Emacs hangs when file with complex expressions is opened.

[suman . nandan]

Hi Emacs Experts !
If I try to open a C++ file with the following statement, my emacs
hangs:
------------------------------------------------------------------------------
...
definition(fsmGrammar const& )
 {
        version = (*(anychar_p & ~ch_p(':')))
[&MvNativeFsmParser::getCurrentState] >>  chseq_p("::") >> ch_p('(')
>>  (*(anychar_p & ~ch_p(')')))
[&MvNativeFsmParser::captureInputSignal] >> ch_p(')')  >>
( *(anychar_p & ~ch_p('{')) )[&MvNativeFsmParser::getNextState] >>
ch_p('{')  >> ch_p('}') >> ch_p(',')  >> ch_p('{') >> *( (*(anychar_p
& ~ch_p('=') & ~ch_p('}')))[&MvNativeFsmParser::captureSignalName]  >>
ch_p('=') >> int_p[&MvNativeFsmParser::captureSignalValue] >>
*ch_p(',')) >>  ch_p('}')
                                                           | epsilon_p
                                                           |chseq_p("#") >> 
*(anychar_p);
 }
...
-------------------------------------------------------------------------------
However if I comment the above few lines and try opening the file with
Emacs, it works fine.
My guess is that, Emacs internally tries to parse it and store
something for easier navigation.
Is there any way I can speedup this?
My Emacs version is 21.3.1.

Thanks in advance !!
Suman Nandan.