Use the AST on-disk hash table for name lookup inside a DeclContext.
*Huge* improvement over the amount of deserializing that we do for C++ lookup.
e.g, if he have the Carbon header precompiled and include it on a file containing this:
int x;
these are the before/after stats:
BEFORE:
*** AST File Statistics:
578 stat cache hits
4 stat cache misses
548/30654 source location entries read (1.787695%)
15907/16501 types read (96.400223%)
53525/59955 declarations read (89.275291%)
33993/43525 identifiers read (78.099945%)
41516/51891 statements read (80.006165%)
77/5317 macros read (1.448185%)
0/6335 lexical declcontexts read (0.000000%)
1/5424 visible declcontexts read (0.018437%)
AFTER using the on-disk table:
*** AST File Statistics:
578 stat cache hits
4 stat cache misses
548/30654 source location entries read (1.787695%)
10/16501 types read (0.060602%)
9/59955 declarations read (0.015011%)
161/43525 identifiers read (0.369902%)
20/51891 statements read (0.038542%)
6/5317 macros read (0.112846%)
0/6335 lexical declcontexts read (0.000000%)
2/5424 visible declcontexts read (0.036873%)
There's only one issue affecting mostly the precompiled preambles which I will address soon.
llvm-svn: 111636
diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index 05fa7cd..b24b353 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -846,6 +846,54 @@
typedef OnDiskChainedHashTable<ASTDeclContextNameLookupTrait>
ASTDeclContextNameLookupTable;
+bool ASTReader::ReadDeclContextStorage(llvm::BitstreamCursor &Cursor,
+ const std::pair<uint64_t, uint64_t> &Offsets,
+ DeclContextInfo &Info) {
+ SavedStreamPosition SavedPosition(Cursor);
+ // First the lexical decls.
+ if (Offsets.first != 0) {
+ Cursor.JumpToBit(Offsets.first);
+
+ RecordData Record;
+ const char *Blob;
+ unsigned BlobLen;
+ unsigned Code = Cursor.ReadCode();
+ unsigned RecCode = Cursor.ReadRecord(Code, Record, &Blob, &BlobLen);
+ if (RecCode != DECL_CONTEXT_LEXICAL) {
+ Error("Expected lexical block");
+ return true;
+ }
+
+ Info.LexicalDecls = reinterpret_cast<const DeclID*>(Blob);
+ Info.NumLexicalDecls = BlobLen / sizeof(DeclID);
+ } else {
+ Info.LexicalDecls = 0;
+ Info.NumLexicalDecls = 0;
+ }
+
+ // Now the lookup table.
+ if (Offsets.second != 0) {
+ Cursor.JumpToBit(Offsets.second);
+
+ RecordData Record;
+ const char *Blob;
+ unsigned BlobLen;
+ unsigned Code = Cursor.ReadCode();
+ unsigned RecCode = Cursor.ReadRecord(Code, Record, &Blob, &BlobLen);
+ if (RecCode != DECL_CONTEXT_VISIBLE) {
+ Error("Expected visible lookup table block");
+ return true;
+ }
+ Info.NameLookupTableData
+ = ASTDeclContextNameLookupTable::Create(
+ (const unsigned char *)Blob + Record[0],
+ (const unsigned char *)Blob,
+ ASTDeclContextNameLookupTrait(*this));
+ }
+
+ return false;
+}
+
void ASTReader::Error(const char *Msg) {
Diag(diag::err_fe_pch_malformed) << Msg;
}
@@ -1674,7 +1722,7 @@
case TU_UPDATE_LEXICAL: {
DeclContextInfo Info = {
- /* No visible information */ 0, 0,
+ /* No visible information */ 0,
reinterpret_cast<const DeclID *>(BlobStart),
BlobLen / sizeof(DeclID)
};
@@ -3119,54 +3167,33 @@
DeclarationName Name) {
assert(DC->hasExternalVisibleStorage() &&
"DeclContext has no visible decls in storage");
+ if (!Name)
+ return DeclContext::lookup_result(DeclContext::lookup_iterator(0),
+ DeclContext::lookup_iterator(0));
- llvm::SmallVector<VisibleDeclaration, 64> Decls;
+ llvm::SmallVector<NamedDecl *, 64> Decls;
// There might be lexical decls in multiple parts of the chain, for the TU
// and namespaces.
DeclContextInfos &Infos = DeclContextOffsets[DC];
for (DeclContextInfos::iterator I = Infos.begin(), E = Infos.end();
I != E; ++I) {
- uint64_t Offset = I->OffsetToVisibleDecls;
- if (Offset == 0)
+ if (!I->NameLookupTableData)
continue;
- llvm::BitstreamCursor &DeclsCursor = *I->Stream;
-
- // Keep track of where we are in the stream, then jump back there
- // after reading this context.
- SavedStreamPosition SavedPosition(DeclsCursor);
-
- // Load the record containing all of the declarations visible in
- // this context.
- DeclsCursor.JumpToBit(Offset);
- RecordData Record;
- unsigned Code = DeclsCursor.ReadCode();
- unsigned RecCode = DeclsCursor.ReadRecord(Code, Record);
- if (RecCode != DECL_CONTEXT_VISIBLE) {
- Error("Expected visible block");
- return DeclContext::lookup_result(DeclContext::lookup_iterator(),
- DeclContext::lookup_iterator());
- }
-
- if (Record.empty())
+ ASTDeclContextNameLookupTable *LookupTable =
+ (ASTDeclContextNameLookupTable*)I->NameLookupTableData;
+ ASTDeclContextNameLookupTable::iterator Pos = LookupTable->find(Name);
+ if (Pos == LookupTable->end())
continue;
- unsigned Idx = 0;
- while (Idx < Record.size()) {
- Decls.push_back(VisibleDeclaration());
- Decls.back().Name = ReadDeclarationName(Record, Idx);
-
- unsigned Size = Record[Idx++];
- llvm::SmallVector<unsigned, 4> &LoadedDecls = Decls.back().Declarations;
- LoadedDecls.reserve(Size);
- for (unsigned J = 0; J < Size; ++J)
- LoadedDecls.push_back(Record[Idx++]);
- }
+ ASTDeclContextNameLookupTrait::data_type Data = *Pos;
+ for (; Data.first != Data.second; ++Data.first)
+ Decls.push_back(cast<NamedDecl>(GetDecl(*Data.first)));
}
++NumVisibleDeclContextsRead;
- SetExternalVisibleDecls(DC, Decls);
+ SetExternalVisibleDeclsForName(DC, Name, Decls);
return const_cast<DeclContext*>(DC)->lookup(Name);
}