[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: GMP bignum results using double cells.
From: |
Marius Vollmer |
Subject: |
Re: GMP bignum results using double cells. |
Date: |
27 Feb 2003 14:33:50 +0100 |
User-agent: |
Gnus/5.09 (Gnus v5.9.0) Emacs/21.2 |
Rob Browning <address@hidden> writes:
> It looks like the new code is substantially better than 1.7, though if
> I understand correctly, and gc time is included in user time, then it
> appears the improvement was on the gc side, not the computation side.
That looks very good to me. Certainly good enough to integrate it
into the 1.7 branch.
> Marius, for now, rather than use SCM_CELL_ADDR_1, I mirrored the
> handling of real values like this:
>
> #define SCM_I_BIG_MPZ(x) (((scm_t_big_mpz *) SCM2PTR (x))->mpz)
> #define SCM_BIGP(x) (!SCM_IMP (x) && SCM_TYP16 (x) == scm_tc16_big)
>
> typedef struct scm_t_big_mpz
> {
> SCM type;
> mpz_t mpz;
> } scm_t_big_mpz;
>
> However, this means that numbers.h now has to include gmp.h, and with
> the SCM_CELL_ADDR_1 approach, it wouldn't. I'd be happy to arrange
> things whichever way you prefer.
Do we need to define scm_t_big_mpz in numbers.h? Couldn't it just be
an declared-but-undefined struct there? Like
#define SCM_I_BIG_MPZ(x) (((scm_t_big_mpz *) SCM2PTR (x))->mpz)
#define SCM_BIGP(x) (!SCM_IMP (x) && SCM_TYP16 (x) == scm_tc16_big)
typedef struct scm_t_big_mpz scm_t_big_mpz;
and later in numbers.c
struct scm_t_big_mpz
{
SCM type;
mpz_t mpz;
};
> Also, I was trying to figure out how to add the test for
>
> sizeof (mpz_t) <= 3 * (sizeof (scm_t_bits))
>
> In order to put it in configure.in, we have to have access to the
> definition of scm_t_bits (or at least SIZEOF_SCM_T_BITS) at configure
> time. Any thoughts?
We can also put the test somewhere in init.c and have Guile abort
noisily when it fails.
--
GPG: D5D4E405 - 2F9B BCCC 8527 692A 04E3 331E FAF8 226A D5D4 E405