X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FMC%2FMCAssembler.cpp;h=7d8455492780caef76a3cc5ded58c37b6ab8e21d;hb=6d8cf082f643a585b82e8dd136641ee4638b8c7a;hp=4a5db8ce22224a3eaeaaf8f17622aac24be3850b;hpb=207e06ea0446c51cb1d89f6400ec7becc46487f8;p=oota-llvm.git diff --git a/lib/MC/MCAssembler.cpp b/lib/MC/MCAssembler.cpp index 4a5db8ce222..7d845549278 100644 --- a/lib/MC/MCAssembler.cpp +++ b/lib/MC/MCAssembler.cpp @@ -19,9 +19,9 @@ #include "llvm/ADT/Statistic.h" #include "llvm/ADT/StringExtras.h" #include "llvm/ADT/Twine.h" +#include "llvm/Support/Debug.h" #include "llvm/Support/ErrorHandling.h" #include "llvm/Support/raw_ostream.h" -#include "llvm/Support/Debug.h" #include "llvm/Target/TargetRegistry.h" #include "llvm/Target/TargetAsmBackend.h" @@ -30,11 +30,13 @@ using namespace llvm; namespace { namespace stats { -STATISTIC(RelaxedInstructions, "Number of relaxed instructions"); -STATISTIC(RelaxationSteps, "Number of assembler layout and relaxation steps"); STATISTIC(EmittedFragments, "Number of emitted assembler fragments"); STATISTIC(EvaluateFixup, "Number of evaluated fixups"); +STATISTIC(FragmentLayouts, "Number of fragment layouts"); STATISTIC(ObjectBytes, "Number of emitted object file bytes"); +STATISTIC(RelaxationSteps, "Number of assembler layout and relaxation steps"); +STATISTIC(RelaxedInstructions, "Number of relaxed instructions"); +STATISTIC(SectionLayouts, "Number of section layouts"); } } @@ -45,20 +47,130 @@ STATISTIC(ObjectBytes, "Number of emitted object file bytes"); /* *** */ +MCAsmLayout::MCAsmLayout(MCAssembler &Asm) + : Assembler(Asm), LastValidFragment(0) + { + // Compute the section layout order. Virtual sections must go last. + for (MCAssembler::iterator it = Asm.begin(), ie = Asm.end(); it != ie; ++it) + if (!Asm.getBackend().isVirtualSection(it->getSection())) + SectionOrder.push_back(&*it); + for (MCAssembler::iterator it = Asm.begin(), ie = Asm.end(); it != ie; ++it) + if (Asm.getBackend().isVirtualSection(it->getSection())) + SectionOrder.push_back(&*it); +} + +bool MCAsmLayout::isSectionUpToDate(const MCSectionData *SD) const { + // The first section is always up-to-date. + unsigned Index = SD->getLayoutOrder(); + if (!Index) + return true; + + // Otherwise, sections are always implicitly computed when the preceeding + // fragment is layed out. + const MCSectionData *Prev = getSectionOrder()[Index - 1]; + return isFragmentUpToDate(&(Prev->getFragmentList().back())); +} + +bool MCAsmLayout::isFragmentUpToDate(const MCFragment *F) const { + return (LastValidFragment && + F->getLayoutOrder() <= LastValidFragment->getLayoutOrder()); +} + +void MCAsmLayout::UpdateForSlide(MCFragment *F, int SlideAmount) { + // If this fragment wasn't already up-to-date, we don't need to do anything. + if (!isFragmentUpToDate(F)) + return; + + // Otherwise, reset the last valid fragment to the predecessor of the + // invalidated fragment. + LastValidFragment = F->getPrevNode(); + if (!LastValidFragment) { + unsigned Index = F->getParent()->getLayoutOrder(); + if (Index != 0) { + MCSectionData *Prev = getSectionOrder()[Index - 1]; + LastValidFragment = &(Prev->getFragmentList().back()); + } + } +} + +void MCAsmLayout::EnsureValid(const MCFragment *F) const { + // Advance the layout position until the fragment is up-to-date. + while (!isFragmentUpToDate(F)) { + // Advance to the next fragment. + MCFragment *Cur = LastValidFragment; + if (Cur) + Cur = Cur->getNextNode(); + if (!Cur) { + unsigned NextIndex = 0; + if (LastValidFragment) + NextIndex = LastValidFragment->getParent()->getLayoutOrder() + 1; + Cur = SectionOrder[NextIndex]->begin(); + } + + const_cast(this)->LayoutFragment(Cur); + } +} + +void MCAsmLayout::FragmentReplaced(MCFragment *Src, MCFragment *Dst) { + if (LastValidFragment == Src) + LastValidFragment = Dst; + + Dst->Offset = Src->Offset; + Dst->EffectiveSize = Src->EffectiveSize; +} + uint64_t MCAsmLayout::getFragmentAddress(const MCFragment *F) const { - return F->getAddress(); + assert(F->getParent() && "Missing section()!"); + return getSectionAddress(F->getParent()) + getFragmentOffset(F); +} + +uint64_t MCAsmLayout::getFragmentEffectiveSize(const MCFragment *F) const { + EnsureValid(F); + assert(F->EffectiveSize != ~UINT64_C(0) && "Address not set!"); + return F->EffectiveSize; +} + +uint64_t MCAsmLayout::getFragmentOffset(const MCFragment *F) const { + EnsureValid(F); + assert(F->Offset != ~UINT64_C(0) && "Address not set!"); + return F->Offset; } uint64_t MCAsmLayout::getSymbolAddress(const MCSymbolData *SD) const { - return SD->getAddress(); + assert(SD->getFragment() && "Invalid getAddress() on undefined symbol!"); + return getFragmentAddress(SD->getFragment()) + SD->getOffset(); } uint64_t MCAsmLayout::getSectionAddress(const MCSectionData *SD) const { - return SD->getAddress(); + EnsureValid(SD->begin()); + assert(SD->Address != ~UINT64_C(0) && "Address not set!"); + return SD->Address; +} + +uint64_t MCAsmLayout::getSectionAddressSize(const MCSectionData *SD) const { + // The size is the last fragment's end offset. + const MCFragment &F = SD->getFragmentList().back(); + return getFragmentOffset(&F) + getFragmentEffectiveSize(&F); +} + +uint64_t MCAsmLayout::getSectionFileSize(const MCSectionData *SD) const { + // Virtual sections have no file size. + if (getAssembler().getBackend().isVirtualSection(SD->getSection())) + return 0; + + // Otherwise, the file size is the same as the address space size. + return getSectionAddressSize(SD); } -void MCAsmLayout::setSectionAddress(MCSectionData *SD, uint64_t Value) { - SD->setAddress(Value); +uint64_t MCAsmLayout::getSectionSize(const MCSectionData *SD) const { + // The logical size is the address space size minus any tail padding. + uint64_t Size = getSectionAddressSize(SD); + const MCAlignFragment *AF = + dyn_cast(&(SD->getFragmentList().back())); + if (AF && AF->hasOnlyAlignAddress()) + Size -= getFragmentEffectiveSize(AF); + + return Size; } /* *** */ @@ -67,22 +179,12 @@ MCFragment::MCFragment() : Kind(FragmentType(~0)) { } MCFragment::MCFragment(FragmentType _Kind, MCSectionData *_Parent) - : Kind(_Kind), - Parent(_Parent), - FileSize(~UINT64_C(0)) + : Kind(_Kind), Parent(_Parent), Atom(0), EffectiveSize(~UINT64_C(0)) { if (Parent) Parent->getFragmentList().push_back(this); } -MCFragment::~MCFragment() { -} - -uint64_t MCFragment::getAddress() const { - assert(getParent() && "Missing Section!"); - return getParent()->getAddress() + Offset; -} - /* *** */ MCSectionData::MCSectionData() : Section(0) {} @@ -91,8 +193,6 @@ MCSectionData::MCSectionData(const MCSection &_Section, MCAssembler *A) : Section(&_Section), Alignment(1), Address(~UINT64_C(0)), - Size(~UINT64_C(0)), - FileSize(~UINT64_C(0)), HasInstructions(false) { if (A) @@ -118,7 +218,7 @@ MCSymbolData::MCSymbolData(const MCSymbol &_Symbol, MCFragment *_Fragment, MCAssembler::MCAssembler(MCContext &_Context, TargetAsmBackend &_Backend, MCCodeEmitter &_Emitter, raw_ostream &_OS) : Context(_Context), Backend(_Backend), Emitter(_Emitter), - OS(_OS), SubsectionsViaSymbols(false) + OS(_OS), RelaxAll(false), SubsectionsViaSymbols(false) { } @@ -126,7 +226,7 @@ MCAssembler::~MCAssembler() { } static bool isScatteredFixupFullyResolvedSimple(const MCAssembler &Asm, - const MCAsmFixup &Fixup, + const MCFixup &Fixup, const MCValue Target, const MCSection *BaseSection) { // The effective fixup address is @@ -143,7 +243,7 @@ static bool isScatteredFixupFullyResolvedSimple(const MCAssembler &Asm, // resolved. This also works in conjunction with absolutized .set, which // requires the compiler to use .set to absolutize the differences between // symbols which the compiler knows to be assembly time constants, so we don't - // need to worry about consider symbol differences fully resolved. + // need to worry about considering symbol differences fully resolved. // Non-relative fixups are only resolved if constant. if (!BaseSection) @@ -164,7 +264,7 @@ static bool isScatteredFixupFullyResolvedSimple(const MCAssembler &Asm, static bool isScatteredFixupFullyResolved(const MCAssembler &Asm, const MCAsmLayout &Layout, - const MCAsmFixup &Fixup, + const MCFixup &Fixup, const MCValue Target, const MCSymbolData *BaseSymbol) { // The effective fixup address is @@ -208,72 +308,46 @@ static bool isScatteredFixupFullyResolved(const MCAssembler &Asm, return !B_Base && BaseSymbol == A_Base; } -bool MCAssembler::isSymbolLinkerVisible(const MCSymbolData *SD) const { +bool MCAssembler::isSymbolLinkerVisible(const MCSymbol &Symbol) const { // Non-temporary labels should always be visible to the linker. - if (!SD->getSymbol().isTemporary()) + if (!Symbol.isTemporary()) return true; // Absolute temporary labels are never visible. - if (!SD->getFragment()) + if (!Symbol.isInSection()) return false; // Otherwise, check if the section requires symbols even for temporary labels. - return getBackend().doesSectionRequireSymbols( - SD->getFragment()->getParent()->getSection()); + return getBackend().doesSectionRequireSymbols(Symbol.getSection()); } -// FIXME-PERF: This routine is really slow. -const MCSymbolData *MCAssembler::getAtomForAddress(const MCAsmLayout &Layout, - const MCSectionData *Section, - uint64_t Address) const { - const MCSymbolData *Best = 0; - uint64_t BestAddress = 0; - - for (MCAssembler::const_symbol_iterator it = symbol_begin(), - ie = symbol_end(); it != ie; ++it) { - // Ignore non-linker visible symbols. - if (!isSymbolLinkerVisible(it)) - continue; - - // Ignore symbols not in the same section. - if (!it->getFragment() || it->getFragment()->getParent() != Section) - continue; - - // Otherwise, find the closest symbol preceding this address (ties are - // resolved in favor of the last defined symbol). - uint64_t SymbolAddress = Layout.getSymbolAddress(it); - if (SymbolAddress <= Address && (!Best || SymbolAddress >= BestAddress)) { - Best = it; - BestAddress = SymbolAddress; - } - } - - return Best; -} - -// FIXME-PERF: This routine is really slow. const MCSymbolData *MCAssembler::getAtom(const MCAsmLayout &Layout, const MCSymbolData *SD) const { // Linker visible symbols define atoms. - if (isSymbolLinkerVisible(SD)) + if (isSymbolLinkerVisible(SD->getSymbol())) return SD; // Absolute and undefined symbols have no defining atom. if (!SD->getFragment()) return 0; - // Otherwise, search by address. - return getAtomForAddress(Layout, SD->getFragment()->getParent(), - Layout.getSymbolAddress(SD)); + // Non-linker visible symbols in sections which can't be atomized have no + // defining atom. + if (!getBackend().isSectionAtomizable( + SD->getFragment()->getParent()->getSection())) + return 0; + + // Otherwise, return the atom for the containing fragment. + return SD->getFragment()->getAtom(); } bool MCAssembler::EvaluateFixup(const MCAsmLayout &Layout, - const MCAsmFixup &Fixup, const MCFragment *DF, + const MCFixup &Fixup, const MCFragment *DF, MCValue &Target, uint64_t &Value) const { ++stats::EvaluateFixup; - if (!Fixup.Value->EvaluateAsRelocatable(Target, &Layout)) - llvm_report_error("expected relocatable expression"); + if (!Fixup.getValue()->EvaluateAsRelocatable(Target, &Layout)) + report_fatal_error("expected relocatable expression"); // FIXME: How do non-scattered symbols work in ELF? I presume the linker // doesn't support small relocations, but then under what criteria does the @@ -281,8 +355,8 @@ bool MCAssembler::EvaluateFixup(const MCAsmLayout &Layout, Value = Target.getConstant(); - bool IsPCRel = - Emitter.getFixupKindInfo(Fixup.Kind).Flags & MCFixupKindInfo::FKF_IsPCRel; + bool IsPCRel = Emitter.getFixupKindInfo( + Fixup.getKind()).Flags & MCFixupKindInfo::FKF_IsPCRel; bool IsResolved = true; if (const MCSymbolRefExpr *A = Target.getSymA()) { if (A->getSymbol().isDefined()) @@ -305,8 +379,7 @@ bool MCAssembler::EvaluateFixup(const MCAsmLayout &Layout, // symbol) that the fixup value is relative to. const MCSymbolData *BaseSymbol = 0; if (IsPCRel) { - BaseSymbol = getAtomForAddress( - Layout, DF->getParent(), Layout.getFragmentAddress(DF)+Fixup.Offset); + BaseSymbol = DF->getAtom(); if (!BaseSymbol) IsResolved = false; } @@ -325,119 +398,158 @@ bool MCAssembler::EvaluateFixup(const MCAsmLayout &Layout, } if (IsPCRel) - Value -= Layout.getFragmentAddress(DF) + Fixup.Offset; + Value -= Layout.getFragmentAddress(DF) + Fixup.getOffset(); return IsResolved; } -void MCAssembler::LayoutSection(MCSectionData &SD, - MCAsmLayout &Layout) { - uint64_t Address, StartAddress = Address = Layout.getSectionAddress(&SD); +uint64_t MCAssembler::ComputeFragmentSize(MCAsmLayout &Layout, + const MCFragment &F, + uint64_t SectionAddress, + uint64_t FragmentOffset) const { + switch (F.getKind()) { + case MCFragment::FT_Data: + return cast(F).getContents().size(); + case MCFragment::FT_Fill: + return cast(F).getSize(); + case MCFragment::FT_Inst: + return cast(F).getInstSize(); - for (MCSectionData::iterator it = SD.begin(), ie = SD.end(); it != ie; ++it) { - MCFragment &F = *it; + case MCFragment::FT_Align: { + const MCAlignFragment &AF = cast(F); - F.setOffset(Address - StartAddress); + assert((!AF.hasOnlyAlignAddress() || !AF.getNextNode()) && + "Invalid OnlyAlignAddress bit, not the last fragment!"); - // Evaluate fragment size. - switch (F.getKind()) { - case MCFragment::FT_Align: { - MCAlignFragment &AF = cast(F); + uint64_t Size = OffsetToAlignment(SectionAddress + FragmentOffset, + AF.getAlignment()); - uint64_t Size = OffsetToAlignment(Address, AF.getAlignment()); - if (Size > AF.getMaxBytesToEmit()) - AF.setFileSize(0); - else - AF.setFileSize(Size); - break; - } + // Honor MaxBytesToEmit. + if (Size > AF.getMaxBytesToEmit()) + return 0; - case MCFragment::FT_Data: - F.setFileSize(cast(F).getContents().size()); - break; + return Size; + } - case MCFragment::FT_Fill: { - MCFillFragment &FF = cast(F); - F.setFileSize(FF.getValueSize() * FF.getCount()); - break; - } + case MCFragment::FT_Org: { + const MCOrgFragment &OF = cast(F); - case MCFragment::FT_Inst: - F.setFileSize(cast(F).getInstSize()); - break; + // FIXME: We should compute this sooner, we don't want to recurse here, and + // we would like to be more functional. + int64_t TargetLocation; + if (!OF.getOffset().EvaluateAsAbsolute(TargetLocation, &Layout)) + report_fatal_error("expected assembly-time absolute expression"); - case MCFragment::FT_Org: { - MCOrgFragment &OF = cast(F); + // FIXME: We need a way to communicate this error. + int64_t Offset = TargetLocation - FragmentOffset; + if (Offset < 0) + report_fatal_error("invalid .org offset '" + Twine(TargetLocation) + + "' (at offset '" + Twine(FragmentOffset) + "'"); - int64_t TargetLocation; - if (!OF.getOffset().EvaluateAsAbsolute(TargetLocation, &Layout)) - llvm_report_error("expected assembly-time absolute expression"); + return Offset; + } + } - // FIXME: We need a way to communicate this error. - int64_t Offset = TargetLocation - F.getOffset(); - if (Offset < 0) - llvm_report_error("invalid .org offset '" + Twine(TargetLocation) + - "' (at offset '" + Twine(F.getOffset()) + "'"); + assert(0 && "invalid fragment kind"); + return 0; +} - F.setFileSize(Offset); - break; - } +void MCAsmLayout::LayoutFile() { + // Initialize the first section and set the valid fragment layout point. All + // actual layout computations are done lazily. + LastValidFragment = 0; + if (!getSectionOrder().empty()) + getSectionOrder().front()->Address = 0; +} - case MCFragment::FT_ZeroFill: { - MCZeroFillFragment &ZFF = cast(F); +void MCAsmLayout::LayoutFragment(MCFragment *F) { + MCFragment *Prev = F->getPrevNode(); + + // We should never try to recompute something which is up-to-date. + assert(!isFragmentUpToDate(F) && "Attempt to recompute up-to-date fragment!"); + // We should never try to compute the fragment layout if the section isn't + // up-to-date. + assert(isSectionUpToDate(F->getParent()) && + "Attempt to compute fragment before it's section!"); + // We should never try to compute the fragment layout if it's predecessor + // isn't up-to-date. + assert((!Prev || isFragmentUpToDate(Prev)) && + "Attempt to compute fragment before it's predecessor!"); + + ++stats::FragmentLayouts; + + // Compute the fragment start address. + uint64_t StartAddress = F->getParent()->Address; + uint64_t Address = StartAddress; + if (Prev) + Address += Prev->Offset + Prev->EffectiveSize; + + // Compute fragment offset and size. + F->Offset = Address - StartAddress; + F->EffectiveSize = getAssembler().ComputeFragmentSize(*this, *F, StartAddress, + F->Offset); + LastValidFragment = F; + + // If this is the last fragment in a section, update the next section address. + if (!F->getNextNode()) { + unsigned NextIndex = F->getParent()->getLayoutOrder() + 1; + if (NextIndex != getSectionOrder().size()) + LayoutSection(getSectionOrder()[NextIndex]); + } +} - // Align the fragment offset; it is safe to adjust the offset freely since - // this is only in virtual sections. - Address = RoundUpToAlignment(Address, ZFF.getAlignment()); - F.setOffset(Address - StartAddress); +void MCAsmLayout::LayoutSection(MCSectionData *SD) { + unsigned SectionOrderIndex = SD->getLayoutOrder(); - // FIXME: This is misnamed. - F.setFileSize(ZFF.getSize()); - break; - } - } + ++stats::SectionLayouts; - Address += F.getFileSize(); + // Compute the section start address. + uint64_t StartAddress = 0; + if (SectionOrderIndex) { + MCSectionData *Prev = getSectionOrder()[SectionOrderIndex - 1]; + StartAddress = getSectionAddress(Prev) + getSectionAddressSize(Prev); } - // Set the section sizes. - SD.setSize(Address - StartAddress); - if (getBackend().isVirtualSection(SD.getSection())) - SD.setFileSize(0); - else - SD.setFileSize(Address - StartAddress); + // Honor the section alignment requirements. + StartAddress = RoundUpToAlignment(StartAddress, SD->getAlignment()); + + // Set the section address. + SD->Address = StartAddress; } /// WriteFragmentData - Write the \arg F data to the output file. -static void WriteFragmentData(const MCAssembler &Asm, const MCFragment &F, - MCObjectWriter *OW) { +static void WriteFragmentData(const MCAssembler &Asm, const MCAsmLayout &Layout, + const MCFragment &F, MCObjectWriter *OW) { uint64_t Start = OW->getStream().tell(); (void) Start; ++stats::EmittedFragments; // FIXME: Embed in fragments instead? + uint64_t FragmentSize = Layout.getFragmentEffectiveSize(&F); switch (F.getKind()) { case MCFragment::FT_Align: { MCAlignFragment &AF = cast(F); - uint64_t Count = AF.getFileSize() / AF.getValueSize(); + uint64_t Count = FragmentSize / AF.getValueSize(); + + assert(AF.getValueSize() && "Invalid virtual align in concrete fragment!"); // FIXME: This error shouldn't actually occur (the front end should emit // multiple .align directives to enforce the semantics it wants), but is // severe enough that we want to report it. How to handle this? - if (Count * AF.getValueSize() != AF.getFileSize()) - llvm_report_error("undefined .align directive, value size '" + + if (Count * AF.getValueSize() != FragmentSize) + report_fatal_error("undefined .align directive, value size '" + Twine(AF.getValueSize()) + "' is not a divisor of padding size '" + - Twine(AF.getFileSize()) + "'"); + Twine(FragmentSize) + "'"); // See if we are aligning with nops, and if so do that first to try to fill // the Count bytes. Then if that did not fill any bytes or there are any // bytes left to fill use the the Value and ValueSize to fill the rest. // If we are aligning with nops, ask that target to emit the right data. - if (AF.getEmitNops()) { + if (AF.hasEmitNops()) { if (!Asm.getBackend().WriteNopData(Count, OW)) - llvm_report_error("unable to write nop sequence of " + + report_fatal_error("unable to write nop sequence of " + Twine(Count) + " bytes"); break; } @@ -458,14 +570,17 @@ static void WriteFragmentData(const MCAssembler &Asm, const MCFragment &F, case MCFragment::FT_Data: { MCDataFragment &DF = cast(F); - assert(DF.getFileSize() == DF.getContents().size() && "Invalid size!"); + assert(FragmentSize == DF.getContents().size() && "Invalid size!"); OW->WriteBytes(DF.getContents().str()); break; } case MCFragment::FT_Fill: { MCFillFragment &FF = cast(F); - for (uint64_t i = 0, e = FF.getCount(); i != e; ++i) { + + assert(FF.getValueSize() && "Invalid virtual align in concrete fragment!"); + + for (uint64_t i = 0, e = FF.getSize() / FF.getValueSize(); i != e; ++i) { switch (FF.getValueSize()) { default: assert(0 && "Invalid size!"); @@ -485,26 +600,40 @@ static void WriteFragmentData(const MCAssembler &Asm, const MCFragment &F, case MCFragment::FT_Org: { MCOrgFragment &OF = cast(F); - for (uint64_t i = 0, e = OF.getFileSize(); i != e; ++i) + for (uint64_t i = 0, e = FragmentSize; i != e; ++i) OW->Write8(uint8_t(OF.getValue())); break; } - - case MCFragment::FT_ZeroFill: { - assert(0 && "Invalid zero fill fragment in concrete section!"); - break; - } } - assert(OW->getStream().tell() - Start == F.getFileSize()); + assert(OW->getStream().tell() - Start == FragmentSize); } void MCAssembler::WriteSectionData(const MCSectionData *SD, + const MCAsmLayout &Layout, MCObjectWriter *OW) const { // Ignore virtual sections. if (getBackend().isVirtualSection(SD->getSection())) { - assert(SD->getFileSize() == 0); + assert(Layout.getSectionFileSize(SD) == 0 && "Invalid size for section!"); + + // Check that contents are only things legal inside a virtual section. + for (MCSectionData::const_iterator it = SD->begin(), + ie = SD->end(); it != ie; ++it) { + switch (it->getKind()) { + default: + assert(0 && "Invalid fragment in virtual section!"); + case MCFragment::FT_Align: + assert(!cast(it)->getValueSize() && + "Invalid align in virtual section!"); + break; + case MCFragment::FT_Fill: + assert(!cast(it)->getValueSize() && + "Invalid fill in virtual section!"); + break; + } + } + return; } @@ -513,13 +642,9 @@ void MCAssembler::WriteSectionData(const MCSectionData *SD, for (MCSectionData::const_iterator it = SD->begin(), ie = SD->end(); it != ie; ++it) - WriteFragmentData(*this, *it, OW); - - // Add section padding. - assert(SD->getFileSize() >= SD->getSize() && "Invalid section sizes!"); - OW->WriteZeros(SD->getFileSize() - SD->getSize()); + WriteFragmentData(*this, Layout, *it, OW); - assert(OW->getStream().tell() - Start == SD->getFileSize()); + assert(OW->getStream().tell() - Start == Layout.getSectionFileSize(SD)); } void MCAssembler::Finish() { @@ -527,8 +652,56 @@ void MCAssembler::Finish() { llvm::errs() << "assembler backend - pre-layout\n--\n"; dump(); }); - // Layout until everything fits. + // Create the layout object. MCAsmLayout Layout(*this); + + // Insert additional align fragments for concrete sections to explicitly pad + // the previous section to match their alignment requirements. This is for + // 'gas' compatibility, it shouldn't strictly be necessary. + // + // FIXME: This may be Mach-O specific. + for (unsigned i = 1, e = Layout.getSectionOrder().size(); i < e; ++i) { + MCSectionData *SD = Layout.getSectionOrder()[i]; + + // Ignore sections without alignment requirements. + unsigned Align = SD->getAlignment(); + if (Align <= 1) + continue; + + // Ignore virtual sections, they don't cause file size modifications. + if (getBackend().isVirtualSection(SD->getSection())) + continue; + + // Otherwise, create a new align fragment at the end of the previous + // section. + MCAlignFragment *AF = new MCAlignFragment(Align, 0, 1, Align, + Layout.getSectionOrder()[i - 1]); + AF->setOnlyAlignAddress(true); + } + + // Create dummy fragments and assign section ordinals. + unsigned SectionIndex = 0; + for (MCAssembler::iterator it = begin(), ie = end(); it != ie; ++it) { + // Create dummy fragments to eliminate any empty sections, this simplifies + // layout. + if (it->getFragmentList().empty()) + new MCFillFragment(0, 1, 0, it); + + it->setOrdinal(SectionIndex++); + } + + // Assign layout order indices to sections and fragments. + unsigned FragmentIndex = 0; + for (unsigned i = 0, e = Layout.getSectionOrder().size(); i != e; ++i) { + MCSectionData *SD = Layout.getSectionOrder()[i]; + SD->setLayoutOrder(i); + + for (MCSectionData::iterator it2 = SD->begin(), + ie2 = SD->end(); it2 != ie2; ++it2) + it2->setLayoutOrder(FragmentIndex++); + } + + // Layout until everything fits. while (LayoutOnce(Layout)) continue; @@ -546,7 +719,7 @@ void MCAssembler::Finish() { uint64_t StartOffset = OS.tell(); llvm::OwningPtr Writer(getBackend().createObjectWriter(OS)); if (!Writer) - llvm_report_error("unable to create object writer!"); + report_fatal_error("unable to create object writer!"); // Allow the object writer a chance to perform post-layout binding (for // example, to set the index fields in the symbol data). @@ -562,7 +735,7 @@ void MCAssembler::Finish() { for (MCDataFragment::fixup_iterator it3 = DF->fixup_begin(), ie3 = DF->fixup_end(); it3 != ie3; ++it3) { - MCAsmFixup &Fixup = *it3; + MCFixup &Fixup = *it3; // Evaluate the fixup. MCValue Target; @@ -581,14 +754,16 @@ void MCAssembler::Finish() { // Write the object file. Writer->WriteObject(*this, Layout); - OS.flush(); stats::ObjectBytes += OS.tell() - StartOffset; } -bool MCAssembler::FixupNeedsRelaxation(const MCAsmFixup &Fixup, +bool MCAssembler::FixupNeedsRelaxation(const MCFixup &Fixup, const MCFragment *DF, const MCAsmLayout &Layout) const { + if (getRelaxAll()) + return true; + // If we cannot resolve the fixup value, it requires relaxation. MCValue Target; uint64_t Value; @@ -596,6 +771,8 @@ bool MCAssembler::FixupNeedsRelaxation(const MCAsmFixup &Fixup, return true; // Otherwise, relax if the value is too big for a (signed) i8. + // + // FIXME: This is target dependent! return int64_t(Value) != int64_t(int8_t(Value)); } @@ -604,7 +781,7 @@ bool MCAssembler::FragmentNeedsRelaxation(const MCInstFragment *IF, // If this inst doesn't ever need relaxation, ignore it. This occurs when we // are intentionally pushing out inst fragments, or because we relaxed a // previous instruction to one that doesn't need relaxation. - if (!getBackend().MayNeedRelaxation(IF->getInst(), IF->getFixups())) + if (!getBackend().MayNeedRelaxation(IF->getInst())) return false; for (MCInstFragment::const_fixup_iterator it = IF->fixup_begin(), @@ -618,50 +795,11 @@ bool MCAssembler::FragmentNeedsRelaxation(const MCInstFragment *IF, bool MCAssembler::LayoutOnce(MCAsmLayout &Layout) { ++stats::RelaxationSteps; - // Layout the concrete sections and fragments. - uint64_t Address = 0; - MCSectionData *Prev = 0; - for (iterator it = begin(), ie = end(); it != ie; ++it) { - MCSectionData &SD = *it; - - // Skip virtual sections. - if (getBackend().isVirtualSection(SD.getSection())) - continue; - - // Align this section if necessary by adding padding bytes to the previous - // section. - if (uint64_t Pad = OffsetToAlignment(Address, it->getAlignment())) { - assert(Prev && "Missing prev section!"); - Prev->setFileSize(Prev->getFileSize() + Pad); - Address += Pad; - } - - // Layout the section fragments and its size. - Layout.setSectionAddress(&SD, Address); - LayoutSection(SD, Layout); - Address += SD.getFileSize(); - - Prev = &SD; - } - - // Layout the virtual sections. - for (iterator it = begin(), ie = end(); it != ie; ++it) { - MCSectionData &SD = *it; - - if (!getBackend().isVirtualSection(SD.getSection())) - continue; - - // Align this section if necessary by adding padding bytes to the previous - // section. - if (uint64_t Pad = OffsetToAlignment(Address, it->getAlignment())) - Address += Pad; - - Layout.setSectionAddress(&SD, Address); - LayoutSection(SD, Layout); - Address += SD.getSize(); - } + // Layout the sections in order. + Layout.LayoutFile(); // Scan for fragments that need relaxation. + bool WasRelaxed = false; for (iterator it = begin(), ie = end(); it != ie; ++it) { MCSectionData &SD = *it; @@ -680,7 +818,7 @@ bool MCAssembler::LayoutOnce(MCAsmLayout &Layout) { // Relax the fragment. MCInst Relaxed; - getBackend().RelaxInstruction(IF, Relaxed); + getBackend().RelaxInstruction(IF->getInst(), Relaxed); // Encode the new instruction. // @@ -693,24 +831,21 @@ bool MCAssembler::LayoutOnce(MCAsmLayout &Layout) { VecOS.flush(); // Update the instruction fragment. + int SlideAmount = Code.size() - IF->getInstSize(); IF->setInst(Relaxed); IF->getCode() = Code; IF->getFixups().clear(); - for (unsigned i = 0, e = Fixups.size(); i != e; ++i) { - MCFixup &F = Fixups[i]; - IF->getFixups().push_back(MCAsmFixup(F.getOffset(), *F.getValue(), - F.getKind())); - } + // FIXME: Eliminate copy. + for (unsigned i = 0, e = Fixups.size(); i != e; ++i) + IF->getFixups().push_back(Fixups[i]); - // Restart layout. - // - // FIXME-PERF: This is O(N^2), but will be eliminated once we have a - // smart MCAsmLayout object. - return true; + // Update the layout, and remember that we relaxed. + Layout.UpdateForSlide(IF, SlideAmount); + WasRelaxed = true; } } - return false; + return WasRelaxed; } void MCAssembler::FinishLayout(MCAsmLayout &Layout) { @@ -738,8 +873,9 @@ void MCAssembler::FinishLayout(MCAsmLayout &Layout) { // Update the data fragments layout data. DF->setParent(IF->getParent()); - DF->setOffset(IF->getOffset()); - DF->setFileSize(IF->getInstSize()); + DF->setAtom(IF->getAtom()); + DF->setLayoutOrder(IF->getLayoutOrder()); + Layout.FragmentReplaced(IF, DF); // Copy in the data and the fixups. DF->getContents().append(IF->getCode().begin(), IF->getCode().end()); @@ -757,9 +893,10 @@ void MCAssembler::FinishLayout(MCAsmLayout &Layout) { namespace llvm { -raw_ostream &operator<<(raw_ostream &OS, const MCAsmFixup &AF) { - OS << ""; +raw_ostream &operator<<(raw_ostream &OS, const MCFixup &AF) { + OS << ""; return OS; } @@ -768,94 +905,82 @@ raw_ostream &operator<<(raw_ostream &OS, const MCAsmFixup &AF) { void MCFragment::dump() { raw_ostream &OS = llvm::errs(); - OS << ""; -} - -void MCAlignFragment::dump() { - raw_ostream &OS = llvm::errs(); - - OS << "MCFragment::dump(); - OS << "\n "; - OS << " Alignment:" << getAlignment() - << " Value:" << getValue() << " ValueSize:" << getValueSize() - << " MaxBytesToEmit:" << getMaxBytesToEmit() << ">"; -} + OS << "<"; + switch (getKind()) { + case MCFragment::FT_Align: OS << "MCAlignFragment"; break; + case MCFragment::FT_Data: OS << "MCDataFragment"; break; + case MCFragment::FT_Fill: OS << "MCFillFragment"; break; + case MCFragment::FT_Inst: OS << "MCInstFragment"; break; + case MCFragment::FT_Org: OS << "MCOrgFragment"; break; + } -void MCDataFragment::dump() { - raw_ostream &OS = llvm::errs(); + OS << ""; - OS << "MCFragment::dump(); - OS << "\n "; - OS << " Contents:["; - for (unsigned i = 0, e = getContents().size(); i != e; ++i) { - if (i) OS << ","; - OS << hexdigit((Contents[i] >> 4) & 0xF) << hexdigit(Contents[i] & 0xF); - } - OS << "] (" << getContents().size() << " bytes)"; - - if (!getFixups().empty()) { - OS << ",\n "; - OS << " Fixups:["; - for (fixup_iterator it = fixup_begin(), ie = fixup_end(); it != ie; ++it) { - if (it != fixup_begin()) OS << ",\n "; - OS << *it; + switch (getKind()) { + case MCFragment::FT_Align: { + const MCAlignFragment *AF = cast(this); + if (AF->hasEmitNops()) + OS << " (emit nops)"; + if (AF->hasOnlyAlignAddress()) + OS << " (only align section)"; + OS << "\n "; + OS << " Alignment:" << AF->getAlignment() + << " Value:" << AF->getValue() << " ValueSize:" << AF->getValueSize() + << " MaxBytesToEmit:" << AF->getMaxBytesToEmit() << ">"; + break; + } + case MCFragment::FT_Data: { + const MCDataFragment *DF = cast(this); + OS << "\n "; + OS << " Contents:["; + const SmallVectorImpl &Contents = DF->getContents(); + for (unsigned i = 0, e = Contents.size(); i != e; ++i) { + if (i) OS << ","; + OS << hexdigit((Contents[i] >> 4) & 0xF) << hexdigit(Contents[i] & 0xF); } - OS << "]"; + OS << "] (" << Contents.size() << " bytes)"; + + if (!DF->getFixups().empty()) { + OS << ",\n "; + OS << " Fixups:["; + for (MCDataFragment::const_fixup_iterator it = DF->fixup_begin(), + ie = DF->fixup_end(); it != ie; ++it) { + if (it != DF->fixup_begin()) OS << ",\n "; + OS << *it; + } + OS << "]"; + } + break; + } + case MCFragment::FT_Fill: { + const MCFillFragment *FF = cast(this); + OS << " Value:" << FF->getValue() << " ValueSize:" << FF->getValueSize() + << " Size:" << FF->getSize(); + break; + } + case MCFragment::FT_Inst: { + const MCInstFragment *IF = cast(this); + OS << "\n "; + OS << " Inst:"; + IF->getInst().dump_pretty(OS); + break; + } + case MCFragment::FT_Org: { + const MCOrgFragment *OF = cast(this); + OS << "\n "; + OS << " Offset:" << OF->getOffset() << " Value:" << OF->getValue(); + break; + } } - - OS << ">"; -} - -void MCFillFragment::dump() { - raw_ostream &OS = llvm::errs(); - - OS << "MCFragment::dump(); - OS << "\n "; - OS << " Value:" << getValue() << " ValueSize:" << getValueSize() - << " Count:" << getCount() << ">"; -} - -void MCInstFragment::dump() { - raw_ostream &OS = llvm::errs(); - - OS << "MCFragment::dump(); - OS << "\n "; - OS << " Inst:"; - getInst().dump_pretty(OS); OS << ">"; } -void MCOrgFragment::dump() { - raw_ostream &OS = llvm::errs(); - - OS << "MCFragment::dump(); - OS << "\n "; - OS << " Offset:" << getOffset() << " Value:" << getValue() << ">"; -} - -void MCZeroFillFragment::dump() { - raw_ostream &OS = llvm::errs(); - - OS << "MCFragment::dump(); - OS << "\n "; - OS << " Size:" << getSize() << " Alignment:" << getAlignment() << ">"; -} - void MCSectionData::dump() { raw_ostream &OS = llvm::errs(); OS << "