| /* mpfr_ui_div -- divide a machine integer by a floating-point number |
| mpfr_si_div -- divide a machine number by a floating-point number |
| |
| Copyright 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 Free Software Foundation, Inc. |
| Contributed by the Arenaire and Cacao projects, INRIA. |
| |
| This file is part of the GNU MPFR Library. |
| |
| The GNU MPFR Library is free software; you can redistribute it and/or modify |
| it under the terms of the GNU Lesser General Public License as published by |
| the Free Software Foundation; either version 2.1 of the License, or (at your |
| option) any later version. |
| |
| The GNU MPFR Library is distributed in the hope that it will be useful, but |
| WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY |
| or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public |
| License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public License |
| along with the GNU MPFR Library; see the file COPYING.LIB. If not, write to |
| the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, |
| MA 02110-1301, USA. */ |
| |
| |
| #define MPFR_NEED_LONGLONG_H |
| #include "mpfr-impl.h" |
| |
| int |
| mpfr_ui_div (mpfr_ptr y, unsigned long int u, mpfr_srcptr x, mp_rnd_t rnd_mode) |
| { |
| mpfr_t uu; |
| mp_limb_t up[1]; |
| unsigned long cnt; |
| |
| if (MPFR_UNLIKELY(MPFR_IS_SINGULAR(x))) |
| { |
| if (MPFR_IS_NAN(x)) |
| { |
| MPFR_SET_NAN(y); |
| MPFR_RET_NAN; |
| } |
| else if (MPFR_IS_INF(x)) /* u/Inf = 0 */ |
| { |
| MPFR_SET_ZERO(y); |
| MPFR_SET_SAME_SIGN(y,x); |
| MPFR_RET(0); |
| } |
| else /* u / 0 */ |
| { |
| MPFR_ASSERTD(MPFR_IS_ZERO(x)); |
| if (u) |
| { |
| /* u > 0, so y = sign(x) * Inf */ |
| MPFR_SET_SAME_SIGN(y, x); |
| MPFR_SET_INF(y); |
| MPFR_RET(0); |
| } |
| else |
| { |
| /* 0 / 0 */ |
| MPFR_SET_NAN(y); |
| MPFR_RET_NAN; |
| } |
| } |
| } |
| else if (MPFR_LIKELY(u != 0)) |
| { |
| MPFR_TMP_INIT1(up, uu, BITS_PER_MP_LIMB); |
| MPFR_ASSERTN(u == (mp_limb_t) u); |
| count_leading_zeros(cnt, (mp_limb_t) u); |
| up[0] = (mp_limb_t) u << cnt; |
| MPFR_SET_EXP (uu, BITS_PER_MP_LIMB - cnt); |
| return mpfr_div (y, uu, x, rnd_mode); |
| } |
| else /* u = 0, and x != 0 */ |
| { |
| MPFR_SET_ZERO(y); /* if u=0, then set y to 0 */ |
| MPFR_SET_SAME_SIGN(y, x); /* u considered as +0: sign(+0/x) = sign(x) */ |
| MPFR_RET(0); |
| } |
| } |
| |
| |
| int mpfr_si_div (mpfr_ptr y, long int u, mpfr_srcptr x,mp_rnd_t rnd_mode) |
| { |
| int res; |
| |
| if (u >= 0) |
| res = mpfr_ui_div (y, u, x, rnd_mode); |
| else |
| { |
| res = -mpfr_ui_div (y, -u, x, MPFR_INVERT_RND(rnd_mode)); |
| MPFR_CHANGE_SIGN (y); |
| } |
| return res; |
| } |