Line data Source code
1 : //===- lib/MC/MCAssembler.cpp - Assembler Backend Implementation ----------===//
2 : //
3 : // The LLVM Compiler Infrastructure
4 : //
5 : // This file is distributed under the University of Illinois Open Source
6 : // License. See LICENSE.TXT for details.
7 : //
8 : //===----------------------------------------------------------------------===//
9 :
10 : #include "llvm/MC/MCAssembler.h"
11 : #include "llvm/ADT/ArrayRef.h"
12 : #include "llvm/ADT/SmallString.h"
13 : #include "llvm/ADT/SmallVector.h"
14 : #include "llvm/ADT/Statistic.h"
15 : #include "llvm/ADT/StringRef.h"
16 : #include "llvm/ADT/Twine.h"
17 : #include "llvm/MC/MCAsmBackend.h"
18 : #include "llvm/MC/MCAsmInfo.h"
19 : #include "llvm/MC/MCAsmLayout.h"
20 : #include "llvm/MC/MCCodeEmitter.h"
21 : #include "llvm/MC/MCCodeView.h"
22 : #include "llvm/MC/MCContext.h"
23 : #include "llvm/MC/MCDwarf.h"
24 : #include "llvm/MC/MCExpr.h"
25 : #include "llvm/MC/MCFixup.h"
26 : #include "llvm/MC/MCFixupKindInfo.h"
27 : #include "llvm/MC/MCFragment.h"
28 : #include "llvm/MC/MCInst.h"
29 : #include "llvm/MC/MCObjectWriter.h"
30 : #include "llvm/MC/MCSection.h"
31 : #include "llvm/MC/MCSectionELF.h"
32 : #include "llvm/MC/MCSymbol.h"
33 : #include "llvm/MC/MCValue.h"
34 : #include "llvm/Support/Casting.h"
35 : #include "llvm/Support/Debug.h"
36 : #include "llvm/Support/ErrorHandling.h"
37 : #include "llvm/Support/LEB128.h"
38 : #include "llvm/Support/MathExtras.h"
39 : #include "llvm/Support/raw_ostream.h"
40 : #include <cassert>
41 : #include <cstdint>
42 : #include <cstring>
43 : #include <tuple>
44 : #include <utility>
45 :
46 : using namespace llvm;
47 :
48 : #define DEBUG_TYPE "assembler"
49 :
50 : namespace {
51 : namespace stats {
52 :
53 : STATISTIC(EmittedFragments, "Number of emitted assembler fragments - total");
54 : STATISTIC(EmittedRelaxableFragments,
55 : "Number of emitted assembler fragments - relaxable");
56 : STATISTIC(EmittedDataFragments,
57 : "Number of emitted assembler fragments - data");
58 : STATISTIC(EmittedCompactEncodedInstFragments,
59 : "Number of emitted assembler fragments - compact encoded inst");
60 : STATISTIC(EmittedAlignFragments,
61 : "Number of emitted assembler fragments - align");
62 : STATISTIC(EmittedFillFragments,
63 : "Number of emitted assembler fragments - fill");
64 : STATISTIC(EmittedOrgFragments,
65 : "Number of emitted assembler fragments - org");
66 : STATISTIC(evaluateFixup, "Number of evaluated fixups");
67 : STATISTIC(FragmentLayouts, "Number of fragment layouts");
68 : STATISTIC(ObjectBytes, "Number of emitted object file bytes");
69 : STATISTIC(RelaxationSteps, "Number of assembler layout and relaxation steps");
70 : STATISTIC(RelaxedInstructions, "Number of relaxed instructions");
71 : STATISTIC(PaddingFragmentsRelaxations,
72 : "Number of Padding Fragments relaxations");
73 : STATISTIC(PaddingFragmentsBytes,
74 : "Total size of all padding from adding Fragments");
75 :
76 : } // end namespace stats
77 : } // end anonymous namespace
78 :
79 : // FIXME FIXME FIXME: There are number of places in this file where we convert
80 : // what is a 64-bit assembler value used for computation into a value in the
81 : // object file, which may truncate it. We should detect that truncation where
82 : // invalid and report errors back.
83 :
84 : /* *** */
85 :
86 35527 : MCAssembler::MCAssembler(MCContext &Context,
87 : std::unique_ptr<MCAsmBackend> Backend,
88 : std::unique_ptr<MCCodeEmitter> Emitter,
89 35527 : std::unique_ptr<MCObjectWriter> Writer)
90 : : Context(Context), Backend(std::move(Backend)),
91 : Emitter(std::move(Emitter)), Writer(std::move(Writer)),
92 : BundleAlignSize(0), RelaxAll(false), SubsectionsViaSymbols(false),
93 71054 : IncrementalLinkerCompatible(false), ELFHeaderEFlags(0) {
94 35527 : VersionInfo.Major = 0; // Major version == 0 for "none specified"
95 35527 : }
96 :
97 : MCAssembler::~MCAssembler() = default;
98 :
99 8140 : void MCAssembler::reset() {
100 : Sections.clear();
101 : Symbols.clear();
102 : IndirectSymbols.clear();
103 : DataRegions.clear();
104 : LinkerOptions.clear();
105 : FileNames.clear();
106 8140 : ThumbFuncs.clear();
107 8140 : BundleAlignSize = 0;
108 8140 : RelaxAll = false;
109 8140 : SubsectionsViaSymbols = false;
110 8140 : IncrementalLinkerCompatible = false;
111 8140 : ELFHeaderEFlags = 0;
112 : LOHContainer.reset();
113 8140 : VersionInfo.Major = 0;
114 :
115 : // reset objects owned by us
116 8140 : if (getBackendPtr())
117 8140 : getBackendPtr()->reset();
118 8140 : if (getEmitterPtr())
119 8140 : getEmitterPtr()->reset();
120 8139 : if (getWriterPtr())
121 8139 : getWriterPtr()->reset();
122 : getLOHContainer().reset();
123 8140 : }
124 :
125 806226 : bool MCAssembler::registerSection(MCSection &Section) {
126 806226 : if (Section.isRegistered())
127 : return false;
128 701494 : Sections.push_back(&Section);
129 : Section.setIsRegistered(true);
130 701494 : return true;
131 : }
132 :
133 10178650 : bool MCAssembler::isThumbFunc(const MCSymbol *Symbol) const {
134 10178650 : if (ThumbFuncs.count(Symbol))
135 : return true;
136 :
137 10177992 : if (!Symbol->isVariable())
138 : return false;
139 :
140 : const MCExpr *Expr = Symbol->getVariableValue();
141 :
142 920 : MCValue V;
143 920 : if (!Expr->evaluateAsRelocatable(V, nullptr, nullptr))
144 : return false;
145 :
146 919 : if (V.getSymB() || V.getRefKind() != MCSymbolRefExpr::VK_None)
147 : return false;
148 :
149 905 : const MCSymbolRefExpr *Ref = V.getSymA();
150 905 : if (!Ref)
151 : return false;
152 :
153 702 : if (Ref->getKind() != MCSymbolRefExpr::VK_None)
154 : return false;
155 :
156 702 : const MCSymbol &Sym = Ref->getSymbol();
157 702 : if (!isThumbFunc(&Sym))
158 : return false;
159 :
160 4 : ThumbFuncs.insert(Symbol); // Cache it.
161 4 : return true;
162 : }
163 :
164 84169 : bool MCAssembler::isSymbolLinkerVisible(const MCSymbol &Symbol) const {
165 : // Non-temporary labels should always be visible to the linker.
166 84169 : if (!Symbol.isTemporary())
167 : return true;
168 :
169 : // Absolute temporary labels are never visible.
170 75696 : if (!Symbol.isInSection())
171 : return false;
172 :
173 47088 : if (Symbol.isUsedInReloc())
174 66 : return true;
175 :
176 : return false;
177 : }
178 :
179 1842 : const MCSymbol *MCAssembler::getAtom(const MCSymbol &S) const {
180 : // Linker visible symbols define atoms.
181 1842 : if (isSymbolLinkerVisible(S))
182 : return &S;
183 :
184 : // Absolute and undefined symbols have no defining atom.
185 1132 : if (!S.isInSection())
186 : return nullptr;
187 :
188 : // Non-linker visible symbols in sections which can't be atomized have no
189 : // defining atom.
190 871 : if (!getContext().getAsmInfo()->isSectionAtomizableBySymbols(
191 871 : *S.getFragment()->getParent()))
192 : return nullptr;
193 :
194 : // Otherwise, return the atom for the containing fragment.
195 821 : return S.getFragment()->getAtom();
196 : }
197 :
198 8234432 : bool MCAssembler::evaluateFixup(const MCAsmLayout &Layout,
199 : const MCFixup &Fixup, const MCFragment *DF,
200 : MCValue &Target, uint64_t &Value,
201 : bool &WasForced) const {
202 : ++stats::evaluateFixup;
203 :
204 : // FIXME: This code has some duplication with recordRelocation. We should
205 : // probably merge the two into a single callback that tries to evaluate a
206 : // fixup and records a relocation if one is needed.
207 :
208 : // On error claim to have completely evaluated the fixup, to prevent any
209 : // further processing from being done.
210 8234432 : const MCExpr *Expr = Fixup.getValue();
211 8234432 : MCContext &Ctx = getContext();
212 8234432 : Value = 0;
213 8234432 : WasForced = false;
214 8234432 : if (!Expr->evaluateAsRelocatable(Target, &Layout, &Fixup)) {
215 21 : Ctx.reportError(Fixup.getLoc(), "expected relocatable expression");
216 21 : return true;
217 : }
218 8234412 : if (const MCSymbolRefExpr *RefB = Target.getSymB()) {
219 213129 : if (RefB->getKind() != MCSymbolRefExpr::VK_None) {
220 6 : Ctx.reportError(Fixup.getLoc(),
221 : "unsupported subtraction of qualified symbol");
222 6 : return true;
223 : }
224 : }
225 :
226 : assert(getBackendPtr() && "Expected assembler backend");
227 8234406 : bool IsPCRel = getBackendPtr()->getFixupKindInfo(Fixup.getKind()).Flags &
228 : MCFixupKindInfo::FKF_IsPCRel;
229 :
230 : bool IsResolved = false;
231 8234406 : if (IsPCRel) {
232 4863042 : if (Target.getSymB()) {
233 : IsResolved = false;
234 4863035 : } else if (!Target.getSymA()) {
235 : IsResolved = false;
236 : } else {
237 : const MCSymbolRefExpr *A = Target.getSymA();
238 4863022 : const MCSymbol &SA = A->getSymbol();
239 9658433 : if (A->getKind() != MCSymbolRefExpr::VK_None || SA.isUndefined()) {
240 : IsResolved = false;
241 4063808 : } else if (auto *Writer = getWriterPtr()) {
242 4063808 : IsResolved = Writer->isSymbolRefDifferenceFullyResolvedImpl(
243 4063808 : *this, SA, *DF, false, true);
244 : }
245 : }
246 : } else {
247 3371364 : IsResolved = Target.isAbsolute();
248 : }
249 :
250 8234406 : Value = Target.getConstant();
251 :
252 8234406 : if (const MCSymbolRefExpr *A = Target.getSymA()) {
253 7555605 : const MCSymbol &Sym = A->getSymbol();
254 7555605 : if (Sym.isDefined())
255 6693829 : Value += Layout.getSymbolOffset(Sym);
256 : }
257 8234405 : if (const MCSymbolRefExpr *B = Target.getSymB()) {
258 426246 : const MCSymbol &Sym = B->getSymbol();
259 213123 : if (Sym.isDefined())
260 213096 : Value -= Layout.getSymbolOffset(Sym);
261 : }
262 :
263 8234405 : bool ShouldAlignPC = getBackend().getFixupKindInfo(Fixup.getKind()).Flags &
264 : MCFixupKindInfo::FKF_IsAlignedDownTo32Bits;
265 : assert((ShouldAlignPC ? IsPCRel : true) &&
266 : "FKF_IsAlignedDownTo32Bits is only allowed on PC-relative fixups!");
267 :
268 8234405 : if (IsPCRel) {
269 4863042 : uint32_t Offset = Layout.getFragmentOffset(DF) + Fixup.getOffset();
270 :
271 : // A number of ARM fixups in Thumb mode require that the effective PC
272 : // address be determined as the 32-bit aligned version of the actual offset.
273 4863042 : if (ShouldAlignPC) Offset &= ~0x3;
274 4863042 : Value -= Offset;
275 : }
276 :
277 : // Let the backend force a relocation if needed.
278 8234405 : if (IsResolved && getBackend().shouldForceRelocation(*this, Fixup, Target)) {
279 : IsResolved = false;
280 190 : WasForced = true;
281 : }
282 :
283 : return IsResolved;
284 : }
285 :
286 12793747 : uint64_t MCAssembler::computeFragmentSize(const MCAsmLayout &Layout,
287 : const MCFragment &F) const {
288 : assert(getBackendPtr() && "Requires assembler backend");
289 12793747 : switch (F.getKind()) {
290 : case MCFragment::FT_Data:
291 13751452 : return cast<MCDataFragment>(F).getContents().size();
292 : case MCFragment::FT_Relaxable:
293 766242 : return cast<MCRelaxableFragment>(F).getContents().size();
294 : case MCFragment::FT_CompactEncodedInst:
295 816 : return cast<MCCompactEncodedInstFragment>(F).getContents().size();
296 : case MCFragment::FT_Fill: {
297 : auto &FF = cast<MCFillFragment>(F);
298 552937 : int64_t NumValues = 0;
299 552937 : if (!FF.getNumValues().evaluateAsAbsolute(NumValues, Layout)) {
300 4 : getContext().reportError(FF.getLoc(),
301 : "expected assembly-time absolute expression");
302 2 : return 0;
303 : }
304 552935 : int64_t Size = NumValues * FF.getValueSize();
305 552935 : if (Size < 0) {
306 8 : getContext().reportError(FF.getLoc(), "invalid number of bytes");
307 4 : return 0;
308 : }
309 552931 : return Size;
310 : }
311 :
312 : case MCFragment::FT_LEB:
313 1091606 : return cast<MCLEBFragment>(F).getContents().size();
314 :
315 : case MCFragment::FT_Padding:
316 0 : return cast<MCPaddingFragment>(F).getSize();
317 :
318 : case MCFragment::FT_SymbolId:
319 : return 4;
320 :
321 : case MCFragment::FT_Align: {
322 : const MCAlignFragment &AF = cast<MCAlignFragment>(F);
323 1313694 : unsigned Offset = Layout.getFragmentOffset(&AF);
324 1313695 : unsigned Size = OffsetToAlignment(Offset, AF.getAlignment());
325 : // If we are padding with nops, force the padding to be larger than the
326 : // minimum nop size.
327 1313695 : if (Size > 0 && AF.hasEmitNops()) {
328 42228 : while (Size % getBackend().getMinimumNopSize())
329 0 : Size += AF.getAlignment();
330 : }
331 1313695 : if (Size > AF.getMaxBytesToEmit())
332 : return 0;
333 1313686 : return Size;
334 : }
335 :
336 : case MCFragment::FT_Org: {
337 : const MCOrgFragment &OF = cast<MCOrgFragment>(F);
338 40 : MCValue Value;
339 40 : if (!OF.getOffset().evaluateAsValue(Value, Layout)) {
340 4 : getContext().reportError(OF.getLoc(),
341 : "expected assembly-time absolute expression");
342 2 : return 0;
343 : }
344 :
345 38 : uint64_t FragmentOffset = Layout.getFragmentOffset(&OF);
346 38 : int64_t TargetLocation = Value.getConstant();
347 38 : if (const MCSymbolRefExpr *A = Value.getSymA()) {
348 : uint64_t Val;
349 15 : if (!Layout.getSymbolOffset(A->getSymbol(), Val)) {
350 8 : getContext().reportError(OF.getLoc(), "expected absolute expression");
351 4 : return 0;
352 : }
353 11 : TargetLocation += Val;
354 : }
355 34 : int64_t Size = TargetLocation - FragmentOffset;
356 34 : if (Size < 0 || Size >= 0x40000000) {
357 8 : getContext().reportError(
358 4 : OF.getLoc(), "invalid .org offset '" + Twine(TargetLocation) +
359 8 : "' (at offset '" + Twine(FragmentOffset) + "')");
360 4 : return 0;
361 : }
362 : return Size;
363 : }
364 :
365 : case MCFragment::FT_Dwarf:
366 2482444 : return cast<MCDwarfLineAddrFragment>(F).getContents().size();
367 : case MCFragment::FT_DwarfFrame:
368 3760596 : return cast<MCDwarfCallFrameFragment>(F).getContents().size();
369 : case MCFragment::FT_CVInlineLines:
370 96 : return cast<MCCVInlineLineTableFragment>(F).getContents().size();
371 : case MCFragment::FT_CVDefRange:
372 820 : return cast<MCCVDefRangeFragment>(F).getContents().size();
373 : case MCFragment::FT_Dummy:
374 : llvm_unreachable("Should not have been added");
375 : }
376 :
377 0 : llvm_unreachable("invalid fragment kind");
378 : }
379 :
380 6802158 : void MCAsmLayout::layoutFragment(MCFragment *F) {
381 : MCFragment *Prev = F->getPrevNode();
382 :
383 : // We should never try to recompute something which is valid.
384 : assert(!isFragmentValid(F) && "Attempt to recompute a valid fragment!");
385 : // We should never try to compute the fragment layout if its predecessor
386 : // isn't valid.
387 : assert((!Prev || isFragmentValid(Prev)) &&
388 : "Attempt to compute fragment before its predecessor!");
389 :
390 : ++stats::FragmentLayouts;
391 :
392 : // Compute fragment offset and size.
393 6100804 : if (Prev)
394 6100804 : F->Offset = Prev->Offset + getAssembler().computeFragmentSize(*this, *Prev);
395 : else
396 701354 : F->Offset = 0;
397 6802159 : LastValidFragment[F->getParent()] = F;
398 :
399 : // If bundling is enabled and this fragment has instructions in it, it has to
400 : // obey the bundling restrictions. With padding, we'll have:
401 : //
402 : //
403 : // BundlePadding
404 : // |||
405 : // -------------------------------------
406 : // Prev |##########| F |
407 : // -------------------------------------
408 : // ^
409 : // |
410 : // F->Offset
411 : //
412 : // The fragment's offset will point to after the padding, and its computed
413 : // size won't include the padding.
414 : //
415 : // When the -mc-relax-all flag is used, we optimize bundling by writting the
416 : // padding directly into fragments when the instructions are emitted inside
417 : // the streamer. When the fragment is larger than the bundle size, we need to
418 : // ensure that it's bundle aligned. This means that if we end up with
419 : // multiple fragments, we must emit bundle padding between fragments.
420 : //
421 : // ".align N" is an example of a directive that introduces multiple
422 : // fragments. We could add a special case to handle ".align N" by emitting
423 : // within-fragment padding (which would produce less padding when N is less
424 : // than the bundle size), but for now we don't.
425 : //
426 6802160 : if (Assembler.isBundlingEnabled() && F->hasInstructions()) {
427 : assert(isa<MCEncodedFragment>(F) &&
428 : "Only MCEncodedFragment implementations have instructions");
429 : MCEncodedFragment *EF = cast<MCEncodedFragment>(F);
430 758 : uint64_t FSize = Assembler.computeFragmentSize(*this, *EF);
431 :
432 1516 : if (!Assembler.getRelaxAll() && FSize > Assembler.getBundleAlignSize())
433 1 : report_fatal_error("Fragment can't be larger than a bundle size");
434 :
435 : uint64_t RequiredBundlePadding =
436 757 : computeBundlePadding(Assembler, EF, EF->Offset, FSize);
437 757 : if (RequiredBundlePadding > UINT8_MAX)
438 0 : report_fatal_error("Padding cannot exceed 255 bytes");
439 757 : EF->setBundlePadding(static_cast<uint8_t>(RequiredBundlePadding));
440 757 : EF->Offset += RequiredBundlePadding;
441 : }
442 6802159 : }
443 :
444 18793845 : void MCAssembler::registerSymbol(const MCSymbol &Symbol, bool *Created) {
445 18793845 : bool New = !Symbol.isRegistered();
446 18793845 : if (Created)
447 53 : *Created = New;
448 18793845 : if (New) {
449 : Symbol.setIsRegistered(true);
450 8576279 : Symbols.push_back(&Symbol);
451 : }
452 18793845 : }
453 :
454 3967216 : void MCAssembler::writeFragmentPadding(raw_ostream &OS,
455 : const MCEncodedFragment &EF,
456 : uint64_t FSize) const {
457 : assert(getBackendPtr() && "Expected assembler backend");
458 : // Should NOP padding be written out before this fragment?
459 3967216 : unsigned BundlePadding = EF.getBundlePadding();
460 3967216 : if (BundlePadding > 0) {
461 : assert(isBundlingEnabled() &&
462 : "Writing bundle padding with disabled bundling");
463 : assert(EF.hasInstructions() &&
464 : "Writing bundle padding for a fragment without instructions");
465 :
466 431 : unsigned TotalLength = BundlePadding + static_cast<unsigned>(FSize);
467 431 : if (EF.alignToBundleEnd() && TotalLength > getBundleAlignSize()) {
468 : // If the padding itself crosses a bundle boundary, it must be emitted
469 : // in 2 pieces, since even nop instructions must not cross boundaries.
470 : // v--------------v <- BundleAlignSize
471 : // v---------v <- BundlePadding
472 : // ----------------------------
473 : // | Prev |####|####| F |
474 : // ----------------------------
475 : // ^-------------------^ <- TotalLength
476 128 : unsigned DistanceToBoundary = TotalLength - getBundleAlignSize();
477 128 : if (!getBackend().writeNopData(OS, DistanceToBoundary))
478 0 : report_fatal_error("unable to write NOP sequence of " +
479 : Twine(DistanceToBoundary) + " bytes");
480 128 : BundlePadding -= DistanceToBoundary;
481 : }
482 431 : if (!getBackend().writeNopData(OS, BundlePadding))
483 0 : report_fatal_error("unable to write NOP sequence of " +
484 : Twine(BundlePadding) + " bytes");
485 : }
486 3967216 : }
487 :
488 : /// Write the fragment \p F to the output file.
489 5929842 : static void writeFragment(raw_ostream &OS, const MCAssembler &Asm,
490 : const MCAsmLayout &Layout, const MCFragment &F) {
491 : // FIXME: Embed in fragments instead?
492 5929842 : uint64_t FragmentSize = Asm.computeFragmentSize(Layout, F);
493 :
494 5929842 : support::endianness Endian = Asm.getBackend().Endian;
495 :
496 : if (const MCEncodedFragment *EF = dyn_cast<MCEncodedFragment>(&F))
497 3967193 : Asm.writeFragmentPadding(OS, *EF, FragmentSize);
498 :
499 : // This variable (and its dummy usage) is to participate in the assert at
500 : // the end of the function.
501 : uint64_t Start = OS.tell();
502 : (void) Start;
503 :
504 : ++stats::EmittedFragments;
505 :
506 5929842 : switch (F.getKind()) {
507 : case MCFragment::FT_Align: {
508 : ++stats::EmittedAlignFragments;
509 : const MCAlignFragment &AF = cast<MCAlignFragment>(F);
510 : assert(AF.getValueSize() && "Invalid virtual align in concrete fragment!");
511 :
512 609498 : uint64_t Count = FragmentSize / AF.getValueSize();
513 :
514 : // FIXME: This error shouldn't actually occur (the front end should emit
515 : // multiple .align directives to enforce the semantics it wants), but is
516 : // severe enough that we want to report it. How to handle this?
517 609498 : if (Count * AF.getValueSize() != FragmentSize)
518 0 : report_fatal_error("undefined .align directive, value size '" +
519 : Twine(AF.getValueSize()) +
520 : "' is not a divisor of padding size '" +
521 : Twine(FragmentSize) + "'");
522 :
523 : // See if we are aligning with nops, and if so do that first to try to fill
524 : // the Count bytes. Then if that did not fill any bytes or there are any
525 : // bytes left to fill use the Value and ValueSize to fill the rest.
526 : // If we are aligning with nops, ask that target to emit the right data.
527 609498 : if (AF.hasEmitNops()) {
528 232632 : if (!Asm.getBackend().writeNopData(OS, Count))
529 0 : report_fatal_error("unable to write nop sequence of " +
530 : Twine(Count) + " bytes");
531 : break;
532 : }
533 :
534 : // Otherwise, write out in multiples of the value size.
535 1048461 : for (uint64_t i = 0; i != Count; ++i) {
536 671595 : switch (AF.getValueSize()) {
537 0 : default: llvm_unreachable("Invalid size!");
538 671592 : case 1: OS << char(AF.getValue()); break;
539 3 : case 2:
540 3 : support::endian::write<uint16_t>(OS, AF.getValue(), Endian);
541 3 : break;
542 0 : case 4:
543 0 : support::endian::write<uint32_t>(OS, AF.getValue(), Endian);
544 0 : break;
545 0 : case 8:
546 0 : support::endian::write<uint64_t>(OS, AF.getValue(), Endian);
547 0 : break;
548 : }
549 : }
550 : break;
551 : }
552 :
553 : case MCFragment::FT_Data:
554 : ++stats::EmittedDataFragments;
555 : OS << cast<MCDataFragment>(F).getContents();
556 : break;
557 :
558 : case MCFragment::FT_Relaxable:
559 : ++stats::EmittedRelaxableFragments;
560 : OS << cast<MCRelaxableFragment>(F).getContents();
561 : break;
562 :
563 : case MCFragment::FT_CompactEncodedInst:
564 : ++stats::EmittedCompactEncodedInstFragments;
565 : OS << cast<MCCompactEncodedInstFragment>(F).getContents();
566 : break;
567 :
568 : case MCFragment::FT_Fill: {
569 : ++stats::EmittedFillFragments;
570 : const MCFillFragment &FF = cast<MCFillFragment>(F);
571 248790 : uint64_t V = FF.getValue();
572 248790 : unsigned VSize = FF.getValueSize();
573 : const unsigned MaxChunkSize = 16;
574 : char Data[MaxChunkSize];
575 : // Duplicate V into Data as byte vector to reduce number of
576 : // writes done. As such, do endian conversion here.
577 497587 : for (unsigned I = 0; I != VSize; ++I) {
578 248797 : unsigned index = Endian == support::little ? I : (VSize - I - 1);
579 248797 : Data[I] = uint8_t(V >> (index * 8));
580 : }
581 3980633 : for (unsigned I = VSize; I < MaxChunkSize; ++I)
582 3731843 : Data[I] = Data[I - VSize];
583 :
584 : // Set to largest multiple of VSize in Data.
585 248790 : const unsigned NumPerChunk = MaxChunkSize / VSize;
586 : // Set ChunkSize to largest multiple of VSize in Data
587 248790 : const unsigned ChunkSize = VSize * NumPerChunk;
588 :
589 : // Do copies by chunk.
590 248790 : StringRef Ref(Data, ChunkSize);
591 110267186 : for (uint64_t I = 0, E = FragmentSize / ChunkSize; I != E; ++I)
592 110018396 : OS << Ref;
593 :
594 : // do remainder if needed.
595 248790 : unsigned TrailingCount = FragmentSize % ChunkSize;
596 248790 : if (TrailingCount)
597 68047 : OS.write(Data, TrailingCount);
598 : break;
599 : }
600 :
601 : case MCFragment::FT_LEB: {
602 : const MCLEBFragment &LF = cast<MCLEBFragment>(F);
603 : OS << LF.getContents();
604 : break;
605 : }
606 :
607 : case MCFragment::FT_Padding: {
608 0 : if (!Asm.getBackend().writeNopData(OS, FragmentSize))
609 0 : report_fatal_error("unable to write nop sequence of " +
610 : Twine(FragmentSize) + " bytes");
611 : break;
612 : }
613 :
614 : case MCFragment::FT_SymbolId: {
615 : const MCSymbolIdFragment &SF = cast<MCSymbolIdFragment>(F);
616 15 : support::endian::write<uint32_t>(OS, SF.getSymbol()->getIndex(), Endian);
617 15 : break;
618 : }
619 :
620 : case MCFragment::FT_Org: {
621 : ++stats::EmittedOrgFragments;
622 : const MCOrgFragment &OF = cast<MCOrgFragment>(F);
623 :
624 2482 : for (uint64_t i = 0, e = FragmentSize; i != e; ++i)
625 2463 : OS << char(OF.getValue());
626 :
627 : break;
628 : }
629 :
630 : case MCFragment::FT_Dwarf: {
631 : const MCDwarfLineAddrFragment &OF = cast<MCDwarfLineAddrFragment>(F);
632 : OS << OF.getContents();
633 : break;
634 : }
635 : case MCFragment::FT_DwarfFrame: {
636 : const MCDwarfCallFrameFragment &CF = cast<MCDwarfCallFrameFragment>(F);
637 : OS << CF.getContents();
638 : break;
639 : }
640 : case MCFragment::FT_CVInlineLines: {
641 : const auto &OF = cast<MCCVInlineLineTableFragment>(F);
642 : OS << OF.getContents();
643 : break;
644 : }
645 : case MCFragment::FT_CVDefRange: {
646 : const auto &DRF = cast<MCCVDefRangeFragment>(F);
647 : OS << DRF.getContents();
648 : break;
649 : }
650 : case MCFragment::FT_Dummy:
651 : llvm_unreachable("Should not have been added");
652 : }
653 :
654 : assert(OS.tell() - Start == FragmentSize &&
655 : "The stream should advance by fragment size");
656 5929842 : }
657 :
658 700632 : void MCAssembler::writeSectionData(raw_ostream &OS, const MCSection *Sec,
659 : const MCAsmLayout &Layout) const {
660 : assert(getBackendPtr() && "Expected assembler backend");
661 :
662 : // Ignore virtual sections.
663 700632 : if (Sec->isVirtualSection()) {
664 : assert(Layout.getSectionFileSize(Sec) == 0 && "Invalid size for section!");
665 :
666 : // Check that contents are only things legal inside a virtual section.
667 160841 : for (const MCFragment &F : *Sec) {
668 130932 : switch (F.getKind()) {
669 0 : default: llvm_unreachable("Invalid fragment in virtual section!");
670 : case MCFragment::FT_Data: {
671 : // Check that we aren't trying to write a non-zero contents (or fixups)
672 : // into a virtual section. This is to support clients which use standard
673 : // directives to fill the contents of virtual sections.
674 : const MCDataFragment &DF = cast<MCDataFragment>(F);
675 65886 : if (DF.fixup_begin() != DF.fixup_end())
676 1 : report_fatal_error("cannot have fixups in virtual section!");
677 106791 : for (unsigned i = 0, e = DF.getContents().size(); i != e; ++i)
678 81814 : if (DF.getContents()[i]) {
679 : if (auto *ELFSec = dyn_cast<const MCSectionELF>(Sec))
680 1 : report_fatal_error("non-zero initializer found in section '" +
681 1 : ELFSec->getSectionName() + "'");
682 : else
683 0 : report_fatal_error("non-zero initializer found in virtual section");
684 : }
685 : break;
686 : }
687 : case MCFragment::FT_Align:
688 : // Check that we aren't trying to write a non-zero value into a virtual
689 : // section.
690 : assert((cast<MCAlignFragment>(F).getValueSize() == 0 ||
691 : cast<MCAlignFragment>(F).getValue() == 0) &&
692 : "Invalid align in virtual section!");
693 : break;
694 : case MCFragment::FT_Fill:
695 : assert((cast<MCFillFragment>(F).getValue() == 0) &&
696 : "Invalid fill in virtual section!");
697 : break;
698 : }
699 : }
700 :
701 : return;
702 : }
703 :
704 : uint64_t Start = OS.tell();
705 : (void)Start;
706 :
707 6600563 : for (const MCFragment &F : *Sec)
708 5929842 : writeFragment(OS, *this, Layout, F);
709 :
710 : assert(OS.tell() - Start == Layout.getSectionAddressSize(Sec));
711 : }
712 :
713 : std::tuple<MCValue, uint64_t, bool>
714 7861353 : MCAssembler::handleFixup(const MCAsmLayout &Layout, MCFragment &F,
715 : const MCFixup &Fixup) {
716 : // Evaluate the fixup.
717 7861353 : MCValue Target;
718 : uint64_t FixedValue;
719 : bool WasForced;
720 7861353 : bool IsResolved = evaluateFixup(Layout, Fixup, &F, Target, FixedValue,
721 : WasForced);
722 7861353 : if (!IsResolved) {
723 : // The fixup was unresolved, we need a relocation. Inform the object
724 : // writer of the relocation, and give it an opportunity to adjust the
725 : // fixup value if need be.
726 5288256 : if (Target.getSymA() && Target.getSymB() &&
727 213120 : getBackend().requiresDiffExpressionRelocations()) {
728 : // The fixup represents the difference between two symbols, which the
729 : // backend has indicated must be resolved at link time. Split up the fixup
730 : // into two relocations, one for the add, and one for the sub, and emit
731 : // both of these. The constant will be associated with the add half of the
732 : // expression.
733 : MCFixup FixupAdd = MCFixup::createAddFor(Fixup);
734 : MCValue TargetAdd =
735 0 : MCValue::get(Target.getSymA(), nullptr, Target.getConstant());
736 0 : getWriter().recordRelocation(*this, Layout, &F, FixupAdd, TargetAdd,
737 0 : FixedValue);
738 : MCFixup FixupSub = MCFixup::createSubFor(Fixup);
739 0 : MCValue TargetSub = MCValue::get(Target.getSymB());
740 0 : getWriter().recordRelocation(*this, Layout, &F, FixupSub, TargetSub,
741 0 : FixedValue);
742 : } else {
743 5075136 : getWriter().recordRelocation(*this, Layout, &F, Fixup, Target,
744 5075136 : FixedValue);
745 : }
746 : }
747 15722690 : return std::make_tuple(Target, FixedValue, IsResolved);
748 : }
749 :
750 12410 : void MCAssembler::layout(MCAsmLayout &Layout) {
751 : assert(getBackendPtr() && "Expected assembler backend");
752 : DEBUG_WITH_TYPE("mc-dump", {
753 : errs() << "assembler backend - pre-layout\n--\n";
754 : dump(); });
755 :
756 : // Create dummy fragments and assign section ordinals.
757 : unsigned SectionIndex = 0;
758 713739 : for (MCSection &Sec : *this) {
759 : // Create dummy fragments to eliminate any empty sections, this simplifies
760 : // layout.
761 701328 : if (Sec.getFragmentList().empty())
762 198 : new MCDataFragment(&Sec);
763 :
764 701329 : Sec.setOrdinal(SectionIndex++);
765 : }
766 :
767 : // Assign layout order indices to sections and fragments.
768 713732 : for (unsigned i = 0, e = Layout.getSectionOrder().size(); i != e; ++i) {
769 1402642 : MCSection *Sec = Layout.getSectionOrder()[i];
770 : Sec->setLayoutOrder(i);
771 :
772 : unsigned FragmentIndex = 0;
773 6763080 : for (MCFragment &Frag : *Sec)
774 6061759 : Frag.setLayoutOrder(FragmentIndex++);
775 : }
776 :
777 : // Layout until everything fits.
778 19011 : while (layoutOnce(Layout))
779 6600 : if (getContext().hadError())
780 : return;
781 :
782 : DEBUG_WITH_TYPE("mc-dump", {
783 : errs() << "assembler backend - post-relaxation\n--\n";
784 : dump(); });
785 :
786 : // Finalize the layout, including fragment lowering.
787 12410 : finishLayout(Layout);
788 :
789 : DEBUG_WITH_TYPE("mc-dump", {
790 : errs() << "assembler backend - final-layout\n--\n";
791 : dump(); });
792 :
793 : // Allow the object writer a chance to perform post-layout binding (for
794 : // example, to set the index fields in the symbol data).
795 12409 : getWriter().executePostLayoutBinding(*this, Layout);
796 :
797 : // Evaluate and apply the fixups, generating relocation entries as necessary.
798 713731 : for (MCSection &Sec : *this) {
799 6763073 : for (MCFragment &Frag : Sec) {
800 : // Data and relaxable fragments both have fixups. So only process
801 : // those here.
802 : // FIXME: Is there a better way to do this? MCEncodedFragmentWithFixups
803 : // being templated makes this tricky.
804 4033448 : if (isa<MCEncodedFragment>(&Frag) &&
805 : isa<MCCompactEncodedInstFragment>(&Frag))
806 2028229 : continue;
807 2028299 : if (!isa<MCEncodedFragment>(&Frag) && !isa<MCCVDefRangeFragment>(&Frag))
808 : continue;
809 : ArrayRef<MCFixup> Fixups;
810 4033518 : MutableArrayRef<char> Contents;
811 : const MCSubtargetInfo *STI = nullptr;
812 : if (auto *FragWithFixups = dyn_cast<MCDataFragment>(&Frag)) {
813 : Fixups = FragWithFixups->getFixups();
814 3284653 : Contents = FragWithFixups->getContents();
815 3284653 : STI = FragWithFixups->getSubtargetInfo();
816 : assert(!FragWithFixups->hasInstructions() || STI != nullptr);
817 : } else if (auto *FragWithFixups = dyn_cast<MCRelaxableFragment>(&Frag)) {
818 : Fixups = FragWithFixups->getFixups();
819 128049 : Contents = FragWithFixups->getContents();
820 128049 : STI = FragWithFixups->getSubtargetInfo();
821 : assert(!FragWithFixups->hasInstructions() || STI != nullptr);
822 : } else if (auto *FragWithFixups = dyn_cast<MCCVDefRangeFragment>(&Frag)) {
823 : Fixups = FragWithFixups->getFixups();
824 205 : Contents = FragWithFixups->getContents();
825 : } else if (auto *FragWithFixups = dyn_cast<MCDwarfLineAddrFragment>(&Frag)) {
826 : Fixups = FragWithFixups->getFixups();
827 620611 : Contents = FragWithFixups->getContents();
828 : } else
829 0 : llvm_unreachable("Unknown fragment with fixups!");
830 11894862 : for (const MCFixup &Fixup : Fixups) {
831 : uint64_t FixedValue;
832 : bool IsResolved;
833 7861353 : MCValue Target;
834 : std::tie(Target, FixedValue, IsResolved) =
835 7861353 : handleFixup(Layout, Frag, Fixup);
836 7861345 : getBackend().applyFixup(*this, Fixup, Target, Contents, FixedValue,
837 7861345 : IsResolved, STI);
838 : }
839 : }
840 : }
841 : }
842 :
843 12357 : void MCAssembler::Finish() {
844 : // Create the layout object.
845 24696 : MCAsmLayout Layout(*this);
846 12357 : layout(Layout);
847 :
848 : // Write the object file.
849 12342 : stats::ObjectBytes += getWriter().writeObject(*this, Layout);
850 12339 : }
851 :
852 373079 : bool MCAssembler::fixupNeedsRelaxation(const MCFixup &Fixup,
853 : const MCRelaxableFragment *DF,
854 : const MCAsmLayout &Layout) const {
855 : assert(getBackendPtr() && "Expected assembler backend");
856 373079 : MCValue Target;
857 : uint64_t Value;
858 : bool WasForced;
859 373079 : bool Resolved = evaluateFixup(Layout, Fixup, DF, Target, Value, WasForced);
860 746154 : if (Target.getSymA() &&
861 373079 : Target.getSymA()->getKind() == MCSymbolRefExpr::VK_X86_ABS8 &&
862 8 : Fixup.getKind() == FK_Data_1)
863 : return false;
864 373071 : return getBackend().fixupNeedsRelaxationAdvanced(Fixup, Resolved, Value, DF,
865 373071 : Layout, WasForced);
866 : }
867 :
868 500400 : bool MCAssembler::fragmentNeedsRelaxation(const MCRelaxableFragment *F,
869 : const MCAsmLayout &Layout) const {
870 : assert(getBackendPtr() && "Expected assembler backend");
871 : // If this inst doesn't ever need relaxation, ignore it. This occurs when we
872 : // are intentionally pushing out inst fragments, or because we relaxed a
873 : // previous instruction to one that doesn't need relaxation.
874 1000800 : if (!getBackend().mayNeedRelaxation(F->getInst(), *F->getSubtargetInfo()))
875 : return false;
876 :
877 707704 : for (const MCFixup &Fixup : F->getFixups())
878 373079 : if (fixupNeedsRelaxation(Fixup, F, Layout))
879 : return true;
880 :
881 : return false;
882 : }
883 :
884 500400 : bool MCAssembler::relaxInstruction(MCAsmLayout &Layout,
885 : MCRelaxableFragment &F) {
886 : assert(getEmitterPtr() &&
887 : "Expected CodeEmitter defined for relaxInstruction");
888 500400 : if (!fragmentNeedsRelaxation(&F, Layout))
889 : return false;
890 :
891 : ++stats::RelaxedInstructions;
892 :
893 : // FIXME-PERF: We could immediately lower out instructions if we can tell
894 : // they are fully resolved, to avoid retesting on later passes.
895 :
896 : // Relax the fragment.
897 :
898 : MCInst Relaxed;
899 81680 : getBackend().relaxInstruction(F.getInst(), *F.getSubtargetInfo(), Relaxed);
900 :
901 : // Encode the new instruction.
902 : //
903 : // FIXME-PERF: If it matters, we could let the target do this. It can
904 : // probably do so more efficiently in many cases.
905 : SmallVector<MCFixup, 4> Fixups;
906 : SmallString<256> Code;
907 : raw_svector_ostream VecOS(Code);
908 40840 : getEmitter().encodeInstruction(Relaxed, VecOS, Fixups, *F.getSubtargetInfo());
909 :
910 : // Update the fragment.
911 : F.setInst(Relaxed);
912 40840 : F.getContents() = Code;
913 40840 : F.getFixups() = Fixups;
914 :
915 : return true;
916 : }
917 :
918 0 : bool MCAssembler::relaxPaddingFragment(MCAsmLayout &Layout,
919 : MCPaddingFragment &PF) {
920 : assert(getBackendPtr() && "Expected assembler backend");
921 : uint64_t OldSize = PF.getSize();
922 0 : if (!getBackend().relaxFragment(&PF, Layout))
923 0 : return false;
924 : uint64_t NewSize = PF.getSize();
925 :
926 : ++stats::PaddingFragmentsRelaxations;
927 : stats::PaddingFragmentsBytes += NewSize;
928 : stats::PaddingFragmentsBytes -= OldSize;
929 : return true;
930 : }
931 :
932 676796 : bool MCAssembler::relaxLEB(MCAsmLayout &Layout, MCLEBFragment &LF) {
933 676796 : uint64_t OldSize = LF.getContents().size();
934 : int64_t Value;
935 676796 : bool Abs = LF.getValue().evaluateKnownAbsolute(Value, Layout);
936 676796 : if (!Abs)
937 1 : report_fatal_error("sleb128 and uleb128 expressions must be absolute");
938 : SmallString<8> &Data = LF.getContents();
939 : Data.clear();
940 676795 : raw_svector_ostream OSE(Data);
941 : // The compiler can generate EH table assembly that is impossible to assemble
942 : // without either adding padding to an LEB fragment or adding extra padding
943 : // to a later alignment fragment. To accommodate such tables, relaxation can
944 : // only increase an LEB fragment size here, not decrease it. See PR35809.
945 676795 : if (LF.isSigned())
946 3 : encodeSLEB128(Value, OSE, OldSize);
947 : else
948 676792 : encodeULEB128(Value, OSE, OldSize);
949 676795 : return OldSize != LF.getContents().size();
950 : }
951 :
952 2381365 : bool MCAssembler::relaxDwarfLineAddr(MCAsmLayout &Layout,
953 : MCDwarfLineAddrFragment &DF) {
954 2381365 : MCContext &Context = Layout.getAssembler().getContext();
955 2381365 : uint64_t OldSize = DF.getContents().size();
956 : int64_t AddrDelta;
957 : bool Abs;
958 2381365 : if (getBackend().requiresDiffExpressionRelocations())
959 0 : Abs = DF.getAddrDelta().evaluateAsAbsolute(AddrDelta, Layout);
960 : else {
961 2381365 : Abs = DF.getAddrDelta().evaluateKnownAbsolute(AddrDelta, Layout);
962 : assert(Abs && "We created a line delta with an invalid expression");
963 : }
964 : int64_t LineDelta;
965 2381365 : LineDelta = DF.getLineDelta();
966 : SmallVectorImpl<char> &Data = DF.getContents();
967 : Data.clear();
968 : raw_svector_ostream OSE(Data);
969 : DF.getFixups().clear();
970 :
971 2381365 : if (Abs) {
972 4762730 : MCDwarfLineAddr::Encode(Context, getDWARFLinetableParams(), LineDelta,
973 : AddrDelta, OSE);
974 : } else {
975 : uint32_t Offset;
976 : uint32_t Size;
977 0 : bool SetDelta = MCDwarfLineAddr::FixedEncode(Context,
978 : getDWARFLinetableParams(),
979 : LineDelta, AddrDelta,
980 : OSE, &Offset, &Size);
981 : // Add Fixups for address delta or new address.
982 : const MCExpr *FixupExpr;
983 0 : if (SetDelta) {
984 0 : FixupExpr = &DF.getAddrDelta();
985 : } else {
986 0 : const MCBinaryExpr *ABE = cast<MCBinaryExpr>(&DF.getAddrDelta());
987 0 : FixupExpr = ABE->getLHS();
988 : }
989 0 : DF.getFixups().push_back(
990 0 : MCFixup::create(Offset, FixupExpr,
991 0 : MCFixup::getKindForSize(Size, false /*isPCRel*/)));
992 : }
993 :
994 2381365 : return OldSize != Data.size();
995 : }
996 :
997 2908800 : bool MCAssembler::relaxDwarfCallFrameFragment(MCAsmLayout &Layout,
998 : MCDwarfCallFrameFragment &DF) {
999 2908800 : MCContext &Context = Layout.getAssembler().getContext();
1000 2908800 : uint64_t OldSize = DF.getContents().size();
1001 : int64_t AddrDelta;
1002 2908800 : bool Abs = DF.getAddrDelta().evaluateKnownAbsolute(AddrDelta, Layout);
1003 : assert(Abs && "We created call frame with an invalid expression");
1004 : (void) Abs;
1005 : SmallString<8> &Data = DF.getContents();
1006 : Data.clear();
1007 2908800 : raw_svector_ostream OSE(Data);
1008 2908800 : MCDwarfFrameEmitter::EncodeAdvanceLoc(Context, AddrDelta, OSE);
1009 2908800 : return OldSize != Data.size();
1010 : }
1011 :
1012 72 : bool MCAssembler::relaxCVInlineLineTable(MCAsmLayout &Layout,
1013 : MCCVInlineLineTableFragment &F) {
1014 72 : unsigned OldSize = F.getContents().size();
1015 72 : getContext().getCVContext().encodeInlineLineTable(Layout, F);
1016 72 : return OldSize != F.getContents().size();
1017 : }
1018 :
1019 615 : bool MCAssembler::relaxCVDefRange(MCAsmLayout &Layout,
1020 : MCCVDefRangeFragment &F) {
1021 615 : unsigned OldSize = F.getContents().size();
1022 615 : getContext().getCVContext().encodeDefRange(Layout, F);
1023 615 : return OldSize != F.getContents().size();
1024 : }
1025 :
1026 1031051 : bool MCAssembler::layoutSectionOnce(MCAsmLayout &Layout, MCSection &Sec) {
1027 : // Holds the first fragment which needed relaxing during this layout. It will
1028 : // remain NULL if none were relaxed.
1029 : // When a fragment is relaxed, all the fragments following it should get
1030 : // invalidated because their offset is going to change.
1031 : MCFragment *FirstRelaxedFragment = nullptr;
1032 :
1033 : // Attempt to relax all the fragments in the section.
1034 19096801 : for (MCSection::iterator I = Sec.begin(), IE = Sec.end(); I != IE; ++I) {
1035 : // Check if this is a fragment that needs relaxation.
1036 : bool RelaxedFrag = false;
1037 18065751 : switch(I->getKind()) {
1038 : default:
1039 : break;
1040 : case MCFragment::FT_Relaxable:
1041 : assert(!getRelaxAll() &&
1042 : "Did not expect a MCRelaxableFragment in RelaxAll mode");
1043 500400 : RelaxedFrag = relaxInstruction(Layout, *cast<MCRelaxableFragment>(I));
1044 500400 : break;
1045 : case MCFragment::FT_Dwarf:
1046 2381365 : RelaxedFrag = relaxDwarfLineAddr(Layout,
1047 : *cast<MCDwarfLineAddrFragment>(I));
1048 2381365 : break;
1049 : case MCFragment::FT_DwarfFrame:
1050 : RelaxedFrag =
1051 2908800 : relaxDwarfCallFrameFragment(Layout,
1052 : *cast<MCDwarfCallFrameFragment>(I));
1053 2908800 : break;
1054 : case MCFragment::FT_LEB:
1055 676796 : RelaxedFrag = relaxLEB(Layout, *cast<MCLEBFragment>(I));
1056 676795 : break;
1057 : case MCFragment::FT_Padding:
1058 0 : RelaxedFrag = relaxPaddingFragment(Layout, *cast<MCPaddingFragment>(I));
1059 0 : break;
1060 : case MCFragment::FT_CVInlineLines:
1061 : RelaxedFrag =
1062 72 : relaxCVInlineLineTable(Layout, *cast<MCCVInlineLineTableFragment>(I));
1063 72 : break;
1064 : case MCFragment::FT_CVDefRange:
1065 615 : RelaxedFrag = relaxCVDefRange(Layout, *cast<MCCVDefRangeFragment>(I));
1066 615 : break;
1067 : }
1068 18065750 : if (RelaxedFrag && !FirstRelaxedFragment)
1069 : FirstRelaxedFragment = &*I;
1070 : }
1071 1031050 : if (FirstRelaxedFragment) {
1072 12257 : Layout.invalidateFragmentsFrom(FirstRelaxedFragment);
1073 12257 : return true;
1074 : }
1075 : return false;
1076 : }
1077 :
1078 19011 : bool MCAssembler::layoutOnce(MCAsmLayout &Layout) {
1079 : ++stats::RelaxationSteps;
1080 :
1081 : bool WasRelaxed = false;
1082 1037795 : for (iterator it = begin(), ie = end(); it != ie; ++it) {
1083 : MCSection &Sec = *it;
1084 1031042 : while (layoutSectionOnce(Layout, Sec))
1085 : WasRelaxed = true;
1086 : }
1087 :
1088 19010 : return WasRelaxed;
1089 : }
1090 :
1091 12410 : void MCAssembler::finishLayout(MCAsmLayout &Layout) {
1092 : assert(getBackendPtr() && "Expected assembler backend");
1093 : // The layout is done. Mark every fragment as valid.
1094 713737 : for (unsigned int i = 0, n = Layout.getSectionOrder().size(); i != n; ++i) {
1095 1402656 : MCSection &Section = *Layout.getSectionOrder()[i];
1096 701328 : Layout.getFragmentOffset(&*Section.rbegin());
1097 701327 : computeFragmentSize(Layout, *Section.rbegin());
1098 : }
1099 12409 : getBackend().finishLayout(*this, Layout);
1100 12409 : }
1101 :
1102 : #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
1103 : LLVM_DUMP_METHOD void MCAssembler::dump() const{
1104 : raw_ostream &OS = errs();
1105 :
1106 : OS << "<MCAssembler\n";
1107 : OS << " Sections:[\n ";
1108 : for (const_iterator it = begin(), ie = end(); it != ie; ++it) {
1109 : if (it != begin()) OS << ",\n ";
1110 : it->dump();
1111 : }
1112 : OS << "],\n";
1113 : OS << " Symbols:[";
1114 :
1115 : for (const_symbol_iterator it = symbol_begin(), ie = symbol_end(); it != ie; ++it) {
1116 : if (it != symbol_begin()) OS << ",\n ";
1117 : OS << "(";
1118 : it->dump();
1119 : OS << ", Index:" << it->getIndex() << ", ";
1120 : OS << ")";
1121 : }
1122 : OS << "]>\n";
1123 : }
1124 : #endif
|
