Emit & read more compressed bytecode by not emitting a bytecodeblock for
each basic block in function. Instead, just emit a stream of instructions,
chopping up basic blocks based on when we find terminator instructions. This
saves a fairly substantial chunk of bytecode space. In stripped, sample
cases, for example, we get this reduction in size:
197.parser: 163036 -> 137180: 18.8% reduction
254.gap : 844936 -> 689392: 22.6%
255.vortex: 621724 -> 528444: 17.7%
...
Not bad for something this simple. :) Note that this doesn't require a new
bytecode version number at all, though version 1.1 should not need to support
the old format.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@10280 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Bytecode/Writer/Writer.cpp b/lib/Bytecode/Writer/Writer.cpp
index 9c9e1ab..7fa22b8 100644
--- a/lib/Bytecode/Writer/Writer.cpp
+++ b/lib/Bytecode/Writer/Writer.cpp
@@ -225,9 +225,13 @@
// Output information about the constants in the function...
outputConstants(true);
- // Output basic block nodes...
- for (Function::const_iterator I = F->begin(), E = F->end(); I != E; ++I)
- processBasicBlock(*I);
+ { // Output all of the instructions in the body of the function
+ BytecodeBlock ILBlock(BytecodeFormat::InstructionList, Out);
+
+ for (Function::const_iterator BB = F->begin(), E = F->end(); BB != E;++BB)
+ for(BasicBlock::const_iterator I = BB->begin(), E = BB->end(); I!=E;++I)
+ processInstruction(*I);
+ }
// If needed, output the symbol table for the function...
outputSymbolTable(F->getSymbolTable());
@@ -236,14 +240,6 @@
}
}
-
-void BytecodeWriter::processBasicBlock(const BasicBlock &BB) {
- BytecodeBlock FunctionBlock(BytecodeFormat::BasicBlock, Out);
- // Process all the instructions in the bb...
- for(BasicBlock::const_iterator I = BB.begin(), E = BB.end(); I != E; ++I)
- processInstruction(*I);
-}
-
void BytecodeWriter::outputSymbolTable(const SymbolTable &MST) {
BytecodeBlock FunctionBlock(BytecodeFormat::SymbolTable, Out);