projects / thirdparty / glibc.git / blame
| Commit | Line | Data |
|---|---|---|
| dfd2257a UD |
1 | /* Round argument to nearest integral value according to current rounding |
| 2 | direction. | |
| 688903eb | 3 | Copyright (C) 1997-2018 Free Software Foundation, Inc. |
| dfd2257a UD |
4 | This file is part of the GNU C Library. |
| 5 | Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997. | |
| 6 | ||
| 7 | The GNU C Library is free software; you can redistribute it and/or | |
| 41bdb6e2 AJ |
8 | modify it under the terms of the GNU Lesser General Public |
| 9 | License as published by the Free Software Foundation; either | |
| 10 | version 2.1 of the License, or (at your option) any later version. | |
| dfd2257a UD |
11 | |
| 12 | The GNU C Library is distributed in the hope that it will be useful, | |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 41bdb6e2 | 15 | Lesser General Public License for more details. |
| dfd2257a | 16 | |
| 41bdb6e2 | 17 | You should have received a copy of the GNU Lesser General Public |
| 59ba27a6 PE |
18 | License along with the GNU C Library; if not, see |
| 19 | <http://www.gnu.org/licenses/>. */ | |
| dfd2257a | 20 | |
| 06d97e5e JM |
21 | #include <fenv.h> |
| 22 | #include <limits.h> | |
| dfd2257a UD |
23 | #include <math.h> |
| 24 | ||
| 1ed0291c | 25 | #include <math_private.h> |
| 2f49ce7d | 26 | #include <libm-alias-float.h> |
| 06d97e5e | 27 | #include <fix-fp-int-convert-overflow.h> |
| dfd2257a | 28 | |
| 6624dbc0 | 29 | static const float two23[2] = |
| dfd2257a UD |
30 | { |
| 31 | 8.3886080000e+06, /* 0x4B000000 */ | |
| 32 | -8.3886080000e+06, /* 0xCB000000 */ | |
| 33 | }; | |
| 34 | ||
| 35 | ||
| 36 | long int | |
| 37 | __lrintf (float x) | |
| 38 | { | |
| 39 | int32_t j0; | |
| 24ab7723 | 40 | uint32_t i0; |
| 54142c44 | 41 | float w; |
| dfd2257a UD |
42 | float t; |
| 43 | long int result; | |
| 44 | int sx; | |
| 45 | ||
| 6973fc01 | 46 | GET_FLOAT_WORD (i0, x); |
| dfd2257a UD |
47 | |
| 48 | sx = i0 >> 31; | |
| 49 | j0 = ((i0 >> 23) & 0xff) - 0x7f; | |
| 6973fc01 | 50 | i0 &= 0x7fffff; |
| dfd2257a UD |
51 | i0 |= 0x800000; |
| 52 | ||
| cc3fa755 | 53 | if (j0 < (int32_t) (sizeof (long int) * 8) - 1) |
| dfd2257a | 54 | { |
| 6624dbc0 | 55 | if (j0 >= 23) |
| dfd2257a UD |
56 | result = (long int) i0 << (j0 - 23); |
| 57 | else | |
| 58 | { | |
| 54142c44 | 59 | w = math_narrow_eval (two23[sx] + x); |
| dfd2257a | 60 | t = w - two23[sx]; |
| 6973fc01 | 61 | GET_FLOAT_WORD (i0, t); |
| dfd2257a | 62 | j0 = ((i0 >> 23) & 0xff) - 0x7f; |
| 6973fc01 UD |
63 | i0 &= 0x7fffff; |
| 64 | i0 |= 0x800000; | |
| dfd2257a | 65 | |
| 6624dbc0 | 66 | result = (j0 < 0 ? 0 : i0 >> (23 - j0)); |
| dfd2257a UD |
67 | } |
| 68 | } | |
| 69 | else | |
| 70 | { | |
| 06d97e5e JM |
71 | #ifdef FE_INVALID |
| 72 | /* The number is too large. Unless it rounds to LONG_MIN, | |
| 73 | FE_INVALID must be raised and the return value is | |
| 74 | unspecified. */ | |
| 75 | if (FIX_FLT_LONG_CONVERT_OVERFLOW && x != (float) LONG_MIN) | |
| 76 | { | |
| 77 | feraiseexcept (FE_INVALID); | |
| 78 | return sx == 0 ? LONG_MAX : LONG_MIN; | |
| 79 | } | |
| 80 | #endif | |
| dfd2257a UD |
81 | return (long int) x; |
| 82 | } | |
| 83 | ||
| 84 | return sx ? -result : result; | |
| 85 | } | |
| 86 | ||
| 2f49ce7d | 87 | libm_alias_float (__lrint, lrint) |