Changeset 214029 in webkit for trunk/Source/JavaScriptCore/parser/Nodes.cpp

Timestamp:

Mar 15, 2017, 10:12:53 PM (8 years ago)

Author:

Yusuke Suzuki

Message:

[JSC] Default parameter part should be retrieved by op_get_argument opcode instead of changing arity
​https://bugs.webkit.org/show_bug.cgi?id=164582

Reviewed by Saam Barati.

JSTests:

• stress/function-with-defaults-inlining.js: Added.

(shouldBe):
(ok):
(a):

• stress/function-with-defaults-non-inlining.js: Added.

(shouldBe):
(ok):
(a):

Source/JavaScriptCore:

Previously we implement the default parameters as follows.

1. We count the default parameters as the usual parameters.
2. We just get the argument register.
3. Check it with op_is_undefined.
4. And fill the binding with either the argument register or default value.

The above is simple. However, it has the side effect that it always increase the arity of the function.
While function.length does not increase, internally, the number of parameters of CodeBlock increases.
This effectively prevent our DFG / FTL to perform inlining: currently we only allows DFG to inline
the function with the arity less than or equal the number of passing arguments. It is OK. But when using
default parameters, we frequently do not pass the argument for the parameter with the default value.
Thus, in our current implementation, we frequently need to fixup the arity. And we frequently fail
to inline the function.

This patch fixes the above problem by not increasing the arity of the function. When we encounter the
parameter with the default value, we use op_argument to get the argument instead of using the argument
registers.

This improves six-speed defaults.es6 performance by 4.45x.

defaults.es6 968.4126+-101.2350 ^{217.6602+-14.8831} definitely 4.4492x faster

• bytecode/UnlinkedFunctionExecutable.cpp:

(JSC::UnlinkedFunctionExecutable::UnlinkedFunctionExecutable):

• bytecode/UnlinkedFunctionExecutable.h:
• bytecompiler/BytecodeGenerator.cpp:

(JSC::BytecodeGenerator::BytecodeGenerator):
(JSC::BytecodeGenerator::initializeDefaultParameterValuesAndSetupFunctionScopeStack):
(JSC::BytecodeGenerator::initializeNextParameter):
(JSC::BytecodeGenerator::initializeParameters):

• bytecompiler/BytecodeGenerator.h:
• bytecompiler/NodesCodegen.cpp:

(JSC::FunctionNode::emitBytecode):

• dfg/DFGByteCodeParser.cpp:

(JSC::DFG::ByteCodeParser::inliningCost):

• parser/ASTBuilder.h:

(JSC::ASTBuilder::createFunctionMetadata):

• parser/Nodes.cpp:

(JSC::FunctionMetadataNode::FunctionMetadataNode):

• parser/Nodes.h:

(JSC::FunctionParameters::size):
(JSC::FunctionParameters::at):
(JSC::FunctionParameters::append):
(JSC::FunctionParameters::isSimpleParameterList):

• parser/Parser.cpp:

(JSC::Parser<LexerType>::isArrowFunctionParameters):
(JSC::Parser<LexerType>::parseGeneratorFunctionSourceElements):
(JSC::Parser<LexerType>::parseAsyncFunctionSourceElements):
(JSC::Parser<LexerType>::parseFormalParameters):
(JSC::Parser<LexerType>::parseFunctionBody):
(JSC::Parser<LexerType>::parseFunctionParameters):
(JSC::Parser<LexerType>::parseFunctionInfo):

• parser/Parser.h:
• parser/SyntaxChecker.h:

(JSC::SyntaxChecker::createFunctionMetadata):

• runtime/FunctionExecutable.h:
• runtime/JSFunction.cpp:

(JSC::JSFunction::createBuiltinFunction):
(JSC::JSFunction::reifyLength):

File:

• trunk/Source/JavaScriptCore/parser/Nodes.cpp (modified) (2 diffs)

trunk/Source/JavaScriptCore/parser/Nodes.cpp

@@ -136 +136 @@
     const JSTokenLocation& endLocation, unsigned startColumn, unsigned endColumn, 
     int functionKeywordStart, int functionNameStart, int parametersStart, bool isInStrictContext, 
-    ConstructorKind constructorKind, SuperBinding superBinding, unsigned parameterCount, unsigned functionLength, SourceParseMode mode, bool isArrowFunctionBodyExpression)
+    ConstructorKind constructorKind, SuperBinding superBinding, unsigned parameterCount, SourceParseMode mode, bool isArrowFunctionBodyExpression)
         : Node(endLocation)
         , m_startColumn(startColumn)
@@ -145 +145 @@
         , m_startStartOffset(startLocation.startOffset)
         , m_parameterCount(parameterCount)
-        , m_functionLength(functionLength)
         , m_parseMode(mode)
         , m_isInStrictContext(isInStrictContext)