Reduce parser overhead in JSC
authoroliver@apple.com <oliver@apple.com@268f45cc-cd09-0410-ab3c-d52691b4dbfc>
Wed, 7 Nov 2012 00:13:54 +0000 (00:13 +0000)
committeroliver@apple.com <oliver@apple.com@268f45cc-cd09-0410-ab3c-d52691b4dbfc>
Wed, 7 Nov 2012 00:13:54 +0000 (00:13 +0000)
commitbad5b2348bfaf398ae15eb6930b01ed39482a777
tree2b6f19da6a50e365464e9b42e5201d4ae162b38b
parentcc1f677c96afc2f9dbef0272c2c4fe567c24f346
Reduce parser overhead in JSC
https://bugs.webkit.org/show_bug.cgi?id=101127

Reviewed by Filip Pizlo.

An exciting journey into the world of architecture in which our hero
adds yet another layer to JSC codegeneration.

This patch adds a marginally more compact form of bytecode that is
free from any data specific to a given execution context, and that
does store any data structures necessary for execution.  To actually
execute this UnlinkedBytecode we still need to instantiate a real
CodeBlock, but this is a much faster linear time operation than any
of the earlier parsing or code generation passes.

As the unlinked code is context free we can then simply use a cache
from source to unlinked code mapping to completely avoid all of the
old parser overhead.  The cache is currently very simple and memory
heavy, using the complete source text as a key (rather than SourceCode
or equivalent), and a random eviction policy.

This seems to produce a substantial win when loading identical content
in different contexts.

* API/tests/testapi.c:
(main):
* CMakeLists.txt:
* GNUmakefile.list.am:
* JavaScriptCore.vcproj/JavaScriptCore/JavaScriptCore.vcproj:
* JavaScriptCore.xcodeproj/project.pbxproj:
* bytecode/CodeBlock.cpp:
* bytecode/CodeBlock.h:
    Moved a number of fields, and a bunch of logic to UnlinkedCodeBlock.h/cpp
* bytecode/Opcode.h:
    Added a global const init no op instruction needed to get correct
    behaviour without any associated semantics.
* bytecode/UnlinkedCodeBlock.cpp: Added.
* bytecode/UnlinkedCodeBlock.h: Added.
    A fairly shallow, GC allocated version of the old CodeBlock
    classes with a 32bit instruction size, and just metadata
    size tracking.
* bytecompiler/BytecodeGenerator.cpp:
* bytecompiler/BytecodeGenerator.h:
    Replace direct access to m_symbolTable with access through
    symbolTable().  ProgramCode no longer has a symbol table at
    all so some previously unconditional (and pointless) uses
    of symbolTable get null checks.
    A few other changes to deal with type changes due to us generating
    unlinked code (eg. pointer free, so profile indices rather than
    pointers).
* dfg/DFGByteCodeParser.cpp:
* dfg/DFGCapabilities.h:
    Support global_init_nop
* interpreter/Interpreter.cpp:
    Now get the ProgramExecutable to initialise new global properties
    before starting execution.
* jit/JIT.cpp:
* jit/JITDriver.h:
* jit/JITStubs.cpp:
* llint/LLIntData.cpp:
* llint/LLIntSlowPaths.cpp:
* llint/LowLevelInterpreter.asm:
* llint/LowLevelInterpreter32_64.asm:
* llint/LowLevelInterpreter64.asm:
    Adding init_global_const_nop everywhere else
* parser/Parser.h:
* parser/ParserModes.h: Added.
* parser/ParserTokens.h:
    Parser no longer needs a global object or callframe to function
* runtime/CodeCache.cpp: Added.
* runtime/CodeCache.h: Added.
    A simple, random eviction, Source->UnlinkedCode cache
* runtime/Executable.cpp:
* runtime/Executable.h:
    Executables now reference their unlinked counterparts, and
    request code specifically for the target global object.
* runtime/JSGlobalData.cpp:
* runtime/JSGlobalData.h:
    GlobalData now owns a CodeCache and a set of new structures
    for the unlinked code types.
* runtime/JSGlobalObject.cpp:
* runtime/JSGlobalObject.h:
    Utility functions used by executables to perform compilation

* runtime/JSType.h:
  Add new JSTypes for unlinked code

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@133688 268f45cc-cd09-0410-ab3c-d52691b4dbfc
50 files changed:
Source/JavaScriptCore/CMakeLists.txt
Source/JavaScriptCore/ChangeLog
Source/JavaScriptCore/GNUmakefile.list.am
Source/JavaScriptCore/JavaScriptCore.vcproj/JavaScriptCore/JavaScriptCore.vcproj
Source/JavaScriptCore/JavaScriptCore.xcodeproj/project.pbxproj
Source/JavaScriptCore/Target.pri
Source/JavaScriptCore/bytecode/CodeBlock.cpp
Source/JavaScriptCore/bytecode/CodeBlock.h
Source/JavaScriptCore/bytecode/Opcode.h
Source/JavaScriptCore/bytecode/UnlinkedCodeBlock.cpp [new file with mode: 0644]
Source/JavaScriptCore/bytecode/UnlinkedCodeBlock.h [new file with mode: 0644]
Source/JavaScriptCore/bytecompiler/BytecodeGenerator.cpp
Source/JavaScriptCore/bytecompiler/BytecodeGenerator.h
Source/JavaScriptCore/debugger/Debugger.cpp
Source/JavaScriptCore/dfg/DFGByteCodeCache.h
Source/JavaScriptCore/dfg/DFGByteCodeParser.cpp
Source/JavaScriptCore/dfg/DFGCapabilities.h
Source/JavaScriptCore/dfg/DFGOperations.cpp
Source/JavaScriptCore/heap/Heap.cpp
Source/JavaScriptCore/heap/MarkedAllocator.h
Source/JavaScriptCore/heap/SlotVisitor.cpp
Source/JavaScriptCore/interpreter/Interpreter.cpp
Source/JavaScriptCore/jit/JIT.cpp
Source/JavaScriptCore/jit/JIT.h
Source/JavaScriptCore/jit/JITDriver.h
Source/JavaScriptCore/jit/JITOpcodes.cpp
Source/JavaScriptCore/jit/JITOpcodes32_64.cpp
Source/JavaScriptCore/jit/JITStubs.cpp
Source/JavaScriptCore/jit/JITStubs.h
Source/JavaScriptCore/llint/LLIntData.cpp
Source/JavaScriptCore/llint/LLIntSlowPaths.cpp
Source/JavaScriptCore/llint/LLIntSlowPaths.h
Source/JavaScriptCore/llint/LowLevelInterpreter.asm
Source/JavaScriptCore/llint/LowLevelInterpreter32_64.asm
Source/JavaScriptCore/llint/LowLevelInterpreter64.asm
Source/JavaScriptCore/parser/Parser.h
Source/JavaScriptCore/parser/ParserModes.h [new file with mode: 0644]
Source/JavaScriptCore/parser/ParserTokens.h
Source/JavaScriptCore/runtime/Arguments.h
Source/JavaScriptCore/runtime/CodeCache.cpp [new file with mode: 0644]
Source/JavaScriptCore/runtime/CodeCache.h [new file with mode: 0644]
Source/JavaScriptCore/runtime/Executable.cpp
Source/JavaScriptCore/runtime/Executable.h
Source/JavaScriptCore/runtime/ExecutionHarness.h
Source/JavaScriptCore/runtime/JSActivation.h
Source/JavaScriptCore/runtime/JSGlobalData.cpp
Source/JavaScriptCore/runtime/JSGlobalData.h
Source/JavaScriptCore/runtime/JSGlobalObject.cpp
Source/JavaScriptCore/runtime/JSGlobalObject.h
Source/JavaScriptCore/runtime/JSType.h