Reinhold Kainhofer <reinh...@kainhofer.com> writes:
> Am Tuesday, 16. August 2011, 23:36:15 schrieb Reinhold Kainhofer:
>> However, I'm not sure if this will really work out or give us much benefit.
>> In particular, we have lots of checks for == SCM_EOL or == SCM_BOOL_T. E.g.
>> very deep inside the core of lilypond:
>>
>> inline bool ly_cheap_is_list (SCM x) {return scm_is_pair (x) || x==SCM_EOL;
>> }
>
> Most of the errors will come from the implementation of ly_symbol2scm
> (lily/include/lily-guile-macros.hh):
>
> #ifdef CACHE_SYMBOLS
> [...]
> /* Using this trick we cache the value of scm_from_locale_symbol ("fooo")
> where
> "fooo" is a constant string. This is done at the cost of one static
> variable per ly_symbol2scm() use, and one boolean evaluation for
> every call.
> */
> #define ly_symbol2scm(x) \
> ({ \
> static SCM cached; \
> /* We store this one locally, since G++ -O2 fucks up else */ \
> SCM value = cached; \
> if (__builtin_constant_p ((x))) \
> { \
> if (!cached) \
> value = cached = scm_gc_protect_object (scm_or_str2symbol (x)); \
> } \
> else \
> value = scm_or_str2symbol (x); \
> value; \
> })
> #else
>
>
> The "problem" is the !cached, which was added by Han-Wen in version 1.5.19 in
> commit 6c00542bf11cd4759b2e39537aeb3d9a533a3519 in October 2001 (before it
> was
> also there as a check "(cached)?cached:scm_...").
-- C Macro: scm_t_bits SCM_UNPACK (SCM X)
Transforms the `SCM' value X into its representation as an
integral type. Only after applying `SCM_UNPACK' it is possible to
access the bits and contents of the `SCM' value.
--
David Kastrup
_______________________________________________
lilypond-devel mailing list
lilypond-devel@gnu.org
https://lists.gnu.org/mailman/listinfo/lilypond-devel
