add an abbreviation for common PARM_VAR_DECL. All but 9 of the
parm var decls in leopard cocoa.h end up using this abbreviation,
which shrinks the bitcode file by about 50K: 7217736->7167120.
Before:
Block ID #12 (DECLS_BLOCK):
Num Instances: 1
Total Size: 2.23595e+07b/2.79494e+06B/698736W
% of file: 38.7233
Num SubBlocks: 0
Num Abbrevs: 0
Num Records: 139387
% Abbrev Recs: 0
After:
Block ID #12 (DECLS_BLOCK):
Num Instances: 1
Total Size: 2.02405e+07b/2.53006e+06B/632516W
% of file: 35.301
Num SubBlocks: 0
Num Abbrevs: 1
Num Records: 139387
% Abbrev Recs: 19.2902
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@70199 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Frontend/PCHWriterDecl.cpp b/lib/Frontend/PCHWriterDecl.cpp
index e2cf3d8..799c77b 100644
--- a/lib/Frontend/PCHWriterDecl.cpp
+++ b/lib/Frontend/PCHWriterDecl.cpp
@@ -30,10 +30,12 @@
public:
pch::DeclCode Code;
+ unsigned AbbrevToUse;
PCHDeclWriter(PCHWriter &Writer, ASTContext &Context,
PCHWriter::RecordData &Record)
- : Writer(Writer), Context(Context), Record(Record) { }
+ : Writer(Writer), Context(Context), Record(Record) {
+ }
void VisitDecl(Decl *D);
void VisitTranslationUnitDecl(TranslationUnitDecl *D);
@@ -349,12 +351,34 @@
// FIXME: why isn't the "default argument" just stored as the initializer
// in VarDecl?
Code = pch::DECL_PARM_VAR;
+
+
+ // If the assumptions about the DECL_PARM_VAR abbrev are true, use it. Here
+ // we dynamically check for the properties that we optimize for, but don't
+ // know are true of all PARM_VAR_DECLs.
+ if (!D->hasAttrs() &&
+ !D->isImplicit() &&
+ D->getAccess() == AS_none &&
+ D->getStorageClass() == 0 &&
+ !D->hasCXXDirectInitializer() && // Can params have this ever?
+ D->getObjCDeclQualifier() == 0)
+ AbbrevToUse = Writer.getParmVarDeclAbbrev();
+
+ // Check things we know are true of *every* PARM_VAR_DECL, which is more than
+ // just us assuming it.
+ assert(!D->isInvalidDecl() && "Shouldn't emit invalid decls");
+ assert(!D->isThreadSpecified() && "PARM_VAR_DECL can't be __thread");
+ assert(D->getAccess() == AS_none && "PARM_VAR_DECL can't be public/private");
+ assert(!D->isDeclaredInCondition() && "PARM_VAR_DECL can't be in condition");
+ assert(D->getPreviousDeclaration() == 0 && "PARM_VAR_DECL can't be redecl");
+ assert(D->getInit() == 0 && "PARM_VAR_DECL never has init");
}
void PCHDeclWriter::VisitOriginalParmVarDecl(OriginalParmVarDecl *D) {
VisitParmVarDecl(D);
Writer.AddTypeRef(D->getOriginalType(), Record);
Code = pch::DECL_ORIGINAL_PARM_VAR;
+ AbbrevToUse = 0;
}
void PCHDeclWriter::VisitFileScopeAsmDecl(FileScopeAsmDecl *D) {
@@ -395,11 +419,48 @@
// PCHWriter Implementation
//===----------------------------------------------------------------------===//
+void PCHWriter::WriteDeclsBlockAbbrevs() {
+ using namespace llvm;
+ // Abbreviation for DECL_PARM_VAR.
+ BitCodeAbbrev *Abv = new BitCodeAbbrev();
+ Abv->Add(BitCodeAbbrevOp(pch::DECL_PARM_VAR));
+
+ // Decl
+ Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
+ Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LexicalDeclContext
+ Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Location
+ Abv->Add(BitCodeAbbrevOp(0)); // isInvalidDecl (!?)
+ Abv->Add(BitCodeAbbrevOp(0)); // HasAttrs
+ Abv->Add(BitCodeAbbrevOp(0)); // isImplicit
+ Abv->Add(BitCodeAbbrevOp(AS_none)); // C++ AccessSpecifier
+
+ // NamedDecl
+ Abv->Add(BitCodeAbbrevOp(0)); // NameKind = Identifier
+ Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
+ // ValueDecl
+ Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
+ // VarDecl
+ Abv->Add(BitCodeAbbrevOp(0)); // StorageClass
+ Abv->Add(BitCodeAbbrevOp(0)); // isThreadSpecified
+ Abv->Add(BitCodeAbbrevOp(0)); // hasCXXDirectInitializer
+ Abv->Add(BitCodeAbbrevOp(0)); // isDeclaredInCondition
+ Abv->Add(BitCodeAbbrevOp(0)); // PrevDecl
+ Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeSpecStartLoc
+ Abv->Add(BitCodeAbbrevOp(0)); // HasInit
+ // ParmVarDecl
+ Abv->Add(BitCodeAbbrevOp(0)); // ObjCDeclQualifier
+
+ ParmVarDeclAbbrev = Stream.EmitAbbrev(Abv);
+}
+
/// \brief Write a block containing all of the declarations.
void PCHWriter::WriteDeclsBlock(ASTContext &Context) {
// Enter the declarations block.
- Stream.EnterSubblock(pch::DECLS_BLOCK_ID, 2);
+ Stream.EnterSubblock(pch::DECLS_BLOCK_ID, 3);
+ // Output the abbreviations that we will use in this block.
+ WriteDeclsBlockAbbrevs();
+
// Emit all of the declarations.
RecordData Record;
PCHDeclWriter W(*this, Context, Record);
@@ -439,6 +500,7 @@
// Build and emit a record for this declaration
Record.clear();
W.Code = (pch::DeclCode)0;
+ W.AbbrevToUse = 0;
W.Visit(D);
if (DC) W.VisitDeclContext(DC, LexicalOffset, VisibleOffset);
@@ -448,8 +510,8 @@
assert(false && "Unhandled declaration kind while generating PCH");
exit(-1);
}
- Stream.EmitRecord(W.Code, Record);
-
+ Stream.EmitRecord(W.Code, Record, W.AbbrevToUse);
+
// If the declaration had any attributes, write them now.
if (D->hasAttrs())
WriteAttributeRecord(D->getAttrs());