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1 /* mpf_fits_s*_p -- test whether an mpf fits a C signed type. | |
2 | |
3 Copyright 2001, 2002 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 this is equivalent to mpz_set_f + mpz_fits_s*_p. */ | |
25 | |
26 int | |
27 FUNCTION (mpf_srcptr f) | |
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 } | |
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