Re: DR Grammars / parse time in GCC

[Hans Aberg]

At 20:44 +1000 2001/07/06, Tim Josling wrote:
>For combine.c it is 1.95/4.36 seconds so you are right. I will
>rebuild gcc with profile on and see if that is really the parse
>or if it is code executed within the parse actions.
...
>> > This will be slower but should often be fast enough. Eg if you
>> > look at GCC the parse time is negligible as a percentage.
>>
>> Sure? I darkly remember I've seen on the gcc mailinglist a profile where
>> they said gcc spends a majority of time in the function yyparse(). Altough
>> since both the parser grammar and the action rules reside in this function
>> it's hard to say what takes what...

I figure that as C/C++ compilers cannot parse without building lookup
tables, the only way to figure out which parse algorithms are better is to
make different verison of gcc, and then compare compile times.

  Hans Aberg