1 /* mpf_trunc -- truncate an mpf to an integer. 2 3 Copyright 2001 Free Software Foundation, Inc. 4 5 This file is part of the GNU MP Library. 6 7 The GNU MP 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 3 of the License, or (at your 10 option) any later version. 11 12 The GNU MP 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 GNU MP Library. If not, see http://www.gnu.org/licenses/. */ 19 20 #include "gmp.h" 21 #include "gmp-impl.h" 22 23 24 /* Notice the use of prec+1 ensures mpf_trunc is equivalent to mpf_set if u 25 is already an integer. */ 26 27 void 28 mpf_trunc (mpf_ptr r, mpf_srcptr u) 29 { 30 mp_ptr rp; 31 mp_srcptr up; 32 mp_size_t size, asize, prec; 33 mp_exp_t exp; 34 35 exp = EXP(u); 36 size = SIZ(u); 37 if (size == 0 || exp <= 0) 38 { 39 /* u is only a fraction */ 40 SIZ(r) = 0; 41 EXP(r) = 0; 42 return; 43 } 44 45 up = PTR(u); 46 EXP(r) = exp; 47 asize = ABS (size); 48 up += asize; 49 50 /* skip fraction part of u */ 51 asize = MIN (asize, exp); 52 53 /* don't lose precision in the copy */ 54 prec = PREC(r) + 1; 55 56 /* skip excess over target precision */ 57 asize = MIN (asize, prec); 58 59 up -= asize; 60 rp = PTR(r); 61 SIZ(r) = (size >= 0 ? asize : -asize); 62 if (rp != up) 63 MPN_COPY_INCR (rp, up, asize); 64 } 65