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):
* dfg/DFGNode.h:
(JSC::DFG::Node::hasHeapPrediction):
* dfg/DFGNodeType.h:
(DFG):
* dfg/DFGOperations.cpp:
* dfg/DFGOperations.h:
* dfg/DFGPredictionPropagationPhase.cpp:
(JSC::DFG::PredictionPropagationPhase::propagate):
* dfg/DFGSpeculativeJIT.cpp:
(JSC::DFG::SpeculativeJIT::compileRegExpExec):
(DFG):
* dfg/DFGSpeculativeJIT.h:
(JSC::DFG::SpeculativeJIT::callOperation):
* dfg/DFGSpeculativeJIT32_64.cpp:
(JSC::DFG::SpeculativeJIT::compile):
* dfg/DFGSpeculativeJIT64.cpp:
(JSC::DFG::SpeculativeJIT::compile):
* jsc.cpp:
(GlobalObject::addConstructableFunction):
* runtime/Intrinsic.h:
* runtime/JSFunction.cpp:
(JSC::JSFunction::create):
(JSC):
* runtime/JSFunction.h:
(JSFunction):
* runtime/Lookup.cpp:
(JSC::setUpStaticFunctionSlot):
* runtime/RegExpObject.cpp:
(JSC::RegExpObject::exec):
(JSC::RegExpObject::match):
* runtime/RegExpObject.h:
(RegExpObject):
* runtime/RegExpPrototype.cpp:
(JSC::regExpProtoFuncTest):
(JSC::regExpProtoFuncExec):
git-svn-id: http://svn.webkit.org/repository/webkit/trunk@111129 268f45cc-cd09-0410-ab3c-d52691b4dbfc
diff --git a/Source/JavaScriptCore/dfg/DFGAbstractState.cpp b/Source/JavaScriptCore/dfg/DFGAbstractState.cpp
index c93fc15..70f8a4e 100644
--- a/Source/JavaScriptCore/dfg/DFGAbstractState.cpp
+++ b/Source/JavaScriptCore/dfg/DFGAbstractState.cpp
@@ -629,6 +629,13 @@
forNode(nodeIndex).makeTop();
break;
+ case RegExpExec:
+ case RegExpTest:
+ forNode(node.child1()).filter(PredictCell);
+ forNode(node.child2()).filter(PredictCell);
+ forNode(nodeIndex).makeTop();
+ break;
+
case Jump:
break;
