1 //===- MCExpr.cpp - Assembly Level Expression Implementation --------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 #define DEBUG_TYPE "mcexpr"
11 #include "llvm/MC/MCExpr.h"
12 #include "llvm/ADT/Statistic.h"
13 #include "llvm/ADT/StringSwitch.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/Debug.h"
22 #include "llvm/Support/ErrorHandling.h"
23 #include "llvm/Support/raw_ostream.h"
28 STATISTIC(MCExprEvaluate, "Number of MCExpr evaluations");
32 void MCExpr::print(raw_ostream &OS) const {
35 return cast<MCTargetExpr>(this)->PrintImpl(OS);
36 case MCExpr::Constant:
37 OS << cast<MCConstantExpr>(*this).getValue();
40 case MCExpr::SymbolRef: {
41 const MCSymbolRefExpr &SRE = cast<MCSymbolRefExpr>(*this);
42 const MCSymbol &Sym = SRE.getSymbol();
43 // Parenthesize names that start with $ so that they don't look like
45 bool UseParens = Sym.getName()[0] == '$';
47 OS << '(' << Sym << ')';
51 if (SRE.getKind() != MCSymbolRefExpr::VK_None) {
52 if (SRE.getMCAsmInfo().useParensForSymbolVariant())
53 OS << '(' << MCSymbolRefExpr::getVariantKindName(SRE.getKind()) << ')';
55 OS << '@' << MCSymbolRefExpr::getVariantKindName(SRE.getKind());
62 const MCUnaryExpr &UE = cast<MCUnaryExpr>(*this);
63 switch (UE.getOpcode()) {
64 case MCUnaryExpr::LNot: OS << '!'; break;
65 case MCUnaryExpr::Minus: OS << '-'; break;
66 case MCUnaryExpr::Not: OS << '~'; break;
67 case MCUnaryExpr::Plus: OS << '+'; break;
69 OS << *UE.getSubExpr();
73 case MCExpr::Binary: {
74 const MCBinaryExpr &BE = cast<MCBinaryExpr>(*this);
76 // Only print parens around the LHS if it is non-trivial.
77 if (isa<MCConstantExpr>(BE.getLHS()) || isa<MCSymbolRefExpr>(BE.getLHS())) {
80 OS << '(' << *BE.getLHS() << ')';
83 switch (BE.getOpcode()) {
84 case MCBinaryExpr::Add:
85 // Print "X-42" instead of "X+-42".
86 if (const MCConstantExpr *RHSC = dyn_cast<MCConstantExpr>(BE.getRHS())) {
87 if (RHSC->getValue() < 0) {
88 OS << RHSC->getValue();
95 case MCBinaryExpr::And: OS << '&'; break;
96 case MCBinaryExpr::Div: OS << '/'; break;
97 case MCBinaryExpr::EQ: OS << "=="; break;
98 case MCBinaryExpr::GT: OS << '>'; break;
99 case MCBinaryExpr::GTE: OS << ">="; break;
100 case MCBinaryExpr::LAnd: OS << "&&"; break;
101 case MCBinaryExpr::LOr: OS << "||"; break;
102 case MCBinaryExpr::LT: OS << '<'; break;
103 case MCBinaryExpr::LTE: OS << "<="; break;
104 case MCBinaryExpr::Mod: OS << '%'; break;
105 case MCBinaryExpr::Mul: OS << '*'; break;
106 case MCBinaryExpr::NE: OS << "!="; break;
107 case MCBinaryExpr::Or: OS << '|'; break;
108 case MCBinaryExpr::Shl: OS << "<<"; break;
109 case MCBinaryExpr::Shr: OS << ">>"; break;
110 case MCBinaryExpr::Sub: OS << '-'; break;
111 case MCBinaryExpr::Xor: OS << '^'; break;
114 // Only print parens around the LHS if it is non-trivial.
115 if (isa<MCConstantExpr>(BE.getRHS()) || isa<MCSymbolRefExpr>(BE.getRHS())) {
118 OS << '(' << *BE.getRHS() << ')';
124 llvm_unreachable("Invalid expression kind!");
127 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
128 void MCExpr::dump() const {
136 const MCBinaryExpr *MCBinaryExpr::Create(Opcode Opc, const MCExpr *LHS,
137 const MCExpr *RHS, MCContext &Ctx) {
138 return new (Ctx) MCBinaryExpr(Opc, LHS, RHS);
141 const MCUnaryExpr *MCUnaryExpr::Create(Opcode Opc, const MCExpr *Expr,
143 return new (Ctx) MCUnaryExpr(Opc, Expr);
146 const MCConstantExpr *MCConstantExpr::Create(int64_t Value, MCContext &Ctx) {
147 return new (Ctx) MCConstantExpr(Value);
152 const MCSymbolRefExpr *MCSymbolRefExpr::Create(const MCSymbol *Sym,
155 return new (Ctx) MCSymbolRefExpr(Sym, Kind, Ctx.getAsmInfo());
158 const MCSymbolRefExpr *MCSymbolRefExpr::Create(StringRef Name, VariantKind Kind,
160 return Create(Ctx.GetOrCreateSymbol(Name), Kind, Ctx);
163 StringRef MCSymbolRefExpr::getVariantKindName(VariantKind Kind) {
165 case VK_Invalid: return "<<invalid>>";
166 case VK_None: return "<<none>>";
168 case VK_GOT: return "GOT";
169 case VK_GOTOFF: return "GOTOFF";
170 case VK_GOTPCREL: return "GOTPCREL";
171 case VK_GOTTPOFF: return "GOTTPOFF";
172 case VK_INDNTPOFF: return "INDNTPOFF";
173 case VK_NTPOFF: return "NTPOFF";
174 case VK_GOTNTPOFF: return "GOTNTPOFF";
175 case VK_PLT: return "PLT";
176 case VK_TLSGD: return "TLSGD";
177 case VK_TLSLD: return "TLSLD";
178 case VK_TLSLDM: return "TLSLDM";
179 case VK_TPOFF: return "TPOFF";
180 case VK_DTPOFF: return "DTPOFF";
181 case VK_TLVP: return "TLVP";
182 case VK_SECREL: return "SECREL32";
183 case VK_ARM_NONE: return "none";
184 case VK_ARM_TARGET1: return "target1";
185 case VK_ARM_TARGET2: return "target2";
186 case VK_ARM_PREL31: return "prel31";
187 case VK_PPC_LO: return "l";
188 case VK_PPC_HI: return "h";
189 case VK_PPC_HA: return "ha";
190 case VK_PPC_HIGHER: return "higher";
191 case VK_PPC_HIGHERA: return "highera";
192 case VK_PPC_HIGHEST: return "highest";
193 case VK_PPC_HIGHESTA: return "highesta";
194 case VK_PPC_GOT_LO: return "got@l";
195 case VK_PPC_GOT_HI: return "got@h";
196 case VK_PPC_GOT_HA: return "got@ha";
197 case VK_PPC_TOCBASE: return "tocbase";
198 case VK_PPC_TOC: return "toc";
199 case VK_PPC_TOC_LO: return "toc@l";
200 case VK_PPC_TOC_HI: return "toc@h";
201 case VK_PPC_TOC_HA: return "toc@ha";
202 case VK_PPC_DTPMOD: return "dtpmod";
203 case VK_PPC_TPREL: return "tprel";
204 case VK_PPC_TPREL_LO: return "tprel@l";
205 case VK_PPC_TPREL_HI: return "tprel@h";
206 case VK_PPC_TPREL_HA: return "tprel@ha";
207 case VK_PPC_TPREL_HIGHER: return "tprel@higher";
208 case VK_PPC_TPREL_HIGHERA: return "tprel@highera";
209 case VK_PPC_TPREL_HIGHEST: return "tprel@highest";
210 case VK_PPC_TPREL_HIGHESTA: return "tprel@highesta";
211 case VK_PPC_DTPREL: return "dtprel";
212 case VK_PPC_DTPREL_LO: return "dtprel@l";
213 case VK_PPC_DTPREL_HI: return "dtprel@h";
214 case VK_PPC_DTPREL_HA: return "dtprel@ha";
215 case VK_PPC_DTPREL_HIGHER: return "dtprel@higher";
216 case VK_PPC_DTPREL_HIGHERA: return "dtprel@highera";
217 case VK_PPC_DTPREL_HIGHEST: return "dtprel@highest";
218 case VK_PPC_DTPREL_HIGHESTA: return "dtprel@highesta";
219 case VK_PPC_GOT_TPREL: return "got@tprel";
220 case VK_PPC_GOT_TPREL_LO: return "got@tprel@l";
221 case VK_PPC_GOT_TPREL_HI: return "got@tprel@h";
222 case VK_PPC_GOT_TPREL_HA: return "got@tprel@ha";
223 case VK_PPC_GOT_DTPREL: return "got@dtprel";
224 case VK_PPC_GOT_DTPREL_LO: return "got@dtprel@l";
225 case VK_PPC_GOT_DTPREL_HI: return "got@dtprel@h";
226 case VK_PPC_GOT_DTPREL_HA: return "got@dtprel@ha";
227 case VK_PPC_TLS: return "tls";
228 case VK_PPC_GOT_TLSGD: return "got@tlsgd";
229 case VK_PPC_GOT_TLSGD_LO: return "got@tlsgd@l";
230 case VK_PPC_GOT_TLSGD_HI: return "got@tlsgd@h";
231 case VK_PPC_GOT_TLSGD_HA: return "got@tlsgd@ha";
232 case VK_PPC_TLSGD: return "tlsgd";
233 case VK_PPC_GOT_TLSLD: return "got@tlsld";
234 case VK_PPC_GOT_TLSLD_LO: return "got@tlsld@l";
235 case VK_PPC_GOT_TLSLD_HI: return "got@tlsld@h";
236 case VK_PPC_GOT_TLSLD_HA: return "got@tlsld@ha";
237 case VK_PPC_TLSLD: return "tlsld";
238 case VK_Mips_GPREL: return "GPREL";
239 case VK_Mips_GOT_CALL: return "GOT_CALL";
240 case VK_Mips_GOT16: return "GOT16";
241 case VK_Mips_GOT: return "GOT";
242 case VK_Mips_ABS_HI: return "ABS_HI";
243 case VK_Mips_ABS_LO: return "ABS_LO";
244 case VK_Mips_TLSGD: return "TLSGD";
245 case VK_Mips_TLSLDM: return "TLSLDM";
246 case VK_Mips_DTPREL_HI: return "DTPREL_HI";
247 case VK_Mips_DTPREL_LO: return "DTPREL_LO";
248 case VK_Mips_GOTTPREL: return "GOTTPREL";
249 case VK_Mips_TPREL_HI: return "TPREL_HI";
250 case VK_Mips_TPREL_LO: return "TPREL_LO";
251 case VK_Mips_GPOFF_HI: return "GPOFF_HI";
252 case VK_Mips_GPOFF_LO: return "GPOFF_LO";
253 case VK_Mips_GOT_DISP: return "GOT_DISP";
254 case VK_Mips_GOT_PAGE: return "GOT_PAGE";
255 case VK_Mips_GOT_OFST: return "GOT_OFST";
256 case VK_Mips_HIGHER: return "HIGHER";
257 case VK_Mips_HIGHEST: return "HIGHEST";
258 case VK_Mips_GOT_HI16: return "GOT_HI16";
259 case VK_Mips_GOT_LO16: return "GOT_LO16";
260 case VK_Mips_CALL_HI16: return "CALL_HI16";
261 case VK_Mips_CALL_LO16: return "CALL_LO16";
262 case VK_COFF_IMGREL32: return "IMGREL32";
264 llvm_unreachable("Invalid variant kind");
267 MCSymbolRefExpr::VariantKind
268 MCSymbolRefExpr::getVariantKindForName(StringRef Name) {
269 return StringSwitch<VariantKind>(Name)
272 .Case("GOTOFF", VK_GOTOFF)
273 .Case("gotoff", VK_GOTOFF)
274 .Case("GOTPCREL", VK_GOTPCREL)
275 .Case("gotpcrel", VK_GOTPCREL)
276 .Case("GOTTPOFF", VK_GOTTPOFF)
277 .Case("gottpoff", VK_GOTTPOFF)
278 .Case("INDNTPOFF", VK_INDNTPOFF)
279 .Case("indntpoff", VK_INDNTPOFF)
280 .Case("NTPOFF", VK_NTPOFF)
281 .Case("ntpoff", VK_NTPOFF)
282 .Case("GOTNTPOFF", VK_GOTNTPOFF)
283 .Case("gotntpoff", VK_GOTNTPOFF)
286 .Case("TLSGD", VK_TLSGD)
287 .Case("tlsgd", VK_TLSGD)
288 .Case("TLSLD", VK_TLSLD)
289 .Case("tlsld", VK_TLSLD)
290 .Case("TLSLDM", VK_TLSLDM)
291 .Case("tlsldm", VK_TLSLDM)
292 .Case("TPOFF", VK_TPOFF)
293 .Case("tpoff", VK_TPOFF)
294 .Case("DTPOFF", VK_DTPOFF)
295 .Case("dtpoff", VK_DTPOFF)
296 .Case("TLVP", VK_TLVP)
297 .Case("tlvp", VK_TLVP)
298 .Case("IMGREL", VK_COFF_IMGREL32)
299 .Case("imgrel", VK_COFF_IMGREL32)
300 .Case("SECREL32", VK_SECREL)
301 .Case("secrel32", VK_SECREL)
302 .Case("L", VK_PPC_LO)
303 .Case("l", VK_PPC_LO)
304 .Case("H", VK_PPC_HI)
305 .Case("h", VK_PPC_HI)
306 .Case("HA", VK_PPC_HA)
307 .Case("ha", VK_PPC_HA)
308 .Case("HIGHER", VK_PPC_HIGHER)
309 .Case("higher", VK_PPC_HIGHER)
310 .Case("HIGHERA", VK_PPC_HIGHERA)
311 .Case("highera", VK_PPC_HIGHERA)
312 .Case("HIGHEST", VK_PPC_HIGHEST)
313 .Case("highest", VK_PPC_HIGHEST)
314 .Case("HIGHESTA", VK_PPC_HIGHESTA)
315 .Case("highesta", VK_PPC_HIGHESTA)
316 .Case("GOT@L", VK_PPC_GOT_LO)
317 .Case("got@l", VK_PPC_GOT_LO)
318 .Case("GOT@H", VK_PPC_GOT_HI)
319 .Case("got@h", VK_PPC_GOT_HI)
320 .Case("GOT@HA", VK_PPC_GOT_HA)
321 .Case("got@ha", VK_PPC_GOT_HA)
322 .Case("TOCBASE", VK_PPC_TOCBASE)
323 .Case("tocbase", VK_PPC_TOCBASE)
324 .Case("TOC", VK_PPC_TOC)
325 .Case("toc", VK_PPC_TOC)
326 .Case("TOC@L", VK_PPC_TOC_LO)
327 .Case("toc@l", VK_PPC_TOC_LO)
328 .Case("TOC@H", VK_PPC_TOC_HI)
329 .Case("toc@h", VK_PPC_TOC_HI)
330 .Case("TOC@HA", VK_PPC_TOC_HA)
331 .Case("toc@ha", VK_PPC_TOC_HA)
332 .Case("TLS", VK_PPC_TLS)
333 .Case("tls", VK_PPC_TLS)
334 .Case("DTPMOD", VK_PPC_DTPMOD)
335 .Case("dtpmod", VK_PPC_DTPMOD)
336 .Case("TPREL", VK_PPC_TPREL)
337 .Case("tprel", VK_PPC_TPREL)
338 .Case("TPREL@L", VK_PPC_TPREL_LO)
339 .Case("tprel@l", VK_PPC_TPREL_LO)
340 .Case("TPREL@H", VK_PPC_TPREL_HI)
341 .Case("tprel@h", VK_PPC_TPREL_HI)
342 .Case("TPREL@HA", VK_PPC_TPREL_HA)
343 .Case("tprel@ha", VK_PPC_TPREL_HA)
344 .Case("TPREL@HIGHER", VK_PPC_TPREL_HIGHER)
345 .Case("tprel@higher", VK_PPC_TPREL_HIGHER)
346 .Case("TPREL@HIGHERA", VK_PPC_TPREL_HIGHERA)
347 .Case("tprel@highera", VK_PPC_TPREL_HIGHERA)
348 .Case("TPREL@HIGHEST", VK_PPC_TPREL_HIGHEST)
349 .Case("tprel@highest", VK_PPC_TPREL_HIGHEST)
350 .Case("TPREL@HIGHESTA", VK_PPC_TPREL_HIGHESTA)
351 .Case("tprel@highesta", VK_PPC_TPREL_HIGHESTA)
352 .Case("DTPREL", VK_PPC_DTPREL)
353 .Case("dtprel", VK_PPC_DTPREL)
354 .Case("DTPREL@L", VK_PPC_DTPREL_LO)
355 .Case("dtprel@l", VK_PPC_DTPREL_LO)
356 .Case("DTPREL@H", VK_PPC_DTPREL_HI)
357 .Case("dtprel@h", VK_PPC_DTPREL_HI)
358 .Case("DTPREL@HA", VK_PPC_DTPREL_HA)
359 .Case("dtprel@ha", VK_PPC_DTPREL_HA)
360 .Case("DTPREL@HIGHER", VK_PPC_DTPREL_HIGHER)
361 .Case("dtprel@higher", VK_PPC_DTPREL_HIGHER)
362 .Case("DTPREL@HIGHERA", VK_PPC_DTPREL_HIGHERA)
363 .Case("dtprel@highera", VK_PPC_DTPREL_HIGHERA)
364 .Case("DTPREL@HIGHEST", VK_PPC_DTPREL_HIGHEST)
365 .Case("dtprel@highest", VK_PPC_DTPREL_HIGHEST)
366 .Case("DTPREL@HIGHESTA", VK_PPC_DTPREL_HIGHESTA)
367 .Case("dtprel@highesta", VK_PPC_DTPREL_HIGHESTA)
368 .Case("GOT@TPREL", VK_PPC_GOT_TPREL)
369 .Case("got@tprel", VK_PPC_GOT_TPREL)
370 .Case("GOT@TPREL@L", VK_PPC_GOT_TPREL_LO)
371 .Case("got@tprel@l", VK_PPC_GOT_TPREL_LO)
372 .Case("GOT@TPREL@H", VK_PPC_GOT_TPREL_HI)
373 .Case("got@tprel@h", VK_PPC_GOT_TPREL_HI)
374 .Case("GOT@TPREL@HA", VK_PPC_GOT_TPREL_HA)
375 .Case("got@tprel@ha", VK_PPC_GOT_TPREL_HA)
376 .Case("GOT@DTPREL", VK_PPC_GOT_DTPREL)
377 .Case("got@dtprel", VK_PPC_GOT_DTPREL)
378 .Case("GOT@DTPREL@L", VK_PPC_GOT_DTPREL_LO)
379 .Case("got@dtprel@l", VK_PPC_GOT_DTPREL_LO)
380 .Case("GOT@DTPREL@H", VK_PPC_GOT_DTPREL_HI)
381 .Case("got@dtprel@h", VK_PPC_GOT_DTPREL_HI)
382 .Case("GOT@DTPREL@HA", VK_PPC_GOT_DTPREL_HA)
383 .Case("got@dtprel@ha", VK_PPC_GOT_DTPREL_HA)
384 .Case("GOT@TLSGD", VK_PPC_GOT_TLSGD)
385 .Case("got@tlsgd", VK_PPC_GOT_TLSGD)
386 .Case("GOT@TLSGD@L", VK_PPC_GOT_TLSGD_LO)
387 .Case("got@tlsgd@l", VK_PPC_GOT_TLSGD_LO)
388 .Case("GOT@TLSGD@H", VK_PPC_GOT_TLSGD_HI)
389 .Case("got@tlsgd@h", VK_PPC_GOT_TLSGD_HI)
390 .Case("GOT@TLSGD@HA", VK_PPC_GOT_TLSGD_HA)
391 .Case("got@tlsgd@ha", VK_PPC_GOT_TLSGD_HA)
392 .Case("GOT@TLSLD", VK_PPC_GOT_TLSLD)
393 .Case("got@tlsld", VK_PPC_GOT_TLSLD)
394 .Case("GOT@TLSLD@L", VK_PPC_GOT_TLSLD_LO)
395 .Case("got@tlsld@l", VK_PPC_GOT_TLSLD_LO)
396 .Case("GOT@TLSLD@H", VK_PPC_GOT_TLSLD_HI)
397 .Case("got@tlsld@h", VK_PPC_GOT_TLSLD_HI)
398 .Case("GOT@TLSLD@HA", VK_PPC_GOT_TLSLD_HA)
399 .Case("got@tlsld@ha", VK_PPC_GOT_TLSLD_HA)
400 .Case("NONE", VK_ARM_NONE)
401 .Case("none", VK_ARM_NONE)
402 .Case("TARGET1", VK_ARM_TARGET1)
403 .Case("target1", VK_ARM_TARGET1)
404 .Case("TARGET2", VK_ARM_TARGET2)
405 .Case("target2", VK_ARM_TARGET2)
406 .Case("PREL31", VK_ARM_PREL31)
407 .Case("prel31", VK_ARM_PREL31)
408 .Default(VK_Invalid);
413 void MCTargetExpr::anchor() {}
417 bool MCExpr::EvaluateAsAbsolute(int64_t &Res) const {
418 return EvaluateAsAbsolute(Res, 0, 0, 0);
421 bool MCExpr::EvaluateAsAbsolute(int64_t &Res,
422 const MCAsmLayout &Layout) const {
423 return EvaluateAsAbsolute(Res, &Layout.getAssembler(), &Layout, 0);
426 bool MCExpr::EvaluateAsAbsolute(int64_t &Res,
427 const MCAsmLayout &Layout,
428 const SectionAddrMap &Addrs) const {
429 return EvaluateAsAbsolute(Res, &Layout.getAssembler(), &Layout, &Addrs);
432 bool MCExpr::EvaluateAsAbsolute(int64_t &Res, const MCAssembler &Asm) const {
433 return EvaluateAsAbsolute(Res, &Asm, 0, 0);
436 bool MCExpr::EvaluateAsAbsolute(int64_t &Res, const MCAssembler *Asm,
437 const MCAsmLayout *Layout,
438 const SectionAddrMap *Addrs) const {
441 // Fast path constants.
442 if (const MCConstantExpr *CE = dyn_cast<MCConstantExpr>(this)) {
443 Res = CE->getValue();
447 // FIXME: The use if InSet = Addrs is a hack. Setting InSet causes us
448 // absolutize differences across sections and that is what the MachO writer
451 EvaluateAsRelocatableImpl(Value, Asm, Layout, Addrs, /*InSet*/ Addrs);
453 // Record the current value.
454 Res = Value.getConstant();
456 return IsRelocatable && Value.isAbsolute();
459 /// \brief Helper method for \see EvaluateSymbolAdd().
460 static void AttemptToFoldSymbolOffsetDifference(const MCAssembler *Asm,
461 const MCAsmLayout *Layout,
462 const SectionAddrMap *Addrs,
464 const MCSymbolRefExpr *&A,
465 const MCSymbolRefExpr *&B,
470 const MCSymbol &SA = A->getSymbol();
471 const MCSymbol &SB = B->getSymbol();
473 if (SA.isUndefined() || SB.isUndefined())
476 if (!Asm->getWriter().IsSymbolRefDifferenceFullyResolved(*Asm, A, B, InSet))
479 MCSymbolData &AD = Asm->getSymbolData(SA);
480 MCSymbolData &BD = Asm->getSymbolData(SB);
482 if (AD.getFragment() == BD.getFragment()) {
483 Addend += (AD.getOffset() - BD.getOffset());
485 // Pointers to Thumb symbols need to have their low-bit set to allow
487 if (Asm->isThumbFunc(&SA))
490 // Clear the symbol expr pointers to indicate we have folded these
499 const MCSectionData &SecA = *AD.getFragment()->getParent();
500 const MCSectionData &SecB = *BD.getFragment()->getParent();
502 if ((&SecA != &SecB) && !Addrs)
506 Addend += (Layout->getSymbolOffset(&Asm->getSymbolData(A->getSymbol())) -
507 Layout->getSymbolOffset(&Asm->getSymbolData(B->getSymbol())));
508 if (Addrs && (&SecA != &SecB))
509 Addend += (Addrs->lookup(&SecA) - Addrs->lookup(&SecB));
511 // Pointers to Thumb symbols need to have their low-bit set to allow
513 if (Asm->isThumbFunc(&SA))
516 // Clear the symbol expr pointers to indicate we have folded these
521 /// \brief Evaluate the result of an add between (conceptually) two MCValues.
523 /// This routine conceptually attempts to construct an MCValue:
524 /// Result = (Result_A - Result_B + Result_Cst)
525 /// from two MCValue's LHS and RHS where
526 /// Result = LHS + RHS
528 /// Result = (LHS_A - LHS_B + LHS_Cst) + (RHS_A - RHS_B + RHS_Cst).
530 /// This routine attempts to aggresively fold the operands such that the result
531 /// is representable in an MCValue, but may not always succeed.
533 /// \returns True on success, false if the result is not representable in an
536 /// NOTE: It is really important to have both the Asm and Layout arguments.
537 /// They might look redundant, but this function can be used before layout
538 /// is done (see the object streamer for example) and having the Asm argument
539 /// lets us avoid relaxations early.
540 static bool EvaluateSymbolicAdd(const MCAssembler *Asm,
541 const MCAsmLayout *Layout,
542 const SectionAddrMap *Addrs,
544 const MCValue &LHS,const MCSymbolRefExpr *RHS_A,
545 const MCSymbolRefExpr *RHS_B, int64_t RHS_Cst,
547 // FIXME: This routine (and other evaluation parts) are *incredibly* sloppy
548 // about dealing with modifiers. This will ultimately bite us, one day.
549 const MCSymbolRefExpr *LHS_A = LHS.getSymA();
550 const MCSymbolRefExpr *LHS_B = LHS.getSymB();
551 int64_t LHS_Cst = LHS.getConstant();
553 // Fold the result constant immediately.
554 int64_t Result_Cst = LHS_Cst + RHS_Cst;
556 assert((!Layout || Asm) &&
557 "Must have an assembler object if layout is given!");
559 // If we have a layout, we can fold resolved differences.
561 // First, fold out any differences which are fully resolved. By
562 // reassociating terms in
563 // Result = (LHS_A - LHS_B + LHS_Cst) + (RHS_A - RHS_B + RHS_Cst).
564 // we have the four possible differences:
569 // Since we are attempting to be as aggressive as possible about folding, we
570 // attempt to evaluate each possible alternative.
571 AttemptToFoldSymbolOffsetDifference(Asm, Layout, Addrs, InSet, LHS_A, LHS_B,
573 AttemptToFoldSymbolOffsetDifference(Asm, Layout, Addrs, InSet, LHS_A, RHS_B,
575 AttemptToFoldSymbolOffsetDifference(Asm, Layout, Addrs, InSet, RHS_A, LHS_B,
577 AttemptToFoldSymbolOffsetDifference(Asm, Layout, Addrs, InSet, RHS_A, RHS_B,
581 // We can't represent the addition or subtraction of two symbols.
582 if ((LHS_A && RHS_A) || (LHS_B && RHS_B))
585 // At this point, we have at most one additive symbol and one subtractive
586 // symbol -- find them.
587 const MCSymbolRefExpr *A = LHS_A ? LHS_A : RHS_A;
588 const MCSymbolRefExpr *B = LHS_B ? LHS_B : RHS_B;
590 // If we have a negated symbol, then we must have also have a non-negated
591 // symbol in order to encode the expression.
595 Res = MCValue::get(A, B, Result_Cst);
599 bool MCExpr::EvaluateAsRelocatable(MCValue &Res,
600 const MCAsmLayout &Layout) const {
601 return EvaluateAsRelocatableImpl(Res, &Layout.getAssembler(), &Layout,
605 bool MCExpr::EvaluateAsRelocatableImpl(MCValue &Res,
606 const MCAssembler *Asm,
607 const MCAsmLayout *Layout,
608 const SectionAddrMap *Addrs,
610 ++stats::MCExprEvaluate;
614 return cast<MCTargetExpr>(this)->EvaluateAsRelocatableImpl(Res, Layout);
617 Res = MCValue::get(cast<MCConstantExpr>(this)->getValue());
621 const MCSymbolRefExpr *SRE = cast<MCSymbolRefExpr>(this);
622 const MCSymbol &Sym = SRE->getSymbol();
624 // Evaluate recursively if this is a variable.
625 if (Sym.isVariable() && SRE->getKind() == MCSymbolRefExpr::VK_None) {
626 bool Ret = Sym.getVariableValue()->EvaluateAsRelocatableImpl(Res, Asm,
630 // If we failed to simplify this to a constant, let the target
632 if (Ret && !Res.getSymA() && !Res.getSymB())
636 Res = MCValue::get(SRE, 0, 0);
641 const MCUnaryExpr *AUE = cast<MCUnaryExpr>(this);
644 if (!AUE->getSubExpr()->EvaluateAsRelocatableImpl(Value, Asm, Layout,
648 switch (AUE->getOpcode()) {
649 case MCUnaryExpr::LNot:
650 if (!Value.isAbsolute())
652 Res = MCValue::get(!Value.getConstant());
654 case MCUnaryExpr::Minus:
655 /// -(a - b + const) ==> (b - a - const)
656 if (Value.getSymA() && !Value.getSymB())
658 Res = MCValue::get(Value.getSymB(), Value.getSymA(),
659 -Value.getConstant());
661 case MCUnaryExpr::Not:
662 if (!Value.isAbsolute())
664 Res = MCValue::get(~Value.getConstant());
666 case MCUnaryExpr::Plus:
675 const MCBinaryExpr *ABE = cast<MCBinaryExpr>(this);
676 MCValue LHSValue, RHSValue;
678 if (!ABE->getLHS()->EvaluateAsRelocatableImpl(LHSValue, Asm, Layout,
680 !ABE->getRHS()->EvaluateAsRelocatableImpl(RHSValue, Asm, Layout,
684 // We only support a few operations on non-constant expressions, handle
686 if (!LHSValue.isAbsolute() || !RHSValue.isAbsolute()) {
687 switch (ABE->getOpcode()) {
690 case MCBinaryExpr::Sub:
691 // Negate RHS and add.
692 return EvaluateSymbolicAdd(Asm, Layout, Addrs, InSet, LHSValue,
693 RHSValue.getSymB(), RHSValue.getSymA(),
694 -RHSValue.getConstant(),
697 case MCBinaryExpr::Add:
698 return EvaluateSymbolicAdd(Asm, Layout, Addrs, InSet, LHSValue,
699 RHSValue.getSymA(), RHSValue.getSymB(),
700 RHSValue.getConstant(),
705 // FIXME: We need target hooks for the evaluation. It may be limited in
706 // width, and gas defines the result of comparisons and right shifts
707 // differently from Apple as.
708 int64_t LHS = LHSValue.getConstant(), RHS = RHSValue.getConstant();
710 switch (ABE->getOpcode()) {
711 case MCBinaryExpr::Add: Result = LHS + RHS; break;
712 case MCBinaryExpr::And: Result = LHS & RHS; break;
713 case MCBinaryExpr::Div: Result = LHS / RHS; break;
714 case MCBinaryExpr::EQ: Result = LHS == RHS; break;
715 case MCBinaryExpr::GT: Result = LHS > RHS; break;
716 case MCBinaryExpr::GTE: Result = LHS >= RHS; break;
717 case MCBinaryExpr::LAnd: Result = LHS && RHS; break;
718 case MCBinaryExpr::LOr: Result = LHS || RHS; break;
719 case MCBinaryExpr::LT: Result = LHS < RHS; break;
720 case MCBinaryExpr::LTE: Result = LHS <= RHS; break;
721 case MCBinaryExpr::Mod: Result = LHS % RHS; break;
722 case MCBinaryExpr::Mul: Result = LHS * RHS; break;
723 case MCBinaryExpr::NE: Result = LHS != RHS; break;
724 case MCBinaryExpr::Or: Result = LHS | RHS; break;
725 case MCBinaryExpr::Shl: Result = LHS << RHS; break;
726 case MCBinaryExpr::Shr: Result = LHS >> RHS; break;
727 case MCBinaryExpr::Sub: Result = LHS - RHS; break;
728 case MCBinaryExpr::Xor: Result = LHS ^ RHS; break;
731 Res = MCValue::get(Result);
736 llvm_unreachable("Invalid assembly expression kind!");
739 const MCSection *MCExpr::FindAssociatedSection() const {
742 // We never look through target specific expressions.
743 return cast<MCTargetExpr>(this)->FindAssociatedSection();
746 return MCSymbol::AbsolutePseudoSection;
749 const MCSymbolRefExpr *SRE = cast<MCSymbolRefExpr>(this);
750 const MCSymbol &Sym = SRE->getSymbol();
753 return &Sym.getSection();
759 return cast<MCUnaryExpr>(this)->getSubExpr()->FindAssociatedSection();
762 const MCBinaryExpr *BE = cast<MCBinaryExpr>(this);
763 const MCSection *LHS_S = BE->getLHS()->FindAssociatedSection();
764 const MCSection *RHS_S = BE->getRHS()->FindAssociatedSection();
766 // If either section is absolute, return the other.
767 if (LHS_S == MCSymbol::AbsolutePseudoSection)
769 if (RHS_S == MCSymbol::AbsolutePseudoSection)
772 // Otherwise, return the first non-null section.
773 return LHS_S ? LHS_S : RHS_S;
777 llvm_unreachable("Invalid assembly expression kind!");