| Austin Schuh | dace2a6 | 2020-08-18 10:56:48 -0700 | [diff] [blame^] | 1 | /* mpf_cmp_ui -- Compare a float with an unsigned integer. |
| 2 | |
| 3 | Copyright 1993-1995, 1999, 2001, 2002, 2015 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 either: |
| 9 | |
| 10 | * the GNU Lesser General Public License as published by the Free |
| 11 | Software Foundation; either version 3 of the License, or (at your |
| 12 | option) any later version. |
| 13 | |
| 14 | or |
| 15 | |
| 16 | * the GNU General Public License as published by the Free Software |
| 17 | Foundation; either version 2 of the License, or (at your option) any |
| 18 | later version. |
| 19 | |
| 20 | or both in parallel, as here. |
| 21 | |
| 22 | The GNU MP Library is distributed in the hope that it will be useful, but |
| 23 | WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY |
| 24 | or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 25 | for more details. |
| 26 | |
| 27 | You should have received copies of the GNU General Public License and the |
| 28 | GNU Lesser General Public License along with the GNU MP Library. If not, |
| 29 | see https://www.gnu.org/licenses/. */ |
| 30 | |
| 31 | #include "gmp-impl.h" |
| 32 | |
| 33 | int |
| 34 | mpf_cmp_ui (mpf_srcptr u, unsigned long int vval) __GMP_NOTHROW |
| 35 | { |
| 36 | mp_srcptr up; |
| 37 | mp_size_t usize; |
| 38 | mp_exp_t uexp; |
| 39 | mp_limb_t ulimb; |
| 40 | |
| 41 | usize = SIZ (u); |
| 42 | |
| 43 | /* 1. Is U negative? */ |
| 44 | if (usize < 0) |
| 45 | return -1; |
| 46 | /* We rely on usize being non-negative in the code that follows. */ |
| 47 | |
| 48 | if (vval == 0) |
| 49 | return usize != 0; |
| 50 | |
| 51 | /* 2. Are the exponents different (V's exponent == 1)? */ |
| 52 | uexp = EXP (u); |
| 53 | |
| 54 | #if GMP_NAIL_BITS != 0 |
| 55 | if (uexp != 1 + (vval > GMP_NUMB_MAX)) |
| 56 | return (uexp < 1 + (vval > GMP_NUMB_MAX)) ? -1 : 1; |
| 57 | #else |
| 58 | if (uexp != 1) |
| 59 | return (uexp < 1) ? -1 : 1; |
| 60 | #endif |
| 61 | |
| 62 | up = PTR (u); |
| 63 | |
| 64 | ASSERT (usize > 0); |
| 65 | ulimb = up[--usize]; |
| 66 | #if GMP_NAIL_BITS != 0 |
| 67 | if (uexp == 2) |
| 68 | { |
| 69 | if ((ulimb >> GMP_NAIL_BITS) != 0) |
| 70 | return 1; |
| 71 | ulimb = (ulimb << GMP_NUMB_BITS); |
| 72 | if (usize != 0) ulimb |= up[--usize]; |
| 73 | } |
| 74 | #endif |
| 75 | |
| 76 | /* 3. Compare the most significant mantissa limb with V. */ |
| 77 | if (ulimb != vval) |
| 78 | return (ulimb < vval) ? -1 : 1; |
| 79 | |
| 80 | /* Ignore zeroes at the low end of U. */ |
| 81 | for (; *up == 0; ++up) |
| 82 | --usize; |
| 83 | |
| 84 | /* 4. Now, if the number of limbs are different, we have a difference |
| 85 | since we have made sure the trailing limbs are not zero. */ |
| 86 | return (usize > 0); |
| 87 | } |