blob: 0bab34e4b21f4f1585f676c6c872474fb4991c8e [file] [log] [blame]
Daniel Dunbarfb4a6b32009-08-21 09:11:24 +00001//===- 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
Daniel Dunbar0adcd352009-08-25 21:10:45 +000010#define DEBUG_TYPE "assembler"
Daniel Dunbarfb4a6b32009-08-21 09:11:24 +000011#include "llvm/MC/MCAssembler.h"
Daniel Dunbar18ff2cc2010-03-11 05:53:33 +000012#include "llvm/MC/MCAsmLayout.h"
Daniel Dunbarb36052f2010-03-19 10:43:23 +000013#include "llvm/MC/MCCodeEmitter.h"
Daniel Dunbar1253a6f2009-10-16 01:58:03 +000014#include "llvm/MC/MCExpr.h"
Daniel Dunbar53b23382010-03-19 09:28:59 +000015#include "llvm/MC/MCObjectWriter.h"
Daniel Dunbar1253a6f2009-10-16 01:58:03 +000016#include "llvm/MC/MCSymbol.h"
17#include "llvm/MC/MCValue.h"
Daniel Dunbar1a9158c2010-03-19 10:43:26 +000018#include "llvm/ADT/OwningPtr.h"
Daniel Dunbar0adcd352009-08-25 21:10:45 +000019#include "llvm/ADT/Statistic.h"
Daniel Dunbarb7c3a4b2010-02-13 09:28:03 +000020#include "llvm/ADT/StringExtras.h"
Daniel Dunbard6f761e2009-08-21 23:07:38 +000021#include "llvm/ADT/Twine.h"
Daniel Dunbarac2884a2010-03-25 22:49:09 +000022#include "llvm/Support/Debug.h"
Daniel Dunbar0705fbf2009-08-21 18:29:01 +000023#include "llvm/Support/ErrorHandling.h"
Daniel Dunbarfb4a6b32009-08-21 09:11:24 +000024#include "llvm/Support/raw_ostream.h"
Daniel Dunbaree0d8922010-03-13 22:10:17 +000025#include "llvm/Target/TargetRegistry.h"
Daniel Dunbardf3c8f22010-03-12 21:00:49 +000026#include "llvm/Target/TargetAsmBackend.h"
Daniel Dunbarf6346762010-02-13 09:29:02 +000027
Chris Lattner23132b12009-08-24 03:52:50 +000028#include <vector>
Daniel Dunbarfb4a6b32009-08-21 09:11:24 +000029using namespace llvm;
30
Daniel Dunbarff547842010-03-23 23:47:14 +000031namespace {
32namespace stats {
Daniel Dunbar0adcd352009-08-25 21:10:45 +000033STATISTIC(EmittedFragments, "Number of emitted assembler fragments");
Daniel Dunbarff547842010-03-23 23:47:14 +000034STATISTIC(EvaluateFixup, "Number of evaluated fixups");
Daniel Dunbarac2884a2010-03-25 22:49:09 +000035STATISTIC(FragmentLayouts, "Number of fragment layouts");
Daniel Dunbarff547842010-03-23 23:47:14 +000036STATISTIC(ObjectBytes, "Number of emitted object file bytes");
Daniel Dunbarac2884a2010-03-25 22:49:09 +000037STATISTIC(RelaxationSteps, "Number of assembler layout and relaxation steps");
38STATISTIC(RelaxedInstructions, "Number of relaxed instructions");
39STATISTIC(SectionLayouts, "Number of section layouts");
Daniel Dunbarff547842010-03-23 23:47:14 +000040}
41}
Daniel Dunbar0adcd352009-08-25 21:10:45 +000042
Daniel Dunbar8f4d1462009-08-28 07:08:35 +000043// FIXME FIXME FIXME: There are number of places in this file where we convert
44// what is a 64-bit assembler value used for computation into a value in the
45// object file, which may truncate it. We should detect that truncation where
46// invalid and report errors back.
47
Daniel Dunbarfb4a6b32009-08-21 09:11:24 +000048/* *** */
49
Daniel Dunbarbc1a0cf2010-05-12 15:42:59 +000050MCAsmLayout::MCAsmLayout(MCAssembler &Asm) : Assembler(Asm) {
51 // Compute the section layout order. Virtual sections must go last.
52 for (MCAssembler::iterator it = Asm.begin(), ie = Asm.end(); it != ie; ++it)
53 if (!Asm.getBackend().isVirtualSection(it->getSection()))
54 SectionOrder.push_back(&*it);
55 for (MCAssembler::iterator it = Asm.begin(), ie = Asm.end(); it != ie; ++it)
56 if (Asm.getBackend().isVirtualSection(it->getSection()))
57 SectionOrder.push_back(&*it);
58}
59
Daniel Dunbar0cc8bd42010-03-25 19:35:56 +000060void MCAsmLayout::UpdateForSlide(MCFragment *F, int SlideAmount) {
61 // We shouldn't have to do anything special to support negative slides, and it
Daniel Dunbar651804c2010-05-11 17:22:50 +000062 // is a perfectly valid thing to do as long as other parts of the system can
63 // guarantee convergence.
Daniel Dunbar0cc8bd42010-03-25 19:35:56 +000064 assert(SlideAmount >= 0 && "Negative slides not yet supported");
65
66 // Update the layout by simply recomputing the layout for the entire
67 // file. This is trivially correct, but very slow.
68 //
69 // FIXME-PERF: This is O(N^2), but will be eliminated once we get smarter.
70
Daniel Dunbard13a0ca2010-05-12 17:56:47 +000071 // Layout the sections in order.
72 for (unsigned i = 0, e = getSectionOrder().size(); i != e; ++i)
73 getAssembler().LayoutSection(*this, i);
Daniel Dunbar0cc8bd42010-03-25 19:35:56 +000074}
75
Daniel Dunbar207e06e2010-03-24 03:43:40 +000076uint64_t MCAsmLayout::getFragmentAddress(const MCFragment *F) const {
Daniel Dunbar7c3d45a2010-03-25 01:03:24 +000077 assert(F->getParent() && "Missing section()!");
Daniel Dunbar432cd5f2010-03-25 02:00:02 +000078 return getSectionAddress(F->getParent()) + getFragmentOffset(F);
79}
80
81uint64_t MCAsmLayout::getFragmentEffectiveSize(const MCFragment *F) const {
82 assert(F->EffectiveSize != ~UINT64_C(0) && "Address not set!");
83 return F->EffectiveSize;
84}
85
86void MCAsmLayout::setFragmentEffectiveSize(MCFragment *F, uint64_t Value) {
87 F->EffectiveSize = Value;
88}
89
90uint64_t MCAsmLayout::getFragmentOffset(const MCFragment *F) const {
91 assert(F->Offset != ~UINT64_C(0) && "Address not set!");
92 return F->Offset;
93}
94
95void MCAsmLayout::setFragmentOffset(MCFragment *F, uint64_t Value) {
96 F->Offset = Value;
Daniel Dunbar207e06e2010-03-24 03:43:40 +000097}
98
99uint64_t MCAsmLayout::getSymbolAddress(const MCSymbolData *SD) const {
Daniel Dunbar7c3d45a2010-03-25 01:03:24 +0000100 assert(SD->getFragment() && "Invalid getAddress() on undefined symbol!");
101 return getFragmentAddress(SD->getFragment()) + SD->getOffset();
Daniel Dunbar207e06e2010-03-24 03:43:40 +0000102}
103
104uint64_t MCAsmLayout::getSectionAddress(const MCSectionData *SD) const {
Daniel Dunbar7c3d45a2010-03-25 01:03:24 +0000105 assert(SD->Address != ~UINT64_C(0) && "Address not set!");
106 return SD->Address;
Daniel Dunbar207e06e2010-03-24 03:43:40 +0000107}
108
109void MCAsmLayout::setSectionAddress(MCSectionData *SD, uint64_t Value) {
Daniel Dunbar7c3d45a2010-03-25 01:03:24 +0000110 SD->Address = Value;
Daniel Dunbar207e06e2010-03-24 03:43:40 +0000111}
112
Daniel Dunbar5d428512010-03-25 02:00:07 +0000113uint64_t MCAsmLayout::getSectionSize(const MCSectionData *SD) const {
114 assert(SD->Size != ~UINT64_C(0) && "File size not set!");
115 return SD->Size;
116}
117void MCAsmLayout::setSectionSize(MCSectionData *SD, uint64_t Value) {
118 SD->Size = Value;
119}
120
121uint64_t MCAsmLayout::getSectionFileSize(const MCSectionData *SD) const {
122 assert(SD->FileSize != ~UINT64_C(0) && "File size not set!");
123 return SD->FileSize;
124}
125void MCAsmLayout::setSectionFileSize(MCSectionData *SD, uint64_t Value) {
126 SD->FileSize = Value;
127}
128
Daniel Dunbar207e06e2010-03-24 03:43:40 +0000129/* *** */
130
Daniel Dunbar0705fbf2009-08-21 18:29:01 +0000131MCFragment::MCFragment() : Kind(FragmentType(~0)) {
132}
133
Daniel Dunbar5e835962009-08-26 02:48:04 +0000134MCFragment::MCFragment(FragmentType _Kind, MCSectionData *_Parent)
Daniel Dunbar071f73d2010-05-10 22:45:09 +0000135 : Kind(_Kind), Parent(_Parent), Atom(0), EffectiveSize(~UINT64_C(0))
Daniel Dunbarfb4a6b32009-08-21 09:11:24 +0000136{
Daniel Dunbar5e835962009-08-26 02:48:04 +0000137 if (Parent)
138 Parent->getFragmentList().push_back(this);
Daniel Dunbarfb4a6b32009-08-21 09:11:24 +0000139}
140
Daniel Dunbar0705fbf2009-08-21 18:29:01 +0000141MCFragment::~MCFragment() {
142}
143
Daniel Dunbarfb4a6b32009-08-21 09:11:24 +0000144/* *** */
145
Daniel Dunbar81e40002009-08-27 00:38:04 +0000146MCSectionData::MCSectionData() : Section(0) {}
Daniel Dunbarfb4a6b32009-08-21 09:11:24 +0000147
148MCSectionData::MCSectionData(const MCSection &_Section, MCAssembler *A)
Daniel Dunbar81e40002009-08-27 00:38:04 +0000149 : Section(&_Section),
Daniel Dunbarfb4a6b32009-08-21 09:11:24 +0000150 Alignment(1),
Daniel Dunbar5e835962009-08-26 02:48:04 +0000151 Address(~UINT64_C(0)),
Daniel Dunbar6742e342009-08-26 04:13:32 +0000152 Size(~UINT64_C(0)),
Daniel Dunbar3f6a9602009-08-26 13:58:10 +0000153 FileSize(~UINT64_C(0)),
Daniel Dunbare1ec6172010-02-02 21:44:01 +0000154 HasInstructions(false)
Daniel Dunbarfb4a6b32009-08-21 09:11:24 +0000155{
156 if (A)
157 A->getSectionList().push_back(this);
158}
159
Daniel Dunbarfb4a6b32009-08-21 09:11:24 +0000160/* *** */
161
Daniel Dunbarefbb5332009-09-01 04:09:03 +0000162MCSymbolData::MCSymbolData() : Symbol(0) {}
Daniel Dunbarf3d2ef02009-08-22 10:13:24 +0000163
Daniel Dunbarcb579b32009-08-31 08:08:06 +0000164MCSymbolData::MCSymbolData(const MCSymbol &_Symbol, MCFragment *_Fragment,
Daniel Dunbarf3d2ef02009-08-22 10:13:24 +0000165 uint64_t _Offset, MCAssembler *A)
Daniel Dunbarefbb5332009-09-01 04:09:03 +0000166 : Symbol(&_Symbol), Fragment(_Fragment), Offset(_Offset),
Daniel Dunbar8f4d1462009-08-28 07:08:35 +0000167 IsExternal(false), IsPrivateExtern(false),
168 CommonSize(0), CommonAlign(0), Flags(0), Index(0)
Daniel Dunbarf3d2ef02009-08-22 10:13:24 +0000169{
170 if (A)
171 A->getSymbolList().push_back(this);
172}
173
174/* *** */
175
Daniel Dunbar1f3e4452010-03-11 01:34:27 +0000176MCAssembler::MCAssembler(MCContext &_Context, TargetAsmBackend &_Backend,
Daniel Dunbarcf871e52010-03-19 10:43:18 +0000177 MCCodeEmitter &_Emitter, raw_ostream &_OS)
178 : Context(_Context), Backend(_Backend), Emitter(_Emitter),
Daniel Dunbarac2884a2010-03-25 22:49:09 +0000179 OS(_OS), RelaxAll(false), SubsectionsViaSymbols(false)
Daniel Dunbar6009db42009-08-26 21:22:22 +0000180{
181}
Daniel Dunbarfb4a6b32009-08-21 09:11:24 +0000182
183MCAssembler::~MCAssembler() {
184}
185
Daniel Dunbar939f8d72010-03-19 03:18:12 +0000186static bool isScatteredFixupFullyResolvedSimple(const MCAssembler &Asm,
187 const MCAsmFixup &Fixup,
Daniel Dunbar939f8d72010-03-19 03:18:12 +0000188 const MCValue Target,
189 const MCSection *BaseSection) {
190 // The effective fixup address is
191 // addr(atom(A)) + offset(A)
192 // - addr(atom(B)) - offset(B)
193 // - addr(<base symbol>) + <fixup offset from base symbol>
194 // and the offsets are not relocatable, so the fixup is fully resolved when
195 // addr(atom(A)) - addr(atom(B)) - addr(<base symbol>)) == 0.
196 //
197 // The simple (Darwin, except on x86_64) way of dealing with this was to
198 // assume that any reference to a temporary symbol *must* be a temporary
199 // symbol in the same atom, unless the sections differ. Therefore, any PCrel
200 // relocation to a temporary symbol (in the same section) is fully
201 // resolved. This also works in conjunction with absolutized .set, which
202 // requires the compiler to use .set to absolutize the differences between
203 // symbols which the compiler knows to be assembly time constants, so we don't
Daniel Dunbar31e8e1d2010-05-04 00:33:07 +0000204 // need to worry about considering symbol differences fully resolved.
Daniel Dunbar939f8d72010-03-19 03:18:12 +0000205
206 // Non-relative fixups are only resolved if constant.
207 if (!BaseSection)
208 return Target.isAbsolute();
209
210 // Otherwise, relative fixups are only resolved if not a difference and the
211 // target is a temporary in the same section.
212 if (Target.isAbsolute() || Target.getSymB())
213 return false;
214
215 const MCSymbol *A = &Target.getSymA()->getSymbol();
216 if (!A->isTemporary() || !A->isInSection() ||
217 &A->getSection() != BaseSection)
218 return false;
219
220 return true;
221}
222
Daniel Dunbar034843a2010-03-19 03:18:18 +0000223static bool isScatteredFixupFullyResolved(const MCAssembler &Asm,
Daniel Dunbar207e06e2010-03-24 03:43:40 +0000224 const MCAsmLayout &Layout,
Daniel Dunbar034843a2010-03-19 03:18:18 +0000225 const MCAsmFixup &Fixup,
Daniel Dunbar034843a2010-03-19 03:18:18 +0000226 const MCValue Target,
227 const MCSymbolData *BaseSymbol) {
228 // The effective fixup address is
229 // addr(atom(A)) + offset(A)
230 // - addr(atom(B)) - offset(B)
231 // - addr(BaseSymbol) + <fixup offset from base symbol>
232 // and the offsets are not relocatable, so the fixup is fully resolved when
233 // addr(atom(A)) - addr(atom(B)) - addr(BaseSymbol) == 0.
234 //
235 // Note that "false" is almost always conservatively correct (it means we emit
236 // a relocation which is unnecessary), except when it would force us to emit a
237 // relocation which the target cannot encode.
238
239 const MCSymbolData *A_Base = 0, *B_Base = 0;
240 if (const MCSymbolRefExpr *A = Target.getSymA()) {
241 // Modified symbol references cannot be resolved.
242 if (A->getKind() != MCSymbolRefExpr::VK_None)
243 return false;
244
Daniel Dunbar207e06e2010-03-24 03:43:40 +0000245 A_Base = Asm.getAtom(Layout, &Asm.getSymbolData(A->getSymbol()));
Daniel Dunbar034843a2010-03-19 03:18:18 +0000246 if (!A_Base)
247 return false;
248 }
249
250 if (const MCSymbolRefExpr *B = Target.getSymB()) {
251 // Modified symbol references cannot be resolved.
252 if (B->getKind() != MCSymbolRefExpr::VK_None)
253 return false;
254
Daniel Dunbar207e06e2010-03-24 03:43:40 +0000255 B_Base = Asm.getAtom(Layout, &Asm.getSymbolData(B->getSymbol()));
Daniel Dunbar034843a2010-03-19 03:18:18 +0000256 if (!B_Base)
257 return false;
258 }
259
260 // If there is no base, A and B have to be the same atom for this fixup to be
261 // fully resolved.
262 if (!BaseSymbol)
263 return A_Base == B_Base;
264
265 // Otherwise, B must be missing and A must be the base.
266 return !B_Base && BaseSymbol == A_Base;
267}
268
Daniel Dunbar23869852010-03-19 03:18:09 +0000269bool MCAssembler::isSymbolLinkerVisible(const MCSymbolData *SD) const {
270 // Non-temporary labels should always be visible to the linker.
271 if (!SD->getSymbol().isTemporary())
272 return true;
273
274 // Absolute temporary labels are never visible.
275 if (!SD->getFragment())
276 return false;
277
278 // Otherwise, check if the section requires symbols even for temporary labels.
279 return getBackend().doesSectionRequireSymbols(
280 SD->getFragment()->getParent()->getSection());
281}
282
Daniel Dunbar207e06e2010-03-24 03:43:40 +0000283const MCSymbolData *MCAssembler::getAtom(const MCAsmLayout &Layout,
284 const MCSymbolData *SD) const {
Daniel Dunbar8ad0dcc2010-03-19 03:18:15 +0000285 // Linker visible symbols define atoms.
286 if (isSymbolLinkerVisible(SD))
287 return SD;
288
289 // Absolute and undefined symbols have no defining atom.
290 if (!SD->getFragment())
291 return 0;
292
Daniel Dunbara5f1d572010-05-12 00:38:17 +0000293 // Non-linker visible symbols in sections which can't be atomized have no
294 // defining atom.
295 if (!getBackend().isSectionAtomizable(
296 SD->getFragment()->getParent()->getSection()))
297 return 0;
298
Daniel Dunbar651804c2010-05-11 17:22:50 +0000299 // Otherwise, return the atom for the containing fragment.
300 return SD->getFragment()->getAtom();
Daniel Dunbar8ad0dcc2010-03-19 03:18:15 +0000301}
302
Daniel Dunbar9d39e612010-03-22 21:49:41 +0000303bool MCAssembler::EvaluateFixup(const MCAsmLayout &Layout,
304 const MCAsmFixup &Fixup, const MCFragment *DF,
Daniel Dunbardf3c8f22010-03-12 21:00:49 +0000305 MCValue &Target, uint64_t &Value) const {
Daniel Dunbarff547842010-03-23 23:47:14 +0000306 ++stats::EvaluateFixup;
307
Daniel Dunbardf3c8f22010-03-12 21:00:49 +0000308 if (!Fixup.Value->EvaluateAsRelocatable(Target, &Layout))
Chris Lattner75361b62010-04-07 22:58:41 +0000309 report_fatal_error("expected relocatable expression");
Daniel Dunbardf3c8f22010-03-12 21:00:49 +0000310
311 // FIXME: How do non-scattered symbols work in ELF? I presume the linker
312 // doesn't support small relocations, but then under what criteria does the
313 // assembler allow symbol differences?
314
315 Value = Target.getConstant();
316
Daniel Dunbarb36052f2010-03-19 10:43:23 +0000317 bool IsPCRel =
318 Emitter.getFixupKindInfo(Fixup.Kind).Flags & MCFixupKindInfo::FKF_IsPCRel;
319 bool IsResolved = true;
Daniel Dunbar9a1d2002010-03-18 00:59:10 +0000320 if (const MCSymbolRefExpr *A = Target.getSymA()) {
321 if (A->getSymbol().isDefined())
Daniel Dunbar207e06e2010-03-24 03:43:40 +0000322 Value += Layout.getSymbolAddress(&getSymbolData(A->getSymbol()));
Daniel Dunbardf3c8f22010-03-12 21:00:49 +0000323 else
324 IsResolved = false;
Daniel Dunbardf3c8f22010-03-12 21:00:49 +0000325 }
Daniel Dunbar9a1d2002010-03-18 00:59:10 +0000326 if (const MCSymbolRefExpr *B = Target.getSymB()) {
327 if (B->getSymbol().isDefined())
Daniel Dunbar207e06e2010-03-24 03:43:40 +0000328 Value -= Layout.getSymbolAddress(&getSymbolData(B->getSymbol()));
Daniel Dunbardf3c8f22010-03-12 21:00:49 +0000329 else
330 IsResolved = false;
Daniel Dunbar939f8d72010-03-19 03:18:12 +0000331 }
Daniel Dunbardf3c8f22010-03-12 21:00:49 +0000332
Daniel Dunbar939f8d72010-03-19 03:18:12 +0000333 // If we are using scattered symbols, determine whether this value is actually
334 // resolved; scattering may cause atoms to move.
335 if (IsResolved && getBackend().hasScatteredSymbols()) {
336 if (getBackend().hasReliableSymbolDifference()) {
Daniel Dunbar034843a2010-03-19 03:18:18 +0000337 // If this is a PCrel relocation, find the base atom (identified by its
338 // symbol) that the fixup value is relative to.
339 const MCSymbolData *BaseSymbol = 0;
340 if (IsPCRel) {
Daniel Dunbar651804c2010-05-11 17:22:50 +0000341 BaseSymbol = DF->getAtom();
Daniel Dunbar034843a2010-03-19 03:18:18 +0000342 if (!BaseSymbol)
343 IsResolved = false;
344 }
345
346 if (IsResolved)
Daniel Dunbar207e06e2010-03-24 03:43:40 +0000347 IsResolved = isScatteredFixupFullyResolved(*this, Layout, Fixup, Target,
Daniel Dunbar034843a2010-03-19 03:18:18 +0000348 BaseSymbol);
Daniel Dunbar939f8d72010-03-19 03:18:12 +0000349 } else {
350 const MCSection *BaseSection = 0;
351 if (IsPCRel)
352 BaseSection = &DF->getParent()->getSection();
353
Daniel Dunbarc6f59822010-03-22 21:49:38 +0000354 IsResolved = isScatteredFixupFullyResolvedSimple(*this, Fixup, Target,
Daniel Dunbar939f8d72010-03-19 03:18:12 +0000355 BaseSection);
356 }
Daniel Dunbardf3c8f22010-03-12 21:00:49 +0000357 }
358
359 if (IsPCRel)
Daniel Dunbar207e06e2010-03-24 03:43:40 +0000360 Value -= Layout.getFragmentAddress(DF) + Fixup.Offset;
Daniel Dunbardf3c8f22010-03-12 21:00:49 +0000361
362 return IsResolved;
363}
364
Daniel Dunbarf0d17d22010-05-12 21:35:25 +0000365void MCAssembler::LayoutFragment(MCAsmLayout &Layout, MCFragment &F) {
366 uint64_t StartAddress = Layout.getSectionAddress(F.getParent());
367
368 // Get the fragment start address.
369 uint64_t Address = StartAddress;
370 MCSectionData::iterator it = &F;
371 if (MCFragment *Prev = F.getPrevNode())
372 Address = (StartAddress + Layout.getFragmentOffset(Prev) +
373 Layout.getFragmentEffectiveSize(Prev));
374
375 ++stats::FragmentLayouts;
376
377 uint64_t FragmentOffset = Address - StartAddress;
378 Layout.setFragmentOffset(&F, FragmentOffset);
379
380 // Evaluate fragment size.
381 uint64_t EffectiveSize = 0;
382 switch (F.getKind()) {
383 case MCFragment::FT_Align: {
384 MCAlignFragment &AF = cast<MCAlignFragment>(F);
385
386 EffectiveSize = OffsetToAlignment(Address, AF.getAlignment());
387 if (EffectiveSize > AF.getMaxBytesToEmit())
388 EffectiveSize = 0;
389 break;
390 }
391
392 case MCFragment::FT_Data:
393 EffectiveSize = cast<MCDataFragment>(F).getContents().size();
394 break;
395
396 case MCFragment::FT_Fill: {
Daniel Dunbar4e544872010-05-12 22:51:38 +0000397 EffectiveSize = cast<MCFillFragment>(F).getSize();
Daniel Dunbarf0d17d22010-05-12 21:35:25 +0000398 break;
399 }
400
401 case MCFragment::FT_Inst:
402 EffectiveSize = cast<MCInstFragment>(F).getInstSize();
403 break;
404
405 case MCFragment::FT_Org: {
406 MCOrgFragment &OF = cast<MCOrgFragment>(F);
407
408 int64_t TargetLocation;
409 if (!OF.getOffset().EvaluateAsAbsolute(TargetLocation, &Layout))
410 report_fatal_error("expected assembly-time absolute expression");
411
412 // FIXME: We need a way to communicate this error.
413 int64_t Offset = TargetLocation - FragmentOffset;
414 if (Offset < 0)
415 report_fatal_error("invalid .org offset '" + Twine(TargetLocation) +
416 "' (at offset '" + Twine(FragmentOffset) + "'");
417
418 EffectiveSize = Offset;
419 break;
420 }
Daniel Dunbarf0d17d22010-05-12 21:35:25 +0000421 }
422
423 Layout.setFragmentEffectiveSize(&F, EffectiveSize);
424}
425
Daniel Dunbard13a0ca2010-05-12 17:56:47 +0000426void MCAssembler::LayoutSection(MCAsmLayout &Layout,
427 unsigned SectionOrderIndex) {
428 MCSectionData &SD = *Layout.getSectionOrder()[SectionOrderIndex];
Daniel Dunbarf476b002010-03-25 18:16:42 +0000429 bool IsVirtual = getBackend().isVirtualSection(SD.getSection());
430
Daniel Dunbarac2884a2010-03-25 22:49:09 +0000431 ++stats::SectionLayouts;
432
Daniel Dunbard13a0ca2010-05-12 17:56:47 +0000433 // Get the section start address.
434 uint64_t StartAddress = 0;
435 if (SectionOrderIndex) {
436 MCSectionData *Prev = Layout.getSectionOrder()[SectionOrderIndex - 1];
437 StartAddress = Layout.getSectionAddress(Prev) + Layout.getSectionSize(Prev);
438 }
439
Daniel Dunbarf476b002010-03-25 18:16:42 +0000440 // Align this section if necessary by adding padding bytes to the previous
441 // section. It is safe to adjust this out-of-band, because no symbol or
442 // fragment is allowed to point past the end of the section at any time.
443 if (uint64_t Pad = OffsetToAlignment(StartAddress, SD.getAlignment())) {
444 // Unless this section is virtual (where we are allowed to adjust the offset
445 // freely), the padding goes in the previous section.
446 if (!IsVirtual) {
Daniel Dunbar52f8dff2010-05-12 21:47:55 +0000447 assert(SectionOrderIndex && "Invalid initial section address!");
448 MCSectionData *Prev = Layout.getSectionOrder()[SectionOrderIndex - 1];
449 Layout.setSectionFileSize(Prev, Layout.getSectionFileSize(Prev) + Pad);
Daniel Dunbarf476b002010-03-25 18:16:42 +0000450 }
451
452 StartAddress += Pad;
453 }
454
455 // Set the aligned section address.
Daniel Dunbarbe644a32010-03-25 18:16:38 +0000456 Layout.setSectionAddress(&SD, StartAddress);
Daniel Dunbar0705fbf2009-08-21 18:29:01 +0000457
Daniel Dunbarf0d17d22010-05-12 21:35:25 +0000458 for (MCSectionData::iterator it = SD.begin(), ie = SD.end(); it != ie; ++it)
459 LayoutFragment(Layout, *it);
Daniel Dunbar0705fbf2009-08-21 18:29:01 +0000460
Daniel Dunbar6742e342009-08-26 04:13:32 +0000461 // Set the section sizes.
Daniel Dunbar2d891a22010-05-12 21:35:22 +0000462 uint64_t Size = 0;
463 if (!SD.getFragmentList().empty()) {
464 MCFragment *F = &SD.getFragmentList().back();
465 Size = Layout.getFragmentOffset(F) + Layout.getFragmentEffectiveSize(F);
466 }
467 Layout.setSectionSize(&SD, Size);
468 Layout.setSectionFileSize(&SD, IsVirtual ? 0 : Size);
Daniel Dunbar0705fbf2009-08-21 18:29:01 +0000469}
470
Daniel Dunbar53b23382010-03-19 09:28:59 +0000471/// WriteFragmentData - Write the \arg F data to the output file.
Daniel Dunbar432cd5f2010-03-25 02:00:02 +0000472static void WriteFragmentData(const MCAssembler &Asm, const MCAsmLayout &Layout,
473 const MCFragment &F, MCObjectWriter *OW) {
Daniel Dunbar53b23382010-03-19 09:28:59 +0000474 uint64_t Start = OW->getStream().tell();
Daniel Dunbar0705fbf2009-08-21 18:29:01 +0000475 (void) Start;
Daniel Dunbar7eb85192009-10-16 01:58:15 +0000476
Daniel Dunbarff547842010-03-23 23:47:14 +0000477 ++stats::EmittedFragments;
Daniel Dunbar0adcd352009-08-25 21:10:45 +0000478
Daniel Dunbar0705fbf2009-08-21 18:29:01 +0000479 // FIXME: Embed in fragments instead?
Daniel Dunbar432cd5f2010-03-25 02:00:02 +0000480 uint64_t FragmentSize = Layout.getFragmentEffectiveSize(&F);
Daniel Dunbar0705fbf2009-08-21 18:29:01 +0000481 switch (F.getKind()) {
Daniel Dunbard6f761e2009-08-21 23:07:38 +0000482 case MCFragment::FT_Align: {
483 MCAlignFragment &AF = cast<MCAlignFragment>(F);
Daniel Dunbar432cd5f2010-03-25 02:00:02 +0000484 uint64_t Count = FragmentSize / AF.getValueSize();
Daniel Dunbard6f761e2009-08-21 23:07:38 +0000485
Daniel Dunbare73d49e2010-05-12 22:51:27 +0000486 assert(AF.getValueSize() && "Invalid virtual align in concrete fragment!");
487
Daniel Dunbard6f761e2009-08-21 23:07:38 +0000488 // FIXME: This error shouldn't actually occur (the front end should emit
489 // multiple .align directives to enforce the semantics it wants), but is
490 // severe enough that we want to report it. How to handle this?
Daniel Dunbar432cd5f2010-03-25 02:00:02 +0000491 if (Count * AF.getValueSize() != FragmentSize)
Chris Lattner75361b62010-04-07 22:58:41 +0000492 report_fatal_error("undefined .align directive, value size '" +
Daniel Dunbar7eb85192009-10-16 01:58:15 +0000493 Twine(AF.getValueSize()) +
Daniel Dunbard6f761e2009-08-21 23:07:38 +0000494 "' is not a divisor of padding size '" +
Daniel Dunbar432cd5f2010-03-25 02:00:02 +0000495 Twine(FragmentSize) + "'");
Daniel Dunbard6f761e2009-08-21 23:07:38 +0000496
Kevin Enderby6e720482010-02-23 18:26:34 +0000497 // See if we are aligning with nops, and if so do that first to try to fill
498 // the Count bytes. Then if that did not fill any bytes or there are any
499 // bytes left to fill use the the Value and ValueSize to fill the rest.
Daniel Dunbar8f9b80e2010-03-23 02:36:58 +0000500 // If we are aligning with nops, ask that target to emit the right data.
Daniel Dunbar1c154132010-05-12 22:56:23 +0000501 if (AF.hasEmitNops()) {
Daniel Dunbar8f9b80e2010-03-23 02:36:58 +0000502 if (!Asm.getBackend().WriteNopData(Count, OW))
Chris Lattner75361b62010-04-07 22:58:41 +0000503 report_fatal_error("unable to write nop sequence of " +
Daniel Dunbar8f9b80e2010-03-23 02:36:58 +0000504 Twine(Count) + " bytes");
505 break;
Kevin Enderby6e720482010-02-23 18:26:34 +0000506 }
507
Daniel Dunbar8f9b80e2010-03-23 02:36:58 +0000508 // Otherwise, write out in multiples of the value size.
Daniel Dunbard6f761e2009-08-21 23:07:38 +0000509 for (uint64_t i = 0; i != Count; ++i) {
510 switch (AF.getValueSize()) {
511 default:
512 assert(0 && "Invalid size!");
Daniel Dunbarbdd92812010-03-19 09:28:55 +0000513 case 1: OW->Write8 (uint8_t (AF.getValue())); break;
514 case 2: OW->Write16(uint16_t(AF.getValue())); break;
515 case 4: OW->Write32(uint32_t(AF.getValue())); break;
516 case 8: OW->Write64(uint64_t(AF.getValue())); break;
Daniel Dunbard6f761e2009-08-21 23:07:38 +0000517 }
518 }
519 break;
520 }
Daniel Dunbar0705fbf2009-08-21 18:29:01 +0000521
Daniel Dunbar3a30b822010-02-13 09:28:15 +0000522 case MCFragment::FT_Data: {
Daniel Dunbar3f4dcd92010-03-22 23:16:48 +0000523 MCDataFragment &DF = cast<MCDataFragment>(F);
Daniel Dunbar432cd5f2010-03-25 02:00:02 +0000524 assert(FragmentSize == DF.getContents().size() && "Invalid size!");
Daniel Dunbar3f4dcd92010-03-22 23:16:48 +0000525 OW->WriteBytes(DF.getContents().str());
Daniel Dunbar0705fbf2009-08-21 18:29:01 +0000526 break;
Daniel Dunbar3a30b822010-02-13 09:28:15 +0000527 }
Daniel Dunbar0705fbf2009-08-21 18:29:01 +0000528
Daniel Dunbar0705fbf2009-08-21 18:29:01 +0000529 case MCFragment::FT_Fill: {
530 MCFillFragment &FF = cast<MCFillFragment>(F);
Daniel Dunbare2fee5b2010-05-12 22:51:35 +0000531
532 assert(FF.getValueSize() && "Invalid virtual align in concrete fragment!");
533
Daniel Dunbar3153fec2010-05-12 22:51:32 +0000534 for (uint64_t i = 0, e = FF.getSize() / FF.getValueSize(); i != e; ++i) {
Daniel Dunbar0705fbf2009-08-21 18:29:01 +0000535 switch (FF.getValueSize()) {
536 default:
537 assert(0 && "Invalid size!");
Daniel Dunbarbdd92812010-03-19 09:28:55 +0000538 case 1: OW->Write8 (uint8_t (FF.getValue())); break;
539 case 2: OW->Write16(uint16_t(FF.getValue())); break;
540 case 4: OW->Write32(uint32_t(FF.getValue())); break;
541 case 8: OW->Write64(uint64_t(FF.getValue())); break;
Daniel Dunbar0705fbf2009-08-21 18:29:01 +0000542 }
543 }
544 break;
545 }
Daniel Dunbar7eb85192009-10-16 01:58:15 +0000546
Daniel Dunbar3f4dcd92010-03-22 23:16:48 +0000547 case MCFragment::FT_Inst:
548 llvm_unreachable("unexpected inst fragment after lowering");
549 break;
550
Daniel Dunbard6f761e2009-08-21 23:07:38 +0000551 case MCFragment::FT_Org: {
552 MCOrgFragment &OF = cast<MCOrgFragment>(F);
553
Daniel Dunbar432cd5f2010-03-25 02:00:02 +0000554 for (uint64_t i = 0, e = FragmentSize; i != e; ++i)
Daniel Dunbarbdd92812010-03-19 09:28:55 +0000555 OW->Write8(uint8_t(OF.getValue()));
Daniel Dunbard6f761e2009-08-21 23:07:38 +0000556
557 break;
558 }
Daniel Dunbar0705fbf2009-08-21 18:29:01 +0000559 }
560
Daniel Dunbar432cd5f2010-03-25 02:00:02 +0000561 assert(OW->getStream().tell() - Start == FragmentSize);
Daniel Dunbar0705fbf2009-08-21 18:29:01 +0000562}
563
Daniel Dunbar53b23382010-03-19 09:28:59 +0000564void MCAssembler::WriteSectionData(const MCSectionData *SD,
Daniel Dunbar432cd5f2010-03-25 02:00:02 +0000565 const MCAsmLayout &Layout,
Daniel Dunbar53b23382010-03-19 09:28:59 +0000566 MCObjectWriter *OW) const {
Daniel Dunbar5d428512010-03-25 02:00:07 +0000567 uint64_t SectionSize = Layout.getSectionSize(SD);
568 uint64_t SectionFileSize = Layout.getSectionFileSize(SD);
569
Daniel Dunbard5a8e982009-08-28 05:49:21 +0000570 // Ignore virtual sections.
Daniel Dunbarcc5b84c2010-03-19 09:29:03 +0000571 if (getBackend().isVirtualSection(SD->getSection())) {
Daniel Dunbar5d428512010-03-25 02:00:07 +0000572 assert(SectionFileSize == 0 && "Invalid size for section!");
Daniel Dunbare2fee5b2010-05-12 22:51:35 +0000573
574 // Check that contents are only things legal inside a virtual section.
575 for (MCSectionData::const_iterator it = SD->begin(),
576 ie = SD->end(); it != ie; ++it) {
577 switch (it->getKind()) {
578 default:
579 assert(0 && "Invalid fragment in virtual section!");
580 case MCFragment::FT_Align:
581 assert(!cast<MCAlignFragment>(it)->getValueSize() &&
582 "Invalid align in virtual section!");
583 break;
584 case MCFragment::FT_Fill:
585 assert(!cast<MCFillFragment>(it)->getValueSize() &&
586 "Invalid fill in virtual section!");
587 break;
Daniel Dunbare2fee5b2010-05-12 22:51:35 +0000588 }
589 }
590
Daniel Dunbard5a8e982009-08-28 05:49:21 +0000591 return;
592 }
593
Daniel Dunbar53b23382010-03-19 09:28:59 +0000594 uint64_t Start = OW->getStream().tell();
Daniel Dunbar0705fbf2009-08-21 18:29:01 +0000595 (void) Start;
Daniel Dunbar7eb85192009-10-16 01:58:15 +0000596
Daniel Dunbar53b23382010-03-19 09:28:59 +0000597 for (MCSectionData::const_iterator it = SD->begin(),
598 ie = SD->end(); it != ie; ++it)
Daniel Dunbar432cd5f2010-03-25 02:00:02 +0000599 WriteFragmentData(*this, Layout, *it, OW);
Daniel Dunbar0705fbf2009-08-21 18:29:01 +0000600
Daniel Dunbar6742e342009-08-26 04:13:32 +0000601 // Add section padding.
Daniel Dunbar5d428512010-03-25 02:00:07 +0000602 assert(SectionFileSize >= SectionSize && "Invalid section sizes!");
603 OW->WriteZeros(SectionFileSize - SectionSize);
Daniel Dunbar6742e342009-08-26 04:13:32 +0000604
Daniel Dunbar5d428512010-03-25 02:00:07 +0000605 assert(OW->getStream().tell() - Start == SectionFileSize);
Daniel Dunbar0705fbf2009-08-21 18:29:01 +0000606}
607
Daniel Dunbarfb4a6b32009-08-21 09:11:24 +0000608void MCAssembler::Finish() {
Daniel Dunbarb7c3a4b2010-02-13 09:28:03 +0000609 DEBUG_WITH_TYPE("mc-dump", {
610 llvm::errs() << "assembler backend - pre-layout\n--\n";
611 dump(); });
612
Daniel Dunbar5a6e97a2010-03-25 07:10:11 +0000613 // Assign section and fragment ordinals, all subsequent backend code is
614 // responsible for updating these in place.
615 unsigned SectionIndex = 0;
616 unsigned FragmentIndex = 0;
617 for (MCAssembler::iterator it = begin(), ie = end(); it != ie; ++it) {
618 it->setOrdinal(SectionIndex++);
619
620 for (MCSectionData::iterator it2 = it->begin(),
621 ie2 = it->end(); it2 != ie2; ++it2)
622 it2->setOrdinal(FragmentIndex++);
623 }
624
Daniel Dunbarf08fde42010-03-12 22:07:14 +0000625 // Layout until everything fits.
Daniel Dunbar8d39eb42010-03-22 20:35:35 +0000626 MCAsmLayout Layout(*this);
627 while (LayoutOnce(Layout))
Daniel Dunbarf08fde42010-03-12 22:07:14 +0000628 continue;
629
630 DEBUG_WITH_TYPE("mc-dump", {
Daniel Dunbar3f4dcd92010-03-22 23:16:48 +0000631 llvm::errs() << "assembler backend - post-relaxation\n--\n";
632 dump(); });
633
634 // Finalize the layout, including fragment lowering.
635 FinishLayout(Layout);
636
637 DEBUG_WITH_TYPE("mc-dump", {
638 llvm::errs() << "assembler backend - final-layout\n--\n";
Daniel Dunbarf08fde42010-03-12 22:07:14 +0000639 dump(); });
640
Daniel Dunbarff547842010-03-23 23:47:14 +0000641 uint64_t StartOffset = OS.tell();
Daniel Dunbar1a9158c2010-03-19 10:43:26 +0000642 llvm::OwningPtr<MCObjectWriter> Writer(getBackend().createObjectWriter(OS));
643 if (!Writer)
Chris Lattner75361b62010-04-07 22:58:41 +0000644 report_fatal_error("unable to create object writer!");
Daniel Dunbarbacba992010-03-19 07:09:33 +0000645
646 // Allow the object writer a chance to perform post-layout binding (for
647 // example, to set the index fields in the symbol data).
Daniel Dunbar1a9158c2010-03-19 10:43:26 +0000648 Writer->ExecutePostLayoutBinding(*this);
Daniel Dunbarbacba992010-03-19 07:09:33 +0000649
Daniel Dunbarb1e98942010-03-19 07:09:47 +0000650 // Evaluate and apply the fixups, generating relocation entries as necessary.
Daniel Dunbarb1e98942010-03-19 07:09:47 +0000651 for (MCAssembler::iterator it = begin(), ie = end(); it != ie; ++it) {
652 for (MCSectionData::iterator it2 = it->begin(),
653 ie2 = it->end(); it2 != ie2; ++it2) {
654 MCDataFragment *DF = dyn_cast<MCDataFragment>(it2);
655 if (!DF)
656 continue;
657
658 for (MCDataFragment::fixup_iterator it3 = DF->fixup_begin(),
659 ie3 = DF->fixup_end(); it3 != ie3; ++it3) {
660 MCAsmFixup &Fixup = *it3;
661
662 // Evaluate the fixup.
663 MCValue Target;
664 uint64_t FixedValue;
665 if (!EvaluateFixup(Layout, Fixup, DF, Target, FixedValue)) {
666 // The fixup was unresolved, we need a relocation. Inform the object
667 // writer of the relocation, and give it an opportunity to adjust the
668 // fixup value if need be.
Daniel Dunbar207e06e2010-03-24 03:43:40 +0000669 Writer->RecordRelocation(*this, Layout, DF, Fixup, Target,FixedValue);
Daniel Dunbarb1e98942010-03-19 07:09:47 +0000670 }
671
Daniel Dunbar87190c42010-03-19 09:28:12 +0000672 getBackend().ApplyFixup(Fixup, *DF, FixedValue);
Daniel Dunbarb1e98942010-03-19 07:09:47 +0000673 }
674 }
675 }
676
Daniel Dunbarbacba992010-03-19 07:09:33 +0000677 // Write the object file.
Daniel Dunbar207e06e2010-03-24 03:43:40 +0000678 Writer->WriteObject(*this, Layout);
Daniel Dunbarf08fde42010-03-12 22:07:14 +0000679 OS.flush();
Daniel Dunbarff547842010-03-23 23:47:14 +0000680
681 stats::ObjectBytes += OS.tell() - StartOffset;
Daniel Dunbarf08fde42010-03-12 22:07:14 +0000682}
683
Daniel Dunbar9d39e612010-03-22 21:49:41 +0000684bool MCAssembler::FixupNeedsRelaxation(const MCAsmFixup &Fixup,
685 const MCFragment *DF,
Daniel Dunbar8d39eb42010-03-22 20:35:35 +0000686 const MCAsmLayout &Layout) const {
Daniel Dunbarac2884a2010-03-25 22:49:09 +0000687 if (getRelaxAll())
688 return true;
689
Daniel Dunbarf08fde42010-03-12 22:07:14 +0000690 // If we cannot resolve the fixup value, it requires relaxation.
691 MCValue Target;
692 uint64_t Value;
693 if (!EvaluateFixup(Layout, Fixup, DF, Target, Value))
694 return true;
695
696 // Otherwise, relax if the value is too big for a (signed) i8.
Daniel Dunbar31e8e1d2010-05-04 00:33:07 +0000697 //
698 // FIXME: This is target dependent!
Daniel Dunbarf08fde42010-03-12 22:07:14 +0000699 return int64_t(Value) != int64_t(int8_t(Value));
700}
701
Daniel Dunbard8036fb2010-03-23 05:09:03 +0000702bool MCAssembler::FragmentNeedsRelaxation(const MCInstFragment *IF,
703 const MCAsmLayout &Layout) const {
704 // If this inst doesn't ever need relaxation, ignore it. This occurs when we
705 // are intentionally pushing out inst fragments, or because we relaxed a
706 // previous instruction to one that doesn't need relaxation.
707 if (!getBackend().MayNeedRelaxation(IF->getInst(), IF->getFixups()))
708 return false;
709
710 for (MCInstFragment::const_fixup_iterator it = IF->fixup_begin(),
711 ie = IF->fixup_end(); it != ie; ++it)
712 if (FixupNeedsRelaxation(*it, IF, Layout))
713 return true;
714
715 return false;
716}
717
Daniel Dunbar8d39eb42010-03-22 20:35:35 +0000718bool MCAssembler::LayoutOnce(MCAsmLayout &Layout) {
Daniel Dunbarff547842010-03-23 23:47:14 +0000719 ++stats::RelaxationSteps;
720
Daniel Dunbard13a0ca2010-05-12 17:56:47 +0000721 // Layout the sections in order.
722 for (unsigned i = 0, e = Layout.getSectionOrder().size(); i != e; ++i)
723 LayoutSection(Layout, i);
Daniel Dunbard5a8e982009-08-28 05:49:21 +0000724
Daniel Dunbard8036fb2010-03-23 05:09:03 +0000725 // Scan for fragments that need relaxation.
Daniel Dunbar0cc8bd42010-03-25 19:35:56 +0000726 bool WasRelaxed = false;
Daniel Dunbarf08fde42010-03-12 22:07:14 +0000727 for (iterator it = begin(), ie = end(); it != ie; ++it) {
728 MCSectionData &SD = *it;
Daniel Dunbarb7c3a4b2010-02-13 09:28:03 +0000729
Daniel Dunbarf08fde42010-03-12 22:07:14 +0000730 for (MCSectionData::iterator it2 = SD.begin(),
731 ie2 = SD.end(); it2 != ie2; ++it2) {
Daniel Dunbard8036fb2010-03-23 05:09:03 +0000732 // Check if this is an instruction fragment that needs relaxation.
733 MCInstFragment *IF = dyn_cast<MCInstFragment>(it2);
734 if (!IF || !FragmentNeedsRelaxation(IF, Layout))
Daniel Dunbarf08fde42010-03-12 22:07:14 +0000735 continue;
Daniel Dunbar0705fbf2009-08-21 18:29:01 +0000736
Daniel Dunbarff547842010-03-23 23:47:14 +0000737 ++stats::RelaxedInstructions;
738
Daniel Dunbard8036fb2010-03-23 05:09:03 +0000739 // FIXME-PERF: We could immediately lower out instructions if we can tell
740 // they are fully resolved, to avoid retesting on later passes.
Daniel Dunbarf08fde42010-03-12 22:07:14 +0000741
Daniel Dunbard8036fb2010-03-23 05:09:03 +0000742 // Relax the fragment.
Daniel Dunbarf08fde42010-03-12 22:07:14 +0000743
Daniel Dunbard8036fb2010-03-23 05:09:03 +0000744 MCInst Relaxed;
745 getBackend().RelaxInstruction(IF, Relaxed);
Daniel Dunbarf08fde42010-03-12 22:07:14 +0000746
Daniel Dunbard8036fb2010-03-23 05:09:03 +0000747 // Encode the new instruction.
748 //
749 // FIXME-PERF: If it matters, we could let the target do this. It can
750 // probably do so more efficiently in many cases.
751 SmallVector<MCFixup, 4> Fixups;
752 SmallString<256> Code;
753 raw_svector_ostream VecOS(Code);
754 getEmitter().EncodeInstruction(Relaxed, VecOS, Fixups);
755 VecOS.flush();
Daniel Dunbarf08fde42010-03-12 22:07:14 +0000756
Daniel Dunbard8036fb2010-03-23 05:09:03 +0000757 // Update the instruction fragment.
Daniel Dunbar0cc8bd42010-03-25 19:35:56 +0000758 int SlideAmount = Code.size() - IF->getInstSize();
Daniel Dunbard8036fb2010-03-23 05:09:03 +0000759 IF->setInst(Relaxed);
760 IF->getCode() = Code;
761 IF->getFixups().clear();
762 for (unsigned i = 0, e = Fixups.size(); i != e; ++i) {
763 MCFixup &F = Fixups[i];
764 IF->getFixups().push_back(MCAsmFixup(F.getOffset(), *F.getValue(),
765 F.getKind()));
Daniel Dunbarf08fde42010-03-12 22:07:14 +0000766 }
Daniel Dunbard8036fb2010-03-23 05:09:03 +0000767
Daniel Dunbarac2884a2010-03-25 22:49:09 +0000768 // Update the layout, and remember that we relaxed. If we are relaxing
769 // everything, we can skip this step since nothing will depend on updating
770 // the values.
771 if (!getRelaxAll())
772 Layout.UpdateForSlide(IF, SlideAmount);
Daniel Dunbar0cc8bd42010-03-25 19:35:56 +0000773 WasRelaxed = true;
Daniel Dunbarf08fde42010-03-12 22:07:14 +0000774 }
775 }
776
Daniel Dunbar0cc8bd42010-03-25 19:35:56 +0000777 return WasRelaxed;
Daniel Dunbarfb4a6b32009-08-21 09:11:24 +0000778}
Daniel Dunbarb7c3a4b2010-02-13 09:28:03 +0000779
Daniel Dunbar3f4dcd92010-03-22 23:16:48 +0000780void MCAssembler::FinishLayout(MCAsmLayout &Layout) {
781 // Lower out any instruction fragments, to simplify the fixup application and
782 // output.
783 //
784 // FIXME-PERF: We don't have to do this, but the assumption is that it is
785 // cheap (we will mostly end up eliminating fragments and appending on to data
786 // fragments), so the extra complexity downstream isn't worth it. Evaluate
787 // this assumption.
788 for (iterator it = begin(), ie = end(); it != ie; ++it) {
789 MCSectionData &SD = *it;
790
791 for (MCSectionData::iterator it2 = SD.begin(),
792 ie2 = SD.end(); it2 != ie2; ++it2) {
793 MCInstFragment *IF = dyn_cast<MCInstFragment>(it2);
794 if (!IF)
795 continue;
796
797 // Create a new data fragment for the instruction.
798 //
Daniel Dunbar337055e2010-03-23 03:13:05 +0000799 // FIXME-PERF: Reuse previous data fragment if possible.
Daniel Dunbar3f4dcd92010-03-22 23:16:48 +0000800 MCDataFragment *DF = new MCDataFragment();
801 SD.getFragmentList().insert(it2, DF);
802
803 // Update the data fragments layout data.
Daniel Dunbar432cd5f2010-03-25 02:00:02 +0000804 //
805 // FIXME: Add MCAsmLayout utility for this.
Daniel Dunbar9799de92010-03-23 01:39:05 +0000806 DF->setParent(IF->getParent());
Daniel Dunbar651804c2010-05-11 17:22:50 +0000807 DF->setAtom(IF->getAtom());
Daniel Dunbar5a6e97a2010-03-25 07:10:11 +0000808 DF->setOrdinal(IF->getOrdinal());
Daniel Dunbar432cd5f2010-03-25 02:00:02 +0000809 Layout.setFragmentOffset(DF, Layout.getFragmentOffset(IF));
810 Layout.setFragmentEffectiveSize(DF, Layout.getFragmentEffectiveSize(IF));
Daniel Dunbar3f4dcd92010-03-22 23:16:48 +0000811
Daniel Dunbar9799de92010-03-23 01:39:05 +0000812 // Copy in the data and the fixups.
813 DF->getContents().append(IF->getCode().begin(), IF->getCode().end());
814 for (unsigned i = 0, e = IF->getFixups().size(); i != e; ++i)
815 DF->getFixups().push_back(IF->getFixups()[i]);
Daniel Dunbar3f4dcd92010-03-22 23:16:48 +0000816
817 // Delete the instruction fragment and update the iterator.
818 SD.getFragmentList().erase(IF);
819 it2 = DF;
820 }
821 }
822}
823
Daniel Dunbarb7c3a4b2010-02-13 09:28:03 +0000824// Debugging methods
825
826namespace llvm {
827
828raw_ostream &operator<<(raw_ostream &OS, const MCAsmFixup &AF) {
Daniel Dunbar2be2fd02010-02-13 09:28:54 +0000829 OS << "<MCAsmFixup" << " Offset:" << AF.Offset << " Value:" << *AF.Value
830 << " Kind:" << AF.Kind << ">";
Daniel Dunbarb7c3a4b2010-02-13 09:28:03 +0000831 return OS;
832}
833
834}
835
836void MCFragment::dump() {
837 raw_ostream &OS = llvm::errs();
838
839 OS << "<MCFragment " << (void*) this << " Offset:" << Offset
Daniel Dunbar432cd5f2010-03-25 02:00:02 +0000840 << " EffectiveSize:" << EffectiveSize;
Daniel Dunbarb7c3a4b2010-02-13 09:28:03 +0000841
Daniel Dunbarb7c3a4b2010-02-13 09:28:03 +0000842 OS << ">";
843}
844
845void MCAlignFragment::dump() {
846 raw_ostream &OS = llvm::errs();
847
848 OS << "<MCAlignFragment ";
849 this->MCFragment::dump();
850 OS << "\n ";
851 OS << " Alignment:" << getAlignment()
852 << " Value:" << getValue() << " ValueSize:" << getValueSize()
853 << " MaxBytesToEmit:" << getMaxBytesToEmit() << ">";
854}
855
856void MCDataFragment::dump() {
857 raw_ostream &OS = llvm::errs();
858
859 OS << "<MCDataFragment ";
860 this->MCFragment::dump();
861 OS << "\n ";
862 OS << " Contents:[";
863 for (unsigned i = 0, e = getContents().size(); i != e; ++i) {
864 if (i) OS << ",";
865 OS << hexdigit((Contents[i] >> 4) & 0xF) << hexdigit(Contents[i] & 0xF);
866 }
Daniel Dunbar2be2fd02010-02-13 09:28:54 +0000867 OS << "] (" << getContents().size() << " bytes)";
Daniel Dunbar0bcf0742010-02-13 09:28:43 +0000868
869 if (!getFixups().empty()) {
870 OS << ",\n ";
871 OS << " Fixups:[";
872 for (fixup_iterator it = fixup_begin(), ie = fixup_end(); it != ie; ++it) {
Daniel Dunbar45aefff2010-03-09 01:12:23 +0000873 if (it != fixup_begin()) OS << ",\n ";
Daniel Dunbar0bcf0742010-02-13 09:28:43 +0000874 OS << *it;
875 }
876 OS << "]";
877 }
878
879 OS << ">";
Daniel Dunbarb7c3a4b2010-02-13 09:28:03 +0000880}
881
882void MCFillFragment::dump() {
883 raw_ostream &OS = llvm::errs();
884
885 OS << "<MCFillFragment ";
886 this->MCFragment::dump();
887 OS << "\n ";
888 OS << " Value:" << getValue() << " ValueSize:" << getValueSize()
Daniel Dunbar3153fec2010-05-12 22:51:32 +0000889 << " Size:" << getSize() << ">";
Daniel Dunbarb7c3a4b2010-02-13 09:28:03 +0000890}
891
Daniel Dunbar3f4dcd92010-03-22 23:16:48 +0000892void MCInstFragment::dump() {
893 raw_ostream &OS = llvm::errs();
894
895 OS << "<MCInstFragment ";
896 this->MCFragment::dump();
897 OS << "\n ";
898 OS << " Inst:";
899 getInst().dump_pretty(OS);
900 OS << ">";
901}
902
Daniel Dunbarb7c3a4b2010-02-13 09:28:03 +0000903void MCOrgFragment::dump() {
904 raw_ostream &OS = llvm::errs();
905
906 OS << "<MCOrgFragment ";
907 this->MCFragment::dump();
908 OS << "\n ";
909 OS << " Offset:" << getOffset() << " Value:" << getValue() << ">";
910}
911
Daniel Dunbarb7c3a4b2010-02-13 09:28:03 +0000912void MCSectionData::dump() {
913 raw_ostream &OS = llvm::errs();
914
915 OS << "<MCSectionData";
916 OS << " Alignment:" << getAlignment() << " Address:" << Address
917 << " Size:" << Size << " FileSize:" << FileSize
Daniel Dunbar45aefff2010-03-09 01:12:23 +0000918 << " Fragments:[\n ";
Daniel Dunbarb7c3a4b2010-02-13 09:28:03 +0000919 for (iterator it = begin(), ie = end(); it != ie; ++it) {
920 if (it != begin()) OS << ",\n ";
921 it->dump();
922 }
923 OS << "]>";
924}
925
926void MCSymbolData::dump() {
927 raw_ostream &OS = llvm::errs();
928
929 OS << "<MCSymbolData Symbol:" << getSymbol()
930 << " Fragment:" << getFragment() << " Offset:" << getOffset()
931 << " Flags:" << getFlags() << " Index:" << getIndex();
932 if (isCommon())
933 OS << " (common, size:" << getCommonSize()
934 << " align: " << getCommonAlignment() << ")";
935 if (isExternal())
936 OS << " (external)";
937 if (isPrivateExtern())
938 OS << " (private extern)";
939 OS << ">";
940}
941
942void MCAssembler::dump() {
943 raw_ostream &OS = llvm::errs();
944
945 OS << "<MCAssembler\n";
Daniel Dunbar45aefff2010-03-09 01:12:23 +0000946 OS << " Sections:[\n ";
Daniel Dunbarb7c3a4b2010-02-13 09:28:03 +0000947 for (iterator it = begin(), ie = end(); it != ie; ++it) {
948 if (it != begin()) OS << ",\n ";
949 it->dump();
950 }
951 OS << "],\n";
952 OS << " Symbols:[";
953
954 for (symbol_iterator it = symbol_begin(), ie = symbol_end(); it != ie; ++it) {
Daniel Dunbar45aefff2010-03-09 01:12:23 +0000955 if (it != symbol_begin()) OS << ",\n ";
Daniel Dunbarb7c3a4b2010-02-13 09:28:03 +0000956 it->dump();
957 }
958 OS << "]>\n";
959}