On Dec 5, 2010, at 17:13 , Basile Starynkevitch wrote: > On Sun, 5 Dec 2010 17:02:37 +0100 > "CUOQ Pascal" <pascal.c...@cea.fr> wrote: > >> ygrek wrote: >> >>> BTW, while we are on this topic, why the following is not in upstream yet? >>> >>> http://eigenclass.org/R2/writings/optimizing-caml_modify >>> >>> Looks like a clear win-win without drawbacks (increased code size shouldn't >>> be significant >>> cause Modify is only used in a couple of places). What do you think? >> >> This is very interesting. Thanks for pointing it out. > > > Sorry to be nitpicking, but... > > IIRC, there might be some rare occasions where the Modify macro could > be called several times in a C routine. And then you've got several > caml_modify_maybe_add_to_ref_table labels in the same C routine. > > With GCC, you could use a local __label__ > http://gcc.gnu.org/onlinedocs/gcc/Local-Labels.html but if you want to > be portable to non GCC compilers, you'll need a Modify macro which > generates a unique label (perhaps using __LINE__ for that purpose). > > I am thinking of something like [UNTESTED CODE] > > #define Modify(fp, val) Modify_at(fp, val, __LINE__) > > #define Modify_at(fp, val, lin) do{ \ > value in_heap = 0; \ > value _old_ = *(fp); \ > *(fp) = (val); \ > if (caml_gc_phase == Phase_mark) { \ > if (Is_in_heap (fp)) { \ > caml_darken (_old_, NULL); \ > in_heap = 1; \ > goto caml_modify_maybe_add_to_ref_table##Lin; \ > } \ > } else { \ > caml_modify_maybe_add_to_ref_table##Lin: \ > if (Is_block (val) && Is_young (val) \ > && ! (Is_block (_old_) && Is_young (_old_)) && \ > (in_heap || Is_in_heap (fp)) ){ \ > if (caml_ref_table.ptr >= caml_ref_table.limit){ \ > CAMLassert (caml_ref_table.ptr == caml_ref_table.limit); \ > caml_realloc_ref_table (&caml_ref_table); \ > } \ > *caml_ref_table.ptr++ = (fp); \ > } \ > } \ > }while(0)
Just use a static inline function, maybe with __attribute__((force_inline)) for GCC. Benedikt _______________________________________________ Caml-list mailing list. Subscription management: http://yquem.inria.fr/cgi-bin/mailman/listinfo/caml-list Archives: http://caml.inria.fr Beginner's list: http://groups.yahoo.com/group/ocaml_beginners Bug reports: http://caml.inria.fr/bin/caml-bugs
