namespace {
namespace stats {
STATISTIC(EmittedFragments, "Number of emitted assembler fragments - total");
-STATISTIC(EmittedInstFragments,
- "Number of emitted assembler fragments - instruction");
+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,
return F->getLayoutOrder() <= LastValid->getLayoutOrder();
}
-void MCAsmLayout::invalidateFragmentsAfter(MCFragment *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 this fragment.
+ // 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;
+ LastValidFragment[&SD] = F->getPrevNode();
}
void MCAsmLayout::ensureValid(const MCFragment *F) const {
return getSectionAddressSize(SD);
}
+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;
+
+ // 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() : Kind(FragmentType(~0)) {
/* *** */
+MCEncodedFragmentWithFixups::~MCEncodedFragmentWithFixups() {
+}
+
+/* *** */
+
MCSectionData::MCSectionData() : Section(0) {}
MCSectionData::MCSectionData(const MCSection &_Section, MCAssembler *A)
: Section(&_Section),
Ordinal(~UINT32_C(0)),
Alignment(1),
+ BundleLockState(NotBundleLocked), BundleGroupBeforeFirstInst(false),
HasInstructions(false)
{
if (A)
MCCodeEmitter &Emitter_, MCObjectWriter &Writer_,
raw_ostream &OS_)
: Context(Context_), Backend(Backend_), Emitter(Emitter_), Writer(Writer_),
- OS(OS_), RelaxAll(false), NoExecStack(false), SubsectionsViaSymbols(false) {
+ OS(OS_), BundleAlignSize(0), RelaxAll(false), NoExecStack(false),
+ SubsectionsViaSymbols(false), ELFHeaderEFlags(0) {
}
MCAssembler::~MCAssembler() {
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 {
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_Fill:
return cast<MCFillFragment>(F).getSize();
- case MCFragment::FT_Inst:
- return cast<MCInstFragment>(F).getInstSize();
case MCFragment::FT_LEB:
return cast<MCLEBFragment>(F).getContents().size();
++stats::FragmentLayouts;
// Compute fragment offset and size.
- uint64_t Offset = 0;
if (Prev)
- Offset += Prev->Offset + getAssembler().computeFragmentSize(*this, *Prev);
-
- F->Offset = Offset;
+ F->Offset = Prev->Offset + getAssembler().computeFragmentSize(*this, *Prev);
+ else
+ F->Offset = 0;
LastValidFragment[F->getParent()] = F;
+
+ // 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;
+ }
}
/// \brief Write the contents of a fragment to the given object writer. Expects
static void writeFragment(const MCAssembler &Asm, const MCAsmLayout &Layout,
const MCFragment &F) {
MCObjectWriter *OW = &Asm.getWriter();
+
+ // 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");
+ }
+
+ // 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 = Asm.computeFragmentSize(Layout, F);
switch (F.getKind()) {
case MCFragment::FT_Align: {
++stats::EmittedAlignFragments;
writeFragmentContents(F, OW);
break;
- case MCFragment::FT_Inst:
- ++stats::EmittedInstFragments;
+ case MCFragment::FT_Relaxable:
+ ++stats::EmittedRelaxableFragments;
+ writeFragmentContents(F, OW);
+ break;
+
+ case MCFragment::FT_CompactEncodedInst:
+ ++stats::EmittedCompactEncodedInstFragments;
writeFragmentContents(F, OW);
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,
for (MCAssembler::iterator it = begin(), ie = end(); it != ie; ++it) {
for (MCSectionData::iterator it2 = it->begin(),
ie2 = it->end(); it2 != ie2; ++it2) {
- MCEncodedFragment *F = dyn_cast<MCEncodedFragment>(it2);
+ MCEncodedFragmentWithFixups *F =
+ dyn_cast<MCEncodedFragmentWithFixups>(it2);
if (F) {
- for (MCEncodedFragment::fixup_iterator it3 = F->fixup_begin(),
+ for (MCEncodedFragmentWithFixups::fixup_iterator it3 = F->fixup_begin(),
ie3 = F->fixup_end(); it3 != ie3; ++it3) {
MCFixup &Fixup = *it3;
uint64_t FixedValue = handleFixup(Layout, *F, Fixup);
}
bool MCAssembler::fixupNeedsRelaxation(const MCFixup &Fixup,
- const MCInstFragment *DF,
+ const MCRelaxableFragment *DF,
const MCAsmLayout &Layout) const {
// If we cannot resolve the fixup value, it requires relaxation.
MCValue Target;
return getBackend().fixupNeedsRelaxation(Fixup, Value, DF, Layout);
}
-bool MCAssembler::fragmentNeedsRelaxation(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(*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(MCAsmLayout &Layout,
- MCInstFragment &IF) {
- if (!fragmentNeedsRelaxation(&IF, 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.
//
getEmitter().EncodeInstruction(Relaxed, VecOS, Fixups);
VecOS.flush();
- // Update the instruction fragment.
- IF.setInst(Relaxed);
- IF.getContents() = Code;
- IF.getFixups() = Fixups;
+ // Update the fragment.
+ F.setInst(Relaxed);
+ F.getContents() = Code;
+ F.getFixups() = Fixups;
return true;
}
switch(I->getKind()) {
default:
break;
- case MCFragment::FT_Inst:
+ case MCFragment::FT_Relaxable:
assert(!getRelaxAll() &&
- "Did not expect a MCInstFragment in RelaxAll mode");
- RelaxedFrag = relaxInstruction(Layout, *cast<MCInstFragment>(I));
+ "Did not expect a MCRelaxableFragment in RelaxAll mode");
+ RelaxedFrag = relaxInstruction(Layout, *cast<MCRelaxableFragment>(I));
break;
case MCFragment::FT_Dwarf:
RelaxedFrag = relaxDwarfLineAddr(Layout,
FirstRelaxedFragment = I;
}
if (FirstRelaxedFragment) {
- Layout.invalidateFragmentsAfter(FirstRelaxedFragment);
+ Layout.invalidateFragmentsFrom(FirstRelaxedFragment);
return true;
}
return false;
switch (getKind()) {
case MCFragment::FT_Align: OS << "MCAlignFragment"; break;
case MCFragment::FT_Data: OS << "MCDataFragment"; 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;
}
OS << "<MCFragment " << (void*) this << " LayoutOrder:" << LayoutOrder
- << " Offset:" << Offset << ">";
+ << " Offset:" << Offset
+ << " HasInstructions:" << hasInstructions()
+ << " BundlePadding:" << static_cast<unsigned>(getBundlePadding()) << ">";
switch (getKind()) {
case MCFragment::FT_Align: {
}
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: {
raw_ostream &OS = llvm::errs();
OS << "<MCSectionData";
- OS << " Alignment:" << getAlignment() << " Fragments:[\n ";
+ OS << " Alignment:" << getAlignment()
+ << " Fragments:[\n ";
for (iterator it = begin(), ie = end(); it != ie; ++it) {
if (it != begin()) OS << ",\n ";
it->dump();
// anchors for MC*Fragment vtables
void MCEncodedFragment::anchor() { }
+void MCEncodedFragmentWithFixups::anchor() { }
void MCDataFragment::anchor() { }
-void MCInstFragment::anchor() { }
+void MCCompactEncodedInstFragment::anchor() { }
+void MCRelaxableFragment::anchor() { }
void MCAlignFragment::anchor() { }
void MCFillFragment::anchor() { }
void MCOrgFragment::anchor() { }
projects / oota-llvm.git / blobdiff