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Implement truncate-quotient with new integer lib

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* libguile/integers.c (scm_integer_truncate_quotient_ii)
(scm_integer_truncate_quotient_iz, scm_integer_truncate_quotient_zi)
(scm_integer_truncate_quotient_zz): New internal functions.
* libguile/integers.h: Declare internal functions.
* libguile/numbers.c (scm_truncate_quotient): Use the new functions.
This commit is contained in:
Andy Wingo 2021-12-13 09:43:28 +01:00
parent 1e1b230223
commit ff636774b4
3 changed files with 77 additions and 58 deletions
Download patch file Download diff file Expand all files Collapse all files

62
libguile/integers.c
View file

@ -812,3 +812,65 @@ scm_integer_ceiling_divide_zz (SCM x, SCM y, SCM *qp, SCM *rp)
*qp = take_mpz (q); *qp = take_mpz (q);
*rp = take_mpz (r); *rp = take_mpz (r);
} }
SCM
scm_integer_truncate_quotient_ii (scm_t_inum x, scm_t_inum y)
{
if (y == 0)
scm_num_overflow ("truncate-quotient");
else
{
scm_t_inum q = x / y;
return long_to_scm (q);
}
}
SCM
scm_integer_truncate_quotient_iz (scm_t_inum x, SCM y)
{
if (x == SCM_MOST_NEGATIVE_FIXNUM &&
bignum_cmp_long (scm_bignum (y), -SCM_MOST_NEGATIVE_FIXNUM) == 0)
{
/* Special case: x == fixnum-min && y == abs (fixnum-min) */
scm_remember_upto_here_1 (y);
return SCM_I_MAKINUM (-1);
}
else
return SCM_INUM0;
}
SCM
scm_integer_truncate_quotient_zi (SCM x, scm_t_inum y)
{
if (y == 0)
scm_num_overflow ("truncate-quotient");
else if (y == 1)
return x;
else
{
mpz_t q, zx;
mpz_init (q);
alias_bignum_to_mpz (scm_bignum (x), zx);
if (y > 0)
mpz_tdiv_q_ui (q, zx, y);
else
{
mpz_tdiv_q_ui (q, zx, -y);
mpz_neg (q, q);
}
scm_remember_upto_here_1 (x);
return take_mpz (q);
}
}
SCM
scm_integer_truncate_quotient_zz (SCM x, SCM y)
{
mpz_t q, zx, zy;
mpz_init (q);
alias_bignum_to_mpz (scm_bignum (x), zx);
alias_bignum_to_mpz (scm_bignum (y), zy);
mpz_tdiv_q (q, zx, zy);
scm_remember_upto_here_2 (x, y);
return take_mpz (q);
}

5
libguile/integers.h
View file

@ -67,6 +67,11 @@ SCM_INTERNAL void scm_integer_ceiling_divide_zi (SCM x, scm_t_inum y,
SCM_INTERNAL void scm_integer_ceiling_divide_zz (SCM x, SCM y, SCM_INTERNAL void scm_integer_ceiling_divide_zz (SCM x, SCM y,
SCM *qp, SCM *rp); SCM *qp, SCM *rp);
SCM_INTERNAL SCM scm_integer_truncate_quotient_ii (scm_t_inum x, scm_t_inum y);
SCM_INTERNAL SCM scm_integer_truncate_quotient_iz (scm_t_inum x, SCM y);
SCM_INTERNAL SCM scm_integer_truncate_quotient_zi (SCM x, scm_t_inum y);
SCM_INTERNAL SCM scm_integer_truncate_quotient_zz (SCM x, SCM y);
#endif /* SCM_INTEGERS_H */ #endif /* SCM_INTEGERS_H */

68
libguile/numbers.c
View file

@ -1815,38 +1815,16 @@ SCM_PRIMITIVE_GENERIC (scm_truncate_quotient, "truncate-quotient", 2, 0, 0,
"@end lisp") "@end lisp")
#define FUNC_NAME s_scm_truncate_quotient #define FUNC_NAME s_scm_truncate_quotient
{ {
if (SCM_LIKELY (SCM_I_INUMP (x))) if (SCM_I_INUMP (x))
{ {
scm_t_inum xx = SCM_I_INUM (x); if (SCM_I_INUMP (y))
if (SCM_LIKELY (SCM_I_INUMP (y))) return scm_integer_truncate_quotient_ii (SCM_I_INUM (x),
{ SCM_I_INUM (y));
scm_t_inum yy = SCM_I_INUM (y);
if (SCM_UNLIKELY (yy == 0))
scm_num_overflow (s_scm_truncate_quotient);
else
{
scm_t_inum qq = xx / yy;
if (SCM_LIKELY (SCM_FIXABLE (qq)))
return SCM_I_MAKINUM (qq);
else
return scm_i_inum2big (qq);
}
}
else if (SCM_BIGP (y)) else if (SCM_BIGP (y))
{ return scm_integer_truncate_quotient_iz (SCM_I_INUM (x), y);
if (SCM_UNLIKELY (xx == SCM_MOST_NEGATIVE_FIXNUM)
&& SCM_UNLIKELY (mpz_cmp_ui (SCM_I_BIG_MPZ (y),
- SCM_MOST_NEGATIVE_FIXNUM) == 0))
{
/* Special case: x == fixnum-min && y == abs (fixnum-min) */
scm_remember_upto_here_1 (y);
return SCM_I_MAKINUM (-1);
}
else
return SCM_INUM0;
}
else if (SCM_REALP (y)) else if (SCM_REALP (y))
return scm_i_inexact_truncate_quotient (xx, SCM_REAL_VALUE (y)); return scm_i_inexact_truncate_quotient (SCM_I_INUM (x),
SCM_REAL_VALUE (y));
else if (SCM_FRACTIONP (y)) else if (SCM_FRACTIONP (y))
return scm_i_exact_rational_truncate_quotient (x, y); return scm_i_exact_rational_truncate_quotient (x, y);
else else
@ -1855,36 +1833,10 @@ SCM_PRIMITIVE_GENERIC (scm_truncate_quotient, "truncate-quotient", 2, 0, 0,
} }
else if (SCM_BIGP (x)) else if (SCM_BIGP (x))
{ {
if (SCM_LIKELY (SCM_I_INUMP (y))) if (SCM_I_INUMP (y))
{ return scm_integer_truncate_quotient_zi (x, SCM_I_INUM (y));
scm_t_inum yy = SCM_I_INUM (y);
if (SCM_UNLIKELY (yy == 0))
scm_num_overflow (s_scm_truncate_quotient);
else if (SCM_UNLIKELY (yy == 1))
return x;
else
{
SCM q = scm_i_mkbig ();
if (yy > 0)
mpz_tdiv_q_ui (SCM_I_BIG_MPZ (q), SCM_I_BIG_MPZ (x), yy);
else
{
mpz_tdiv_q_ui (SCM_I_BIG_MPZ (q), SCM_I_BIG_MPZ (x), -yy);
mpz_neg (SCM_I_BIG_MPZ (q), SCM_I_BIG_MPZ (q));
}
scm_remember_upto_here_1 (x);
return scm_i_normbig (q);
}
}
else if (SCM_BIGP (y)) else if (SCM_BIGP (y))
{ return scm_integer_truncate_quotient_zz (x, y);
SCM q = scm_i_mkbig ();
mpz_tdiv_q (SCM_I_BIG_MPZ (q),
SCM_I_BIG_MPZ (x),
SCM_I_BIG_MPZ (y));
scm_remember_upto_here_2 (x, y);
return scm_i_normbig (q);
}
else if (SCM_REALP (y)) else if (SCM_REALP (y))
return scm_i_inexact_truncate_quotient return scm_i_inexact_truncate_quotient
(scm_i_big2dbl (x), SCM_REAL_VALUE (y)); (scm_i_big2dbl (x), SCM_REAL_VALUE (y));