mirror/guile
mirror/guile
1
Fork 0
mirror of https://git.savannah.gnu.org/git/guile.git synced 2025-04-30 03:40:34 +02:00
Code Activity

Implement scm_logbit_p with new integer library

Browse source 
* libguile/integers.c (scm_integer_logbit_ui, scm_integer_logbit_uz):
* libguile/integers.h: Declare the new internal functions.
* libguile/numbers.c (scm_logbit_p): Use new internal functions.
This commit is contained in:
Andy Wingo 2021-12-19 11:06:36 +01:00
parent 6298d73115
commit 89cd48fcac
3 changed files with 25 additions and 16 deletions
Download patch file Download diff file Expand all files Collapse all files

20
libguile/integers.c
View file

@ -2008,3 +2008,23 @@ scm_integer_logtest_zz (SCM x, SCM y)
{
return scm_is_eq (scm_integer_logand_zz (x, y), SCM_INUM0);
}
int
scm_integer_logbit_ui (unsigned long index, scm_t_inum n)
{
if (index < SCM_LONG_BIT)
/* Assume two's complement representation. */
return (n >> index) & 1;
else
return n < 0;
}
int
scm_integer_logbit_uz (unsigned long index, SCM n)
{
mpz_t zn;
alias_bignum_to_mpz (scm_bignum (n), zn);
int val = mpz_tstbit (zn, index);
scm_remember_upto_here_1 (n);
return val;
}