/* *** */
-MCAsmLayout::MCAsmLayout(MCAssembler &Asm) : Assembler(Asm) {
+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);
}
+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) {
- // We shouldn't have to do anything special to support negative slides, and it
- // is a perfectly valid thing to do as long as other parts of the system can
- // guarantee convergence.
- assert(SlideAmount >= 0 && "Negative slides not yet supported");
+ // If this fragment wasn't already up-to-date, we don't need to do anything.
+ if (!isFragmentUpToDate(F))
+ return;
- // Update the layout by simply recomputing the layout for the entire
- // file. This is trivially correct, but very slow.
- //
- // FIXME-PERF: This is O(N^2), but will be eliminated once we get smarter.
+ // 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());
+ }
+ }
+}
- // Layout the sections in order.
- LayoutFile();
+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;
}
}
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::getSectionAddress(const MCSectionData *SD) const {
+ EnsureValid(SD->begin());
assert(SD->Address != ~UINT64_C(0) && "Address not set!");
return SD->Address;
}
Parent->getFragmentList().push_back(this);
}
-MCFragment::~MCFragment() {
-}
-
/* *** */
MCSectionData::MCSectionData() : Section(0) {}
}
static bool isScatteredFixupFullyResolvedSimple(const MCAssembler &Asm,
- const MCAsmFixup &Fixup,
+ const MCFixup &Fixup,
const MCValue Target,
const MCSection *BaseSection) {
// The effective fixup address is
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
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());
}
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.
}
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))
+ 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
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())
}
if (IsPCRel)
- Value -= Layout.getFragmentAddress(DF) + Fixup.Offset;
+ Value -= Layout.getFragmentAddress(DF) + Fixup.getOffset();
return IsResolved;
}
}
void MCAsmLayout::LayoutFile() {
- // Initialize the first section.
+ // 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;
-
- for (unsigned i = 0, e = getSectionOrder().size(); i != e; ++i) {
- MCSectionData *SD = getSectionOrder()[i];
-
- for (MCSectionData::iterator it = SD->begin(),
- ie = SD->end(); it != ie; ++it)
- LayoutFragment(it);
- }
}
void MCAsmLayout::LayoutFragment(MCFragment *F) {
- uint64_t StartAddress = getSectionAddress(F->getParent());
-
- // Get the fragment start address.
- uint64_t Address = StartAddress;
- MCSectionData::iterator it = F;
- if (MCFragment *Prev = F->getPrevNode())
- Address = (StartAddress + getFragmentOffset(Prev) +
- getFragmentEffectiveSize(Prev));
+ 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()) {
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()) {
- unsigned ValueSize = 1;
- if (getBackend().isVirtualSection(it->getSection()))
- ValueSize = 1;
+ if (it->getFragmentList().empty())
new MCFillFragment(0, 1, 0, it);
- }
it->setOrdinal(SectionIndex++);
}
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;
// 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())
// 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(),
// Relax the fragment.
MCInst Relaxed;
- getBackend().RelaxInstruction(IF, Relaxed);
+ getBackend().RelaxInstruction(IF->getInst(), Relaxed);
// Encode the new instruction.
//
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]);
- // Update the layout, and remember that we relaxed. If we are relaxing
- // everything, we can skip this step since nothing will depend on updating
- // the values.
- if (!getRelaxAll())
- Layout.UpdateForSlide(IF, SlideAmount);
+ // Update the layout, and remember that we relaxed.
+ Layout.UpdateForSlide(IF, SlideAmount);
WasRelaxed = true;
}
}
namespace llvm {
-raw_ostream &operator<<(raw_ostream &OS, const MCAsmFixup &AF) {
- OS << "<MCAsmFixup" << " Offset:" << AF.Offset << " Value:" << *AF.Value
- << " Kind:" << AF.Kind << ">";
+raw_ostream &operator<<(raw_ostream &OS, const MCFixup &AF) {
+ OS << "<MCFixup" << " Offset:" << AF.getOffset()
+ << " Value:" << *AF.getValue()
+ << " Kind:" << AF.getKind() << ">";
return OS;
}
void MCFragment::dump() {
raw_ostream &OS = llvm::errs();
+ 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;
+ }
+
OS << "<MCFragment " << (void*) this << " LayoutOrder:" << LayoutOrder
<< " Offset:" << Offset << " EffectiveSize:" << EffectiveSize << ">";
-}
-
-void MCAlignFragment::dump() {
- raw_ostream &OS = llvm::errs();
-
- OS << "<MCAlignFragment ";
- this->MCFragment::dump();
- if (hasEmitNops())
- OS << " (emit nops)";
- if (hasOnlyAlignAddress())
- OS << " (only align section)";
- OS << "\n ";
- OS << " Alignment:" << getAlignment()
- << " Value:" << getValue() << " ValueSize:" << getValueSize()
- << " MaxBytesToEmit:" << getMaxBytesToEmit() << ">";
-}
-
-void MCDataFragment::dump() {
- raw_ostream &OS = llvm::errs();
- OS << "<MCDataFragment ";
- this->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<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_Data: {
+ const MCDataFragment *DF = cast<MCDataFragment>(this);
+ OS << "\n ";
+ OS << " Contents:[";
+ const SmallVectorImpl<char> &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<MCFillFragment>(this);
+ OS << " Value:" << FF->getValue() << " ValueSize:" << FF->getValueSize()
+ << " Size:" << FF->getSize();
+ break;
+ }
+ case MCFragment::FT_Inst: {
+ const MCInstFragment *IF = cast<MCInstFragment>(this);
+ OS << "\n ";
+ OS << " Inst:";
+ IF->getInst().dump_pretty(OS);
+ break;
+ }
+ case MCFragment::FT_Org: {
+ const MCOrgFragment *OF = cast<MCOrgFragment>(this);
+ OS << "\n ";
+ OS << " Offset:" << OF->getOffset() << " Value:" << OF->getValue();
+ break;
+ }
}
-
- OS << ">";
-}
-
-void MCFillFragment::dump() {
- raw_ostream &OS = llvm::errs();
-
- OS << "<MCFillFragment ";
- this->MCFragment::dump();
- OS << "\n ";
- OS << " Value:" << getValue() << " ValueSize:" << getValueSize()
- << " Size:" << getSize() << ">";
-}
-
-void MCInstFragment::dump() {
- raw_ostream &OS = llvm::errs();
-
- OS << "<MCInstFragment ";
- this->MCFragment::dump();
- OS << "\n ";
- OS << " Inst:";
- getInst().dump_pretty(OS);
OS << ">";
}
-void MCOrgFragment::dump() {
- raw_ostream &OS = llvm::errs();
-
- OS << "<MCOrgFragment ";
- this->MCFragment::dump();
- OS << "\n ";
- OS << " Offset:" << getOffset() << " Value:" << getValue() << ">";
-}
-
void MCSectionData::dump() {
raw_ostream &OS = llvm::errs();
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