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authorAndy Wingo <wingo@pobox.com>2021-12-03 22:34:09 +0100
committerAndy Wingo <wingo@pobox.com>2022-01-13 09:37:16 +0100
commit31da9be6c49eb14c2292312ba9cff737a3a107e6 (patch)
tree737806097926e28bf9f74d34b44012cec3cae8e7
parent44c654aa3e40a86b488ba189be66aee661999cae (diff)
downloadguile-31da9be6c49eb14c2292312ba9cff737a3a107e6.tar.gz
Implement floor-quotient with new integer lib
* libguile/integers.c (scm_integer_floor_quotient_ii) (scm_integer_floor_quotient_iz, scm_integer_floor_quotient_zi) (scm_integer_floor_quotient_zz): New internal functions. (long_to_scm, ulong_to_scm, take_bignum_from_mpz): New helpers. * libguile/integers.h: Declare internal functions. * libguile/numbers.c (scm_floor_quotient): Use the new functions.
-rw-r--r--libguile/integers.c86
-rw-r--r--libguile/integers.h5
-rw-r--r--libguile/numbers.c68
3 files changed, 92 insertions, 67 deletions
diff --git a/libguile/integers.c b/libguile/integers.c
index 34a1d4af8..87483a73f 100644
--- a/libguile/integers.c
+++ b/libguile/integers.c
@@ -180,10 +180,20 @@ long_to_bignum (long i)
};
static SCM
-inum_to_bignum (scm_t_inum i)
+long_to_scm (long i)
{
+ if (SCM_FIXABLE (i))
+ return SCM_I_MAKINUM (i);
return long_to_bignum (i);
-};
+}
+
+static SCM
+ulong_to_scm (unsigned long i)
+{
+ if (SCM_POSFIXABLE (i))
+ return SCM_I_MAKINUM (i);
+ return ulong_to_bignum (i);
+}
static struct scm_bignum *
clone_bignum (struct scm_bignum *z)
@@ -212,6 +222,14 @@ make_bignum_from_mpz (mpz_srcptr mpz)
return mpz_sgn (mpz) < 0 ? negate_bignum (ret) : ret;
}
+static struct scm_bignum *
+take_bignum_from_mpz (mpz_ptr mpz)
+{
+ struct scm_bignum *res = make_bignum_from_mpz (mpz);
+ mpz_clear (mpz);
+ return res;
+}
+
static SCM
normalize_bignum (struct scm_bignum *z)
{
@@ -251,11 +269,7 @@ scm_integer_abs_i (scm_t_inum i)
if (i >= 0)
return SCM_I_MAKINUM (i);
- unsigned long abs = long_magnitude (i);
- if (SCM_LIKELY (SCM_POSFIXABLE (abs)))
- return SCM_I_MAKINUM (abs);
-
- return ulong_to_bignum (abs);
+ return ulong_to_scm (long_magnitude (i));
}
SCM
@@ -266,3 +280,61 @@ scm_integer_abs_z (SCM z)
return SCM_PACK (negate_bignum (clone_bignum (scm_bignum (z))));
}
+
+SCM
+scm_integer_floor_quotient_ii (scm_t_inum x, scm_t_inum y)
+{
+ if (y > 0)
+ {
+ if (x < 0)
+ x = x - y + 1;
+ }
+ else if (y == 0)
+ scm_num_overflow ("floor-quotient");
+ else if (x > 0)
+ x = x - y - 1;
+ scm_t_inum q = x / y;
+ return long_to_scm (q);
+}
+
+SCM
+scm_integer_floor_quotient_iz (scm_t_inum x, SCM y)
+{
+ if (x == 0 || ((x < 0) == bignum_is_negative (scm_bignum (y))))
+ return SCM_INUM0;
+ return SCM_I_MAKINUM (-1);
+}
+
+SCM
+scm_integer_floor_quotient_zi (SCM x, scm_t_inum y)
+{
+ if (y == 0)
+ scm_num_overflow ("floor-quotient");
+ else if (y == 1)
+ return x;
+
+ mpz_t zx, q;
+ alias_bignum_to_mpz (scm_bignum (x), zx);
+ mpz_init (q);
+ if (y > 0)
+ mpz_fdiv_q_ui (q, zx, y);
+ else
+ {
+ mpz_cdiv_q_ui (q, zx, -y);
+ mpz_neg (q, q);
+ }
+ scm_remember_upto_here_1 (x);
+ return SCM_PACK (normalize_bignum (take_bignum_from_mpz (q)));
+}
+
+SCM
+scm_integer_floor_quotient_zz (SCM x, SCM y)
+{
+ mpz_t zx, zy, q;
+ alias_bignum_to_mpz (scm_bignum (x), zx);
+ alias_bignum_to_mpz (scm_bignum (y), zy);
+ mpz_init (q);
+ mpz_fdiv_q (q, zx, zy);
+ scm_remember_upto_here_2 (x, y);
+ return SCM_PACK (normalize_bignum (take_bignum_from_mpz (q)));
+}
diff --git a/libguile/integers.h b/libguile/integers.h
index 753ff1f74..99e4246cd 100644
--- a/libguile/integers.h
+++ b/libguile/integers.h
@@ -29,6 +29,11 @@ SCM_INTERNAL int scm_is_integer_odd_z (SCM z);
SCM_INTERNAL SCM scm_integer_abs_i (scm_t_inum i);
SCM_INTERNAL SCM scm_integer_abs_z (SCM z);
+SCM_INTERNAL SCM scm_integer_floor_quotient_ii (scm_t_inum x, scm_t_inum y);
+SCM_INTERNAL SCM scm_integer_floor_quotient_iz (scm_t_inum x, SCM y);
+SCM_INTERNAL SCM scm_integer_floor_quotient_zi (SCM x, scm_t_inum y);
+SCM_INTERNAL SCM scm_integer_floor_quotient_zz (SCM x, SCM y);
+
#endif /* SCM_INTEGERS_H */
diff --git a/libguile/numbers.c b/libguile/numbers.c
index ea0cf67bb..d79ee214b 100644
--- a/libguile/numbers.c
+++ b/libguile/numbers.c
@@ -1200,40 +1200,14 @@ SCM_PRIMITIVE_GENERIC (scm_floor_quotient, "floor-quotient", 2, 0, 0,
"@end lisp")
#define FUNC_NAME s_scm_floor_quotient
{
- if (SCM_LIKELY (SCM_I_INUMP (x)))
+ if (SCM_I_INUMP (x))
{
- scm_t_inum xx = SCM_I_INUM (x);
- if (SCM_LIKELY (SCM_I_INUMP (y)))
- {
- scm_t_inum yy = SCM_I_INUM (y);
- scm_t_inum xx1 = xx;
- scm_t_inum qq;
- if (SCM_LIKELY (yy > 0))
- {
- if (SCM_UNLIKELY (xx < 0))
- xx1 = xx - yy + 1;
- }
- else if (SCM_UNLIKELY (yy == 0))
- scm_num_overflow (s_scm_floor_quotient);
- else if (xx > 0)
- xx1 = xx - yy - 1;
- qq = xx1 / yy;
- if (SCM_LIKELY (SCM_FIXABLE (qq)))
- return SCM_I_MAKINUM (qq);
- else
- return scm_i_inum2big (qq);
- }
+ if (SCM_I_INUMP (y))
+ return scm_integer_floor_quotient_ii (SCM_I_INUM (x), SCM_I_INUM (y));
else if (SCM_BIGP (y))
- {
- int sign = mpz_sgn (SCM_I_BIG_MPZ (y));
- scm_remember_upto_here_1 (y);
- if (sign > 0)
- return SCM_I_MAKINUM ((xx < 0) ? -1 : 0);
- else
- return SCM_I_MAKINUM ((xx > 0) ? -1 : 0);
- }
+ return scm_integer_floor_quotient_iz (SCM_I_INUM (x), y);
else if (SCM_REALP (y))
- return scm_i_inexact_floor_quotient (xx, SCM_REAL_VALUE (y));
+ return scm_i_inexact_floor_quotient (SCM_I_INUM (x), SCM_REAL_VALUE (y));
else if (SCM_FRACTIONP (y))
return scm_i_exact_rational_floor_quotient (x, y);
else
@@ -1242,36 +1216,10 @@ SCM_PRIMITIVE_GENERIC (scm_floor_quotient, "floor-quotient", 2, 0, 0,
}
else if (SCM_BIGP (x))
{
- if (SCM_LIKELY (SCM_I_INUMP (y)))
- {
- scm_t_inum yy = SCM_I_INUM (y);
- if (SCM_UNLIKELY (yy == 0))
- scm_num_overflow (s_scm_floor_quotient);
- else if (SCM_UNLIKELY (yy == 1))
- return x;
- else
- {
- SCM q = scm_i_mkbig ();
- if (yy > 0)
- mpz_fdiv_q_ui (SCM_I_BIG_MPZ (q), SCM_I_BIG_MPZ (x), yy);
- else
- {
- mpz_cdiv_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);
- }
- }
+ if (SCM_I_INUMP (y))
+ return scm_integer_floor_quotient_zi (x, SCM_I_INUM (y));
else if (SCM_BIGP (y))
- {
- SCM q = scm_i_mkbig ();
- mpz_fdiv_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);
- }
+ return scm_integer_floor_quotient_zz (x, y);
else if (SCM_REALP (y))
return scm_i_inexact_floor_quotient
(scm_i_big2dbl (x), SCM_REAL_VALUE (y));