Changes in directory llvm/lib/Bitcode/Writer:
BitcodeWriter.cpp updated: 1.32 -> 1.33 --- Log message: where possible, encode symtab names with 7 bits per char instead of 8. This shaves 110K off kc++ to 3514K. Before: Block ID #14 (VALUE_SYMTAB): Num Instances: 2345 Total Size: 1.50425e+07b/1.88031e+06B/470077W Average Size: 6414.69b/801.837B/200.459W % of file: 51.8057 Tot/Avg SubBlocks: 0/0 Tot/Avg Abbrevs: 2345/1 Tot/Avg Records: 120924/51.5667 % Abbrev Recs: 85.1791 after: Block ID #14 (VALUE_SYMTAB): Num Instances: 2345 Total Size: 1.41229e+07b/1.76536e+06B/441341W Average Size: 6022.56b/752.82B/188.205W % of file: 50.2295 Tot/Avg SubBlocks: 0/0 Tot/Avg Abbrevs: 4690/2 Tot/Avg Records: 120924/51.5667 % Abbrev Recs: 85.1791 --- Diffs of the changes: (+45 -11) BitcodeWriter.cpp | 56 +++++++++++++++++++++++++++++++++++++++++++----------- 1 files changed, 45 insertions(+), 11 deletions(-) Index: llvm/lib/Bitcode/Writer/BitcodeWriter.cpp diff -u llvm/lib/Bitcode/Writer/BitcodeWriter.cpp:1.32 llvm/lib/Bitcode/Writer/BitcodeWriter.cpp:1.33 --- llvm/lib/Bitcode/Writer/BitcodeWriter.cpp:1.32 Fri May 4 15:34:50 2007 +++ llvm/lib/Bitcode/Writer/BitcodeWriter.cpp Fri May 4 15:52:02 2007 @@ -25,7 +25,17 @@ #include "llvm/Support/MathExtras.h" using namespace llvm; -static const unsigned CurVersion = 0; +/// These are manifest constants used by the bitcode writer. They do not need to +/// be kept in sync with the reader, but need to be consistent within this file. +enum { + CurVersion = 0, + + // VALUE_SYMTAB_BLOCK abbrev id's. + VST_ENTRY_8_ABBREV = bitc::FIRST_APPLICATION_ABBREV, + VST_ENTRY_7_ABBREV + +}; + static unsigned GetEncodedCastOpcode(unsigned Opcode) { switch (Opcode) { @@ -703,13 +713,25 @@ if (VST.empty()) return; Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 3); - // 8-bit fixed width VST_ENTRY strings. - BitCodeAbbrev *Abbv = new BitCodeAbbrev(); - Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY)); - Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); - Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array)); - Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8)); - unsigned AbbrevID = Stream.EmitAbbrev(Abbv); + { // 8-bit fixed width VST_ENTRY strings. + BitCodeAbbrev *Abbv = new BitCodeAbbrev(); + Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY)); + Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); + Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array)); + Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8)); + if (Stream.EmitAbbrev(Abbv) != VST_ENTRY_8_ABBREV) + assert(0 && "Unexpected abbrev ordering!"); + } + + { // 7-bit fixed width VST_ENTRY strings. + BitCodeAbbrev *Abbv = new BitCodeAbbrev(); + Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY)); + Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); + Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array)); + Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7)); + if (Stream.EmitAbbrev(Abbv) != VST_ENTRY_7_ABBREV) + assert(0 && "Unexpected abbrev ordering!"); + } // FIXME: Set up the abbrev, we know how many values there are! @@ -718,6 +740,18 @@ for (ValueSymbolTable::const_iterator SI = VST.begin(), SE = VST.end(); SI != SE; ++SI) { + + const ValueName &Name = *SI; + + // Figure out the encoding to use for the name. + bool is7Bit = true; + for (unsigned i = 0, e = Name.getKeyLength(); i != e; ++i) + if ((unsigned char)Name.getKeyData()[i] & 128) { + is7Bit = false; + break; + } + + unsigned AbbrevToUse = 0; // VST_ENTRY: [valueid, namelen, namechar x N] @@ -727,12 +761,12 @@ Code = bitc::VST_CODE_BBENTRY; } else { Code = bitc::VST_CODE_ENTRY; - AbbrevToUse = AbbrevID; + AbbrevToUse = is7Bit ? VST_ENTRY_7_ABBREV : VST_ENTRY_8_ABBREV; } NameVals.push_back(VE.getValueID(SI->getValue())); - for (const char *P = SI->getKeyData(), - *E = SI->getKeyData()+SI->getKeyLength(); P != E; ++P) + for (const char *P = Name.getKeyData(), + *E = Name.getKeyData()+Name.getKeyLength(); P != E; ++P) NameVals.push_back((unsigned char)*P); // Emit the finished record. _______________________________________________ llvm-commits mailing list llvm-commits@cs.uiuc.edu http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits