Ignore:
Timestamp:
Apr 8, 2022, 10:54:47 AM (3 years ago)
Author:
Chris Dumez
Message:

Reduce number of StringView to String conversions in JSC
​https://bugs.webkit.org/show_bug.cgi?id=238911

Reviewed by Darin Adler.

Source/JavaScriptCore:

  • dfg/DFGLazyJSValue.cpp:

(JSC::DFG::LazyJSValue::getValue const):
Resolve ambiguity by explicitly converting the StringImpl to a String before
calling jsString(). [1]

  • jsc.cpp:

Avoid constructing a String from the StringView, just to compute a hash.
Instead, rely on the StringViewHashTranslator for this.

  • profiler/ProfilerOSRExit.cpp:

(JSC::Profiler::OSRExit::toJS const):
exitKindToString() returns an ASCIILiteral whose length is always greater
than 1 so we can call the more efficient jsNontrivialString() instead of
jsString(). Calling jsString() here had become ambiguous because an
ASCIILiteral can be implicitely converted to both a String and a
StringView [2].

  • runtime/ArrayPrototype.cpp:

(JSC::fastJoin):
Call the new jsString() overload that takes a StringView, to avoid
unnecessarily constructing a String in the case where the length is <= 1 [3].

  • runtime/ErrorInstance.cpp:

(JSC::appendSourceToErrorMessage):

  • runtime/ErrorInstance.h:
  • runtime/ExceptionHelpers.cpp:

(JSC::defaultApproximateSourceError):
(JSC::defaultSourceAppender):
(JSC::functionCallBase):
(JSC::notAFunctionSourceAppender):
(JSC::invalidParameterInSourceAppender):
(JSC::invalidParameterInstanceofSourceAppender):
(JSC::invalidParameterInstanceofNotFunctionSourceAppender):
(JSC::invalidParameterInstanceofhasInstanceValueNotFunctionSourceAppender):
(JSC::invalidPrototypeSourceAppender):

  • runtime/ExceptionHelpers.h:

Call SourceAppender with a StringView since this is what we have. In most
cases, these appenders end up calling makeString() and it is thus beneficial
to avoid temporary/intermediate String constructions.

  • runtime/FunctionExecutable.cpp:

(JSC::FunctionExecutable::toStringSlow):
Same as [3].

  • runtime/IdentifierInlines.h:

(JSC::identifierToJSValue):
(JSC::identifierToSafePublicJSValue):
Same as [1].

  • runtime/IntlDateTimeFormat.cpp:

(JSC::IntlDateTimeFormat::formatToParts const):
(JSC::IntlDateTimeFormat::formatRangeToParts):

  • runtime/IntlLocale.cpp:

(JSC::IntlLocale::textInfo):

  • runtime/IntlNumberFormat.cpp:

(JSC::IntlNumberFormat::formatRangeToPartsInternal):
(JSC::IntlNumberFormat::formatToPartsInternal):
Same as [2].

  • runtime/IntlRelativeTimeFormat.cpp:

(JSC::IntlRelativeTimeFormat::formatToParts const):
Same as [3].

  • runtime/JSArrayBufferPrototype.cpp:

(JSC::JSArrayBufferPrototype::finishCreation):
Same as [2].

  • runtime/JSModuleLoader.cpp:

(JSC::JSModuleLoader::requestImportModule):
(JSC::JSC_DEFINE_HOST_FUNCTION):
Same as [1].

  • runtime/JSString.h:

(JSC::jsString):
Add a jsString() overload that takes in a StringView instead of a String.
This avoids construction of a String for call sites having a StringView
in the event where the view's length is <= 1.

  • runtime/SymbolConstructor.cpp:

(JSC::JSC_DEFINE_HOST_FUNCTION):
Same as [1].

Source/WTF:

Provide a reverseFind(StringView, unsigned) overload on StringView, for consistency
with String and to facilitate the converting of code from String to StringView.

  • wtf/text/StringCommon.h:

(WTF::reverseFindInner):

  • wtf/text/StringImpl.cpp:

(WTF::reverseFindInner): Deleted.

  • wtf/text/StringView.cpp:

(WTF::StringView::reverseFind const):

  • wtf/text/StringView.h:
File:
1 edited

Legend:

Unmodified
Added
Removed

  • trunk/Source/JavaScriptCore/profiler/ProfilerOSRExit.cpp

    r251425 r292619  
    5252    result->putDirect(vm, vm.propertyNames->id, jsNumber(m_id));
    5353    result->putDirect(vm, vm.propertyNames->origin, m_origin.toJS(globalObject));
    54     result->putDirect(vm, vm.propertyNames->exitKind, jsString(vm, exitKindToString(m_exitKind)));
     54    result->putDirect(vm, vm.propertyNames->exitKind, jsNontrivialString(vm, exitKindToString(m_exitKind)));
    5555    result->putDirect(vm, vm.propertyNames->isWatchpoint, jsBoolean(m_isWatchpoint));
    5656    result->putDirect(vm, vm.propertyNames->count, jsNumber(m_counter));
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