1 /* mpfr_sqrt_ui -- square root of a machine integer 2 3 Copyright 2000-2004, 2006-2020 Free Software Foundation, Inc. 4 Contributed by the AriC and Caramba projects, INRIA. 5 6 This file is part of the GNU MPFR Library. 7 8 The GNU MPFR Library is free software; you can redistribute it and/or modify 9 it under the terms of the GNU Lesser General Public License as published by 10 the Free Software Foundation; either version 3 of the License, or (at your 11 option) any later version. 12 13 The GNU MPFR Library is distributed in the hope that it will be useful, but 14 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 15 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 16 License for more details. 17 18 You should have received a copy of the GNU Lesser General Public License 19 along with the GNU MPFR Library; see the file COPYING.LESSER. If not, see 20 https://www.gnu.org/licenses/ or write to the Free Software Foundation, Inc., 21 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. */ 22 23 #define MPFR_NEED_LONGLONG_H 24 #include "mpfr-impl.h" 25 26 int 27 mpfr_sqrt_ui (mpfr_ptr r, unsigned long u, mpfr_rnd_t rnd_mode) 28 { 29 if (u) 30 { 31 mpfr_t uu; 32 int inex; 33 #ifdef MPFR_LONG_WITHIN_LIMB 34 mp_limb_t up[1]; 35 int cnt; 36 MPFR_SAVE_EXPO_DECL (expo); 37 38 MPFR_TMP_INIT1 (up, uu, GMP_NUMB_BITS); 39 MPFR_ASSERTN (u == (mp_limb_t) u); 40 count_leading_zeros (cnt, (mp_limb_t) u); 41 *up = (mp_limb_t) u << cnt; 42 43 MPFR_SAVE_EXPO_MARK (expo); 44 MPFR_SET_EXP (uu, GMP_NUMB_BITS - cnt); 45 inex = mpfr_sqrt (r, uu, rnd_mode); 46 #else 47 MPFR_SAVE_EXPO_DECL (expo); 48 49 mpfr_init2 (uu, sizeof (unsigned long) * CHAR_BIT); 50 /* Warning: u might be outside the current exponent range! */ 51 MPFR_SAVE_EXPO_MARK (expo); 52 mpfr_set_ui (uu, u, MPFR_RNDZ); 53 inex = mpfr_sqrt (r, uu, rnd_mode); 54 mpfr_clear (uu); 55 #endif /* MPFR_LONG_WITHIN_LIMB */ 56 MPFR_SAVE_EXPO_FREE (expo); 57 return mpfr_check_range (r, inex, rnd_mode); 58 } 59 else /* sqrt(0) = 0 */ 60 { 61 MPFR_SET_ZERO(r); 62 MPFR_SET_POS(r); 63 MPFR_RET(0); 64 } 65 } 66