// Then compute the bucket size, minimum of 1 bucket.
if (num > 1024)
Header.bucket_count = num / 4;
- if (num > 16)
+ else if (num > 16)
Header.bucket_count = num / 2;
else
Header.bucket_count = num > 0 ? num : 1;
for (size_t i = 0, e = Data.size(); i < e; ++i) {
uint32_t bucket = Data[i]->HashValue % Header.bucket_count;
Buckets[bucket].push_back(Data[i]);
- Data[i]->Sym = Asm->GetTempSymbol(Prefix, i);
+ Data[i]->Sym = Asm->createTempSymbol(Prefix);
}
+
+ // Sort the contents of the buckets by hash value so that hash
+ // collisions end up together. Stable sort makes testing easier and
+ // doesn't cost much more.
+ for (size_t i = 0; i < Buckets.size(); ++i)
+ std::stable_sort(Buckets[i].begin(), Buckets[i].end(),
+ [] (HashData *LHS, HashData *RHS) {
+ return LHS->HashValue < RHS->HashValue;
+ });
}
// Emits the header for the table via the AsmPrinter.
void DwarfAccelTable::EmitHeader(AsmPrinter *Asm) {
- Asm->OutStreamer.AddComment("Header Magic");
+ Asm->OutStreamer->AddComment("Header Magic");
Asm->EmitInt32(Header.magic);
- Asm->OutStreamer.AddComment("Header Version");
+ Asm->OutStreamer->AddComment("Header Version");
Asm->EmitInt16(Header.version);
- Asm->OutStreamer.AddComment("Header Hash Function");
+ Asm->OutStreamer->AddComment("Header Hash Function");
Asm->EmitInt16(Header.hash_function);
- Asm->OutStreamer.AddComment("Header Bucket Count");
+ Asm->OutStreamer->AddComment("Header Bucket Count");
Asm->EmitInt32(Header.bucket_count);
- Asm->OutStreamer.AddComment("Header Hash Count");
+ Asm->OutStreamer->AddComment("Header Hash Count");
Asm->EmitInt32(Header.hashes_count);
- Asm->OutStreamer.AddComment("Header Data Length");
+ Asm->OutStreamer->AddComment("Header Data Length");
Asm->EmitInt32(Header.header_data_len);
- Asm->OutStreamer.AddComment("HeaderData Die Offset Base");
+ Asm->OutStreamer->AddComment("HeaderData Die Offset Base");
Asm->EmitInt32(HeaderData.die_offset_base);
- Asm->OutStreamer.AddComment("HeaderData Atom Count");
+ Asm->OutStreamer->AddComment("HeaderData Atom Count");
Asm->EmitInt32(HeaderData.Atoms.size());
for (size_t i = 0; i < HeaderData.Atoms.size(); i++) {
Atom A = HeaderData.Atoms[i];
- Asm->OutStreamer.AddComment(dwarf::AtomTypeString(A.type));
+ Asm->OutStreamer->AddComment(dwarf::AtomTypeString(A.type));
Asm->EmitInt16(A.type);
- Asm->OutStreamer.AddComment(dwarf::FormEncodingString(A.form));
+ Asm->OutStreamer->AddComment(dwarf::FormEncodingString(A.form));
Asm->EmitInt16(A.form);
}
}
void DwarfAccelTable::EmitBuckets(AsmPrinter *Asm) {
unsigned index = 0;
for (size_t i = 0, e = Buckets.size(); i < e; ++i) {
- Asm->OutStreamer.AddComment("Bucket " + Twine(i));
+ Asm->OutStreamer->AddComment("Bucket " + Twine(i));
if (Buckets[i].size() != 0)
Asm->EmitInt32(index);
else
Asm->EmitInt32(UINT32_MAX);
- index += Buckets[i].size();
+ // Buckets point in the list of hashes, not to the data. Do not
+ // increment the index multiple times in case of hash collisions.
+ uint64_t PrevHash = UINT64_MAX;
+ for (auto *HD : Buckets[i]) {
+ uint32_t HashValue = HD->HashValue;
+ if (PrevHash != HashValue)
+ ++index;
+ PrevHash = HashValue;
+ }
}
}
// Walk through the buckets and emit the individual hashes for each
// bucket.
void DwarfAccelTable::EmitHashes(AsmPrinter *Asm) {
+ uint64_t PrevHash = UINT64_MAX;
for (size_t i = 0, e = Buckets.size(); i < e; ++i) {
for (HashList::const_iterator HI = Buckets[i].begin(),
HE = Buckets[i].end();
HI != HE; ++HI) {
- Asm->OutStreamer.AddComment("Hash in Bucket " + Twine(i));
- Asm->EmitInt32((*HI)->HashValue);
+ uint32_t HashValue = (*HI)->HashValue;
+ if (PrevHash == HashValue)
+ continue;
+ Asm->OutStreamer->AddComment("Hash in Bucket " + Twine(i));
+ Asm->EmitInt32(HashValue);
+ PrevHash = HashValue;
}
}
}
// element in each bucket. This is done via a symbol subtraction from the
// beginning of the section. The non-section symbol will be output later
// when we emit the actual data.
-void DwarfAccelTable::EmitOffsets(AsmPrinter *Asm, MCSymbol *SecBegin) {
+void DwarfAccelTable::emitOffsets(AsmPrinter *Asm, const MCSymbol *SecBegin) {
+ uint64_t PrevHash = UINT64_MAX;
for (size_t i = 0, e = Buckets.size(); i < e; ++i) {
for (HashList::const_iterator HI = Buckets[i].begin(),
HE = Buckets[i].end();
HI != HE; ++HI) {
- Asm->OutStreamer.AddComment("Offset in Bucket " + Twine(i));
- MCContext &Context = Asm->OutStreamer.getContext();
+ uint32_t HashValue = (*HI)->HashValue;
+ if (PrevHash == HashValue)
+ continue;
+ PrevHash = HashValue;
+ Asm->OutStreamer->AddComment("Offset in Bucket " + Twine(i));
+ MCContext &Context = Asm->OutStreamer->getContext();
const MCExpr *Sub = MCBinaryExpr::CreateSub(
MCSymbolRefExpr::Create((*HI)->Sym, Context),
MCSymbolRefExpr::Create(SecBegin, Context), Context);
- Asm->OutStreamer.EmitValue(Sub, sizeof(uint32_t));
+ Asm->OutStreamer->EmitValue(Sub, sizeof(uint32_t));
}
}
}
// Walk through the buckets and emit the full data for each element in
// the bucket. For the string case emit the dies and the various offsets.
// Terminate each HashData bucket with 0.
-void DwarfAccelTable::EmitData(AsmPrinter *Asm, DwarfDebug *D,
- MCSymbol *StrSym) {
- uint64_t PrevHash = UINT64_MAX;
+void DwarfAccelTable::EmitData(AsmPrinter *Asm, DwarfDebug *D) {
for (size_t i = 0, e = Buckets.size(); i < e; ++i) {
+ uint64_t PrevHash = UINT64_MAX;
for (HashList::const_iterator HI = Buckets[i].begin(),
HE = Buckets[i].end();
HI != HE; ++HI) {
+ // Terminate the previous entry if there is no hash collision
+ // with the current one.
+ if (PrevHash != UINT64_MAX && PrevHash != (*HI)->HashValue)
+ Asm->EmitInt32(0);
// Remember to emit the label for our offset.
- Asm->OutStreamer.EmitLabel((*HI)->Sym);
- Asm->OutStreamer.AddComment((*HI)->Str);
- Asm->EmitSectionOffset((*HI)->Data.StrSym, StrSym);
- Asm->OutStreamer.AddComment("Num DIEs");
+ Asm->OutStreamer->EmitLabel((*HI)->Sym);
+ Asm->OutStreamer->AddComment((*HI)->Str);
+ Asm->emitSectionOffset((*HI)->Data.StrSym);
+ Asm->OutStreamer->AddComment("Num DIEs");
Asm->EmitInt32((*HI)->Data.Values.size());
for (HashDataContents *HD : (*HI)->Data.Values) {
// Emit the DIE offset
Asm->EmitInt8(HD->Flags);
}
}
- // Emit a 0 to terminate the data unless we have a hash collision.
- if (PrevHash != (*HI)->HashValue)
- Asm->EmitInt32(0);
PrevHash = (*HI)->HashValue;
}
+ // Emit the final end marker for the bucket.
+ if (!Buckets[i].empty())
+ Asm->EmitInt32(0);
}
}
// Emit the entire data structure to the output file.
-void DwarfAccelTable::Emit(AsmPrinter *Asm, MCSymbol *SecBegin, DwarfDebug *D,
- MCSymbol *StrSym) {
+void DwarfAccelTable::emit(AsmPrinter *Asm, const MCSymbol *SecBegin,
+ DwarfDebug *D) {
// Emit the header.
EmitHeader(Asm);
EmitHashes(Asm);
// Emit the offsets.
- EmitOffsets(Asm, SecBegin);
+ emitOffsets(Asm, SecBegin);
// Emit the hash data.
- EmitData(Asm, D, StrSym);
+ EmitData(Asm, D);
}
#ifndef NDEBUG
projects / oota-llvm.git / blobdiff