1/* mpf_fits_s*_p -- test whether an mpf fits a C signed type. 2 3Copyright 2001, 2002 Free Software Foundation, Inc. 4 5This file is part of the GNU MP Library. 6 7The GNU MP Library is free software; you can redistribute it and/or modify 8it under the terms of the GNU Lesser General Public License as published by 9the Free Software Foundation; either version 3 of the License, or (at your 10option) any later version. 11 12The GNU MP Library is distributed in the hope that it will be useful, but 13WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 14or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 15License for more details. 16 17You should have received a copy of the GNU Lesser General Public License 18along 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 this is equivalent to mpz_set_f + mpz_fits_s*_p. */ 25 26int 27FUNCTION (mpf_srcptr f) __GMP_NOTHROW 28{ 29 mp_size_t fs, fn; 30 mp_srcptr fp; 31 mp_exp_t exp; 32 mp_limb_t fl; 33 34 fs = SIZ(f); 35 if (fs == 0) 36 return 1; /* zero fits */ 37 38 exp = EXP(f); 39 if (exp < 1) 40 return 1; /* -1 < f < 1 truncates to zero, so fits */ 41 42 fp = PTR(f); 43 fn = ABS (fs); 44 45 if (exp == 1) 46 { 47 fl = fp[fn-1]; 48 } 49#if GMP_NAIL_BITS != 0 50 else if (exp == 2 && MAXIMUM > GMP_NUMB_MAX) 51 { 52 fl = fp[fn-1]; 53 if ((fl >> GMP_NAIL_BITS) != 0) 54 return 0; 55 fl = (fl << GMP_NUMB_BITS); 56 if (fn >= 2) 57 fl |= fp[fn-2]; 58 } 59#endif 60 else 61 return 0; 62 63 return fl <= (fs >= 0 ? (mp_limb_t) MAXIMUM : - (mp_limb_t) MINIMUM); 64} 65