How to use GMP.

[Hashida]

Hi Tomonori Kouya.

When I add "gmp_printf("aaaaa=%Zd\n",&aaaaa);" to my first program,
"aaaaa=6442450944" emerges.

I have not understood from "gmp.h" file yet,
but "MP_INT" seems different from "mpz_t".

Thanks.

Hashida

Hashida wrote:

> Hi Tomonori Kouya.
>
> I thank you for a reply.
>
> Certainly the following list works correctly.
> But I have a point which I can't understand.
> When I convert mpz_t into MP_INT,
> the following list can't be compiled.
> The following message emerges.
>
> incompatible type for argument 1 of '__gmp_init_set_str'
> incompatible type for argument 1 of '__gmp_init'
> incompatible type for argument 1 of '__gmpmul_ui'
> incompatible type for argument 2 of '__gmpmul_ui'
>
> In "gmp.h" file,
> "typedef __mpz_struct MP_INT;"
> and
> "typedef __mpz_struct mpz_t[1];"
> are defined.
>
> "__mpz_struct" is as follows.
>
> typedef struct
> {
>     int    _mp_alloc;
>     int    _mp_size;
>     mp_limb_t *_mp_d;
> } __mpz_struct;
>
> Is "MP_INT" equal to "mpz_t" ?
> "MP_INT" is used in"FreeS/WAN" which is ipsec stack on Linux.
> Because I want to understand "MP_INT" structure, tried with my first
> program.
>
> Regards.
>
> Hashida
>
> juneco@quartz.ocn.ne.jp wrote:
>
> > Tomonori Kouya here.
> >
> > Your program is not standard, I think. If you get correct results only,
> > how about the following list ?
> >
> > #include <stdio.h>
> > #include <gmp.h>
> > #include <stdarg.h>
> > //#include <obstack.h>
> >
> > main()
> > {
> >         mpz_t bbbbb, aaaaa;
> >
> >         mpz_init_set_str(bbbbb,"2147483647", 10);
> >
> >         mpz_init(aaaaa);
> >         mpz_mul_ui(aaaaa, bbbbb, 3);
> >
> >         gmp_printf("bbbbb=%Zd\n",bbbbb);
> >         gmp_printf("aaaaa=%Zd\n",aaaaa);
> >
> >         mpz_clear(bbbbb);
> >         mpz_clear(aaaaa);
> > }
> >
> > Results on Pentium 4 PC with Windows XP and GMP 4.1.2:
> >
> > $ ./a
> > bbbbb=2147483647
> > aaaaa=6442450941
> >
> > Hashida <jhashida@fls.fujitsu.com>さん：
> > > Hi
> > >
> > > I am a beginner for GMP and not good at C.
> > > I can't understand how to use GMP very well.
> > > For example, in arithmetic of 231*3
> > > I wrote the following C program.
> > >
> > > #include <stdio.h>
> > > #include <gmp.h>
> > > #include <stdarg.h>
> > > #include <obstack.h>
> > >
> > > main()
> > > {
> > >         MP_INT *bbbbb=(MP_INT *)malloc(50);
> > >         MP_INT aaaaa;
> > >
> > >         bbbbb->_mp_d=(mp_limb_t *)malloc(10);
> > >
> > >         mpz_init_set_ui(bbbbb,2147483647);
> > >         printf("bbbbb->_mp_alloc=%d\n",bbbbb->_mp_alloc);
> > >         printf("bbbbb->_mp_size=%d\n",bbbbb->_mp_size);
> > >         printf("*(bbbbb->_mp_d)=%d\n",*(bbbbb->_mp_d));
> > >         mpz_init(&aaaaa);
> > >         mpz_mul_ui(&aaaaa, bbbbb, 3);
> > >         printf("aaaaa._mp_alloc=%d\n",aaaaa._mp_alloc);
> > >         printf("aaaaa._mp_size=%d\n",aaaaa._mp_size);
> > >         printf("*(aaaaa._mp_d)=%d\n",*(aaaaa._mp_d));
> > >
> > > }
> > >
> > > The result of the execution of this program is as follows.
> > >
> > > bbbbb->_mp_alloc=1
> > > bbbbb->_mp_size=1
> > > *(bbbbb->_mp_d)=2147483647
> > > aaaaa._mp_alloc=2
> > > aaaaa._mp_size=2
> > > *(aaaaa._mp_d)=2147483645
> > >
> > > 231*3 is 6442450944 in decimal system.
> > >
> > > Please teach me how to recognize 6442450944 from the above result.
> > > Simply the way of the usage of "printf" may be bad, but I don't know.
> > >
> > > Thanks.
> > >
> > > Hashida
> > >
> > _______________________________________________
> > gmp-discuss mailing list
> > gmp-discuss@swox.com
> > https://gmplib.org/mailman/listinfo/gmp-discuss
>
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