Implement support for globally associating abbrevs with block IDs, which
relieves us from having to emit the abbrevs into each instance of the block.
This shrinks kc.bit from 3368K to 3333K, but will be a more significant win
once instructions are abbreviated.
The VST went from:
Block ID #14 (VALUE_SYMTAB):
Num Instances: 2345
Total Size: 1.29508e+07b/1.61885e+06B/404713W
Average Size: 5522.73b/690.342B/172.585W
% of file: 48.0645
Tot/Avg SubBlocks: 0/0
Tot/Avg Abbrevs: 7035/3
Tot/Avg Records: 120924/51.5667
% Abbrev Recs: 100
to:
Block ID #14 (VALUE_SYMTAB):
Num Instances: 2345
Total Size: 1.26713e+07b/1.58391e+06B/395978W
Average Size: 5403.53b/675.442B/168.86W
% of file: 47.5198
Tot/Avg SubBlocks: 0/0
Tot/Avg Abbrevs: 0/0
Tot/Avg Records: 120924/51.5667
% Abbrev Recs: 100
because we didn't emit the same 3 abbrevs 2345 times :)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@36767 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Bitcode/Writer/BitcodeWriter.cpp b/lib/Bitcode/Writer/BitcodeWriter.cpp
index 6ee3a4a..35e75da 100644
--- a/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -714,36 +714,6 @@
if (VST.empty()) return;
Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 3);
- { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
- BitCodeAbbrev *Abbv = new BitCodeAbbrev();
- Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
- 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!");
- }
- { // 7-bit fixed width VST_BBENTRY strings.
- BitCodeAbbrev *Abbv = new BitCodeAbbrev();
- Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
- Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
- Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
- Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
- if (Stream.EmitAbbrev(Abbv) != VST_BBENTRY_7_ABBREV)
- assert(0 && "Unexpected abbrev ordering!");
- }
-
-
// FIXME: Set up the abbrev, we know how many values there are!
// FIXME: We know if the type names can use 7-bit ascii.
SmallVector<unsigned, 64> NameVals;
@@ -909,19 +879,40 @@
// We only want to emit block info records for blocks that have multiple
// instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK. Other
// blocks can defined their abbrevs inline.
- Stream.EnterSubblock(bitc::BLOCKINFO_BLOCK_ID, 2);
-
-#if 0
- // Configure TYPE_SYMTAB_BLOCK's.
-
- // Add an abbrev for VST_ENTRY where the characters each fit in 7 bits.
- BitCodeAbbrev *Abbv = new BitCodeAbbrev();
- Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
- Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8); // Value ID
- Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // Linkage.
+ Stream.EnterBlockInfoBlock(2);
- xxx = Stream.EmitAbbrev(Abbv);
-#endif
+ { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
+ BitCodeAbbrev *Abbv = new BitCodeAbbrev();
+ Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
+ Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
+ Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
+ Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
+ if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
+ 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.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
+ Abbv) != VST_ENTRY_7_ABBREV)
+ assert(0 && "Unexpected abbrev ordering!");
+ }
+ { // 7-bit fixed width VST_BBENTRY strings.
+ BitCodeAbbrev *Abbv = new BitCodeAbbrev();
+ Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
+ Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
+ Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
+ Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
+ if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
+ Abbv) != VST_BBENTRY_7_ABBREV)
+ assert(0 && "Unexpected abbrev ordering!");
+ }
+
Stream.ExitBlock();
}