Re: C++: enum parsing speedups

[Andrew Pinski <pinskia at physics dot uc dot edu>]

On Aug 30, 2004, at 9:24 PM, Zack Weinberg wrote:

> This patch speeds up a couple of paths in the C++ parser's handling of
> 'enum' declarations/definitions.  These have fairly restricted syntax,
> so it is possible to replace the backtracking that was being done with
> a two-token lookahead.  More significantly, build_enumerator was
> constructing an ADD_EXPR just to fold it out again.  It's much faster
> to call add_double and int_fits_type_p directly.

I should note that C also has the same problem with respect of
constructing an PLUS_EXPR and folding it back.  When I just made
this change I found that most of the created expressions
for a file with an enumeration did not get created but I also found
that it did not help compile time speed at all.

Thanks,
Andrew Pinski