diff --git a/libguile/integers.c b/libguile/integers.c index 715d2ed6f..45f769f56 100644 --- a/libguile/integers.c +++ b/libguile/integers.c @@ -1619,3 +1619,126 @@ scm_integer_round_remainder_zz (SCM x, SCM y) { return integer_round_remainder_zz (scm_bignum (x), scm_bignum (y)); } + +static void +integer_round_divide_zz (struct scm_bignum *x, struct scm_bignum *y, + SCM *qp, SCM *rp) +{ + mpz_t q, r, r2, zx, zy; + int cmp, needs_adjustment; + + /* Note that x might be small enough to fit into a fixnum, so we must + not let it escape into the wild */ + mpz_init (q); + mpz_init (r); + mpz_init (r2); + alias_bignum_to_mpz (x, zx); + alias_bignum_to_mpz (y, zy); + + mpz_fdiv_qr (q, r, zx, zy); + scm_remember_upto_here_1 (x); + mpz_mul_2exp (r2, r, 1); /* r2 = 2*r */ + + cmp = mpz_cmpabs (r2, zy); + if (mpz_odd_p (q)) + needs_adjustment = (cmp >= 0); + else + needs_adjustment = (cmp > 0); + + if (needs_adjustment) + { + mpz_add_ui (q, q, 1); + mpz_sub (r, r, zy); + } + + scm_remember_upto_here_1 (y); + mpz_clear (r2); + *qp = take_mpz (q); + *rp = take_mpz (r); +} + +void +scm_integer_round_divide_ii (scm_t_inum x, scm_t_inum y, SCM *qp, SCM *rp) +{ + if (y == 0) + scm_num_overflow ("round-divide"); + + scm_t_inum q = x / y; + scm_t_inum r = x % y; + scm_t_inum ay = y; + scm_t_inum r2 = 2 * r; + + if (y < 0) + { + ay = -ay; + r2 = -r2; + } + + if (q & 1L) + { + if (r2 >= ay) + { q++; r -= y; } + else if (r2 <= -ay) + { q--; r += y; } + } + else + { + if (r2 > ay) + { q++; r -= y; } + else if (r2 < -ay) + { q--; r += y; } + } + *qp = long_to_scm (q); + *rp = SCM_I_MAKINUM (r); +} + +void +scm_integer_round_divide_iz (scm_t_inum x, SCM y, SCM *qp, SCM *rp) +{ + integer_round_divide_zz (long_to_bignum (x), scm_bignum (y), qp, rp); +} + +void +scm_integer_round_divide_zi (SCM x, scm_t_inum y, SCM *qp, SCM *rp) +{ + if (y == 0) + scm_num_overflow ("round-divide"); + + mpz_t q, zx; + mpz_init (q); + alias_bignum_to_mpz (scm_bignum (x), zx); + scm_t_inum r; + int needs_adjustment; + + if (y > 0) + { + r = mpz_fdiv_q_ui (q, zx, y); + if (mpz_odd_p (q)) + needs_adjustment = (2*r >= y); + else + needs_adjustment = (2*r > y); + } + else + { + r = - mpz_cdiv_q_ui (q, zx, -y); + mpz_neg (q, q); + if (mpz_odd_p (q)) + needs_adjustment = (2*r <= y); + else + needs_adjustment = (2*r < y); + } + scm_remember_upto_here_1 (x); + if (needs_adjustment) + { + mpz_add_ui (q, q, 1); + r -= y; + } + *qp = take_mpz (q); + *rp = SCM_I_MAKINUM (r); +} + +void +scm_integer_round_divide_zz (SCM x, SCM y, SCM *qp, SCM *rp) +{ + integer_round_divide_zz (scm_bignum (x), scm_bignum (y), qp, rp); +} diff --git a/libguile/integers.h b/libguile/integers.h index 6628b444d..e1193c231 100644 --- a/libguile/integers.h +++ b/libguile/integers.h @@ -115,6 +115,15 @@ SCM_INTERNAL SCM scm_integer_round_remainder_iz (scm_t_inum x, SCM y); SCM_INTERNAL SCM scm_integer_round_remainder_zi (SCM x, scm_t_inum y); SCM_INTERNAL SCM scm_integer_round_remainder_zz (SCM x, SCM y); +SCM_INTERNAL void scm_integer_round_divide_ii (scm_t_inum x, scm_t_inum y, + SCM *qp, SCM *rp); +SCM_INTERNAL void scm_integer_round_divide_iz (scm_t_inum x, SCM y, + SCM *qp, SCM *rp); +SCM_INTERNAL void scm_integer_round_divide_zi (SCM x, scm_t_inum y, + SCM *qp, SCM *rp); +SCM_INTERNAL void scm_integer_round_divide_zz (SCM x, SCM y, + SCM *qp, SCM *rp); + #endif /* SCM_INTEGERS_H */ diff --git a/libguile/numbers.c b/libguile/numbers.c index 55dfd58cf..32dad4d01 100644 --- a/libguile/numbers.c +++ b/libguile/numbers.c @@ -2644,7 +2644,6 @@ scm_i_exact_rational_round_remainder (SCM x, SCM y) static void scm_i_inexact_round_divide (double x, double y, SCM *qp, SCM *rp); -static void scm_i_bigint_round_divide (SCM x, SCM y, SCM *qp, SCM *rp); static void scm_i_exact_rational_round_divide (SCM x, SCM y, SCM *qp, SCM *rp); SCM_PRIMITIVE_GENERIC (scm_i_round_divide, "round/", 2, 0, 0, @@ -2679,54 +2678,14 @@ SCM_PRIMITIVE_GENERIC (scm_i_round_divide, "round/", 2, 0, 0, void scm_round_divide (SCM x, SCM y, SCM *qp, SCM *rp) { - 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); - if (SCM_UNLIKELY (yy == 0)) - scm_num_overflow (s_scm_round_divide); - else - { - scm_t_inum qq = xx / yy; - scm_t_inum rr = xx % yy; - scm_t_inum ay = yy; - scm_t_inum r2 = 2 * rr; - - if (SCM_LIKELY (yy < 0)) - { - ay = -ay; - r2 = -r2; - } - - if (qq & 1L) - { - if (r2 >= ay) - { qq++; rr -= yy; } - else if (r2 <= -ay) - { qq--; rr += yy; } - } - else - { - if (r2 > ay) - { qq++; rr -= yy; } - else if (r2 < -ay) - { qq--; rr += yy; } - } - if (SCM_LIKELY (SCM_FIXABLE (qq))) - *qp = SCM_I_MAKINUM (qq); - else - *qp = scm_i_inum2big (qq); - *rp = SCM_I_MAKINUM (rr); - } - } + if (SCM_I_INUMP (y)) + scm_integer_round_divide_ii (SCM_I_INUM (x), SCM_I_INUM (y), qp, rp); else if (SCM_BIGP (y)) - /* Pass a denormalized bignum version of x (even though it - can fit in a fixnum) to scm_i_bigint_round_divide */ - scm_i_bigint_round_divide (scm_i_long2big (SCM_I_INUM (x)), y, qp, rp); + scm_integer_round_divide_iz (SCM_I_INUM (x), y, qp, rp); else if (SCM_REALP (y)) - scm_i_inexact_round_divide (xx, SCM_REAL_VALUE (y), qp, rp); + scm_i_inexact_round_divide (SCM_I_INUM (x), SCM_REAL_VALUE (y), qp, rp); else if (SCM_FRACTIONP (y)) scm_i_exact_rational_round_divide (x, y, qp, rp); else @@ -2735,48 +2694,10 @@ scm_round_divide (SCM x, SCM y, SCM *qp, SCM *rp) } 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_round_divide); - else - { - SCM q = scm_i_mkbig (); - scm_t_inum rr; - int needs_adjustment; - - if (yy > 0) - { - rr = mpz_fdiv_q_ui (SCM_I_BIG_MPZ (q), - SCM_I_BIG_MPZ (x), yy); - if (mpz_odd_p (SCM_I_BIG_MPZ (q))) - needs_adjustment = (2*rr >= yy); - else - needs_adjustment = (2*rr > yy); - } - else - { - rr = - 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)); - if (mpz_odd_p (SCM_I_BIG_MPZ (q))) - needs_adjustment = (2*rr <= yy); - else - needs_adjustment = (2*rr < yy); - } - scm_remember_upto_here_1 (x); - if (needs_adjustment) - { - mpz_add_ui (SCM_I_BIG_MPZ (q), SCM_I_BIG_MPZ (q), 1); - rr -= yy; - } - *qp = scm_i_normbig (q); - *rp = SCM_I_MAKINUM (rr); - } - } + if (SCM_I_INUMP (y)) + scm_integer_round_divide_zi (x, SCM_I_INUM (y), qp, rp); else if (SCM_BIGP (y)) - scm_i_bigint_round_divide (x, y, qp, rp); + scm_integer_round_divide_zz (x, y, qp, rp); else if (SCM_REALP (y)) scm_i_inexact_round_divide (scm_i_big2dbl (x), SCM_REAL_VALUE (y), qp, rp); @@ -2826,42 +2747,6 @@ scm_i_inexact_round_divide (double x, double y, SCM *qp, SCM *rp) } } -/* Assumes that both x and y are bigints, though - x might be able to fit into a fixnum. */ -static void -scm_i_bigint_round_divide (SCM x, SCM y, SCM *qp, SCM *rp) -{ - SCM q, r, r2; - int cmp, needs_adjustment; - - /* Note that x might be small enough to fit into a - fixnum, so we must not let it escape into the wild */ - q = scm_i_mkbig (); - r = scm_i_mkbig (); - r2 = scm_i_mkbig (); - - mpz_fdiv_qr (SCM_I_BIG_MPZ (q), SCM_I_BIG_MPZ (r), - SCM_I_BIG_MPZ (x), SCM_I_BIG_MPZ (y)); - scm_remember_upto_here_1 (x); - mpz_mul_2exp (SCM_I_BIG_MPZ (r2), SCM_I_BIG_MPZ (r), 1); /* r2 = 2*r */ - - cmp = mpz_cmpabs (SCM_I_BIG_MPZ (r2), SCM_I_BIG_MPZ (y)); - if (mpz_odd_p (SCM_I_BIG_MPZ (q))) - needs_adjustment = (cmp >= 0); - else - needs_adjustment = (cmp > 0); - - if (needs_adjustment) - { - mpz_add_ui (SCM_I_BIG_MPZ (q), SCM_I_BIG_MPZ (q), 1); - mpz_sub (SCM_I_BIG_MPZ (r), SCM_I_BIG_MPZ (r), SCM_I_BIG_MPZ (y)); - } - - scm_remember_upto_here_2 (r2, y); - *qp = scm_i_normbig (q); - *rp = scm_i_normbig (r); -} - static void scm_i_exact_rational_round_divide (SCM x, SCM y, SCM *qp, SCM *rp) {