void SVMELFProgramWriter::rwCompress(MCAssembler &Asm, const MCAsmLayout &Layout, SVMMemoryLayout &ML) { /* * Look for all segments with initialized data for RAM, flatten them, and * compress the resulting data. Create a new segment with the compressed * RWDATA. This segment will always be included in the binary. The originals * are considered debug-only sections, since they are no longer needed * at runtime. */ // Flattened binary contents of RAM std::vector<uint8_t> plaintext; // Iterate over SPS_RW sections for (MCAssembler::const_iterator IS = Asm.begin(), ES = Asm.end(); IS != ES; ++IS) { const MCSectionData *SD = &*IS; if (ML.getSectionKind(SD) != SPS_RW_PLAIN) continue; int offset = ML.getSectionMemAddress(SD) - SVMTargetMachine::getRAMBase(); int limit = SVMTargetMachine::getRAMSize(); // Iterate over fragments, pasting them into 'plaintext' for (MCSectionData::const_iterator IF = SD->begin(), EF = SD->end(); IF != EF; ++IF) { const MCFragment *F = &*IF; if (F->getKind() == MCFragment::FT_Data) { const MCDataFragment *DF = cast<MCDataFragment>(F); int fragmentOffset = Layout.getFragmentOffset(F); for (unsigned i = 0; i < DF->getContents().size(); i++) { int totalOffset = fragmentOffset + offset + i; if (totalOffset < limit) { while (totalOffset >= int(plaintext.size())) plaintext.push_back(0); plaintext[totalOffset] = DF->getContents()[i]; } } } } } // FastLZ requires a minimum of 16 bytes to compress. Pad our section data. while (plaintext.size() < 16) plaintext.push_back(0); // Compress using FastLZ level 1 std::vector<uint8_t> compressed(plaintext.size() * 2); compressed.resize(fastlz_compress_level(1, &plaintext[0], plaintext.size(), &compressed[0])); // Create the new section const MCSectionELF *LZSection = Asm.getContext().getELFSection(".rwdata.lz", ELF::SHT_NOTE, 0, SectionKind::getDataNoRel()); MCSectionData &LZSectionSD = Asm.getOrCreateSectionData(*LZSection); LZSectionSD.setAlignment(1); // Force it to be interpreted as SPS_RW, and set the decompressed size ML.setSectionKind(&LZSectionSD, SPS_RW_Z); ML.setSectionMemSize(&LZSectionSD, plaintext.size()); // Add compressed data MCDataFragment *F = new MCDataFragment(&LZSectionSD); F->getContents().append(compressed.begin(), compressed.end()); }
void MCELFStreamer::EmitInstToData(const MCInst &Inst, const MCSubtargetInfo &STI) { MCAssembler &Assembler = getAssembler(); SmallVector<MCFixup, 4> Fixups; SmallString<256> Code; raw_svector_ostream VecOS(Code); Assembler.getEmitter().encodeInstruction(Inst, VecOS, Fixups, STI); for (unsigned i = 0, e = Fixups.size(); i != e; ++i) fixSymbolsInTLSFixups(Fixups[i].getValue()); // There are several possibilities here: // // If bundling is disabled, append the encoded instruction to the current data // fragment (or create a new such fragment if the current fragment is not a // data fragment). // // If bundling is enabled: // - If we're not in a bundle-locked group, emit the instruction into a // fragment of its own. If there are no fixups registered for the // instruction, emit a MCCompactEncodedInstFragment. Otherwise, emit a // MCDataFragment. // - If we're in a bundle-locked group, append the instruction to the current // data fragment because we want all the instructions in a group to get into // the same fragment. Be careful not to do that for the first instruction in // the group, though. MCDataFragment *DF; if (Assembler.isBundlingEnabled()) { MCSection &Sec = *getCurrentSectionOnly(); if (Assembler.getRelaxAll() && isBundleLocked()) // If the -mc-relax-all flag is used and we are bundle-locked, we re-use // the current bundle group. DF = BundleGroups.back(); else if (Assembler.getRelaxAll() && !isBundleLocked()) // When not in a bundle-locked group and the -mc-relax-all flag is used, // we create a new temporary fragment which will be later merged into // the current fragment. DF = new MCDataFragment(); else if (isBundleLocked() && !Sec.isBundleGroupBeforeFirstInst()) // If we are bundle-locked, we re-use the current fragment. // The bundle-locking directive ensures this is a new data fragment. DF = cast<MCDataFragment>(getCurrentFragment()); else if (!isBundleLocked() && Fixups.size() == 0) { // Optimize memory usage by emitting the instruction to a // MCCompactEncodedInstFragment when not in a bundle-locked group and // there are no fixups registered. MCCompactEncodedInstFragment *CEIF = new MCCompactEncodedInstFragment(); insert(CEIF); CEIF->getContents().append(Code.begin(), Code.end()); return; } else { DF = new MCDataFragment(); insert(DF); } if (Sec.getBundleLockState() == MCSection::BundleLockedAlignToEnd) { // If this fragment is for a group marked "align_to_end", set a flag // in the fragment. This can happen after the fragment has already been // created if there are nested bundle_align groups and an inner one // is the one marked align_to_end. DF->setAlignToBundleEnd(true); } // We're now emitting an instruction in a bundle group, so this flag has // to be turned off. Sec.setBundleGroupBeforeFirstInst(false); } else { DF = getOrCreateDataFragment(); } // Add the fixups and data. for (unsigned i = 0, e = Fixups.size(); i != e; ++i) { Fixups[i].setOffset(Fixups[i].getOffset() + DF->getContents().size()); DF->getFixups().push_back(Fixups[i]); } DF->setHasInstructions(true); DF->getContents().append(Code.begin(), Code.end()); if (Assembler.isBundlingEnabled() && Assembler.getRelaxAll()) { if (!isBundleLocked()) { mergeFragment(getOrCreateDataFragment(), DF); delete DF; } } }
void MCObjectStreamer::EmitBytes(StringRef Data) { MCLineEntry::Make(this, getCurrentSection().first); MCDataFragment *DF = getOrCreateDataFragment(); flushPendingLabels(DF, DF->getContents().size()); DF->getContents().append(Data.begin(), Data.end()); }
void MCELFStreamer::EmitInstToData(const MCInst &Inst) { MCAssembler &Assembler = getAssembler(); SmallVector<MCFixup, 4> Fixups; SmallString<256> Code; raw_svector_ostream VecOS(Code); Assembler.getEmitter().EncodeInstruction(Inst, VecOS, Fixups); VecOS.flush(); for (unsigned i = 0, e = Fixups.size(); i != e; ++i) fixSymbolsInTLSFixups(Fixups[i].getValue()); // There are several possibilities here: // // If bundling is disabled, append the encoded instruction to the current data // fragment (or create a new such fragment if the current fragment is not a // data fragment). // // If bundling is enabled: // - If we're not in a bundle-locked group, emit the instruction into a // fragment of its own. If there are no fixups registered for the // instruction, emit a MCCompactEncodedInstFragment. Otherwise, emit a // MCDataFragment. // - If we're in a bundle-locked group, append the instruction to the current // data fragment because we want all the instructions in a group to get into // the same fragment. Be careful not to do that for the first instruction in // the group, though. MCDataFragment *DF; if (Assembler.isBundlingEnabled()) { MCSectionData *SD = getCurrentSectionData(); if (SD->isBundleLocked() && !SD->isBundleGroupBeforeFirstInst()) // If we are bundle-locked, we re-use the current fragment. // The bundle-locking directive ensures this is a new data fragment. DF = cast<MCDataFragment>(getCurrentFragment()); else if (!SD->isBundleLocked() && Fixups.size() == 0) { // Optimize memory usage by emitting the instruction to a // MCCompactEncodedInstFragment when not in a bundle-locked group and // there are no fixups registered. MCCompactEncodedInstFragment *CEIF = new MCCompactEncodedInstFragment(); insert(CEIF); CEIF->getContents().append(Code.begin(), Code.end()); return; } else { DF = new MCDataFragment(); insert(DF); if (SD->getBundleLockState() == MCSectionData::BundleLockedAlignToEnd) { // If this is a new fragment created for a bundle-locked group, and the // group was marked as "align_to_end", set a flag in the fragment. DF->setAlignToBundleEnd(true); } } // We're now emitting an instruction in a bundle group, so this flag has // to be turned off. SD->setBundleGroupBeforeFirstInst(false); } else { DF = getOrCreateDataFragment(); } // Add the fixups and data. for (unsigned i = 0, e = Fixups.size(); i != e; ++i) { Fixups[i].setOffset(Fixups[i].getOffset() + DF->getContents().size()); DF->getFixups().push_back(Fixups[i]); } DF->setHasInstructions(true); DF->getContents().append(Code.begin(), Code.end()); }
// Associate GPRel32 fixup with data and resize data area void MCObjectStreamer::EmitGPRel64Value(const MCExpr *Value) { MCDataFragment *DF = getOrCreateDataFragment(); DF->addFixup(MCFixup::Create(DF->getContents().size(), Value, FK_GPRel_4)); DF->getContents().resize(DF->getContents().size() + 8, 0); }