Load most of the source manager's information lazily from the PCH
file. In particular, only eagerly load source location entries for
files and for the predefines buffer. Other buffers and
macro-instantiation source location entries are loaded lazily.
With the Cocoa-prefixed "Hello, World", we only load 815/26555 source
location entities. This halves the amount of user time we spend in
this "Hello, World" program with -fsyntax-only (down to .007s).
This optimization is part 1 of 2 for the source manager. This
eliminates most of the user time in loading a PCH file. We still spend
too much time initialize File structures (especially in the calls to
stat), so we need to either make the loading of source location
entries for files lazy or import the stat cache from the PTH
implementation.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@70196 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Basic/SourceManager.cpp b/lib/Basic/SourceManager.cpp
index 9ed2163..5057663 100644
--- a/lib/Basic/SourceManager.cpp
+++ b/lib/Basic/SourceManager.cpp
@@ -308,6 +308,17 @@
return Entry;
}
+void SourceManager::PreallocateSLocEntries(ExternalSLocEntrySource *Source,
+ unsigned NumSLocEntries,
+ unsigned NextOffset) {
+ ExternalSLocEntries = Source;
+ this->NextOffset = NextOffset;
+ SLocEntryLoaded.resize(NumSLocEntries + 1);
+ SLocEntryLoaded[0] = true;
+ SLocEntryTable.resize(SLocEntryTable.size() + NumSLocEntries);
+}
+
+
//===----------------------------------------------------------------------===//
// Methods to create new FileID's and instantiations.
//===----------------------------------------------------------------------===//
@@ -317,7 +328,26 @@
/// corresponds to a file or some other input source.
FileID SourceManager::createFileID(const ContentCache *File,
SourceLocation IncludePos,
- SrcMgr::CharacteristicKind FileCharacter) {
+ SrcMgr::CharacteristicKind FileCharacter,
+ unsigned PreallocatedID,
+ unsigned Offset) {
+ SLocEntry NewEntry = SLocEntry::get(NextOffset,
+ FileInfo::get(IncludePos, File,
+ FileCharacter));
+ if (PreallocatedID) {
+ // If we're filling in a preallocated ID, just load in the file
+ // entry and return.
+ assert(PreallocatedID < SLocEntryLoaded.size() &&
+ "Preallocate ID out-of-range");
+ assert(!SLocEntryLoaded[PreallocatedID] &&
+ "Source location entry already loaded");
+ assert(Offset && "Preallocate source location cannot have zero offset");
+ SLocEntryTable[PreallocatedID]
+ = SLocEntry::get(Offset, FileInfo::get(IncludePos, File, FileCharacter));
+ SLocEntryLoaded[PreallocatedID] = true;
+ return LastFileIDLookup = FileID::get(PreallocatedID);
+ }
+
SLocEntryTable.push_back(SLocEntry::get(NextOffset,
FileInfo::get(IncludePos, File,
FileCharacter)));
@@ -336,8 +366,22 @@
SourceLocation SourceManager::createInstantiationLoc(SourceLocation SpellingLoc,
SourceLocation ILocStart,
SourceLocation ILocEnd,
- unsigned TokLength) {
+ unsigned TokLength,
+ unsigned PreallocatedID,
+ unsigned Offset) {
InstantiationInfo II = InstantiationInfo::get(ILocStart,ILocEnd, SpellingLoc);
+ if (PreallocatedID) {
+ // If we're filling in a preallocated ID, just load in the
+ // instantiation entry and return.
+ assert(PreallocatedID < SLocEntryLoaded.size() &&
+ "Preallocate ID out-of-range");
+ assert(!SLocEntryLoaded[PreallocatedID] &&
+ "Source location entry already loaded");
+ assert(Offset && "Preallocate source location cannot have zero offset");
+ SLocEntryTable[PreallocatedID] = SLocEntry::get(Offset, II);
+ SLocEntryLoaded[PreallocatedID] = true;
+ return SourceLocation::getMacroLoc(Offset);
+ }
SLocEntryTable.push_back(SLocEntry::get(NextOffset, II));
assert(NextOffset+TokLength+1 > NextOffset && "Ran out of source locations!");
NextOffset += TokLength+1;
@@ -391,6 +435,8 @@
unsigned NumProbes = 0;
while (1) {
--I;
+ if (ExternalSLocEntries)
+ getSLocEntry(FileID::get(I - SLocEntryTable.begin()));
if (I->getOffset() <= SLocOffset) {
#if 0
printf("lin %d -> %d [%s] %d %d\n", SLocOffset,
@@ -399,7 +445,7 @@
LastFileIDLookup.ID, int(SLocEntryTable.end()-I));
#endif
FileID Res = FileID::get(I-SLocEntryTable.begin());
-
+
// If this isn't an instantiation, remember it. We have good locality
// across FileID lookups.
if (!I->isInstantiation())
@@ -421,7 +467,7 @@
NumProbes = 0;
while (1) {
unsigned MiddleIndex = (GreaterIndex-LessIndex)/2+LessIndex;
- unsigned MidOffset = SLocEntryTable[MiddleIndex].getOffset();
+ unsigned MidOffset = getSLocEntry(FileID::get(MiddleIndex)).getOffset();
++NumProbes;
@@ -865,3 +911,5 @@
llvm::cerr << "FileID scans: " << NumLinearScans << " linear, "
<< NumBinaryProbes << " binary.\n";
}
+
+ExternalSLocEntrySource::~ExternalSLocEntrySource() { }