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
29using namespace llvm;
30
31#define DEBUG_TYPE "mcexpr"
32
33namespace {
34namespace stats {
35
36STATISTIC(MCExprEvaluate, "Number of MCExpr evaluations");
37
38} // end namespace stats
39} // end anonymous namespace
40
41void MCExpr::print(raw_ostream &OS, const MCAsmInfo *MAI, bool InParens) const {
42 switch (getKind()) {
43 case MCExpr::Target:
44 return cast<MCTargetExpr>(Val: this)->printImpl(OS, MAI);
45 case MCExpr::Constant: {
46 auto Value = cast<MCConstantExpr>(Val: *this).getValue();
47 auto PrintInHex = cast<MCConstantExpr>(Val: *this).useHexFormat();
48 auto SizeInBytes = cast<MCConstantExpr>(Val: *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(Val: Value);
55 break;
56 case 1:
57 OS << format(Fmt: "0x%02" PRIx64, Vals: Value);
58 break;
59 case 2:
60 OS << format(Fmt: "0x%04" PRIx64, Vals: Value);
61 break;
62 case 4:
63 OS << format(Fmt: "0x%08" PRIx64, Vals: Value);
64 break;
65 case 8:
66 OS << format(Fmt: "0x%016" PRIx64, Vals: Value);
67 break;
68 }
69 else
70 OS << Value;
71 return;
72 }
73 case MCExpr::SymbolRef: {
74 const MCSymbolRefExpr &SRE = cast<MCSymbolRefExpr>(Val: *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>(Val: *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>(Val: *this);
116
117 // Only print parens around the LHS if it is non-trivial.
118 if (isa<MCConstantExpr>(Val: BE.getLHS()) || isa<MCSymbolRefExpr>(Val: 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>(Val: 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>(Val: BE.getRHS()) || isa<MCSymbolRefExpr>(Val: 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)
175LLVM_DUMP_METHOD void MCExpr::dump() const {
176 dbgs() << *this;
177 dbgs() << '\n';
178}
179#endif
180
181/* *** */
182
183const 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
189const MCUnaryExpr *MCUnaryExpr::create(Opcode Opc, const MCExpr *Expr,
190 MCContext &Ctx, SMLoc Loc) {
191 return new (Ctx) MCUnaryExpr(Opc, Expr, Loc);
192}
193
194const 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
202MCSymbolRefExpr::MCSymbolRefExpr(const MCSymbol *Symbol, VariantKind Kind,
203 const MCAsmInfo *MAI, SMLoc Loc)
204 : MCExpr(MCExpr::SymbolRef, Loc,
205 encodeSubclassData(Kind, HasSubsectionsViaSymbols: MAI->hasSubsectionsViaSymbols())),
206 Symbol(Symbol) {
207 assert(Symbol);
208}
209
210const 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
216const MCSymbolRefExpr *MCSymbolRefExpr::create(StringRef Name, VariantKind Kind,
217 MCContext &Ctx) {
218 return create(Sym: Ctx.getOrCreateSymbol(Name), Kind, Ctx);
219}
220
221StringRef 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
393MCSymbolRefExpr::VariantKind
394MCSymbolRefExpr::getVariantKindForName(StringRef Name) {
395 return StringSwitch<VariantKind>(Name.lower())
396 .Case(S: "dtprel", Value: VK_DTPREL)
397 .Case(S: "dtpoff", Value: VK_DTPOFF)
398 .Case(S: "got", Value: VK_GOT)
399 .Case(S: "gotoff", Value: VK_GOTOFF)
400 .Case(S: "gotrel", Value: VK_GOTREL)
401 .Case(S: "pcrel", Value: VK_PCREL)
402 .Case(S: "gotpcrel", Value: VK_GOTPCREL)
403 .Case(S: "gotpcrel_norelax", Value: VK_GOTPCREL_NORELAX)
404 .Case(S: "gottpoff", Value: VK_GOTTPOFF)
405 .Case(S: "indntpoff", Value: VK_INDNTPOFF)
406 .Case(S: "ntpoff", Value: VK_NTPOFF)
407 .Case(S: "gotntpoff", Value: VK_GOTNTPOFF)
408 .Case(S: "plt", Value: VK_PLT)
409 .Case(S: "tlscall", Value: VK_TLSCALL)
410 .Case(S: "tlsdesc", Value: VK_TLSDESC)
411 .Case(S: "tlsgd", Value: VK_TLSGD)
412 .Case(S: "tlsld", Value: VK_TLSLD)
413 .Case(S: "tlsldm", Value: VK_TLSLDM)
414 .Case(S: "tpoff", Value: VK_TPOFF)
415 .Case(S: "tprel", Value: VK_TPREL)
416 .Case(S: "tlvp", Value: VK_TLVP)
417 .Case(S: "tlvppage", Value: VK_TLVPPAGE)
418 .Case(S: "tlvppageoff", Value: VK_TLVPPAGEOFF)
419 .Case(S: "page", Value: VK_PAGE)
420 .Case(S: "pageoff", Value: VK_PAGEOFF)
421 .Case(S: "gotpage", Value: VK_GOTPAGE)
422 .Case(S: "gotpageoff", Value: VK_GOTPAGEOFF)
423 .Case(S: "imgrel", Value: VK_COFF_IMGREL32)
424 .Case(S: "secrel32", Value: VK_SECREL)
425 .Case(S: "size", Value: VK_SIZE)
426 .Case(S: "abs8", Value: VK_X86_ABS8)
427 .Case(S: "pltoff", Value: VK_X86_PLTOFF)
428 .Case(S: "l", Value: VK_PPC_LO)
429 .Case(S: "h", Value: VK_PPC_HI)
430 .Case(S: "ha", Value: VK_PPC_HA)
431 .Case(S: "high", Value: VK_PPC_HIGH)
432 .Case(S: "higha", Value: VK_PPC_HIGHA)
433 .Case(S: "higher", Value: VK_PPC_HIGHER)
434 .Case(S: "highera", Value: VK_PPC_HIGHERA)
435 .Case(S: "highest", Value: VK_PPC_HIGHEST)
436 .Case(S: "highesta", Value: VK_PPC_HIGHESTA)
437 .Case(S: "got@l", Value: VK_PPC_GOT_LO)
438 .Case(S: "got@h", Value: VK_PPC_GOT_HI)
439 .Case(S: "got@ha", Value: VK_PPC_GOT_HA)
440 .Case(S: "local", Value: VK_PPC_LOCAL)
441 .Case(S: "tocbase", Value: VK_PPC_TOCBASE)
442 .Case(S: "toc", Value: VK_PPC_TOC)
443 .Case(S: "toc@l", Value: VK_PPC_TOC_LO)
444 .Case(S: "toc@h", Value: VK_PPC_TOC_HI)
445 .Case(S: "toc@ha", Value: VK_PPC_TOC_HA)
446 .Case(S: "u", Value: VK_PPC_U)
447 .Case(S: "l", Value: VK_PPC_L)
448 .Case(S: "tls", Value: VK_PPC_TLS)
449 .Case(S: "dtpmod", Value: VK_PPC_DTPMOD)
450 .Case(S: "tprel@l", Value: VK_PPC_TPREL_LO)
451 .Case(S: "tprel@h", Value: VK_PPC_TPREL_HI)
452 .Case(S: "tprel@ha", Value: VK_PPC_TPREL_HA)
453 .Case(S: "tprel@high", Value: VK_PPC_TPREL_HIGH)
454 .Case(S: "tprel@higha", Value: VK_PPC_TPREL_HIGHA)
455 .Case(S: "tprel@higher", Value: VK_PPC_TPREL_HIGHER)
456 .Case(S: "tprel@highera", Value: VK_PPC_TPREL_HIGHERA)
457 .Case(S: "tprel@highest", Value: VK_PPC_TPREL_HIGHEST)
458 .Case(S: "tprel@highesta", Value: VK_PPC_TPREL_HIGHESTA)
459 .Case(S: "dtprel@l", Value: VK_PPC_DTPREL_LO)
460 .Case(S: "dtprel@h", Value: VK_PPC_DTPREL_HI)
461 .Case(S: "dtprel@ha", Value: VK_PPC_DTPREL_HA)
462 .Case(S: "dtprel@high", Value: VK_PPC_DTPREL_HIGH)
463 .Case(S: "dtprel@higha", Value: VK_PPC_DTPREL_HIGHA)
464 .Case(S: "dtprel@higher", Value: VK_PPC_DTPREL_HIGHER)
465 .Case(S: "dtprel@highera", Value: VK_PPC_DTPREL_HIGHERA)
466 .Case(S: "dtprel@highest", Value: VK_PPC_DTPREL_HIGHEST)
467 .Case(S: "dtprel@highesta", Value: VK_PPC_DTPREL_HIGHESTA)
468 .Case(S: "got@tprel", Value: VK_PPC_GOT_TPREL)
469 .Case(S: "got@tprel@l", Value: VK_PPC_GOT_TPREL_LO)
470 .Case(S: "got@tprel@h", Value: VK_PPC_GOT_TPREL_HI)
471 .Case(S: "got@tprel@ha", Value: VK_PPC_GOT_TPREL_HA)
472 .Case(S: "got@dtprel", Value: VK_PPC_GOT_DTPREL)
473 .Case(S: "got@dtprel@l", Value: VK_PPC_GOT_DTPREL_LO)
474 .Case(S: "got@dtprel@h", Value: VK_PPC_GOT_DTPREL_HI)
475 .Case(S: "got@dtprel@ha", Value: VK_PPC_GOT_DTPREL_HA)
476 .Case(S: "got@tlsgd", Value: VK_PPC_GOT_TLSGD)
477 .Case(S: "got@tlsgd@l", Value: VK_PPC_GOT_TLSGD_LO)
478 .Case(S: "got@tlsgd@h", Value: VK_PPC_GOT_TLSGD_HI)
479 .Case(S: "got@tlsgd@ha", Value: VK_PPC_GOT_TLSGD_HA)
480 .Case(S: "got@tlsld", Value: VK_PPC_GOT_TLSLD)
481 .Case(S: "got@tlsld@l", Value: VK_PPC_GOT_TLSLD_LO)
482 .Case(S: "got@tlsld@h", Value: VK_PPC_GOT_TLSLD_HI)
483 .Case(S: "got@tlsld@ha", Value: VK_PPC_GOT_TLSLD_HA)
484 .Case(S: "got@pcrel", Value: VK_PPC_GOT_PCREL)
485 .Case(S: "got@tlsgd@pcrel", Value: VK_PPC_GOT_TLSGD_PCREL)
486 .Case(S: "got@tlsld@pcrel", Value: VK_PPC_GOT_TLSLD_PCREL)
487 .Case(S: "got@tprel@pcrel", Value: VK_PPC_GOT_TPREL_PCREL)
488 .Case(S: "tls@pcrel", Value: VK_PPC_TLS_PCREL)
489 .Case(S: "notoc", Value: VK_PPC_NOTOC)
490 .Case(S: "gdgot", Value: VK_Hexagon_GD_GOT)
491 .Case(S: "gdplt", Value: VK_Hexagon_GD_PLT)
492 .Case(S: "iegot", Value: VK_Hexagon_IE_GOT)
493 .Case(S: "ie", Value: VK_Hexagon_IE)
494 .Case(S: "ldgot", Value: VK_Hexagon_LD_GOT)
495 .Case(S: "ldplt", Value: VK_Hexagon_LD_PLT)
496 .Case(S: "none", Value: VK_ARM_NONE)
497 .Case(S: "got_prel", Value: VK_ARM_GOT_PREL)
498 .Case(S: "target1", Value: VK_ARM_TARGET1)
499 .Case(S: "target2", Value: VK_ARM_TARGET2)
500 .Case(S: "prel31", Value: VK_ARM_PREL31)
501 .Case(S: "sbrel", Value: VK_ARM_SBREL)
502 .Case(S: "tlsldo", Value: VK_ARM_TLSLDO)
503 .Case(S: "lo8", Value: VK_AVR_LO8)
504 .Case(S: "hi8", Value: VK_AVR_HI8)
505 .Case(S: "hlo8", Value: VK_AVR_HLO8)
506 .Case(S: "typeindex", Value: VK_WASM_TYPEINDEX)
507 .Case(S: "tbrel", Value: VK_WASM_TBREL)
508 .Case(S: "mbrel", Value: VK_WASM_MBREL)
509 .Case(S: "tlsrel", Value: VK_WASM_TLSREL)
510 .Case(S: "got@tls", Value: VK_WASM_GOT_TLS)
511 .Case(S: "funcindex", Value: VK_WASM_FUNCINDEX)
512 .Case(S: "gotpcrel32@lo", Value: VK_AMDGPU_GOTPCREL32_LO)
513 .Case(S: "gotpcrel32@hi", Value: VK_AMDGPU_GOTPCREL32_HI)
514 .Case(S: "rel32@lo", Value: VK_AMDGPU_REL32_LO)
515 .Case(S: "rel32@hi", Value: VK_AMDGPU_REL32_HI)
516 .Case(S: "rel64", Value: VK_AMDGPU_REL64)
517 .Case(S: "abs32@lo", Value: VK_AMDGPU_ABS32_LO)
518 .Case(S: "abs32@hi", Value: VK_AMDGPU_ABS32_HI)
519 .Case(S: "hi", Value: VK_VE_HI32)
520 .Case(S: "lo", Value: VK_VE_LO32)
521 .Case(S: "pc_hi", Value: VK_VE_PC_HI32)
522 .Case(S: "pc_lo", Value: VK_VE_PC_LO32)
523 .Case(S: "got_hi", Value: VK_VE_GOT_HI32)
524 .Case(S: "got_lo", Value: VK_VE_GOT_LO32)
525 .Case(S: "gotoff_hi", Value: VK_VE_GOTOFF_HI32)
526 .Case(S: "gotoff_lo", Value: VK_VE_GOTOFF_LO32)
527 .Case(S: "plt_hi", Value: VK_VE_PLT_HI32)
528 .Case(S: "plt_lo", Value: VK_VE_PLT_LO32)
529 .Case(S: "tls_gd_hi", Value: VK_VE_TLS_GD_HI32)
530 .Case(S: "tls_gd_lo", Value: VK_VE_TLS_GD_LO32)
531 .Case(S: "tpoff_hi", Value: VK_VE_TPOFF_HI32)
532 .Case(S: "tpoff_lo", Value: VK_VE_TPOFF_LO32)
533 .Default(Value: VK_Invalid);
534}
535
536/* *** */
537
538void MCTargetExpr::anchor() {}
539
540/* *** */
541
542bool MCExpr::evaluateAsAbsolute(int64_t &Res) const {
543 return evaluateAsAbsolute(Res, Asm: nullptr, Layout: nullptr, Addrs: nullptr, InSet: false);
544}
545
546bool MCExpr::evaluateAsAbsolute(int64_t &Res,
547 const MCAsmLayout &Layout) const {
548 return evaluateAsAbsolute(Res, Asm: &Layout.getAssembler(), Layout: &Layout, Addrs: nullptr, InSet: false);
549}
550
551bool 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, Asm: &Layout.getAssembler(), Layout: &Layout, Addrs: &Addrs, InSet: true);
557}
558
559bool MCExpr::evaluateAsAbsolute(int64_t &Res, const MCAssembler &Asm) const {
560 return evaluateAsAbsolute(Res, Asm: &Asm, Layout: nullptr, Addrs: nullptr, InSet: false);
561}
562
563bool MCExpr::evaluateAsAbsolute(int64_t &Res, const MCAssembler *Asm) const {
564 return evaluateAsAbsolute(Res, Asm, Layout: nullptr, Addrs: nullptr, InSet: false);
565}
566
567bool MCExpr::evaluateKnownAbsolute(int64_t &Res,
568 const MCAsmLayout &Layout) const {
569 return evaluateAsAbsolute(Res, Asm: &Layout.getAssembler(), Layout: &Layout, Addrs: nullptr,
570 InSet: true);
571}
572
573bool 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>(Val: this)) {
580 Res = CE->getValue();
581 return true;
582 }
583
584 bool IsRelocatable =
585 evaluateAsRelocatableImpl(Res&: Value, Asm, Layout, Fixup: 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().
594static 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: *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(Func: &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 Asm->getContext().getTargetTriple().isLoongArch()))) {
637 // If both symbols are in the same fragment, return the difference of their
638 // offsets. canGetFragmentOffset(FA) may be false.
639 if (FA == FB && !SA.isVariable() && !SB.isVariable()) {
640 Addend += SA.getOffset() - SB.getOffset();
641 return FinalizeFolding();
642 }
643 // One of the symbol involved is part of a fragment being laid out. Quit now
644 // to avoid a self loop.
645 if (!Layout->canGetFragmentOffset(F: FA) || !Layout->canGetFragmentOffset(F: FB))
646 return;
647
648 // Eagerly evaluate when layout is finalized.
649 Addend += Layout->getSymbolOffset(S: A->getSymbol()) -
650 Layout->getSymbolOffset(S: B->getSymbol());
651 if (Addrs && (&SecA != &SecB))
652 Addend += (Addrs->lookup(Val: &SecA) - Addrs->lookup(Val: &SecB));
653
654 FinalizeFolding();
655 } else {
656 // When layout is not finalized, our ability to resolve differences between
657 // symbols is limited to specific cases where the fragments between two
658 // symbols (including the fragments the symbols are defined in) are
659 // fixed-size fragments so the difference can be calculated. For example,
660 // this is important when the Subtarget is changed and a new MCDataFragment
661 // is created in the case of foo: instr; .arch_extension ext; instr .if . -
662 // foo.
663 if (SA.isVariable() || SB.isVariable() ||
664 FA->getSubsectionNumber() != FB->getSubsectionNumber())
665 return;
666
667 // Try to find a constant displacement from FA to FB, add the displacement
668 // between the offset in FA of SA and the offset in FB of SB.
669 bool Reverse = false;
670 if (FA == FB) {
671 Reverse = SA.getOffset() < SB.getOffset();
672 } else if (!isa<MCDummyFragment>(Val: FA)) {
673 Reverse = std::find_if(first: std::next(x: FA->getIterator()), last: SecA.end(),
674 pred: [&](auto &I) { return &I == FB; }) != SecA.end();
675 }
676
677 uint64_t SAOffset = SA.getOffset(), SBOffset = SB.getOffset();
678 int64_t Displacement = SA.getOffset() - SB.getOffset();
679 if (Reverse) {
680 std::swap(a&: FA, b&: FB);
681 std::swap(a&: SAOffset, b&: SBOffset);
682 Displacement *= -1;
683 }
684
685 [[maybe_unused]] bool Found = false;
686 // Track whether B is before a relaxable instruction and whether A is after
687 // a relaxable instruction. If SA and SB are separated by a linker-relaxable
688 // instruction, the difference cannot be resolved as it may be changed by
689 // the linker.
690 bool BBeforeRelax = false, AAfterRelax = false;
691 for (auto FI = FB->getIterator(), FE = SecA.end(); FI != FE; ++FI) {
692 auto DF = dyn_cast<MCDataFragment>(Val&: FI);
693 if (DF && DF->isLinkerRelaxable()) {
694 if (&*FI != FB || SBOffset != DF->getContents().size())
695 BBeforeRelax = true;
696 if (&*FI != FA || SAOffset == DF->getContents().size())
697 AAfterRelax = true;
698 if (BBeforeRelax && AAfterRelax)
699 return;
700 }
701 if (&*FI == FA) {
702 Found = true;
703 break;
704 }
705
706 int64_t Num;
707 unsigned Count;
708 if (DF) {
709 Displacement += DF->getContents().size();
710 } else if (auto *AF = dyn_cast<MCAlignFragment>(Val&: FI);
711 AF && Layout && AF->hasEmitNops() &&
712 !Asm->getBackend().shouldInsertExtraNopBytesForCodeAlign(
713 AF: *AF, Size&: Count)) {
714 Displacement += Asm->computeFragmentSize(Layout: *Layout, F: *AF);
715 } else if (auto *FF = dyn_cast<MCFillFragment>(Val&: FI);
716 FF && FF->getNumValues().evaluateAsAbsolute(Res&: Num)) {
717 Displacement += Num * FF->getValueSize();
718 } else {
719 return;
720 }
721 }
722 // If the previous loop does not find FA, FA must be a dummy fragment not in
723 // the fragment list (which means SA is a pending label (see
724 // flushPendingLabels)). In either case, we can resolve the difference.
725 assert(Found || isa<MCDummyFragment>(FA));
726 Addend += Reverse ? -Displacement : Displacement;
727 FinalizeFolding();
728 }
729}
730
731/// Evaluate the result of an add between (conceptually) two MCValues.
732///
733/// This routine conceptually attempts to construct an MCValue:
734/// Result = (Result_A - Result_B + Result_Cst)
735/// from two MCValue's LHS and RHS where
736/// Result = LHS + RHS
737/// and
738/// Result = (LHS_A - LHS_B + LHS_Cst) + (RHS_A - RHS_B + RHS_Cst).
739///
740/// This routine attempts to aggressively fold the operands such that the result
741/// is representable in an MCValue, but may not always succeed.
742///
743/// \returns True on success, false if the result is not representable in an
744/// MCValue.
745
746/// NOTE: It is really important to have both the Asm and Layout arguments.
747/// They might look redundant, but this function can be used before layout
748/// is done (see the object streamer for example) and having the Asm argument
749/// lets us avoid relaxations early.
750static bool EvaluateSymbolicAdd(const MCAssembler *Asm,
751 const MCAsmLayout *Layout,
752 const SectionAddrMap *Addrs, bool InSet,
753 const MCValue &LHS, const MCValue &RHS,
754 MCValue &Res) {
755 // FIXME: This routine (and other evaluation parts) are *incredibly* sloppy
756 // about dealing with modifiers. This will ultimately bite us, one day.
757 const MCSymbolRefExpr *LHS_A = LHS.getSymA();
758 const MCSymbolRefExpr *LHS_B = LHS.getSymB();
759 int64_t LHS_Cst = LHS.getConstant();
760
761 const MCSymbolRefExpr *RHS_A = RHS.getSymA();
762 const MCSymbolRefExpr *RHS_B = RHS.getSymB();
763 int64_t RHS_Cst = RHS.getConstant();
764
765 if (LHS.getRefKind() != RHS.getRefKind())
766 return false;
767
768 // Fold the result constant immediately.
769 int64_t Result_Cst = LHS_Cst + RHS_Cst;
770
771 assert((!Layout || Asm) &&
772 "Must have an assembler object if layout is given!");
773
774 // If we have a layout, we can fold resolved differences.
775 if (Asm) {
776 // First, fold out any differences which are fully resolved. By
777 // reassociating terms in
778 // Result = (LHS_A - LHS_B + LHS_Cst) + (RHS_A - RHS_B + RHS_Cst).
779 // we have the four possible differences:
780 // (LHS_A - LHS_B),
781 // (LHS_A - RHS_B),
782 // (RHS_A - LHS_B),
783 // (RHS_A - RHS_B).
784 // Since we are attempting to be as aggressive as possible about folding, we
785 // attempt to evaluate each possible alternative.
786 AttemptToFoldSymbolOffsetDifference(Asm, Layout, Addrs, InSet, A&: LHS_A, B&: LHS_B,
787 Addend&: Result_Cst);
788 AttemptToFoldSymbolOffsetDifference(Asm, Layout, Addrs, InSet, A&: LHS_A, B&: RHS_B,
789 Addend&: Result_Cst);
790 AttemptToFoldSymbolOffsetDifference(Asm, Layout, Addrs, InSet, A&: RHS_A, B&: LHS_B,
791 Addend&: Result_Cst);
792 AttemptToFoldSymbolOffsetDifference(Asm, Layout, Addrs, InSet, A&: RHS_A, B&: RHS_B,
793 Addend&: Result_Cst);
794 }
795
796 // We can't represent the addition or subtraction of two symbols.
797 if ((LHS_A && RHS_A) || (LHS_B && RHS_B))
798 return false;
799
800 // At this point, we have at most one additive symbol and one subtractive
801 // symbol -- find them.
802 const MCSymbolRefExpr *A = LHS_A ? LHS_A : RHS_A;
803 const MCSymbolRefExpr *B = LHS_B ? LHS_B : RHS_B;
804
805 Res = MCValue::get(SymA: A, SymB: B, Val: Result_Cst);
806 return true;
807}
808
809bool MCExpr::evaluateAsRelocatable(MCValue &Res,
810 const MCAsmLayout *Layout,
811 const MCFixup *Fixup) const {
812 MCAssembler *Assembler = Layout ? &Layout->getAssembler() : nullptr;
813 return evaluateAsRelocatableImpl(Res, Asm: Assembler, Layout, Fixup, Addrs: nullptr,
814 InSet: false);
815}
816
817bool MCExpr::evaluateAsValue(MCValue &Res, const MCAsmLayout &Layout) const {
818 MCAssembler *Assembler = &Layout.getAssembler();
819 return evaluateAsRelocatableImpl(Res, Asm: Assembler, Layout: &Layout, Fixup: nullptr, Addrs: nullptr,
820 InSet: true);
821}
822
823static bool canExpand(const MCSymbol &Sym, bool InSet) {
824 if (Sym.isWeakExternal())
825 return false;
826
827 const MCExpr *Expr = Sym.getVariableValue();
828 const auto *Inner = dyn_cast<MCSymbolRefExpr>(Val: Expr);
829 if (Inner) {
830 if (Inner->getKind() == MCSymbolRefExpr::VK_WEAKREF)
831 return false;
832 }
833
834 if (InSet)
835 return true;
836 return !Sym.isInSection();
837}
838
839bool MCExpr::evaluateAsRelocatableImpl(MCValue &Res, const MCAssembler *Asm,
840 const MCAsmLayout *Layout,
841 const MCFixup *Fixup,
842 const SectionAddrMap *Addrs,
843 bool InSet) const {
844 ++stats::MCExprEvaluate;
845
846 switch (getKind()) {
847 case Target:
848 return cast<MCTargetExpr>(Val: this)->evaluateAsRelocatableImpl(Res, Layout,
849 Fixup);
850
851 case Constant:
852 Res = MCValue::get(Val: cast<MCConstantExpr>(Val: this)->getValue());
853 return true;
854
855 case SymbolRef: {
856 const MCSymbolRefExpr *SRE = cast<MCSymbolRefExpr>(Val: this);
857 const MCSymbol &Sym = SRE->getSymbol();
858 const auto Kind = SRE->getKind();
859
860 // Evaluate recursively if this is a variable.
861 if (Sym.isVariable() && (Kind == MCSymbolRefExpr::VK_None || Layout) &&
862 canExpand(Sym, InSet)) {
863 bool IsMachO = SRE->hasSubsectionsViaSymbols();
864 if (Sym.getVariableValue()->evaluateAsRelocatableImpl(
865 Res, Asm, Layout, Fixup, Addrs, InSet: InSet || IsMachO)) {
866 if (Kind != MCSymbolRefExpr::VK_None) {
867 if (Res.isAbsolute()) {
868 Res = MCValue::get(SymA: SRE, SymB: nullptr, Val: 0);
869 return true;
870 }
871 // If the reference has a variant kind, we can only handle expressions
872 // which evaluate exactly to a single unadorned symbol. Attach the
873 // original VariantKind to SymA of the result.
874 if (Res.getRefKind() != MCSymbolRefExpr::VK_None || !Res.getSymA() ||
875 Res.getSymB() || Res.getConstant())
876 return false;
877 Res =
878 MCValue::get(SymA: MCSymbolRefExpr::create(Sym: &Res.getSymA()->getSymbol(),
879 Kind, Ctx&: Asm->getContext()),
880 SymB: Res.getSymB(), Val: Res.getConstant(), RefKind: Res.getRefKind());
881 }
882 if (!IsMachO)
883 return true;
884
885 const MCSymbolRefExpr *A = Res.getSymA();
886 const MCSymbolRefExpr *B = Res.getSymB();
887 // FIXME: This is small hack. Given
888 // a = b + 4
889 // .long a
890 // the OS X assembler will completely drop the 4. We should probably
891 // include it in the relocation or produce an error if that is not
892 // possible.
893 // Allow constant expressions.
894 if (!A && !B)
895 return true;
896 // Allows aliases with zero offset.
897 if (Res.getConstant() == 0 && (!A || !B))
898 return true;
899 }
900 }
901
902 Res = MCValue::get(SymA: SRE, SymB: nullptr, Val: 0);
903 return true;
904 }
905
906 case Unary: {
907 const MCUnaryExpr *AUE = cast<MCUnaryExpr>(Val: this);
908 MCValue Value;
909
910 if (!AUE->getSubExpr()->evaluateAsRelocatableImpl(Res&: Value, Asm, Layout, Fixup,
911 Addrs, InSet))
912 return false;
913
914 switch (AUE->getOpcode()) {
915 case MCUnaryExpr::LNot:
916 if (!Value.isAbsolute())
917 return false;
918 Res = MCValue::get(Val: !Value.getConstant());
919 break;
920 case MCUnaryExpr::Minus:
921 /// -(a - b + const) ==> (b - a - const)
922 if (Value.getSymA() && !Value.getSymB())
923 return false;
924
925 // The cast avoids undefined behavior if the constant is INT64_MIN.
926 Res = MCValue::get(SymA: Value.getSymB(), SymB: Value.getSymA(),
927 Val: -(uint64_t)Value.getConstant());
928 break;
929 case MCUnaryExpr::Not:
930 if (!Value.isAbsolute())
931 return false;
932 Res = MCValue::get(Val: ~Value.getConstant());
933 break;
934 case MCUnaryExpr::Plus:
935 Res = Value;
936 break;
937 }
938
939 return true;
940 }
941
942 case Binary: {
943 const MCBinaryExpr *ABE = cast<MCBinaryExpr>(Val: this);
944 MCValue LHSValue, RHSValue;
945
946 if (!ABE->getLHS()->evaluateAsRelocatableImpl(Res&: LHSValue, Asm, Layout, Fixup,
947 Addrs, InSet) ||
948 !ABE->getRHS()->evaluateAsRelocatableImpl(Res&: RHSValue, Asm, Layout, Fixup,
949 Addrs, InSet)) {
950 // Check if both are Target Expressions, see if we can compare them.
951 if (const MCTargetExpr *L = dyn_cast<MCTargetExpr>(Val: ABE->getLHS())) {
952 if (const MCTargetExpr *R = dyn_cast<MCTargetExpr>(Val: ABE->getRHS())) {
953 switch (ABE->getOpcode()) {
954 case MCBinaryExpr::EQ:
955 Res = MCValue::get(Val: L->isEqualTo(x: R) ? -1 : 0);
956 return true;
957 case MCBinaryExpr::NE:
958 Res = MCValue::get(Val: L->isEqualTo(x: R) ? 0 : -1);
959 return true;
960 default:
961 break;
962 }
963 }
964 }
965 return false;
966 }
967
968 // We only support a few operations on non-constant expressions, handle
969 // those first.
970 if (!LHSValue.isAbsolute() || !RHSValue.isAbsolute()) {
971 switch (ABE->getOpcode()) {
972 default:
973 return false;
974 case MCBinaryExpr::Sub:
975 // Negate RHS and add.
976 // The cast avoids undefined behavior if the constant is INT64_MIN.
977 return EvaluateSymbolicAdd(
978 Asm, Layout, Addrs, InSet, LHS: LHSValue,
979 RHS: MCValue::get(SymA: RHSValue.getSymB(), SymB: RHSValue.getSymA(),
980 Val: -(uint64_t)RHSValue.getConstant(),
981 RefKind: RHSValue.getRefKind()),
982 Res);
983
984 case MCBinaryExpr::Add:
985 return EvaluateSymbolicAdd(
986 Asm, Layout, Addrs, InSet, LHS: LHSValue,
987 RHS: MCValue::get(SymA: RHSValue.getSymA(), SymB: RHSValue.getSymB(),
988 Val: RHSValue.getConstant(), RefKind: RHSValue.getRefKind()),
989 Res);
990 }
991 }
992
993 // FIXME: We need target hooks for the evaluation. It may be limited in
994 // width, and gas defines the result of comparisons differently from
995 // Apple as.
996 int64_t LHS = LHSValue.getConstant(), RHS = RHSValue.getConstant();
997 int64_t Result = 0;
998 auto Op = ABE->getOpcode();
999 switch (Op) {
1000 case MCBinaryExpr::AShr: Result = LHS >> RHS; break;
1001 case MCBinaryExpr::Add: Result = LHS + RHS; break;
1002 case MCBinaryExpr::And: Result = LHS & RHS; break;
1003 case MCBinaryExpr::Div:
1004 case MCBinaryExpr::Mod:
1005 // Handle division by zero. gas just emits a warning and keeps going,
1006 // we try to be stricter.
1007 // FIXME: Currently the caller of this function has no way to understand
1008 // we're bailing out because of 'division by zero'. Therefore, it will
1009 // emit a 'expected relocatable expression' error. It would be nice to
1010 // change this code to emit a better diagnostic.
1011 if (RHS == 0)
1012 return false;
1013 if (ABE->getOpcode() == MCBinaryExpr::Div)
1014 Result = LHS / RHS;
1015 else
1016 Result = LHS % RHS;
1017 break;
1018 case MCBinaryExpr::EQ: Result = LHS == RHS; break;
1019 case MCBinaryExpr::GT: Result = LHS > RHS; break;
1020 case MCBinaryExpr::GTE: Result = LHS >= RHS; break;
1021 case MCBinaryExpr::LAnd: Result = LHS && RHS; break;
1022 case MCBinaryExpr::LOr: Result = LHS || RHS; break;
1023 case MCBinaryExpr::LShr: Result = uint64_t(LHS) >> uint64_t(RHS); break;
1024 case MCBinaryExpr::LT: Result = LHS < RHS; break;
1025 case MCBinaryExpr::LTE: Result = LHS <= RHS; break;
1026 case MCBinaryExpr::Mul: Result = LHS * RHS; break;
1027 case MCBinaryExpr::NE: Result = LHS != RHS; break;
1028 case MCBinaryExpr::Or: Result = LHS | RHS; break;
1029 case MCBinaryExpr::OrNot: Result = LHS | ~RHS; break;
1030 case MCBinaryExpr::Shl: Result = uint64_t(LHS) << uint64_t(RHS); break;
1031 case MCBinaryExpr::Sub: Result = LHS - RHS; break;
1032 case MCBinaryExpr::Xor: Result = LHS ^ RHS; break;
1033 }
1034
1035 switch (Op) {
1036 default:
1037 Res = MCValue::get(Val: Result);
1038 break;
1039 case MCBinaryExpr::EQ:
1040 case MCBinaryExpr::GT:
1041 case MCBinaryExpr::GTE:
1042 case MCBinaryExpr::LT:
1043 case MCBinaryExpr::LTE:
1044 case MCBinaryExpr::NE:
1045 // A comparison operator returns a -1 if true and 0 if false.
1046 Res = MCValue::get(Val: Result ? -1 : 0);
1047 break;
1048 }
1049
1050 return true;
1051 }
1052 }
1053
1054 llvm_unreachable("Invalid assembly expression kind!");
1055}
1056
1057MCFragment *MCExpr::findAssociatedFragment() const {
1058 switch (getKind()) {
1059 case Target:
1060 // We never look through target specific expressions.
1061 return cast<MCTargetExpr>(Val: this)->findAssociatedFragment();
1062
1063 case Constant:
1064 return MCSymbol::AbsolutePseudoFragment;
1065
1066 case SymbolRef: {
1067 const MCSymbolRefExpr *SRE = cast<MCSymbolRefExpr>(Val: this);
1068 const MCSymbol &Sym = SRE->getSymbol();
1069 return Sym.getFragment();
1070 }
1071
1072 case Unary:
1073 return cast<MCUnaryExpr>(Val: this)->getSubExpr()->findAssociatedFragment();
1074
1075 case Binary: {
1076 const MCBinaryExpr *BE = cast<MCBinaryExpr>(Val: this);
1077 MCFragment *LHS_F = BE->getLHS()->findAssociatedFragment();
1078 MCFragment *RHS_F = BE->getRHS()->findAssociatedFragment();
1079
1080 // If either is absolute, return the other.
1081 if (LHS_F == MCSymbol::AbsolutePseudoFragment)
1082 return RHS_F;
1083 if (RHS_F == MCSymbol::AbsolutePseudoFragment)
1084 return LHS_F;
1085
1086 // Not always correct, but probably the best we can do without more context.
1087 if (BE->getOpcode() == MCBinaryExpr::Sub)
1088 return MCSymbol::AbsolutePseudoFragment;
1089
1090 // Otherwise, return the first non-null fragment.
1091 return LHS_F ? LHS_F : RHS_F;
1092 }
1093 }
1094
1095 llvm_unreachable("Invalid assembly expression kind!");
1096}
1097

source code of llvm/lib/MC/MCExpr.cpp