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Don't read all of the records in the PCH file's preprocessor block,

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most of which are ignored. Instead, move the __COUNTER__ value out to
a PCH-level record (since it is handled eagerly) and move the header
file information into the SourceManager block (which is also,
currently, loaded eagerly).

This results in another 17% performance improvement in the
Cocoa-prefixed "Hello, World" with PCH.

llvm-svn: 70097
This commit is contained in:
Douglas Gregor
2009-04-26 00:07:37 +00:00
parent ab2784f2c1
commit eda6a89c4e
5 changed files with 59 additions and 125 deletions
Download Patch File Download Diff File Expand all files Collapse all files

102
clang/lib/Frontend/PCHReader.cpp
View File

@@ -1473,6 +1473,7 @@ PCHReader::PCHReadResult PCHReader::ReadSourceManagerBlock() {
SourceManager &SourceMgr = Context.getSourceManager();
RecordData Record;
unsigned NumHeaderInfos = 0;
while (true) {
unsigned Code = Stream.ReadCode();
if (Code == llvm::bitc::END_BLOCK) {
@@ -1557,6 +1558,16 @@ PCHReader::PCHReadResult PCHReader::ReadSourceManagerBlock() {
if (ParseLineTable(SourceMgr, Record))
return Failure;
break;
case pch::SM_HEADER_FILE_INFO: {
HeaderFileInfo HFI;
HFI.isImport = Record[0];
HFI.DirInfo = Record[1];
HFI.NumIncludes = Record[2];
HFI.ControllingMacroID = Record[3];
PP.getHeaderSearchInfo().setHeaderFileInfoForUID(HFI, NumHeaderInfos++);
break;
}
}
}
}
@@ -1597,10 +1608,6 @@ void PCHReader::ReadMacroRecord(uint64_t Offset) {
pch::PreprocessorRecordTypes RecType =
(pch::PreprocessorRecordTypes)Stream.ReadRecord(Code, Record);
switch (RecType) {
case pch::PP_COUNTER_VALUE:
// Skip this record.
break;
case pch::PP_MACRO_OBJECT_LIKE:
case pch::PP_MACRO_FUNCTION_LIKE: {
// If we already have a macro, that means that we've hit the end
@@ -1663,70 +1670,12 @@ void PCHReader::ReadMacroRecord(uint64_t Offset) {
Macro->AddTokenToBody(Tok);
break;
}
case pch::PP_HEADER_FILE_INFO:
break; // Already processed by ReadPreprocessorBlock().
}
}
}
bool PCHReader::ReadPreprocessorBlock() {
if (Stream.EnterSubBlock(pch::PREPROCESSOR_BLOCK_ID))
return Error("Malformed preprocessor block record");
RecordData Record;
unsigned NumHeaderInfos = 0;
while (true) {
unsigned Code = Stream.ReadCode();
switch (Code) {
case llvm::bitc::END_BLOCK:
if (Stream.ReadBlockEnd())
return Error("Error at end of preprocessor block");
return false;
case llvm::bitc::ENTER_SUBBLOCK:
// No known subblocks, always skip them.
Stream.ReadSubBlockID();
if (Stream.SkipBlock())
return Error("Malformed block record");
continue;
case llvm::bitc::DEFINE_ABBREV:
Stream.ReadAbbrevRecord();
continue;
default: break;
}
// Read a record.
Record.clear();
pch::PreprocessorRecordTypes RecType =
(pch::PreprocessorRecordTypes)Stream.ReadRecord(Code, Record);
switch (RecType) {
default: // Default behavior: ignore unknown records.
break;
case pch::PP_COUNTER_VALUE:
if (!Record.empty())
PP.setCounterValue(Record[0]);
break;
case pch::PP_MACRO_OBJECT_LIKE:
case pch::PP_MACRO_FUNCTION_LIKE:
case pch::PP_TOKEN:
break;
case pch::PP_HEADER_FILE_INFO: {
HeaderFileInfo HFI;
HFI.isImport = Record[0];
HFI.DirInfo = Record[1];
HFI.NumIncludes = Record[2];
HFI.ControllingMacroID = Record[3];
PP.getHeaderSearchInfo().setHeaderFileInfoForUID(HFI, NumHeaderInfos++);
break;
}
}
}
}
PCHReader::PCHReadResult
PCHReader::ReadPCHBlock(uint64_t &PreprocessorBlockOffset) {
PCHReader::ReadPCHBlock() {
if (Stream.EnterSubBlock(pch::PCH_BLOCK_ID)) {
Error("Malformed block record");
return Failure;
@@ -1757,13 +1706,6 @@ PCHReader::ReadPCHBlock(uint64_t &PreprocessorBlockOffset) {
break;
case pch::PREPROCESSOR_BLOCK_ID:
// Skip the preprocessor block for now, but remember where it is. We
// want to read it in after the identifier table.
if (PreprocessorBlockOffset) {
Error("Multiple preprocessor blocks found.");
return Failure;
}
PreprocessorBlockOffset = Stream.GetCurrentBitNo();
if (Stream.SkipBlock()) {
Error("Malformed block record");
return Failure;
@@ -1907,6 +1849,11 @@ PCHReader::ReadPCHBlock(uint64_t &PreprocessorBlockOffset) {
PCHMethodPoolLookupTrait(*this));
TotalSelectorsInMethodPool = Record[1];
break;
case pch::PP_COUNTER_VALUE:
if (!Record.empty())
PP.setCounterValue(Record[0]);
break;
}
}
Error("Premature end of bitstream");
@@ -1938,10 +1885,6 @@ PCHReader::PCHReadResult PCHReader::ReadPCH(const std::string &FileName) {
return IgnorePCH;
}
// We expect a number of well-defined blocks, though we don't necessarily
// need to understand them all.
uint64_t PreprocessorBlockOffset = 0;
while (!Stream.AtEndOfStream()) {
unsigned Code = Stream.ReadCode();
@@ -1961,7 +1904,7 @@ PCHReader::PCHReadResult PCHReader::ReadPCH(const std::string &FileName) {
}
break;
case pch::PCH_BLOCK_ID:
switch (ReadPCHBlock(PreprocessorBlockOffset)) {
switch (ReadPCHBlock()) {
case Success:
break;
@@ -2036,15 +1979,6 @@ PCHReader::PCHReadResult PCHReader::ReadPCH(const std::string &FileName) {
if (unsigned FastEnum
= SpecialTypes[pch::SPECIAL_TYPE_OBJC_FAST_ENUMERATION_STATE])
Context.setObjCFastEnumerationStateType(GetType(FastEnum));
// If we saw the preprocessor block, read it now.
if (PreprocessorBlockOffset) {
SavedStreamPosition SavedPos(Stream);
Stream.JumpToBit(PreprocessorBlockOffset);
if (ReadPreprocessorBlock()) {
Error("Malformed preprocessor block");
return Failure;
}
}
return Success;
}