Strength reduction, RegExp.exec -> RegExp.test
https://bugs.webkit.org/show_bug.cgi?id=81459
Reviewed by Sam Weinig.
RegExp.prototype.exec & RegExp.prototype.test can both be used to test a regular
expression for a match against a string - however exec is more expensive, since
it allocates a matches array object. In cases where the result is consumed in a
boolean context the allocation of the matches array can be trivially elided.
For example:
function f()
{
for (i =0; i < 10000000; ++i)
if(!/a/.exec("a"))
err = true;
}
This is a 2.5x speedup on this example microbenchmark loop.
In a more advanced form of this optimization, we may be able to avoid allocating
the array where access to the array can be observed.
- create_hash_table:
- dfg/DFGAbstractState.cpp:
(JSC::DFG::AbstractState::execute):
- dfg/DFGByteCodeParser.cpp:
(JSC::DFG::ByteCodeParser::handleIntrinsic):
(JSC::DFG::Node::hasHeapPrediction):
(DFG):
- dfg/DFGOperations.cpp:
- dfg/DFGOperations.h:
- dfg/DFGPredictionPropagationPhase.cpp:
(JSC::DFG::PredictionPropagationPhase::propagate):
- dfg/DFGSpeculativeJIT.cpp:
(JSC::DFG::SpeculativeJIT::compileRegExpExec):
(DFG):
(JSC::DFG::SpeculativeJIT::callOperation):
- dfg/DFGSpeculativeJIT32_64.cpp:
(JSC::DFG::SpeculativeJIT::compile):
- dfg/DFGSpeculativeJIT64.cpp:
(JSC::DFG::SpeculativeJIT::compile):
(GlobalObject::addConstructableFunction):
- runtime/Intrinsic.h:
- runtime/JSFunction.cpp:
(JSC::JSFunction::create):
(JSC):
(JSFunction):
(JSC::setUpStaticFunctionSlot):
- runtime/RegExpObject.cpp:
(JSC::RegExpObject::exec):
(JSC::RegExpObject::match):
(RegExpObject):
- runtime/RegExpPrototype.cpp:
(JSC::regExpProtoFuncTest):
(JSC::regExpProtoFuncExec):
