[Bug c/20303] Can't push more than 16 nested visibility

[joseph at codesourcery dot com]

------- Additional Comments From joseph at codesourcery dot com  2005-03-03 22:58 -------
Subject: Re:  Can't push more than 16 nested visibility

On Thu, 3 Mar 2005, pinskia at gcc dot gnu dot org wrote:

> This is a documented behavior.

Arbitrary limits are still generally undesirable, even when documented.

Some limits are very unlikely to be reached by real programs, even 
computer-generated ones, and genuinely motivated by efficiency.  For 
example, the C front end only supports 268435455 (= 2^28 - 1) nested 
scopes.  If there were a real use for more scopes, or for a very few 
programs to exceed other such limits motivated by efficiency concerns, we 
could add a --enable-huge-programs configure option to increase those 
limits at some performance cost to almost all normal programs.  Another 
limit in a similar situation is the limit of USHRT_MAX parameters to a 
preprocessor macro.

In this case, the limit is reached by real code and I very much doubt 
(without profiling information to show to the contrary) that there would 
be any measurable performance difference with using VEC, so we should just 
do that and get rid of the limit.



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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20303