Annotation of OpenXM_contrib/gmp/mpfr/set_ui.c, Revision 1.1
1.1 ! ohara 1: /* mpfr_set_ui -- set a MPFR number from a machine unsigned integer
! 2:
! 3: Copyright 1999, 2000, 2001 Free Software Foundation.
! 4:
! 5: This file is part of the MPFR Library.
! 6:
! 7: The MPFR Library is free software; you can redistribute it and/or modify
! 8: it under the terms of the GNU Lesser General Public License as published by
! 9: the Free Software Foundation; either version 2.1 of the License, or (at your
! 10: option) any later version.
! 11:
! 12: The MPFR Library is distributed in the hope that it will be useful, but
! 13: WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
! 14: or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
! 15: License for more details.
! 16:
! 17: You should have received a copy of the GNU Lesser General Public License
! 18: along with the MPFR Library; see the file COPYING.LIB. If not, write to
! 19: the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
! 20: MA 02111-1307, USA. */
! 21:
! 22: #include "gmp.h"
! 23: #include "gmp-impl.h"
! 24: #include "longlong.h"
! 25: #include "mpfr.h"
! 26: #include "mpfr-impl.h"
! 27:
! 28: int
! 29: mpfr_set_ui (mpfr_ptr x, unsigned long i, mp_rnd_t rnd_mode)
! 30: {
! 31: int inex = 0;
! 32:
! 33: MPFR_CLEAR_FLAGS(x);
! 34: if (i == 0)
! 35: MPFR_SET_ZERO(x); /* the sign will be set later */
! 36: else
! 37: {
! 38: mp_size_t xn;
! 39: unsigned int cnt, nbits;
! 40: mp_limb_t *xp;
! 41:
! 42: xn = (MPFR_PREC(x)-1)/BITS_PER_MP_LIMB;
! 43: count_leading_zeros(cnt, (mp_limb_t) i);
! 44:
! 45: xp = MPFR_MANT(x);
! 46: xp[xn] = ((mp_limb_t) i) << cnt;
! 47: /* don't forget to put zero in lower limbs */
! 48: MPN_ZERO(xp, xn);
! 49:
! 50: MPFR_EXP(x) = nbits = BITS_PER_MP_LIMB - cnt;
! 51: inex = mpfr_check_range(x, rnd_mode);
! 52: if (inex)
! 53: return inex; /* underflow or overflow */
! 54:
! 55: /* round if MPFR_PREC(x) smaller than length of i */
! 56: if (MPFR_PREC(x) < nbits)
! 57: {
! 58: int carry;
! 59: carry = mpfr_round_raw(xp+xn, xp+xn, nbits, 0, MPFR_PREC(x),
! 60: rnd_mode, &inex);
! 61: if (carry)
! 62: {
! 63: mp_exp_t exp = MPFR_EXP(x);
! 64:
! 65: if (exp == __mpfr_emax)
! 66: return mpfr_set_overflow(x, rnd_mode, 1);
! 67:
! 68: MPFR_EXP(x)++;
! 69: xp[xn] = GMP_LIMB_HIGHBIT;
! 70: }
! 71: }
! 72: }
! 73:
! 74: MPFR_SET_POS(x);
! 75:
! 76: MPFR_RET(inex);
! 77: }
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