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[BOLT] Clean up jump table handling in non-reloc mode. NFCI #119614

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Merged
merged 1 commit into from
Dec 13, 2024
Merged

[BOLT] Clean up jump table handling in non-reloc mode. NFCI #119614

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26 changes: 6 additions & 20 deletions bolt/lib/Core/BinaryEmitter.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -730,30 +730,16 @@ void BinaryEmitter::emitJumpTables(const BinaryFunction &BF) {
continue;
if (opts::PrintJumpTables)
JT.print(BC.outs());
if (opts::JumpTables == JTS_BASIC && BC.HasRelocations) {
if (opts::JumpTables == JTS_BASIC) {
JT.updateOriginal();
} else {
MCSection *HotSection, *ColdSection;
if (opts::JumpTables == JTS_BASIC) {
// In non-relocation mode we have to emit jump tables in local sections.
// This way we only overwrite them when the corresponding function is
// overwritten.
std::string Name = ".local." + JT.Labels[0]->getName().str();
std::replace(Name.begin(), Name.end(), '/', '.');
BinarySection &Section =
BC.registerOrUpdateSection(Name, ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
Section.setAnonymous(true);
JT.setOutputSection(Section);
HotSection = BC.getDataSection(Name);
ColdSection = HotSection;
if (BF.isSimple()) {
HotSection = ReadOnlySection;
ColdSection = ReadOnlyColdSection;
} else {
if (BF.isSimple()) {
HotSection = ReadOnlySection;
ColdSection = ReadOnlyColdSection;
} else {
HotSection = BF.hasProfile() ? ReadOnlySection : ReadOnlyColdSection;
ColdSection = HotSection;
}
HotSection = BF.hasProfile() ? ReadOnlySection : ReadOnlyColdSection;
ColdSection = HotSection;
}
emitJumpTable(JT, HotSection, ColdSection);
}
Expand Down
37 changes: 2 additions & 35 deletions bolt/lib/Rewrite/RewriteInstance.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -78,7 +78,6 @@ namespace opts {
extern cl::list<std::string> HotTextMoveSections;
extern cl::opt<bool> Hugify;
extern cl::opt<bool> Instrument;
extern cl::opt<JumpTableSupportLevel> JumpTables;
extern cl::opt<bool> KeepNops;
extern cl::opt<bool> Lite;
extern cl::list<std::string> ReorderData;
Expand Down Expand Up @@ -3841,20 +3840,6 @@ void RewriteInstance::mapCodeSections(BOLTLinker::SectionMapper MapSection) {
assert(Function.getImageSize() <= Function.getMaxSize() &&
"Unexpected large function");

// Map jump tables if updating in-place.
if (opts::JumpTables == JTS_BASIC) {
for (auto &JTI : Function.JumpTables) {
JumpTable *JT = JTI.second;
BinarySection &Section = JT->getOutputSection();
Section.setOutputAddress(JT->getAddress());
Section.setOutputFileOffset(getFileOffsetForAddress(JT->getAddress()));
LLVM_DEBUG(dbgs() << "BOLT-DEBUG: mapping JT " << Section.getName()
<< " to 0x" << Twine::utohexstr(JT->getAddress())
<< '\n');
MapSection(Section, JT->getAddress());
}
}

if (!Function.isSplit())
continue;

Expand Down Expand Up @@ -5637,26 +5622,8 @@ void RewriteInstance::rewriteFile() {
if (Function->getImageAddress() == 0 || Function->getImageSize() == 0)
continue;

if (Function->getImageSize() > Function->getMaxSize()) {
assert(!BC->isX86() && "Unexpected large function.");
if (opts::Verbosity >= 1)
BC->errs() << "BOLT-WARNING: new function size (0x"
<< Twine::utohexstr(Function->getImageSize())
<< ") is larger than maximum allowed size (0x"
<< Twine::utohexstr(Function->getMaxSize())
<< ") for function " << *Function << '\n';

// Remove jump table sections that this function owns in non-reloc mode
// because we don't want to write them anymore.
if (!BC->HasRelocations && opts::JumpTables == JTS_BASIC) {
for (auto &JTI : Function->JumpTables) {
JumpTable *JT = JTI.second;
BinarySection &Section = JT->getOutputSection();
BC->deregisterSection(Section);
}
}
continue;
}
assert(Function->getImageSize() <= Function->getMaxSize() &&
"Unexpected large function");

const auto HasAddress = [](const FunctionFragment &FF) {
return FF.empty() ||
Expand Down
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