Lazy deserialization of macro definitions for precompiled headers.
This optimization improves performance on the Carbon-prefixed "Hello,
World!" example by 57%. For reference, we're now about 2.25x faster
than GCC PCH. We're also pulling in far less of the PCH file:
*** PCH Statistics:
411/20693 types read (1.986179%)
2553/59230 declarations read (4.310316%)
1093/44646 identifiers read (2.448148%)
1/32954 statements read (0.003035%)
21/6187 macros read (0.339421%)
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@69755 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Frontend/PCHWriter.cpp b/lib/Frontend/PCHWriter.cpp
index 1167250..bdcd359 100644
--- a/lib/Frontend/PCHWriter.cpp
+++ b/lib/Frontend/PCHWriter.cpp
@@ -1439,8 +1439,6 @@
// Loop over all the macro definitions that are live at the end of the file,
// emitting each to the PP section.
- // FIXME: Eventually we want to emit an index so that we can lazily load
- // macros.
for (Preprocessor::macro_iterator I = PP.macro_begin(), E = PP.macro_end();
I != E; ++I) {
// FIXME: This emits macros in hash table order, we should do it in a stable
@@ -1452,7 +1450,9 @@
if (MI->isBuiltinMacro())
continue;
+ // FIXME: Remove this identifier reference?
AddIdentifierRef(I->first, Record);
+ MacroOffsets[I->first] = Stream.GetCurrentBitNo();
Record.push_back(MI->getDefinitionLoc().getRawEncoding());
Record.push_back(MI->isUsed());
@@ -1494,7 +1494,7 @@
Stream.EmitRecord(pch::PP_TOKEN, Record);
Record.clear();
}
-
+ ++NumMacros;
}
Stream.ExitBlock();
@@ -1715,6 +1715,7 @@
namespace {
class VISIBILITY_HIDDEN PCHIdentifierTableTrait {
PCHWriter &Writer;
+ Preprocessor &PP;
public:
typedef const IdentifierInfo* key_type;
@@ -1723,19 +1724,23 @@
typedef pch::IdentID data_type;
typedef data_type data_type_ref;
- PCHIdentifierTableTrait(PCHWriter &Writer) : Writer(Writer) { }
+ PCHIdentifierTableTrait(PCHWriter &Writer, Preprocessor &PP)
+ : Writer(Writer), PP(PP) { }
static unsigned ComputeHash(const IdentifierInfo* II) {
return clang::BernsteinHash(II->getName());
}
- static std::pair<unsigned,unsigned>
+ std::pair<unsigned,unsigned>
EmitKeyDataLength(llvm::raw_ostream& Out, const IdentifierInfo* II,
pch::IdentID ID) {
unsigned KeyLen = strlen(II->getName()) + 1;
clang::io::Emit16(Out, KeyLen);
unsigned DataLen = 4 + 4; // 4 bytes for token ID, builtin, flags
// 4 bytes for the persistent ID
+ if (II->hasMacroDefinition() &&
+ !PP.getMacroInfo(const_cast<IdentifierInfo *>(II))->isBuiltinMacro())
+ DataLen += 8;
for (IdentifierResolver::iterator D = IdentifierResolver::begin(II),
DEnd = IdentifierResolver::end();
D != DEnd; ++D)
@@ -1755,15 +1760,21 @@
void EmitData(llvm::raw_ostream& Out, const IdentifierInfo* II,
pch::IdentID ID, unsigned) {
uint32_t Bits = 0;
+ bool hasMacroDefinition =
+ II->hasMacroDefinition() &&
+ !PP.getMacroInfo(const_cast<IdentifierInfo *>(II))->isBuiltinMacro();
Bits = Bits | (uint32_t)II->getTokenID();
Bits = (Bits << 8) | (uint32_t)II->getObjCOrBuiltinID();
- Bits = (Bits << 10) | II->hasMacroDefinition();
+ Bits = (Bits << 10) | hasMacroDefinition;
Bits = (Bits << 1) | II->isExtensionToken();
Bits = (Bits << 1) | II->isPoisoned();
Bits = (Bits << 1) | II->isCPlusPlusOperatorKeyword();
clang::io::Emit32(Out, Bits);
clang::io::Emit32(Out, ID);
+ if (hasMacroDefinition)
+ clang::io::Emit64(Out, Writer.getMacroOffset(II));
+
// Emit the declaration IDs in reverse order, because the
// IdentifierResolver provides the declarations as they would be
// visible (e.g., the function "stat" would come before the struct
@@ -1785,7 +1796,7 @@
/// The identifier table consists of a blob containing string data
/// (the actual identifiers themselves) and a separate "offsets" index
/// that maps identifier IDs to locations within the blob.
-void PCHWriter::WriteIdentifierTable() {
+void PCHWriter::WriteIdentifierTable(Preprocessor &PP) {
using namespace llvm;
// Create and write out the blob that contains the identifier
@@ -1806,7 +1817,7 @@
llvm::SmallVector<char, 4096> IdentifierTable;
uint32_t BucketOffset;
{
- PCHIdentifierTableTrait Trait(*this);
+ PCHIdentifierTableTrait Trait(*this, PP);
llvm::raw_svector_ostream Out(IdentifierTable);
BucketOffset = Generator.Emit(Out, Trait);
}
@@ -1964,7 +1975,8 @@
}
PCHWriter::PCHWriter(llvm::BitstreamWriter &Stream)
- : Stream(Stream), NextTypeID(pch::NUM_PREDEF_TYPE_IDS), NumStatements(0) { }
+ : Stream(Stream), NextTypeID(pch::NUM_PREDEF_TYPE_IDS),
+ NumStatements(0), NumMacros(0) { }
void PCHWriter::WritePCH(Sema &SemaRef) {
ASTContext &Context = SemaRef.Context;
@@ -1989,7 +2001,7 @@
WritePreprocessor(PP);
WriteTypesBlock(Context);
WriteDeclsBlock(Context);
- WriteIdentifierTable();
+ WriteIdentifierTable(PP);
Stream.EmitRecord(pch::TYPE_OFFSET, TypeOffsets);
Stream.EmitRecord(pch::DECL_OFFSET, DeclOffsets);
@@ -2004,6 +2016,7 @@
// Some simple statistics
Record.clear();
Record.push_back(NumStatements);
+ Record.push_back(NumMacros);
Stream.EmitRecord(pch::STATISTICS, Record);
Stream.ExitBlock();
}