#define DEBUG_TYPE "assembler"
#include "llvm/MC/MCAssembler.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/ADT/StringExtras.h"
+#include "llvm/ADT/Twine.h"
+#include "llvm/MC/MCAsmBackend.h"
#include "llvm/MC/MCAsmLayout.h"
#include "llvm/MC/MCCodeEmitter.h"
+#include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCDwarf.h"
#include "llvm/MC/MCExpr.h"
+#include "llvm/MC/MCFixupKindInfo.h"
#include "llvm/MC/MCObjectWriter.h"
#include "llvm/MC/MCSection.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/MC/MCValue.h"
-#include "llvm/MC/MCDwarf.h"
-#include "llvm/ADT/OwningPtr.h"
-#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/LEB128.h"
+#include "llvm/Support/TargetRegistry.h"
#include "llvm/Support/raw_ostream.h"
-#include "llvm/Target/TargetRegistry.h"
-#include "llvm/Target/TargetAsmBackend.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/Compression.h"
+#include "llvm/Support/Host.h"
-#include <vector>
using namespace llvm;
namespace {
namespace stats {
-STATISTIC(EmittedFragments, "Number of emitted assembler fragments");
-STATISTIC(EvaluateFixup, "Number of evaluated fixups");
+STATISTIC(EmittedFragments, "Number of emitted assembler fragments - total");
+STATISTIC(EmittedRelaxableFragments,
+ "Number of emitted assembler fragments - relaxable");
+STATISTIC(EmittedDataFragments,
+ "Number of emitted assembler fragments - data");
+STATISTIC(EmittedCompactEncodedInstFragments,
+ "Number of emitted assembler fragments - compact encoded inst");
+STATISTIC(EmittedAlignFragments,
+ "Number of emitted assembler fragments - align");
+STATISTIC(EmittedFillFragments,
+ "Number of emitted assembler fragments - fill");
+STATISTIC(EmittedOrgFragments,
+ "Number of emitted assembler fragments - org");
+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");
}
}
/* *** */
MCAsmLayout::MCAsmLayout(MCAssembler &Asm)
- : Assembler(Asm), LastValidFragment(0)
+ : Assembler(Asm), LastValidFragment()
{
// 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()))
+ if (!it->getSection().isVirtualSection())
SectionOrder.push_back(&*it);
for (MCAssembler::iterator it = Asm.begin(), ie = Asm.end(); it != ie; ++it)
- if (Asm.getBackend().isVirtualSection(it->getSection()))
+ if (it->getSection().isVirtualSection())
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());
+bool MCAsmLayout::isFragmentValid(const MCFragment *F) const {
+ const MCSectionData &SD = *F->getParent();
+ const MCFragment *LastValid = LastValidFragment.lookup(&SD);
+ if (!LastValid)
+ return false;
+ assert(LastValid->getParent() == F->getParent());
+ return F->getLayoutOrder() <= LastValid->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))
+void MCAsmLayout::invalidateFragmentsFrom(MCFragment *F) {
+ // If this fragment wasn't already valid, we don't need to do anything.
+ if (!isFragmentValid(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());
- }
- }
+ // Otherwise, reset the last valid fragment to the previous fragment
+ // (if this is the first fragment, it will be NULL).
+ const MCSectionData &SD = *F->getParent();
+ LastValidFragment[&SD] = F->getPrevNode();
}
-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<MCAsmLayout*>(this)->LayoutFragment(Cur);
- }
-}
-
-void MCAsmLayout::FragmentReplaced(MCFragment *Src, MCFragment *Dst) {
- if (LastValidFragment == Src)
- LastValidFragment = Dst;
-
- Dst->Offset = Src->Offset;
- Dst->EffectiveSize = Src->EffectiveSize;
-}
+void MCAsmLayout::ensureValid(const MCFragment *F) const {
+ MCSectionData &SD = *F->getParent();
-uint64_t MCAsmLayout::getFragmentAddress(const MCFragment *F) const {
- assert(F->getParent() && "Missing section()!");
- return getSectionAddress(F->getParent()) + getFragmentOffset(F);
-}
+ MCFragment *Cur = LastValidFragment[&SD];
+ if (!Cur)
+ Cur = &*SD.begin();
+ else
+ Cur = Cur->getNextNode();
-uint64_t MCAsmLayout::getFragmentEffectiveSize(const MCFragment *F) const {
- EnsureValid(F);
- assert(F->EffectiveSize != ~UINT64_C(0) && "Address not set!");
- return F->EffectiveSize;
+ // Advance the layout position until the fragment is valid.
+ while (!isFragmentValid(F)) {
+ assert(Cur && "Layout bookkeeping error");
+ const_cast<MCAsmLayout*>(this)->layoutFragment(Cur);
+ Cur = Cur->getNextNode();
+ }
}
uint64_t MCAsmLayout::getFragmentOffset(const MCFragment *F) const {
- EnsureValid(F);
+ ensureValid(F);
assert(F->Offset != ~UINT64_C(0) && "Address not set!");
return F->Offset;
}
-uint64_t MCAsmLayout::getSymbolAddress(const MCSymbolData *SD) const {
- assert(SD->getFragment() && "Invalid getAddress() on undefined symbol!");
- return getFragmentAddress(SD->getFragment()) + SD->getOffset();
-}
+uint64_t MCAsmLayout::getSymbolOffset(const MCSymbolData *SD) const {
+ const MCSymbol &S = SD->getSymbol();
+
+ // If this is a variable, then recursively evaluate now.
+ if (S.isVariable()) {
+ MCValue Target;
+ if (!S.getVariableValue()->EvaluateAsRelocatable(Target, this))
+ report_fatal_error("unable to evaluate offset for variable '" +
+ S.getName() + "'");
+
+ // Verify that any used symbols are defined.
+ if (Target.getSymA() && Target.getSymA()->getSymbol().isUndefined())
+ report_fatal_error("unable to evaluate offset to undefined symbol '" +
+ Target.getSymA()->getSymbol().getName() + "'");
+ if (Target.getSymB() && Target.getSymB()->getSymbol().isUndefined())
+ report_fatal_error("unable to evaluate offset to undefined symbol '" +
+ Target.getSymB()->getSymbol().getName() + "'");
+
+ uint64_t Offset = Target.getConstant();
+ if (Target.getSymA())
+ Offset += getSymbolOffset(&Assembler.getSymbolData(
+ Target.getSymA()->getSymbol()));
+ if (Target.getSymB())
+ Offset -= getSymbolOffset(&Assembler.getSymbolData(
+ Target.getSymB()->getSymbol()));
+ return Offset;
+ }
-uint64_t MCAsmLayout::getSectionAddress(const MCSectionData *SD) const {
- EnsureValid(SD->begin());
- assert(SD->Address != ~UINT64_C(0) && "Address not set!");
- return SD->Address;
+ assert(SD->getFragment() && "Invalid getOffset() on undefined symbol!");
+ return getFragmentOffset(SD->getFragment()) + SD->getOffset();
}
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);
+ return getFragmentOffset(&F) + getAssembler().computeFragmentSize(*this, F);
}
uint64_t MCAsmLayout::getSectionFileSize(const MCSectionData *SD) const {
// Virtual sections have no file size.
- if (getAssembler().getBackend().isVirtualSection(SD->getSection()))
+ if (SD->getSection().isVirtualSection())
return 0;
// Otherwise, the file size is the same as the address space size.
return getSectionAddressSize(SD);
}
-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<MCAlignFragment>(&(SD->getFragmentList().back()));
- if (AF && AF->hasOnlyAlignAddress())
- Size -= getFragmentEffectiveSize(AF);
+uint64_t MCAsmLayout::computeBundlePadding(const MCFragment *F,
+ uint64_t FOffset, uint64_t FSize) {
+ uint64_t BundleSize = Assembler.getBundleAlignSize();
+ assert(BundleSize > 0 &&
+ "computeBundlePadding should only be called if bundling is enabled");
+ uint64_t BundleMask = BundleSize - 1;
+ uint64_t OffsetInBundle = FOffset & BundleMask;
+ uint64_t EndOfFragment = OffsetInBundle + FSize;
- return Size;
+ // There are two kinds of bundling restrictions:
+ //
+ // 1) For alignToBundleEnd(), add padding to ensure that the fragment will
+ // *end* on a bundle boundary.
+ // 2) Otherwise, check if the fragment would cross a bundle boundary. If it
+ // would, add padding until the end of the bundle so that the fragment
+ // will start in a new one.
+ if (F->alignToBundleEnd()) {
+ // Three possibilities here:
+ //
+ // A) The fragment just happens to end at a bundle boundary, so we're good.
+ // B) The fragment ends before the current bundle boundary: pad it just
+ // enough to reach the boundary.
+ // C) The fragment ends after the current bundle boundary: pad it until it
+ // reaches the end of the next bundle boundary.
+ //
+ // Note: this code could be made shorter with some modulo trickery, but it's
+ // intentionally kept in its more explicit form for simplicity.
+ if (EndOfFragment == BundleSize)
+ return 0;
+ else if (EndOfFragment < BundleSize)
+ return BundleSize - EndOfFragment;
+ else { // EndOfFragment > BundleSize
+ return 2 * BundleSize - EndOfFragment;
+ }
+ } else if (EndOfFragment > BundleSize)
+ return BundleSize - OffsetInBundle;
+ else
+ return 0;
}
/* *** */
}
MCFragment::MCFragment(FragmentType _Kind, MCSectionData *_Parent)
- : Kind(_Kind), Parent(_Parent), Atom(0), Offset(~UINT64_C(0)),
- EffectiveSize(~UINT64_C(0))
+ : Kind(_Kind), Parent(_Parent), Atom(0), Offset(~UINT64_C(0))
{
if (Parent)
Parent->getFragmentList().push_back(this);
/* *** */
+MCEncodedFragment::~MCEncodedFragment() {
+}
+
+/* *** */
+
+MCEncodedFragmentWithFixups::~MCEncodedFragmentWithFixups() {
+}
+
+/* *** */
+
+const SmallVectorImpl<char> &MCCompressedFragment::getCompressedContents() const {
+ assert(getParent()->size() == 1 &&
+ "Only compress sections containing a single fragment");
+ if (CompressedContents.empty()) {
+ std::unique_ptr<MemoryBuffer> CompressedSection;
+ zlib::Status Success =
+ zlib::compress(StringRef(getContents().data(), getContents().size()),
+ CompressedSection);
+ (void)Success;
+ assert(Success == zlib::StatusOK);
+ CompressedContents.push_back('Z');
+ CompressedContents.push_back('L');
+ CompressedContents.push_back('I');
+ CompressedContents.push_back('B');
+ uint64_t Size = getContents().size();
+ if (sys::IsLittleEndianHost)
+ Size = sys::SwapByteOrder(Size);
+ CompressedContents.append(reinterpret_cast<char *>(&Size),
+ reinterpret_cast<char *>(&Size + 1));
+ CompressedContents.append(CompressedSection->getBuffer().begin(),
+ CompressedSection->getBuffer().end());
+ }
+ return CompressedContents;
+}
+
+SmallVectorImpl<char> &MCCompressedFragment::getContents() {
+ assert(CompressedContents.empty() &&
+ "Fragment contents should not be altered after compression");
+ return MCDataFragment::getContents();
+}
+
+/* *** */
+
MCSectionData::MCSectionData() : Section(0) {}
MCSectionData::MCSectionData(const MCSection &_Section, MCAssembler *A)
: Section(&_Section),
+ Ordinal(~UINT32_C(0)),
Alignment(1),
- Address(~UINT64_C(0)),
+ BundleLockState(NotBundleLocked), BundleGroupBeforeFirstInst(false),
HasInstructions(false)
{
if (A)
A->getSectionList().push_back(this);
}
+MCSectionData::iterator
+MCSectionData::getSubsectionInsertionPoint(unsigned Subsection) {
+ if (Subsection == 0 && SubsectionFragmentMap.empty())
+ return end();
+
+ SmallVectorImpl<std::pair<unsigned, MCFragment *> >::iterator MI =
+ std::lower_bound(SubsectionFragmentMap.begin(), SubsectionFragmentMap.end(),
+ std::make_pair(Subsection, (MCFragment *)0));
+ bool ExactMatch = false;
+ if (MI != SubsectionFragmentMap.end()) {
+ ExactMatch = MI->first == Subsection;
+ if (ExactMatch)
+ ++MI;
+ }
+ iterator IP;
+ if (MI == SubsectionFragmentMap.end())
+ IP = end();
+ else
+ IP = MI->second;
+ if (!ExactMatch && Subsection != 0) {
+ // The GNU as documentation claims that subsections have an alignment of 4,
+ // although this appears not to be the case.
+ MCFragment *F = new MCDataFragment();
+ SubsectionFragmentMap.insert(MI, std::make_pair(Subsection, F));
+ getFragmentList().insert(IP, F);
+ F->setParent(this);
+ }
+ return IP;
+}
+
/* *** */
MCSymbolData::MCSymbolData() : Symbol(0) {}
/* *** */
-MCAssembler::MCAssembler(MCContext &_Context, TargetAsmBackend &_Backend,
- MCCodeEmitter &_Emitter, bool _PadSectionToAlignment,
- raw_ostream &_OS)
- : Context(_Context), Backend(_Backend), Emitter(_Emitter),
- OS(_OS), RelaxAll(false), SubsectionsViaSymbols(false),
- PadSectionToAlignment(_PadSectionToAlignment)
-{
+MCAssembler::MCAssembler(MCContext &Context_, MCAsmBackend &Backend_,
+ MCCodeEmitter &Emitter_, MCObjectWriter &Writer_,
+ raw_ostream &OS_)
+ : Context(Context_), Backend(Backend_), Emitter(Emitter_), Writer(Writer_),
+ OS(OS_), BundleAlignSize(0), RelaxAll(false), NoExecStack(false),
+ SubsectionsViaSymbols(false), ELFHeaderEFlags(0) {
+ VersionMinInfo.Major = 0; // Major version == 0 for "none specified"
}
MCAssembler::~MCAssembler() {
}
+void MCAssembler::reset() {
+ Sections.clear();
+ Symbols.clear();
+ SectionMap.clear();
+ SymbolMap.clear();
+ IndirectSymbols.clear();
+ DataRegions.clear();
+ ThumbFuncs.clear();
+ RelaxAll = false;
+ NoExecStack = false;
+ SubsectionsViaSymbols = false;
+ ELFHeaderEFlags = 0;
+
+ // reset objects owned by us
+ getBackend().reset();
+ getEmitter().reset();
+ getWriter().reset();
+}
+
bool MCAssembler::isSymbolLinkerVisible(const MCSymbol &Symbol) const {
// Non-temporary labels should always be visible to the linker.
if (!Symbol.isTemporary())
return SD->getFragment()->getAtom();
}
-bool MCAssembler::EvaluateFixup(const MCObjectWriter &Writer,
- const MCAsmLayout &Layout,
+bool MCAssembler::evaluateFixup(const MCAsmLayout &Layout,
const MCFixup &Fixup, const MCFragment *DF,
MCValue &Target, uint64_t &Value) const {
- ++stats::EvaluateFixup;
+ ++stats::evaluateFixup;
if (!Fixup.getValue()->EvaluateAsRelocatable(Target, &Layout))
- report_fatal_error("expected relocatable expression");
+ getContext().FatalError(Fixup.getLoc(), "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
- // assembler allow symbol differences?
+ bool IsPCRel = Backend.getFixupKindInfo(
+ Fixup.getKind()).Flags & MCFixupKindInfo::FKF_IsPCRel;
+
+ bool IsResolved;
+ if (IsPCRel) {
+ if (Target.getSymB()) {
+ IsResolved = false;
+ } else if (!Target.getSymA()) {
+ IsResolved = false;
+ } else {
+ const MCSymbolRefExpr *A = Target.getSymA();
+ const MCSymbol &SA = A->getSymbol();
+ if (A->getKind() != MCSymbolRefExpr::VK_None ||
+ SA.AliasedSymbol().isUndefined()) {
+ IsResolved = false;
+ } else {
+ const MCSymbolData &DataA = getSymbolData(SA);
+ IsResolved =
+ getWriter().IsSymbolRefDifferenceFullyResolvedImpl(*this, DataA,
+ *DF, false, true);
+ }
+ }
+ } else {
+ IsResolved = Target.isAbsolute();
+ }
Value = Target.getConstant();
- bool IsPCRel = Emitter.getFixupKindInfo(
- Fixup.getKind()).Flags & MCFixupKindInfo::FKF_IsPCRel;
- bool IsResolved = true;
if (const MCSymbolRefExpr *A = Target.getSymA()) {
const MCSymbol &Sym = A->getSymbol().AliasedSymbol();
if (Sym.isDefined())
- Value += Layout.getSymbolAddress(&getSymbolData(Sym));
- else
- IsResolved = false;
+ Value += Layout.getSymbolOffset(&getSymbolData(Sym));
}
if (const MCSymbolRefExpr *B = Target.getSymB()) {
const MCSymbol &Sym = B->getSymbol().AliasedSymbol();
if (Sym.isDefined())
- Value -= Layout.getSymbolAddress(&getSymbolData(Sym));
- else
- IsResolved = false;
+ Value -= Layout.getSymbolOffset(&getSymbolData(Sym));
}
- if (IsResolved)
- IsResolved = Writer.IsFixupFullyResolved(*this, Target, IsPCRel, DF);
- if (IsPCRel)
- Value -= Layout.getFragmentAddress(DF) + Fixup.getOffset();
+ bool ShouldAlignPC = Backend.getFixupKindInfo(Fixup.getKind()).Flags &
+ MCFixupKindInfo::FKF_IsAlignedDownTo32Bits;
+ assert((ShouldAlignPC ? IsPCRel : true) &&
+ "FKF_IsAlignedDownTo32Bits is only allowed on PC-relative fixups!");
+
+ if (IsPCRel) {
+ uint32_t Offset = Layout.getFragmentOffset(DF) + Fixup.getOffset();
+
+ // A number of ARM fixups in Thumb mode require that the effective PC
+ // address be determined as the 32-bit aligned version of the actual offset.
+ if (ShouldAlignPC) Offset &= ~0x3;
+ Value -= Offset;
+ }
+
+ // Let the backend adjust the fixup value if necessary, including whether
+ // we need a relocation.
+ Backend.processFixupValue(*this, Layout, Fixup, DF, Target, Value,
+ IsResolved);
return IsResolved;
}
-uint64_t MCAssembler::ComputeFragmentSize(MCAsmLayout &Layout,
- const MCFragment &F,
- uint64_t SectionAddress,
- uint64_t FragmentOffset) const {
+uint64_t MCAssembler::computeFragmentSize(const MCAsmLayout &Layout,
+ const MCFragment &F) const {
switch (F.getKind()) {
case MCFragment::FT_Data:
- return cast<MCDataFragment>(F).getContents().size();
+ case MCFragment::FT_Relaxable:
+ case MCFragment::FT_CompactEncodedInst:
+ return cast<MCEncodedFragment>(F).getContents().size();
+ case MCFragment::FT_Compressed:
+ return cast<MCCompressedFragment>(F).getCompressedContents().size();
case MCFragment::FT_Fill:
return cast<MCFillFragment>(F).getSize();
- case MCFragment::FT_Inst:
- return cast<MCInstFragment>(F).getInstSize();
case MCFragment::FT_LEB:
- return cast<MCLEBFragment>(F).getSize();
+ return cast<MCLEBFragment>(F).getContents().size();
case MCFragment::FT_Align: {
const MCAlignFragment &AF = cast<MCAlignFragment>(F);
-
- assert((!AF.hasOnlyAlignAddress() || !AF.getNextNode()) &&
- "Invalid OnlyAlignAddress bit, not the last fragment!");
-
- uint64_t Size = OffsetToAlignment(SectionAddress + FragmentOffset,
- AF.getAlignment());
-
- // Honor MaxBytesToEmit.
+ unsigned Offset = Layout.getFragmentOffset(&AF);
+ unsigned Size = OffsetToAlignment(Offset, AF.getAlignment());
+ // If we are padding with nops, force the padding to be larger than the
+ // minimum nop size.
+ if (Size > 0 && AF.hasEmitNops()) {
+ while (Size % getBackend().getMinimumNopSize())
+ Size += AF.getAlignment();
+ }
if (Size > AF.getMaxBytesToEmit())
return 0;
-
return Size;
}
- case MCFragment::FT_Org:
- return cast<MCOrgFragment>(F).getSize();
+ case MCFragment::FT_Org: {
+ const MCOrgFragment &OF = cast<MCOrgFragment>(F);
+ int64_t TargetLocation;
+ if (!OF.getOffset().EvaluateAsAbsolute(TargetLocation, Layout))
+ report_fatal_error("expected assembly-time absolute expression");
+
+ // FIXME: We need a way to communicate this error.
+ uint64_t FragmentOffset = Layout.getFragmentOffset(&OF);
+ int64_t Size = TargetLocation - FragmentOffset;
+ if (Size < 0 || Size >= 0x40000000)
+ report_fatal_error("invalid .org offset '" + Twine(TargetLocation) +
+ "' (at offset '" + Twine(FragmentOffset) + "')");
+ return Size;
+ }
case MCFragment::FT_Dwarf:
- return cast<MCDwarfLineAddrFragment>(F).getSize();
+ return cast<MCDwarfLineAddrFragment>(F).getContents().size();
+ case MCFragment::FT_DwarfFrame:
+ return cast<MCDwarfCallFrameFragment>(F).getContents().size();
}
- assert(0 && "invalid fragment kind");
- return 0;
-}
-
-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;
+ llvm_unreachable("invalid fragment kind");
}
-void MCAsmLayout::LayoutFragment(MCFragment *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!");
+ // We should never try to recompute something which is valid.
+ assert(!isFragmentValid(F) && "Attempt to recompute a valid fragment!");
+ // We should never try to compute the fragment layout if its predecessor
+ // isn't valid.
+ assert((!Prev || isFragmentValid(Prev)) &&
+ "Attempt to compute fragment before its predecessor!");
++stats::FragmentLayouts;
- // Compute the fragment start address.
- uint64_t StartAddress = F->getParent()->Address;
- uint64_t Address = StartAddress;
+ // Compute fragment offset and size.
if (Prev)
- Address += Prev->Offset + Prev->EffectiveSize;
+ F->Offset = Prev->Offset + getAssembler().computeFragmentSize(*this, *Prev);
+ else
+ F->Offset = 0;
+ LastValidFragment[F->getParent()] = F;
- // 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]);
+ // If bundling is enabled and this fragment has instructions in it, it has to
+ // obey the bundling restrictions. With padding, we'll have:
+ //
+ //
+ // BundlePadding
+ // |||
+ // -------------------------------------
+ // Prev |##########| F |
+ // -------------------------------------
+ // ^
+ // |
+ // F->Offset
+ //
+ // The fragment's offset will point to after the padding, and its computed
+ // size won't include the padding.
+ //
+ if (Assembler.isBundlingEnabled() && F->hasInstructions()) {
+ assert(isa<MCEncodedFragment>(F) &&
+ "Only MCEncodedFragment implementations have instructions");
+ uint64_t FSize = Assembler.computeFragmentSize(*this, *F);
+
+ if (FSize > Assembler.getBundleAlignSize())
+ report_fatal_error("Fragment can't be larger than a bundle size");
+
+ uint64_t RequiredBundlePadding = computeBundlePadding(F, F->Offset, FSize);
+ if (RequiredBundlePadding > UINT8_MAX)
+ report_fatal_error("Padding cannot exceed 255 bytes");
+ F->setBundlePadding(static_cast<uint8_t>(RequiredBundlePadding));
+ F->Offset += RequiredBundlePadding;
}
}
-void MCAsmLayout::LayoutSection(MCSectionData *SD) {
- unsigned SectionOrderIndex = SD->getLayoutOrder();
+/// \brief Write the contents of a fragment to the given object writer. Expects
+/// a MCEncodedFragment.
+static void writeFragmentContents(const MCFragment &F, MCObjectWriter *OW) {
+ const MCEncodedFragment &EF = cast<MCEncodedFragment>(F);
+ OW->WriteBytes(EF.getContents());
+}
- ++stats::SectionLayouts;
+/// \brief Write the fragment \p F to the output file.
+static void writeFragment(const MCAssembler &Asm, const MCAsmLayout &Layout,
+ const MCFragment &F) {
+ MCObjectWriter *OW = &Asm.getWriter();
- // Compute the section start address.
- uint64_t StartAddress = 0;
- if (SectionOrderIndex) {
- MCSectionData *Prev = getSectionOrder()[SectionOrderIndex - 1];
- StartAddress = getSectionAddress(Prev) + getSectionAddressSize(Prev);
+ // FIXME: Embed in fragments instead?
+ uint64_t FragmentSize = Asm.computeFragmentSize(Layout, F);
+
+ // Should NOP padding be written out before this fragment?
+ unsigned BundlePadding = F.getBundlePadding();
+ if (BundlePadding > 0) {
+ assert(Asm.isBundlingEnabled() &&
+ "Writing bundle padding with disabled bundling");
+ assert(F.hasInstructions() &&
+ "Writing bundle padding for a fragment without instructions");
+
+ unsigned TotalLength = BundlePadding + static_cast<unsigned>(FragmentSize);
+ if (F.alignToBundleEnd() && TotalLength > Asm.getBundleAlignSize()) {
+ // If the padding itself crosses a bundle boundary, it must be emitted
+ // in 2 pieces, since even nop instructions must not cross boundaries.
+ // v--------------v <- BundleAlignSize
+ // v---------v <- BundlePadding
+ // ----------------------------
+ // | Prev |####|####| F |
+ // ----------------------------
+ // ^-------------------^ <- TotalLength
+ unsigned DistanceToBoundary = TotalLength - Asm.getBundleAlignSize();
+ if (!Asm.getBackend().writeNopData(DistanceToBoundary, OW))
+ report_fatal_error("unable to write NOP sequence of " +
+ Twine(DistanceToBoundary) + " bytes");
+ BundlePadding -= DistanceToBoundary;
+ }
+ if (!Asm.getBackend().writeNopData(BundlePadding, OW))
+ report_fatal_error("unable to write NOP sequence of " +
+ Twine(BundlePadding) + " bytes");
}
- // 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 MCAsmLayout &Layout,
- const MCFragment &F, MCObjectWriter *OW) {
+ // This variable (and its dummy usage) is to participate in the assert at
+ // the end of the function.
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<MCAlignFragment>(F);
- uint64_t Count = FragmentSize / AF.getValueSize();
-
+ ++stats::EmittedAlignFragments;
+ const MCAlignFragment &AF = cast<MCAlignFragment>(F);
assert(AF.getValueSize() && "Invalid virtual align in concrete fragment!");
+ uint64_t Count = FragmentSize / AF.getValueSize();
+
// 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?
// 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.
+ // bytes left to fill use the Value and ValueSize to fill the rest.
// If we are aligning with nops, ask that target to emit the right data.
if (AF.hasEmitNops()) {
- if (!Asm.getBackend().WriteNopData(Count, OW))
+ if (!Asm.getBackend().writeNopData(Count, OW))
report_fatal_error("unable to write nop sequence of " +
Twine(Count) + " bytes");
break;
// Otherwise, write out in multiples of the value size.
for (uint64_t i = 0; i != Count; ++i) {
switch (AF.getValueSize()) {
- default:
- assert(0 && "Invalid size!");
+ default: llvm_unreachable("Invalid size!");
case 1: OW->Write8 (uint8_t (AF.getValue())); break;
case 2: OW->Write16(uint16_t(AF.getValue())); break;
case 4: OW->Write32(uint32_t(AF.getValue())); break;
break;
}
- case MCFragment::FT_Data: {
- MCDataFragment &DF = cast<MCDataFragment>(F);
- assert(FragmentSize == DF.getContents().size() && "Invalid size!");
- OW->WriteBytes(DF.getContents().str());
+ case MCFragment::FT_Compressed:
+ ++stats::EmittedDataFragments;
+ OW->WriteBytes(cast<MCCompressedFragment>(F).getCompressedContents());
+ break;
+
+ case MCFragment::FT_Data:
+ ++stats::EmittedDataFragments;
+ writeFragmentContents(F, OW);
+ break;
+
+ case MCFragment::FT_Relaxable:
+ ++stats::EmittedRelaxableFragments;
+ writeFragmentContents(F, OW);
+ break;
+
+ case MCFragment::FT_CompactEncodedInst:
+ ++stats::EmittedCompactEncodedInstFragments;
+ writeFragmentContents(F, OW);
break;
- }
case MCFragment::FT_Fill: {
- MCFillFragment &FF = cast<MCFillFragment>(F);
+ ++stats::EmittedFillFragments;
+ const MCFillFragment &FF = cast<MCFillFragment>(F);
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!");
+ default: llvm_unreachable("Invalid size!");
case 1: OW->Write8 (uint8_t (FF.getValue())); break;
case 2: OW->Write16(uint16_t(FF.getValue())); break;
case 4: OW->Write32(uint32_t(FF.getValue())); break;
break;
}
- case MCFragment::FT_Inst:
- llvm_unreachable("unexpected inst fragment after lowering");
- break;
-
case MCFragment::FT_LEB: {
- MCLEBFragment &LF = cast<MCLEBFragment>(F);
-
- // FIXME: It is probably better if we don't call EvaluateAsAbsolute in
- // here.
- int64_t Value;
- LF.getValue().EvaluateAsAbsolute(Value, &Layout);
- SmallString<32> Tmp;
- raw_svector_ostream OSE(Tmp);
- if (LF.isSigned())
- MCObjectWriter::EncodeSLEB128(Value, OSE);
- else
- MCObjectWriter::EncodeULEB128(Value, OSE);
- OW->WriteBytes(OSE.str());
+ const MCLEBFragment &LF = cast<MCLEBFragment>(F);
+ OW->WriteBytes(LF.getContents().str());
break;
}
case MCFragment::FT_Org: {
- MCOrgFragment &OF = cast<MCOrgFragment>(F);
+ ++stats::EmittedOrgFragments;
+ const MCOrgFragment &OF = cast<MCOrgFragment>(F);
for (uint64_t i = 0, e = FragmentSize; i != e; ++i)
OW->Write8(uint8_t(OF.getValue()));
case MCFragment::FT_Dwarf: {
const MCDwarfLineAddrFragment &OF = cast<MCDwarfLineAddrFragment>(F);
-
- // The AddrDelta is really unsigned and it can only increase.
- int64_t AddrDelta;
- OF.getAddrDelta().EvaluateAsAbsolute(AddrDelta, &Layout);
-
- int64_t LineDelta;
- LineDelta = OF.getLineDelta();
-
- MCDwarfLineAddr::Write(OW, LineDelta, (uint64_t)AddrDelta);
+ OW->WriteBytes(OF.getContents().str());
+ break;
+ }
+ case MCFragment::FT_DwarfFrame: {
+ const MCDwarfCallFrameFragment &CF = cast<MCDwarfCallFrameFragment>(F);
+ OW->WriteBytes(CF.getContents().str());
break;
}
}
- assert(OW->getStream().tell() - Start == FragmentSize);
+ assert(OW->getStream().tell() - Start == FragmentSize &&
+ "The stream should advance by fragment size");
}
-void MCAssembler::WriteSectionData(const MCSectionData *SD,
- const MCAsmLayout &Layout,
- MCObjectWriter *OW) const {
+void MCAssembler::writeSectionData(const MCSectionData *SD,
+ const MCAsmLayout &Layout) const {
// Ignore virtual sections.
- if (getBackend().isVirtualSection(SD->getSection())) {
+ if (SD->getSection().isVirtualSection()) {
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!");
+ default: llvm_unreachable("Invalid fragment in virtual section!");
+ case MCFragment::FT_Compressed:
case MCFragment::FT_Data: {
// Check that we aren't trying to write a non-zero contents (or fixups)
// into a virtual section. This is to support clients which use standard
// directives to fill the contents of virtual sections.
- MCDataFragment &DF = cast<MCDataFragment>(*it);
+ const MCDataFragment &DF = cast<MCDataFragment>(*it);
assert(DF.fixup_begin() == DF.fixup_end() &&
"Cannot have fixups in virtual section!");
for (unsigned i = 0, e = DF.getContents().size(); i != e; ++i)
case MCFragment::FT_Align:
// Check that we aren't trying to write a non-zero value into a virtual
// section.
- assert((!cast<MCAlignFragment>(it)->getValueSize() ||
- !cast<MCAlignFragment>(it)->getValue()) &&
+ assert((cast<MCAlignFragment>(it)->getValueSize() == 0 ||
+ cast<MCAlignFragment>(it)->getValue() == 0) &&
"Invalid align in virtual section!");
break;
case MCFragment::FT_Fill:
- assert(!cast<MCFillFragment>(it)->getValueSize() &&
+ assert((cast<MCFillFragment>(it)->getValueSize() == 0 ||
+ cast<MCFillFragment>(it)->getValue() == 0) &&
"Invalid fill in virtual section!");
break;
}
return;
}
- uint64_t Start = OW->getStream().tell();
- (void) Start;
+ uint64_t Start = getWriter().getStream().tell();
+ (void)Start;
- for (MCSectionData::const_iterator it = SD->begin(),
- ie = SD->end(); it != ie; ++it)
- WriteFragmentData(*this, Layout, *it, OW);
+ for (MCSectionData::const_iterator it = SD->begin(), ie = SD->end();
+ it != ie; ++it)
+ writeFragment(*this, Layout, *it);
- assert(OW->getStream().tell() - Start == Layout.getSectionFileSize(SD));
+ assert(getWriter().getStream().tell() - Start ==
+ Layout.getSectionAddressSize(SD));
}
-void MCAssembler::AddSectionToTheEnd(const MCObjectWriter &Writer,
- MCSectionData &SD, MCAsmLayout &Layout) {
- // Create dummy fragments and assign section ordinals.
- unsigned SectionIndex = size();
- SD.setOrdinal(SectionIndex);
-
- // Assign layout order indices to sections and fragments.
- const MCFragment &Last = *Layout.getSectionOrder().back()->rbegin();
- unsigned FragmentIndex = Last.getLayoutOrder() + 1;
-
- SD.setLayoutOrder(Layout.getSectionOrder().size());
- for (MCSectionData::iterator it2 = SD.begin(),
- ie2 = SD.end(); it2 != ie2; ++it2) {
- it2->setLayoutOrder(FragmentIndex++);
+std::pair<uint64_t, bool> MCAssembler::handleFixup(const MCAsmLayout &Layout,
+ MCFragment &F,
+ const MCFixup &Fixup) {
+ // Evaluate the fixup.
+ MCValue Target;
+ uint64_t FixedValue;
+ bool IsPCRel = Backend.getFixupKindInfo(Fixup.getKind()).Flags &
+ MCFixupKindInfo::FKF_IsPCRel;
+ if (!evaluateFixup(Layout, Fixup, &F, Target, FixedValue)) {
+ // The fixup was unresolved, we need a relocation. Inform the object
+ // writer of the relocation, and give it an opportunity to adjust the
+ // fixup value if need be.
+ getWriter().RecordRelocation(*this, Layout, &F, Fixup, Target, IsPCRel,
+ FixedValue);
}
- Layout.getSectionOrder().push_back(&SD);
-
- Layout.LayoutSection(&SD);
+ return std::make_pair(FixedValue, IsPCRel);
}
-void MCAssembler::Finish(MCObjectWriter *Writer) {
+void MCAssembler::Finish() {
DEBUG_WITH_TYPE("mc-dump", {
llvm::errs() << "assembler backend - pre-layout\n--\n";
dump(); });
// 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.
- if (PadSectionToAlignment) {
- 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) {
}
// 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++);
- }
-
- llvm::OwningPtr<MCObjectWriter> OwnWriter(0);
- if (Writer == 0) {
- //no custom Writer_ : create the default one life-managed by OwningPtr
- OwnWriter.reset(getBackend().createObjectWriter(OS));
- Writer = OwnWriter.get();
- if (!Writer)
- report_fatal_error("unable to create object writer!");
+ unsigned FragmentIndex = 0;
+ for (MCSectionData::iterator iFrag = SD->begin(), iFragEnd = SD->end();
+ iFrag != iFragEnd; ++iFrag)
+ iFrag->setLayoutOrder(FragmentIndex++);
}
// Layout until everything fits.
- while (LayoutOnce(*Writer, Layout))
+ while (layoutOnce(Layout))
continue;
DEBUG_WITH_TYPE("mc-dump", {
dump(); });
// Finalize the layout, including fragment lowering.
- FinishLayout(Layout);
+ finishLayout(Layout);
DEBUG_WITH_TYPE("mc-dump", {
llvm::errs() << "assembler backend - final-layout\n--\n";
// Allow the object writer a chance to perform post-layout binding (for
// example, to set the index fields in the symbol data).
- Writer->ExecutePostLayoutBinding(*this);
+ getWriter().ExecutePostLayoutBinding(*this, Layout);
// Evaluate and apply the fixups, generating relocation entries as necessary.
for (MCAssembler::iterator it = begin(), ie = end(); it != ie; ++it) {
for (MCSectionData::iterator it2 = it->begin(),
ie2 = it->end(); it2 != ie2; ++it2) {
- MCDataFragment *DF = dyn_cast<MCDataFragment>(it2);
- if (!DF)
- continue;
-
- for (MCDataFragment::fixup_iterator it3 = DF->fixup_begin(),
- ie3 = DF->fixup_end(); it3 != ie3; ++it3) {
- MCFixup &Fixup = *it3;
-
- // Evaluate the fixup.
- MCValue Target;
- uint64_t FixedValue;
- if (!EvaluateFixup(*Writer, Layout, Fixup, DF, Target, FixedValue)) {
- // The fixup was unresolved, we need a relocation. Inform the object
- // writer of the relocation, and give it an opportunity to adjust the
- // fixup value if need be.
- Writer->RecordRelocation(*this, Layout, DF, Fixup, Target,FixedValue);
+ MCEncodedFragmentWithFixups *F =
+ dyn_cast<MCEncodedFragmentWithFixups>(it2);
+ if (F) {
+ for (MCEncodedFragmentWithFixups::fixup_iterator it3 = F->fixup_begin(),
+ ie3 = F->fixup_end(); it3 != ie3; ++it3) {
+ MCFixup &Fixup = *it3;
+ uint64_t FixedValue;
+ bool IsPCRel;
+ std::tie(FixedValue, IsPCRel) = handleFixup(Layout, *F, Fixup);
+ getBackend().applyFixup(Fixup, F->getContents().data(),
+ F->getContents().size(), FixedValue, IsPCRel);
}
-
- getBackend().ApplyFixup(Fixup, *DF, FixedValue);
}
}
}
// Write the object file.
- Writer->WriteObject(*this, Layout);
+ getWriter().WriteObject(*this, Layout);
stats::ObjectBytes += OS.tell() - StartOffset;
}
-bool MCAssembler::FixupNeedsRelaxation(const MCObjectWriter &Writer,
- const MCFixup &Fixup,
- const MCFragment *DF,
+bool MCAssembler::fixupNeedsRelaxation(const MCFixup &Fixup,
+ const MCRelaxableFragment *DF,
const MCAsmLayout &Layout) const {
- if (getRelaxAll())
- return true;
-
// If we cannot resolve the fixup value, it requires relaxation.
MCValue Target;
uint64_t Value;
- if (!EvaluateFixup(Writer, Layout, Fixup, DF, Target, Value))
+ if (!evaluateFixup(Layout, Fixup, DF, Target, Value))
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));
+ return getBackend().fixupNeedsRelaxation(Fixup, Value, DF, Layout);
}
-bool MCAssembler::FragmentNeedsRelaxation(const MCObjectWriter &Writer,
- const MCInstFragment *IF,
+bool MCAssembler::fragmentNeedsRelaxation(const MCRelaxableFragment *F,
const MCAsmLayout &Layout) const {
// 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 (!getBackend().mayNeedRelaxation(F->getInst()))
return false;
- for (MCInstFragment::const_fixup_iterator it = IF->fixup_begin(),
- ie = IF->fixup_end(); it != ie; ++it)
- if (FixupNeedsRelaxation(Writer, *it, IF, Layout))
+ for (MCRelaxableFragment::const_fixup_iterator it = F->fixup_begin(),
+ ie = F->fixup_end(); it != ie; ++it)
+ if (fixupNeedsRelaxation(*it, F, Layout))
return true;
return false;
}
-bool MCAssembler::RelaxInstruction(const MCObjectWriter &Writer,
- MCAsmLayout &Layout,
- MCInstFragment &IF) {
- if (!FragmentNeedsRelaxation(Writer, &IF, Layout))
+bool MCAssembler::relaxInstruction(MCAsmLayout &Layout,
+ MCRelaxableFragment &F) {
+ if (!fragmentNeedsRelaxation(&F, Layout))
return false;
++stats::RelaxedInstructions;
// Relax the fragment.
MCInst Relaxed;
- getBackend().RelaxInstruction(IF.getInst(), Relaxed);
+ getBackend().relaxInstruction(F.getInst(), Relaxed);
// Encode the new instruction.
//
SmallVector<MCFixup, 4> Fixups;
SmallString<256> Code;
raw_svector_ostream VecOS(Code);
- getEmitter().EncodeInstruction(Relaxed, VecOS, Fixups);
+ getEmitter().EncodeInstruction(Relaxed, VecOS, Fixups, F.getSubtargetInfo());
VecOS.flush();
- // Update the instruction fragment.
- int SlideAmount = Code.size() - IF.getInstSize();
- IF.setInst(Relaxed);
- IF.getCode() = Code;
- IF.getFixups().clear();
- // FIXME: Eliminate copy.
- for (unsigned i = 0, e = Fixups.size(); i != e; ++i)
- IF.getFixups().push_back(Fixups[i]);
-
- // Update the layout, and remember that we relaxed.
- Layout.UpdateForSlide(&IF, SlideAmount);
- return true;
-}
+ // Update the fragment.
+ F.setInst(Relaxed);
+ F.getContents() = Code;
+ F.getFixups() = Fixups;
-bool MCAssembler::RelaxOrg(const MCObjectWriter &Writer,
- MCAsmLayout &Layout,
- MCOrgFragment &OF) {
- int64_t TargetLocation;
- if (!OF.getOffset().EvaluateAsAbsolute(TargetLocation, &Layout))
- report_fatal_error("expected assembly-time absolute expression");
-
- // FIXME: We need a way to communicate this error.
- uint64_t FragmentOffset = Layout.getFragmentOffset(&OF);
- int64_t Offset = TargetLocation - FragmentOffset;
- if (Offset < 0 || Offset >= 0x40000000)
- report_fatal_error("invalid .org offset '" + Twine(TargetLocation) +
- "' (at offset '" + Twine(FragmentOffset) + "')");
-
- unsigned OldSize = OF.getSize();
- OF.setSize(Offset);
- return OldSize != OF.getSize();
+ return true;
}
-bool MCAssembler::RelaxLEB(const MCObjectWriter &Writer,
- MCAsmLayout &Layout,
- MCLEBFragment &LF) {
- int64_t Value;
- LF.getValue().EvaluateAsAbsolute(Value, &Layout);
- SmallString<32> Tmp;
- raw_svector_ostream OSE(Tmp);
+bool MCAssembler::relaxLEB(MCAsmLayout &Layout, MCLEBFragment &LF) {
+ int64_t Value = 0;
+ uint64_t OldSize = LF.getContents().size();
+ bool IsAbs = LF.getValue().EvaluateAsAbsolute(Value, Layout);
+ (void)IsAbs;
+ assert(IsAbs);
+ SmallString<8> &Data = LF.getContents();
+ Data.clear();
+ raw_svector_ostream OSE(Data);
if (LF.isSigned())
- MCObjectWriter::EncodeSLEB128(Value, OSE);
+ encodeSLEB128(Value, OSE);
else
- MCObjectWriter::EncodeULEB128(Value, OSE);
- uint64_t OldSize = LF.getSize();
- LF.setSize(OSE.GetNumBytesInBuffer());
- return OldSize != LF.getSize();
+ encodeULEB128(Value, OSE);
+ OSE.flush();
+ return OldSize != LF.getContents().size();
}
-bool MCAssembler::RelaxDwarfLineAddr(const MCObjectWriter &Writer,
- MCAsmLayout &Layout,
- MCDwarfLineAddrFragment &DF) {
- int64_t AddrDelta;
- DF.getAddrDelta().EvaluateAsAbsolute(AddrDelta, &Layout);
+bool MCAssembler::relaxDwarfLineAddr(MCAsmLayout &Layout,
+ MCDwarfLineAddrFragment &DF) {
+ MCContext &Context = Layout.getAssembler().getContext();
+ int64_t AddrDelta = 0;
+ uint64_t OldSize = DF.getContents().size();
+ bool IsAbs = DF.getAddrDelta().EvaluateAsAbsolute(AddrDelta, Layout);
+ (void)IsAbs;
+ assert(IsAbs);
int64_t LineDelta;
LineDelta = DF.getLineDelta();
- uint64_t OldSize = DF.getSize();
- DF.setSize(MCDwarfLineAddr::ComputeSize(LineDelta, AddrDelta));
- return OldSize != DF.getSize();
+ SmallString<8> &Data = DF.getContents();
+ Data.clear();
+ raw_svector_ostream OSE(Data);
+ MCDwarfLineAddr::Encode(Context, LineDelta, AddrDelta, OSE);
+ OSE.flush();
+ return OldSize != Data.size();
}
-bool MCAssembler::LayoutOnce(const MCObjectWriter &Writer,
- MCAsmLayout &Layout) {
- ++stats::RelaxationSteps;
+bool MCAssembler::relaxDwarfCallFrameFragment(MCAsmLayout &Layout,
+ MCDwarfCallFrameFragment &DF) {
+ MCContext &Context = Layout.getAssembler().getContext();
+ int64_t AddrDelta = 0;
+ uint64_t OldSize = DF.getContents().size();
+ bool IsAbs = DF.getAddrDelta().EvaluateAsAbsolute(AddrDelta, Layout);
+ (void)IsAbs;
+ assert(IsAbs);
+ SmallString<8> &Data = DF.getContents();
+ Data.clear();
+ raw_svector_ostream OSE(Data);
+ MCDwarfFrameEmitter::EncodeAdvanceLoc(Context, AddrDelta, OSE);
+ OSE.flush();
+ return OldSize != Data.size();
+}
- // Layout the sections in order.
- Layout.LayoutFile();
+bool MCAssembler::layoutSectionOnce(MCAsmLayout &Layout, MCSectionData &SD) {
+ // Holds the first fragment which needed relaxing during this layout. It will
+ // remain NULL if none were relaxed.
+ // When a fragment is relaxed, all the fragments following it should get
+ // invalidated because their offset is going to change.
+ MCFragment *FirstRelaxedFragment = NULL;
+
+ // Attempt to relax all the fragments in the section.
+ for (MCSectionData::iterator I = SD.begin(), IE = SD.end(); I != IE; ++I) {
+ // Check if this is a fragment that needs relaxation.
+ bool RelaxedFrag = false;
+ switch(I->getKind()) {
+ default:
+ break;
+ case MCFragment::FT_Relaxable:
+ assert(!getRelaxAll() &&
+ "Did not expect a MCRelaxableFragment in RelaxAll mode");
+ RelaxedFrag = relaxInstruction(Layout, *cast<MCRelaxableFragment>(I));
+ break;
+ case MCFragment::FT_Dwarf:
+ RelaxedFrag = relaxDwarfLineAddr(Layout,
+ *cast<MCDwarfLineAddrFragment>(I));
+ break;
+ case MCFragment::FT_DwarfFrame:
+ RelaxedFrag =
+ relaxDwarfCallFrameFragment(Layout,
+ *cast<MCDwarfCallFrameFragment>(I));
+ break;
+ case MCFragment::FT_LEB:
+ RelaxedFrag = relaxLEB(Layout, *cast<MCLEBFragment>(I));
+ break;
+ }
+ if (RelaxedFrag && !FirstRelaxedFragment)
+ FirstRelaxedFragment = I;
+ }
+ if (FirstRelaxedFragment) {
+ Layout.invalidateFragmentsFrom(FirstRelaxedFragment);
+ return true;
+ }
+ return false;
+}
+
+bool MCAssembler::layoutOnce(MCAsmLayout &Layout) {
+ ++stats::RelaxationSteps;
- // Scan for fragments that need relaxation.
bool WasRelaxed = false;
for (iterator it = begin(), ie = end(); it != ie; ++it) {
MCSectionData &SD = *it;
-
- for (MCSectionData::iterator it2 = SD.begin(),
- ie2 = SD.end(); it2 != ie2; ++it2) {
- // Check if this is an fragment that needs relaxation.
- switch(it2->getKind()) {
- default:
- break;
- case MCFragment::FT_Inst:
- WasRelaxed |= RelaxInstruction(Writer, Layout,
- *cast<MCInstFragment>(it2));
- break;
- case MCFragment::FT_Org:
- WasRelaxed |= RelaxOrg(Writer, Layout, *cast<MCOrgFragment>(it2));
- break;
- case MCFragment::FT_Dwarf:
- WasRelaxed |= RelaxDwarfLineAddr(Writer, Layout,
- *cast<MCDwarfLineAddrFragment>(it2));
- break;
- case MCFragment::FT_LEB:
- WasRelaxed |= RelaxLEB(Writer, Layout, *cast<MCLEBFragment>(it2));
- break;
- }
- }
+ while (layoutSectionOnce(Layout, SD))
+ WasRelaxed = true;
}
return WasRelaxed;
}
-void MCAssembler::FinishLayout(MCAsmLayout &Layout) {
- // Lower out any instruction fragments, to simplify the fixup application and
- // output.
- //
- // FIXME-PERF: We don't have to do this, but the assumption is that it is
- // cheap (we will mostly end up eliminating fragments and appending on to data
- // fragments), so the extra complexity downstream isn't worth it. Evaluate
- // this assumption.
- for (iterator it = begin(), ie = end(); it != ie; ++it) {
- MCSectionData &SD = *it;
-
- for (MCSectionData::iterator it2 = SD.begin(),
- ie2 = SD.end(); it2 != ie2; ++it2) {
- MCInstFragment *IF = dyn_cast<MCInstFragment>(it2);
- if (!IF)
- continue;
-
- // Create a new data fragment for the instruction.
- //
- // FIXME-PERF: Reuse previous data fragment if possible.
- MCDataFragment *DF = new MCDataFragment();
- SD.getFragmentList().insert(it2, DF);
-
- // Update the data fragments layout data.
- DF->setParent(IF->getParent());
- 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());
- for (unsigned i = 0, e = IF->getFixups().size(); i != e; ++i)
- DF->getFixups().push_back(IF->getFixups()[i]);
-
- // Delete the instruction fragment and update the iterator.
- SD.getFragmentList().erase(IF);
- it2 = DF;
- }
+void MCAssembler::finishLayout(MCAsmLayout &Layout) {
+ // The layout is done. Mark every fragment as valid.
+ for (unsigned int i = 0, n = Layout.getSectionOrder().size(); i != n; ++i) {
+ Layout.getFragmentOffset(&*Layout.getSectionOrder()[i]->rbegin());
}
}
}
+#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
void MCFragment::dump() {
raw_ostream &OS = llvm::errs();
switch (getKind()) {
case MCFragment::FT_Align: OS << "MCAlignFragment"; break;
case MCFragment::FT_Data: OS << "MCDataFragment"; break;
+ case MCFragment::FT_Compressed:
+ OS << "MCCompressedFragment"; break;
+ case MCFragment::FT_CompactEncodedInst:
+ OS << "MCCompactEncodedInstFragment"; break;
case MCFragment::FT_Fill: OS << "MCFillFragment"; break;
- case MCFragment::FT_Inst: OS << "MCInstFragment"; break;
+ case MCFragment::FT_Relaxable: OS << "MCRelaxableFragment"; break;
case MCFragment::FT_Org: OS << "MCOrgFragment"; break;
case MCFragment::FT_Dwarf: OS << "MCDwarfFragment"; break;
+ case MCFragment::FT_DwarfFrame: OS << "MCDwarfCallFrameFragment"; break;
case MCFragment::FT_LEB: OS << "MCLEBFragment"; break;
}
OS << "<MCFragment " << (void*) this << " LayoutOrder:" << LayoutOrder
- << " Offset:" << Offset << " EffectiveSize:" << EffectiveSize << ">";
+ << " Offset:" << Offset
+ << " HasInstructions:" << hasInstructions()
+ << " BundlePadding:" << static_cast<unsigned>(getBundlePadding()) << ">";
switch (getKind()) {
case MCFragment::FT_Align: {
const MCAlignFragment *AF = cast<MCAlignFragment>(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_Compressed:
case MCFragment::FT_Data: {
const MCDataFragment *DF = cast<MCDataFragment>(this);
OS << "\n ";
}
OS << "] (" << Contents.size() << " bytes)";
- if (!DF->getFixups().empty()) {
+ if (DF->fixup_begin() != DF->fixup_end()) {
OS << ",\n ";
OS << " Fixups:[";
for (MCDataFragment::const_fixup_iterator it = DF->fixup_begin(),
}
break;
}
+ case MCFragment::FT_CompactEncodedInst: {
+ const MCCompactEncodedInstFragment *CEIF =
+ cast<MCCompactEncodedInstFragment>(this);
+ OS << "\n ";
+ OS << " Contents:[";
+ const SmallVectorImpl<char> &Contents = CEIF->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 << "] (" << Contents.size() << " bytes)";
+ break;
+ }
case MCFragment::FT_Fill: {
const MCFillFragment *FF = cast<MCFillFragment>(this);
OS << " Value:" << FF->getValue() << " ValueSize:" << FF->getValueSize()
<< " Size:" << FF->getSize();
break;
}
- case MCFragment::FT_Inst: {
- const MCInstFragment *IF = cast<MCInstFragment>(this);
+ case MCFragment::FT_Relaxable: {
+ const MCRelaxableFragment *F = cast<MCRelaxableFragment>(this);
OS << "\n ";
OS << " Inst:";
- IF->getInst().dump_pretty(OS);
+ F->getInst().dump_pretty(OS);
break;
}
case MCFragment::FT_Org: {
<< " LineDelta:" << OF->getLineDelta();
break;
}
+ case MCFragment::FT_DwarfFrame: {
+ const MCDwarfCallFrameFragment *CF = cast<MCDwarfCallFrameFragment>(this);
+ OS << "\n ";
+ OS << " AddrDelta:" << CF->getAddrDelta();
+ break;
+ }
case MCFragment::FT_LEB: {
const MCLEBFragment *LF = cast<MCLEBFragment>(this);
OS << "\n ";
raw_ostream &OS = llvm::errs();
OS << "<MCSectionData";
- OS << " Alignment:" << getAlignment() << " Address:" << Address
+ OS << " Alignment:" << getAlignment()
<< " Fragments:[\n ";
for (iterator it = begin(), ie = end(); it != ie; ++it) {
if (it != begin()) OS << ",\n ";
}
OS << "]>\n";
}
+#endif
+
+// anchors for MC*Fragment vtables
+void MCEncodedFragment::anchor() { }
+void MCEncodedFragmentWithFixups::anchor() { }
+void MCDataFragment::anchor() { }
+void MCCompactEncodedInstFragment::anchor() { }
+void MCRelaxableFragment::anchor() { }
+void MCAlignFragment::anchor() { }
+void MCFillFragment::anchor() { }
+void MCOrgFragment::anchor() { }
+void MCLEBFragment::anchor() { }
+void MCDwarfLineAddrFragment::anchor() { }
+void MCDwarfCallFrameFragment::anchor() { }
projects / oota-llvm.git / blobdiff