given
861 // a = b + 4
862 // .long a
863 // the OS X assembler will completely drop the 4. We should probably
864 // include it in the relocation or produce an error if that is not
865 // possible.
866 // Allow constant expressions.
867 if (!A && !B)
868 return true;
869 // Allows aliases with zero offset.
870 if (Res.getConstant() == 0 && (!A || !B))
871 return true;
872 }
873 }
874
875 Res = MCValue::get(SymA: SRE, SymB: nullptr, Val: 0);
876 return true;
877 }
878
879 case Unary: {
880 const MCUnaryExpr *AUE = cast<MCUnaryExpr>(Val: this);
881 MCValue Value;
882
883 if (!AUE->getSubExpr()->evaluateAsRelocatableImpl(Res&: Value, Asm, Fixup, Addrs,
884 InSet))
885 return false;
886
887 switch (AUE->getOpcode()) {
888 case MCUnaryExpr::LNot:
889 if (!Value.isAbsolute())
890 return false;
891 Res = MCValue::get(Val: !Value.getConstant());
892 break;
893 case MCUnaryExpr::Minus:
894 /// -(a - b + const) ==> (b - a - const)
895 if (Value.getSymA() && !Value.getSymB())
896 return false;
897
898 // The cast avoids undefined behavior if the constant is INT64_MIN.
899 Res = MCValue::get(SymA: Value.getSymB(), SymB: Value.getSymA(),
900 Val: -(uint64_t)Value.getConstant());
901 break;
902 case MCUnaryExpr::Not:
903 if (!Value.isAbsolute())
904 return false;
905 Res = MCValue::get(Val: ~Value.getConstant());
906 break;
907 case MCUnaryExpr::Plus:
908 Res = Value;
909 break;
910 }
911
912 return true;
913 }
914
915 case Binary: {
916 const MCBinaryExpr *ABE = cast<MCBinaryExpr>(Val: this);
917 MCValue LHSValue, RHSValue;
918
919 if (!ABE->getLHS()->evaluateAsRelocatableImpl(Res&: LHSValue, Asm, Fixup, Addrs,
920 InSet) ||
921 !ABE->getRHS()->evaluateAsRelocatableImpl(Res&: RHSValue, Asm, Fixup, Addrs,
922 InSet)) {
923 // Check if both are Target Expressions, see if we can compare them.
924 if (const MCTargetExpr *L = dyn_cast<MCTargetExpr>(Val: ABE->getLHS())) {
925 if (const MCTargetExpr *R = dyn_cast<MCTargetExpr>(Val: ABE->getRHS())) {
926 switch (ABE->getOpcode()) {
927 case MCBinaryExpr::EQ:
928 Res = MCValue::get(Val: L->isEqualTo(x: R) ? -1 : 0);
929 return true;
930 case MCBinaryExpr::NE:
931 Res = MCValue::get(Val: L->isEqualTo(x: R) ? 0 : -1);
932 return true;
933 default:
934 break;
935 }
936 }
937 }
938 return false;
939 }
940
941 // We only support a few operations on non-constant expressions, handle
942 // those first.
943 if (!LHSValue.isAbsolute() || !RHSValue.isAbsolute()) {
944 switch (ABE->getOpcode()) {
945 default:
946 return false;
947 case MCBinaryExpr::Sub:
948 // Negate RHS and add.
949 // The cast avoids undefined behavior if the constant is INT64_MIN.
950 return evaluateSymbolicAdd(
951 Asm, Addrs, InSet, LHS: LHSValue,
952 RHS: MCValue::get(SymA: RHSValue.getSymB(), SymB: RHSValue.getSymA(),
953 Val: -(uint64_t)RHSValue.getConstant(),
954 RefKind: RHSValue.getRefKind()),
955 Res);
956
957 case MCBinaryExpr::Add:
958 return evaluateSymbolicAdd(
959 Asm, Addrs, InSet, LHS: LHSValue,
960 RHS: MCValue::get(SymA: RHSValue.getSymA(), SymB: RHSValue.getSymB(),
961 Val: RHSValue.getConstant(), RefKind: RHSValue.getRefKind()),
962 Res);
963 }
964 }
965
966 // FIXME: We need target hooks for the evaluation. It may be limited in
967 // width, and gas defines the result of comparisons differently from
968 // Apple as.
969 int64_t LHS = LHSValue.getConstant(), RHS = RHSValue.getConstant();
970 int64_t Result = 0;
971 auto Op = ABE->getOpcode();
972 switch (Op) {
973 case MCBinaryExpr::AShr: Result = LHS >> RHS; break;
974 case MCBinaryExpr::Add: Result = LHS + RHS; break;
975 case MCBinaryExpr::And: Result = LHS & RHS; break;
976 case MCBinaryExpr::Div:
977 case MCBinaryExpr::Mod:
978 // Handle division by zero. gas just emits a warning and keeps going,
979 // we try to be stricter.
980 // FIXME: Currently the caller of this function has no way to understand
981 // we're bailing out because of 'division by zero'. Therefore, it will
982 // emit a 'expected relocatable expression' error. It would be nice to
983 // change this code to emit a better diagnostic.
984 if (RHS == 0)
985 return false;
986 if (ABE->getOpcode() == MCBinaryExpr::Div)
987 Result = LHS / RHS;
988 else
989 Result = LHS % RHS;
990 break;
991 case MCBinaryExpr::EQ: Result = LHS == RHS; break;
992 case MCBinaryExpr::GT: Result = LHS > RHS; break;
993 case MCBinaryExpr::GTE: Result = LHS >= RHS; break;
994 case MCBinaryExpr::LAnd: Result = LHS && RHS; break;
995 case MCBinaryExpr::LOr: Result = LHS || RHS; break;
996 case MCBinaryExpr::LShr: Result = uint64_t(LHS) >> uint64_t(RHS); break;
997 case MCBinaryExpr::LT: Result = LHS < RHS; break;
998 case MCBinaryExpr::LTE: Result = LHS <= RHS; break;
999 case MCBinaryExpr::Mul: Result = LHS * RHS; break;
1000 case MCBinaryExpr::NE: Result = LHS != RHS; break;
1001 case MCBinaryExpr::Or: Result = LHS | RHS; break;
1002 case MCBinaryExpr::OrNot: Result = LHS | ~RHS; break;
1003 case MCBinaryExpr::Shl: Result = uint64_t(LHS) << uint64_t(RHS); break;
1004 case MCBinaryExpr::Sub: Result = LHS - RHS; break;
1005 case MCBinaryExpr::Xor: Result = LHS ^ RHS; break;
1006 }
1007
1008 switch (Op) {
1009 default:
1010 Res = MCValue::get(Val: Result);
1011 break;
1012 case MCBinaryExpr::EQ:
1013 case MCBinaryExpr::GT:
1014 case MCBinaryExpr::GTE:
1015 case MCBinaryExpr::LT:
1016 case MCBinaryExpr::LTE:
1017 case MCBinaryExpr::NE:
1018 // A comparison operator returns a -1 if true and 0 if false.
1019 Res = MCValue::get(Val: Result ? -1 : 0);
1020 break;
1021 }
1022
1023 return true;
1024 }
1025 }
1026
1027 llvm_unreachable("Invalid assembly expression kind!");
1028}
1029
1030MCFragment *MCExpr::findAssociatedFragment() const {
1031 switch (getKind()) {
1032 case Target:
1033 // We never look through target specific expressions.
1034 return cast<MCTargetExpr>(Val: this)->findAssociatedFragment();
1035
1036 case Constant:
1037 return MCSymbol::AbsolutePseudoFragment;
1038
1039 case SymbolRef: {
1040 const MCSymbolRefExpr *SRE = cast<MCSymbolRefExpr>(Val: this);
1041 const MCSymbol &Sym = SRE->getSymbol();
1042 return Sym.getFragment();
1043 }
1044
1045 case Unary:
1046 return cast<MCUnaryExpr>(Val: this)->getSubExpr()->findAssociatedFragment();
1047
1048 case Binary: {
1049 const MCBinaryExpr *BE = cast<MCBinaryExpr>(Val: this);
1050 MCFragment *LHS_F = BE->getLHS()->findAssociatedFragment();
1051 MCFragment *RHS_F = BE->getRHS()->findAssociatedFragment();
1052
1053 // If either is absolute, return the other.
1054 if (LHS_F == MCSymbol::AbsolutePseudoFragment)
1055 return RHS_F;
1056 if (RHS_F == MCSymbol::AbsolutePseudoFragment)
1057 return LHS_F;
1058
1059 // Not always correct, but probably the best we can do without more context.
1060 if (BE->getOpcode() == MCBinaryExpr::Sub)
1061 return MCSymbol::AbsolutePseudoFragment;
1062
1063 // Otherwise, return the first non-null fragment.
1064 return LHS_F ? LHS_F : RHS_F;
1065 }
1066 }
1067
1068 llvm_unreachable("Invalid assembly expression kind!");
1069}
1070