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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
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55
clang/lib/Frontend/PCHWriter.cpp
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@@ -1359,7 +1359,8 @@ static unsigned CreateSLocInstantiationAbbrev(llvm::BitstreamWriter &Stream) {
/// entries for files that we actually need. In the common case (no
/// errors), we probably won't have to create file entries for any of
/// the files in the AST.
void PCHWriter::WriteSourceManagerBlock(SourceManager &SourceMgr) {
void PCHWriter::WriteSourceManagerBlock(SourceManager &SourceMgr,
const Preprocessor &PP) {
// Enter the source manager block.
Stream.EnterSubblock(pch::SOURCE_MANAGER_BLOCK_ID, 3);
@@ -1481,6 +1482,22 @@ void PCHWriter::WriteSourceManagerBlock(SourceManager &SourceMgr) {
}
}
// Loop over all the header files.
HeaderSearch &HS = PP.getHeaderSearchInfo();
for (HeaderSearch::header_file_iterator I = HS.header_file_begin(),
E = HS.header_file_end();
I != E; ++I) {
Record.push_back(I->isImport);
Record.push_back(I->DirInfo);
Record.push_back(I->NumIncludes);
if (I->ControllingMacro)
AddIdentifierRef(I->ControllingMacro, Record);
else
Record.push_back(0);
Stream.EmitRecord(pch::SM_HEADER_FILE_INFO, Record);
Record.clear();
}
Stream.ExitBlock();
}
@@ -1488,14 +1505,6 @@ void PCHWriter::WriteSourceManagerBlock(SourceManager &SourceMgr) {
/// preprocessor.
///
void PCHWriter::WritePreprocessor(const Preprocessor &PP) {
// Enter the preprocessor block.
Stream.EnterSubblock(pch::PREPROCESSOR_BLOCK_ID, 2);
// If the PCH file contains __DATE__ or __TIME__ emit a warning about this.
// FIXME: use diagnostics subsystem for localization etc.
if (PP.SawDateOrTime())
fprintf(stderr, "warning: precompiled header used __DATE__ or __TIME__.\n");
RecordData Record;
// If the preprocessor __COUNTER__ value has been bumped, remember it.
@@ -1503,8 +1512,16 @@ void PCHWriter::WritePreprocessor(const Preprocessor &PP) {
Record.push_back(PP.getCounterValue());
Stream.EmitRecord(pch::PP_COUNTER_VALUE, Record);
Record.clear();
}
}
// Enter the preprocessor block.
Stream.EnterSubblock(pch::PREPROCESSOR_BLOCK_ID, 2);
// If the PCH file contains __DATE__ or __TIME__ emit a warning about this.
// FIXME: use diagnostics subsystem for localization etc.
if (PP.SawDateOrTime())
fprintf(stderr, "warning: precompiled header used __DATE__ or __TIME__.\n");
// Loop over all the macro definitions that are live at the end of the file,
// emitting each to the PP section.
for (Preprocessor::macro_iterator I = PP.macro_begin(), E = PP.macro_end();
@@ -1564,22 +1581,6 @@ void PCHWriter::WritePreprocessor(const Preprocessor &PP) {
}
++NumMacros;
}
// Loop over all the header files.
HeaderSearch &HS = PP.getHeaderSearchInfo();
for (HeaderSearch::header_file_iterator I = HS.header_file_begin(),
E = HS.header_file_end();
I != E; ++I) {
Record.push_back(I->isImport);
Record.push_back(I->DirInfo);
Record.push_back(I->NumIncludes);
if (I->ControllingMacro)
AddIdentifierRef(I->ControllingMacro, Record);
else
Record.push_back(0);
Stream.EmitRecord(pch::PP_HEADER_FILE_INFO, Record);
Record.clear();
}
Stream.ExitBlock();
}
@@ -2365,7 +2366,7 @@ void PCHWriter::WritePCH(Sema &SemaRef) {
Stream.EnterSubblock(pch::PCH_BLOCK_ID, 4);
WriteTargetTriple(Context.Target);
WriteLanguageOptions(Context.getLangOptions());
WriteSourceManagerBlock(Context.getSourceManager());
WriteSourceManagerBlock(Context.getSourceManager(), PP);
WritePreprocessor(PP);
WriteTypesBlock(Context);
WriteDeclsBlock(Context);