Bug 115331 – [Windows] [MinGW] [REGRESSION] Latest/April JIT changes make very slow eval of JSON data

• Status: UNCONFIRMED
• Component: JavaScriptCore

[Mozhaev Grigory]

Example html page (see test.html attachment) makes browser based on webkit unresponsive for some minutes.

It happened by calling 'eval' on 900kb JSON data. Stuck happen here in code:

Source/JavaScriptCore/interpreter/interpreter.cpp (1332 line)

JSValue Interpreter::execute(EvalExecutable* eval, CallFrame* callFrame, JSValue thisValue, JSScope* scope) {
....
#elif ENABLE(JIT)
   result = eval->generatedJITCode().execute(&m_stack, newCallFrame, &vm); // stucked here until json will be parsed
#endif // ENABLE(JIT)
...
}

The problem does not appear in Linux, but exists in Windows (compiled using Mingw 32).

Webkit before april this year does well with the same page (a couple of seconds to process), so this looks as REGRESSION.

[Mozhaev Grigory]

Created attachment 199968 [details]
Test page makes webpage to freeze for some minutes.