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());
+ 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) {
+void MCAsmLayout::Invalidate(MCFragment *F) {
// 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());
- }
- }
+ // Otherwise, reset the last valid fragment to this fragment.
+ const MCSectionData &SD = *F->getParent();
+ LastValidFragment[&SD] = F;
}
void MCAsmLayout::EnsureValid(const MCFragment *F) const {
+ MCSectionData &SD = *F->getParent();
+
+ MCFragment *Cur = LastValidFragment[&SD];
+ if (!Cur)
+ Cur = &*SD.begin();
+ else
+ Cur = Cur->getNextNode();
+
// 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);
+ Cur = Cur->getNextNode();
}
}
-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 {
- 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 {
- assert(SD->getFragment() && "Invalid getAddress() on undefined symbol!");
- return getFragmentAddress(SD->getFragment()) + SD->getOffset();
-}
-
-uint64_t MCAsmLayout::getSectionAddress(const MCSectionData *SD) const {
- EnsureValid(SD->begin());
- assert(SD->Address != ~UINT64_C(0) && "Address not set!");
- return SD->Address;
+uint64_t MCAsmLayout::getSymbolOffset(const MCSymbolData *SD) const {
+ 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(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);
-
- return Size;
-}
-
/* *** */
MCFragment::MCFragment() : Kind(FragmentType(~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);
MCSectionData::MCSectionData(const MCSection &_Section, MCAssembler *A)
: Section(&_Section),
+ Ordinal(~UINT32_C(0)),
Alignment(1),
- Address(~UINT64_C(0)),
HasInstructions(false)
{
if (A)
/* *** */
MCAssembler::MCAssembler(MCContext &_Context, TargetAsmBackend &_Backend,
- MCCodeEmitter &_Emitter, bool _PadSectionToAlignment,
- raw_ostream &_OS)
+ MCCodeEmitter &_Emitter, raw_ostream &_OS)
: Context(_Context), Backend(_Backend), Emitter(_Emitter),
- OS(_OS), RelaxAll(false), SubsectionsViaSymbols(false),
- PadSectionToAlignment(_PadSectionToAlignment)
+ OS(_OS), RelaxAll(false), SubsectionsViaSymbols(false)
{
}
Value = Target.getConstant();
- bool IsPCRel = Emitter.getFixupKindInfo(
+ bool IsPCRel = Backend.getFixupKindInfo(
Fixup.getKind()).Flags & MCFixupKindInfo::FKF_IsPCRel;
bool IsResolved = true;
+ bool IsThumb = false;
if (const MCSymbolRefExpr *A = Target.getSymA()) {
- if (A->getSymbol().isDefined())
- Value += Layout.getSymbolAddress(&getSymbolData(A->getSymbol()));
+ const MCSymbol &Sym = A->getSymbol().AliasedSymbol();
+ if (Sym.isDefined())
+ Value += Layout.getSymbolOffset(&getSymbolData(Sym));
else
IsResolved = false;
+ if (isThumbFunc(&Sym))
+ IsThumb = true;
}
if (const MCSymbolRefExpr *B = Target.getSymB()) {
- if (B->getSymbol().isDefined())
- Value -= Layout.getSymbolAddress(&getSymbolData(B->getSymbol()));
+ const MCSymbol &Sym = B->getSymbol().AliasedSymbol();
+ if (Sym.isDefined())
+ Value -= Layout.getSymbolOffset(&getSymbolData(Sym));
else
IsResolved = false;
}
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 = 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 -= Layout.getFragmentOffset(DF) + Offset;
+ }
+
+ // ARM fixups based from a thumb function address need to have the low
+ // bit set. The actual value is always at least 16-bit aligned, so the
+ // low bit is normally clear and available for use as an ISA flag for
+ // interworking.
+ if (IsThumb)
+ Value |= 1;
return IsResolved;
}
-uint64_t MCAssembler::ComputeFragmentSize(MCAsmLayout &Layout,
- const MCFragment &F,
- uint64_t SectionAddress,
- uint64_t FragmentOffset) const {
+uint64_t MCAssembler::ComputeFragmentSize(const MCFragment &F) const {
switch (F.getKind()) {
case MCFragment::FT_Data:
return cast<MCDataFragment>(F).getContents().size();
case MCFragment::FT_Inst:
return cast<MCInstFragment>(F).getInstSize();
- 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());
+ case MCFragment::FT_LEB:
+ return cast<MCLEBFragment>(F).getContents().size();
- // Honor MaxBytesToEmit.
- if (Size > AF.getMaxBytesToEmit())
- return 0;
+ case MCFragment::FT_Align:
+ return cast<MCAlignFragment>(F).getSize();
- return Size;
- }
-
- case MCFragment::FT_Org: {
- const MCOrgFragment &OF = cast<MCOrgFragment>(F);
-
- // 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:
+ return cast<MCOrgFragment>(F).getSize();
- // FIXME: We need a way to communicate this error.
- int64_t Offset = TargetLocation - FragmentOffset;
- if (Offset < 0 || Offset >= 0x40000000)
- report_fatal_error("invalid .org offset '" + Twine(TargetLocation) +
- "' (at offset '" + Twine(FragmentOffset) + "')");
-
- return Offset;
- }
-
- 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();
-
- return MCDwarfLineAddr::ComputeSize(LineDelta, AddrDelta);
- }
+ case MCFragment::FT_Dwarf:
+ return cast<MCDwarfLineAddrFragment>(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;
-}
-
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)) &&
++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]);
- }
-}
-
-void MCAsmLayout::LayoutSection(MCSectionData *SD) {
- unsigned SectionOrderIndex = SD->getLayoutOrder();
-
- ++stats::SectionLayouts;
-
- // Compute the section start address.
- uint64_t StartAddress = 0;
- if (SectionOrderIndex) {
- MCSectionData *Prev = getSectionOrder()[SectionOrderIndex - 1];
- StartAddress = getSectionAddress(Prev) + getSectionAddressSize(Prev);
- }
-
- // Honor the section alignment requirements.
- StartAddress = RoundUpToAlignment(StartAddress, SD->getAlignment());
+ uint64_t Offset = 0;
+ if (Prev)
+ Offset += Prev->Offset + getAssembler().ComputeFragmentSize(*Prev);
- // Set the section address.
- SD->Address = StartAddress;
+ F->Offset = Offset;
+ LastValidFragment[F->getParent()] = F;
}
/// WriteFragmentData - Write the \arg F data to the output file.
++stats::EmittedFragments;
// FIXME: Embed in fragments instead?
- uint64_t FragmentSize = Layout.getFragmentEffectiveSize(&F);
+ uint64_t FragmentSize = Asm.ComputeFragmentSize(F);
switch (F.getKind()) {
case MCFragment::FT_Align: {
MCAlignFragment &AF = cast<MCAlignFragment>(F);
break;
}
- case MCFragment::FT_Inst:
- llvm_unreachable("unexpected inst fragment after lowering");
+ case MCFragment::FT_Inst: {
+ MCInstFragment &IF = cast<MCInstFragment>(F);
+ OW->WriteBytes(StringRef(IF.getCode().begin(), IF.getCode().size()));
break;
+ }
+
+ case MCFragment::FT_LEB: {
+ MCLEBFragment &LF = cast<MCLEBFragment>(F);
+ OW->WriteBytes(LF.getContents().str());
+ break;
+ }
case MCFragment::FT_Org: {
MCOrgFragment &OF = cast<MCOrgFragment>(F);
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;
}
}
const MCAsmLayout &Layout,
MCObjectWriter *OW) 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.
ie = SD->end(); it != ie; ++it)
WriteFragmentData(*this, Layout, *it, OW);
- assert(OW->getStream().tell() - Start == Layout.getSectionFileSize(SD));
+ assert(OW->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 = 0;
- for (MCAssembler::iterator it = begin(), ie = end(); it != ie; ++it)
- SectionIndex++;
-
- SD.setOrdinal(SectionIndex);
-
- // Assign layout order indices to sections and fragments.
- unsigned FragmentIndex = 0;
- unsigned i = 0;
- for (unsigned e = Layout.getSectionOrder().size(); i != e; ++i) {
- MCSectionData *SD = Layout.getSectionOrder()[i];
-
- for (MCSectionData::iterator it2 = SD->begin(),
- ie2 = SD->end(); it2 != ie2; ++it2)
- FragmentIndex++;
- }
-
- SD.setLayoutOrder(i);
- for (MCSectionData::iterator it2 = SD.begin(),
- ie2 = SD.end(); it2 != ie2; ++it2) {
- it2->setLayoutOrder(FragmentIndex++);
- }
- Layout.getSectionOrder().push_back(&SD);
-
- Layout.LayoutSection(&SD);
-
- // Layout until everything fits.
- while (LayoutOnce(Writer, Layout))
- continue;
-}
+uint64_t MCAssembler::HandleFixup(MCObjectWriter &Writer,
+ const MCAsmLayout &Layout,
+ MCFragment &F,
+ const MCFixup &Fixup) {
+ // Evaluate the fixup.
+ MCValue Target;
+ uint64_t FixedValue;
+ if (!EvaluateFixup(Writer, 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.
+ Writer.RecordRelocation(*this, Layout, &F, Fixup, Target, FixedValue);
+ }
+ return FixedValue;
+ }
void MCAssembler::Finish(MCObjectWriter *Writer) {
DEBUG_WITH_TYPE("mc-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;
}
// 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);
+ unsigned FragmentIndex = 0;
for (MCSectionData::iterator it2 = SD->begin(),
ie2 = SD->end(); it2 != ie2; ++it2)
it2->setLayoutOrder(FragmentIndex++);
// 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);
+ Writer->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);
+ if (DF) {
+ for (MCDataFragment::fixup_iterator it3 = DF->fixup_begin(),
+ ie3 = DF->fixup_end(); it3 != ie3; ++it3) {
+ MCFixup &Fixup = *it3;
+ uint64_t FixedValue = HandleFixup(*Writer, Layout, *DF, Fixup);
+ getBackend().ApplyFixup(Fixup, DF->getContents().data(),
+ DF->getContents().size(), FixedValue);
+ }
+ }
+ MCInstFragment *IF = dyn_cast<MCInstFragment>(it2);
+ if (IF) {
+ for (MCInstFragment::fixup_iterator it3 = IF->fixup_begin(),
+ ie3 = IF->fixup_end(); it3 != ie3; ++it3) {
+ MCFixup &Fixup = *it3;
+ uint64_t FixedValue = HandleFixup(*Writer, Layout, *IF, Fixup);
+ getBackend().ApplyFixup(Fixup, IF->getCode().data(),
+ IF->getCode().size(), FixedValue);
}
-
- getBackend().ApplyFixup(Fixup, *DF, FixedValue);
}
}
}
return false;
}
+bool MCAssembler::RelaxInstruction(const MCObjectWriter &Writer,
+ MCAsmLayout &Layout,
+ MCInstFragment &IF) {
+ if (!FragmentNeedsRelaxation(Writer, &IF, Layout))
+ return false;
+
+ ++stats::RelaxedInstructions;
+
+ // FIXME-PERF: We could immediately lower out instructions if we can tell
+ // they are fully resolved, to avoid retesting on later passes.
+
+ // Relax the fragment.
+
+ MCInst Relaxed;
+ getBackend().RelaxInstruction(IF.getInst(), Relaxed);
+
+ // Encode the new instruction.
+ //
+ // FIXME-PERF: If it matters, we could let the target do this. It can
+ // probably do so more efficiently in many cases.
+ SmallVector<MCFixup, 4> Fixups;
+ SmallString<256> Code;
+ raw_svector_ostream VecOS(Code);
+ getEmitter().EncodeInstruction(Relaxed, VecOS, Fixups);
+ VecOS.flush();
+
+ // Update the instruction fragment.
+ 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]);
+
+ return true;
+}
+
+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();
+}
+
+bool MCAssembler::RelaxLEB(const MCObjectWriter &Writer,
+ MCAsmLayout &Layout,
+ MCLEBFragment &LF) {
+ int64_t Value = 0;
+ uint64_t OldSize = LF.getContents().size();
+ LF.getValue().EvaluateAsAbsolute(Value, Layout);
+ SmallString<8> &Data = LF.getContents();
+ Data.clear();
+ raw_svector_ostream OSE(Data);
+ if (LF.isSigned())
+ MCObjectWriter::EncodeSLEB128(Value, OSE);
+ else
+ MCObjectWriter::EncodeULEB128(Value, OSE);
+ OSE.flush();
+ return OldSize != LF.getContents().size();
+}
+
+bool MCAssembler::RelaxDwarfLineAddr(const MCObjectWriter &Writer,
+ MCAsmLayout &Layout,
+ MCDwarfLineAddrFragment &DF) {
+ int64_t AddrDelta = 0;
+ uint64_t OldSize = DF.getContents().size();
+ DF.getAddrDelta().EvaluateAsAbsolute(AddrDelta, Layout);
+ int64_t LineDelta;
+ LineDelta = DF.getLineDelta();
+ SmallString<8> &Data = DF.getContents();
+ Data.clear();
+ raw_svector_ostream OSE(Data);
+ MCDwarfLineAddr::Encode(LineDelta, AddrDelta, OSE);
+ OSE.flush();
+ return OldSize != Data.size();
+}
+
+bool MCAssembler::RelaxAlignment(const MCObjectWriter &Writer,
+ MCAsmLayout &Layout,
+ MCAlignFragment &AF) {
+ unsigned Offset = Layout.getFragmentOffset(&AF);
+ unsigned Size = OffsetToAlignment(Offset, AF.getAlignment());
+ if (Size > AF.getMaxBytesToEmit())
+ Size = 0;
+ unsigned OldSize = AF.getSize();
+ AF.setSize(Size);
+ return OldSize != Size;
+}
+
bool MCAssembler::LayoutOnce(const MCObjectWriter &Writer,
MCAsmLayout &Layout) {
++stats::RelaxationSteps;
- // 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;
+ MCFragment *FirstInvalidFragment = NULL;
for (MCSectionData::iterator it2 = SD.begin(),
ie2 = SD.end(); it2 != ie2; ++it2) {
- // Check if this is an instruction fragment that needs relaxation.
- MCInstFragment *IF = dyn_cast<MCInstFragment>(it2);
- if (!IF || !FragmentNeedsRelaxation(Writer, IF, Layout))
- continue;
-
- ++stats::RelaxedInstructions;
-
- // FIXME-PERF: We could immediately lower out instructions if we can tell
- // they are fully resolved, to avoid retesting on later passes.
-
- // Relax the fragment.
-
- MCInst Relaxed;
- getBackend().RelaxInstruction(IF->getInst(), Relaxed);
-
- // Encode the new instruction.
- //
- // FIXME-PERF: If it matters, we could let the target do this. It can
- // probably do so more efficiently in many cases.
- SmallVector<MCFixup, 4> Fixups;
- SmallString<256> Code;
- raw_svector_ostream VecOS(Code);
- getEmitter().EncodeInstruction(Relaxed, VecOS, Fixups);
- 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]);
-
+ // Check if this is an fragment that needs relaxation.
+ bool relaxedFrag = false;
+ switch(it2->getKind()) {
+ default:
+ break;
+ case MCFragment::FT_Align:
+ relaxedFrag = RelaxAlignment(Writer, Layout,
+ *cast<MCAlignFragment>(it2));
+ break;
+ case MCFragment::FT_Inst:
+ relaxedFrag = RelaxInstruction(Writer, Layout,
+ *cast<MCInstFragment>(it2));
+ break;
+ case MCFragment::FT_Org:
+ relaxedFrag = RelaxOrg(Writer, Layout, *cast<MCOrgFragment>(it2));
+ break;
+ case MCFragment::FT_Dwarf:
+ relaxedFrag = RelaxDwarfLineAddr(Writer, Layout,
+ *cast<MCDwarfLineAddrFragment>(it2));
+ break;
+ case MCFragment::FT_LEB:
+ relaxedFrag = RelaxLEB(Writer, Layout, *cast<MCLEBFragment>(it2));
+ break;
+ }
// Update the layout, and remember that we relaxed.
- Layout.UpdateForSlide(IF, SlideAmount);
- WasRelaxed = true;
+ if (relaxedFrag && !FirstInvalidFragment)
+ FirstInvalidFragment = it2;
+ WasRelaxed |= relaxedFrag;
}
+ if (FirstInvalidFragment)
+ Layout.Invalidate(FirstInvalidFragment);
}
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;
- }
+ // 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());
}
}
case MCFragment::FT_Inst: OS << "MCInstFragment"; break;
case MCFragment::FT_Org: OS << "MCOrgFragment"; break;
case MCFragment::FT_Dwarf: OS << "MCDwarfFragment"; break;
+ case MCFragment::FT_LEB: OS << "MCLEBFragment"; break;
}
OS << "<MCFragment " << (void*) this << " LayoutOrder:" << LayoutOrder
- << " Offset:" << Offset << " EffectiveSize:" << EffectiveSize << ">";
+ << " Offset:" << Offset << ">";
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()
<< " LineDelta:" << OF->getLineDelta();
break;
}
+ case MCFragment::FT_LEB: {
+ const MCLEBFragment *LF = cast<MCLEBFragment>(this);
+ OS << "\n ";
+ OS << " Value:" << LF->getValue() << " Signed:" << LF->isSigned();
+ break;
+ }
}
OS << ">";
}
raw_ostream &OS = llvm::errs();
OS << "<MCSectionData";
- OS << " Alignment:" << getAlignment() << " Address:" << Address
- << " Fragments:[\n ";
+ OS << " Alignment:" << getAlignment() << " Fragments:[\n ";
for (iterator it = begin(), ie = end(); it != ie; ++it) {
if (it != begin()) OS << ",\n ";
it->dump();
projects / oota-llvm.git / blobdiff