diff options
Diffstat (limited to 'mpfr/set_ui.c')
| -rw-r--r-- | mpfr/set_ui.c | 85 |
1 files changed, 48 insertions, 37 deletions
diff --git a/mpfr/set_ui.c b/mpfr/set_ui.c index 9fd88dd98..2ae08b7ff 100644 --- a/mpfr/set_ui.c +++ b/mpfr/set_ui.c @@ -5,64 +5,75 @@ Copyright (C) 1999-2001 Free Software Foundation. This file is part of the MPFR Library. The MPFR Library is free software; you can redistribute it and/or modify -it under the terms of the GNU Library General Public License as published by -the Free Software Foundation; either version 2 of the License, or (at your +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 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 Library General Public +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 Library General Public License +You should have received a copy of the GNU Lesser General Public License along with the MPFR Library; see the file COPYING.LIB. If not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ -#include <stdio.h> #include "gmp.h" #include "gmp-impl.h" #include "longlong.h" #include "mpfr.h" #include "mpfr-impl.h" -void -#if __STDC__ -mpfr_set_ui (mpfr_ptr x, unsigned long int i, mp_rnd_t rnd_mode) -#else -mpfr_set_ui (x, i, rnd_mode) - mpfr_ptr x; - unsigned long int i; - mp_rnd_t rnd_mode; -#endif +int +mpfr_set_ui (mpfr_ptr x, unsigned long i, mp_rnd_t rnd_mode) { - unsigned int xn, cnt; mp_limb_t *xp; + int inex = 0; MPFR_CLEAR_FLAGS(x); - if (i==0) { MPFR_SET_ZERO(x); return; } - xn = (MPFR_PREC(x)-1)/BITS_PER_MP_LIMB; - count_leading_zeros(cnt, (mp_limb_t) i); - - xp = MPFR_MANT(x); - xp[xn] = ((mp_limb_t) i) << cnt; - /* don't forget to put zero in lower limbs */ - MPN_ZERO(xp, xn); - - MPFR_EXP(x) = BITS_PER_MP_LIMB - cnt; - - /* round if MPFR_PREC(x) smaller than length of i */ - if (MPFR_PREC(x) < BITS_PER_MP_LIMB-cnt) { - cnt = mpfr_round_raw(xp+xn, xp+xn, BITS_PER_MP_LIMB-cnt, 0, MPFR_PREC(x), - rnd_mode); - if (cnt) { /* special case 1.000...000 */ - MPFR_EXP(x)++; - xp[xn] = ((mp_limb_t) 1) << (BITS_PER_MP_LIMB-1); + if (i == 0) + MPFR_SET_ZERO(x); /* the sign will be set later */ + else + { + mp_size_t xn; + unsigned int cnt, nbits; + mp_limb_t *xp; + + xn = (MPFR_PREC(x)-1)/BITS_PER_MP_LIMB; + count_leading_zeros(cnt, (mp_limb_t) i); + + xp = MPFR_MANT(x); + xp[xn] = ((mp_limb_t) i) << cnt; + /* don't forget to put zero in lower limbs */ + MPN_ZERO(xp, xn); + + MPFR_EXP(x) = nbits = BITS_PER_MP_LIMB - cnt; + inex = mpfr_check_range(x, rnd_mode); + if (inex) + return inex; /* underflow or overflow */ + + /* round if MPFR_PREC(x) smaller than length of i */ + if (MPFR_PREC(x) < nbits) + { + int carry; + carry = mpfr_round_raw(xp+xn, xp+xn, nbits, 0, MPFR_PREC(x), + rnd_mode, &inex); + if (carry) + { + mp_exp_t exp = MPFR_EXP(x); + + if (exp == __mpfr_emax) + return mpfr_set_overflow(x, rnd_mode, 1); + + MPFR_EXP(x)++; + xp[xn] = MP_LIMB_T_HIGHBIT; + } + } } - } /* warning: don't change the precision of x! */ - if (MPFR_SIGN(x) < 0) MPFR_CHANGE_SIGN(x); + if (MPFR_SIGN(x) < 0) + MPFR_CHANGE_SIGN(x); - return; + MPFR_RET(inex); } - |