Title: [201176] trunk/Source/_javascript_Core
- Revision
- 201176
- Author
- [email protected]
- Date
- 2016-05-19 13:09:47 -0700 (Thu, 19 May 2016)
Log Message
arrow function lexical environment should reuse the same environment as the function's lexical environment where possible
https://bugs.webkit.org/show_bug.cgi?id=157908
Reviewed by Filip Pizlo.
We can safely combine these two environment when we have
a simple parameter list (no default parameters, no destructring parameters).
* bytecompiler/BytecodeGenerator.cpp:
(JSC::BytecodeGenerator::BytecodeGenerator):
(JSC::BytecodeGenerator::initializeDefaultParameterValuesAndSetupFunctionScopeStack):
(JSC::BytecodeGenerator::initializeArrowFunctionContextScopeIfNeeded):
* bytecompiler/BytecodeGenerator.h:
Modified Paths
Diff
Modified: trunk/Source/_javascript_Core/ChangeLog (201175 => 201176)
--- trunk/Source/_javascript_Core/ChangeLog 2016-05-19 19:15:35 UTC (rev 201175)
+++ trunk/Source/_javascript_Core/ChangeLog 2016-05-19 20:09:47 UTC (rev 201176)
@@ -1,3 +1,19 @@
+2016-05-19 Saam barati <[email protected]>
+
+ arrow function lexical environment should reuse the same environment as the function's lexical environment where possible
+ https://bugs.webkit.org/show_bug.cgi?id=157908
+
+ Reviewed by Filip Pizlo.
+
+ We can safely combine these two environment when we have
+ a simple parameter list (no default parameters, no destructring parameters).
+
+ * bytecompiler/BytecodeGenerator.cpp:
+ (JSC::BytecodeGenerator::BytecodeGenerator):
+ (JSC::BytecodeGenerator::initializeDefaultParameterValuesAndSetupFunctionScopeStack):
+ (JSC::BytecodeGenerator::initializeArrowFunctionContextScopeIfNeeded):
+ * bytecompiler/BytecodeGenerator.h:
+
2016-05-19 Michael Saboff <[email protected]>
Unreviewed build fix.
Modified: trunk/Source/_javascript_Core/bytecompiler/BytecodeGenerator.cpp (201175 => 201176)
--- trunk/Source/_javascript_Core/bytecompiler/BytecodeGenerator.cpp 2016-05-19 19:15:35 UTC (rev 201175)
+++ trunk/Source/_javascript_Core/bytecompiler/BytecodeGenerator.cpp 2016-05-19 20:09:47 UTC (rev 201176)
@@ -575,7 +575,8 @@
}
if (needsToUpdateArrowFunctionContext() && !codeBlock->isArrowFunction()) {
- initializeArrowFunctionContextScopeIfNeeded();
+ bool canReuseLexicalEnvironment = isSimpleParameterList;
+ initializeArrowFunctionContextScopeIfNeeded(functionSymbolTable, canReuseLexicalEnvironment);
emitPutThisToArrowFunctionContextScope();
emitPutNewTargetToArrowFunctionContextScope();
emitPutDerivedConstructorToArrowFunctionContextScope();
@@ -893,10 +894,37 @@
}
}
-void BytecodeGenerator::initializeArrowFunctionContextScopeIfNeeded()
+void BytecodeGenerator::initializeArrowFunctionContextScopeIfNeeded(SymbolTable* functionSymbolTable, bool canReuseLexicalEnvironment)
{
ASSERT(!m_arrowFunctionContextLexicalEnvironmentRegister);
+ if (canReuseLexicalEnvironment && m_lexicalEnvironmentRegister) {
+ RELEASE_ASSERT(!m_codeBlock->isArrowFunction());
+ RELEASE_ASSERT(functionSymbolTable);
+
+ m_arrowFunctionContextLexicalEnvironmentRegister = m_lexicalEnvironmentRegister;
+
+ ScopeOffset offset;
+
+ ConcurrentJITLocker locker(ConcurrentJITLocker::NoLockingNecessary);
+ if (isThisUsedInInnerArrowFunction()) {
+ offset = functionSymbolTable->takeNextScopeOffset(locker);
+ functionSymbolTable->set(locker, propertyNames().thisIdentifier.impl(), SymbolTableEntry(VarOffset(offset)));
+ }
+
+ if (m_codeType == FunctionCode && isNewTargetUsedInInnerArrowFunction()) {
+ offset = functionSymbolTable->takeNextScopeOffset();
+ functionSymbolTable->set(locker, propertyNames().newTargetLocalPrivateName.impl(), SymbolTableEntry(VarOffset(offset)));
+ }
+
+ if (isConstructor() && constructorKind() == ConstructorKind::Derived && isSuperUsedInInnerArrowFunction()) {
+ offset = functionSymbolTable->takeNextScopeOffset(locker);
+ functionSymbolTable->set(locker, propertyNames().derivedConstructorPrivateName.impl(), SymbolTableEntry(VarOffset(offset)));
+ }
+
+ return;
+ }
+
VariableEnvironment environment;
if (isThisUsedInInnerArrowFunction()) {
Modified: trunk/Source/_javascript_Core/bytecompiler/BytecodeGenerator.h (201175 => 201176)
--- trunk/Source/_javascript_Core/bytecompiler/BytecodeGenerator.h 2016-05-19 19:15:35 UTC (rev 201175)
+++ trunk/Source/_javascript_Core/bytecompiler/BytecodeGenerator.h 2016-05-19 20:09:47 UTC (rev 201176)
@@ -858,7 +858,7 @@
void initializeParameters(FunctionParameters&);
void initializeVarLexicalEnvironment(int symbolTableConstantIndex, SymbolTable* functionSymbolTable, bool hasCapturedVariables);
void initializeDefaultParameterValuesAndSetupFunctionScopeStack(FunctionParameters&, bool isSimpleParameterList, FunctionNode*, SymbolTable*, int symbolTableConstantIndex, const std::function<bool (UniquedStringImpl*)>& captures, bool shouldCreateArgumentsVariableInParameterScope);
- void initializeArrowFunctionContextScopeIfNeeded();
+ void initializeArrowFunctionContextScopeIfNeeded(SymbolTable* functionSymbolTable = nullptr, bool canReuseLexicalEnvironment = false);
public:
JSString* addStringConstant(const Identifier&);
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