projects / thirdparty / glibc.git / blame
| Commit | Line | Data |
|---|---|---|
| b9b49b44 | 1 | /* Round float value to long long int. |
| bfff8b1b | 2 | Copyright (C) 1997-2017 Free Software Foundation, Inc. |
| b9b49b44 UD |
3 | This file is part of the GNU C Library. |
| 4 | ||
| 5 | The GNU C Library is free software; you can redistribute it and/or | |
| 41bdb6e2 AJ |
6 | modify it under the terms of the GNU Lesser General Public |
| 7 | License as published by the Free Software Foundation; either | |
| 8 | version 2.1 of the License, or (at your option) any later version. | |
| b9b49b44 UD |
9 | |
| 10 | The GNU C Library is distributed in the hope that it will be useful, | |
| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 41bdb6e2 | 13 | Lesser General Public License for more details. |
| b9b49b44 | 14 | |
| 41bdb6e2 | 15 | You should have received a copy of the GNU Lesser General Public |
| 59ba27a6 PE |
16 | License along with the GNU C Library; if not, see |
| 17 | <http://www.gnu.org/licenses/>. */ | |
| b9b49b44 UD |
18 | |
| 19 | #include <math.h> | |
| d7025bad JM |
20 | #include <math_private.h> |
| 21 | #include <stdint.h> | |
| b9b49b44 | 22 | |
| da13146d AM |
23 | /* Round to the nearest integer, with values exactly on a 0.5 boundary |
| 24 | rounded away from zero, regardless of the current rounding mode. | |
| 25 | If (long long)x, when x is out of range of a long long, clips at | |
| 26 | LLONG_MAX or LLONG_MIN, then this implementation also clips. */ | |
| b9b49b44 UD |
27 | |
| 28 | long long int | |
| 29 | __llroundf (float x) | |
| 30 | { | |
| d7025bad JM |
31 | long long xr; |
| 32 | if (HAVE_PPC_FCTIDZ) | |
| 33 | xr = (long long) x; | |
| 34 | else | |
| 35 | { | |
| 36 | float ax = fabsf (x); | |
| 37 | /* Avoid incorrect exceptions from libgcc conversions (as of GCC | |
| 38 | 5): <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59412>. */ | |
| 39 | if (ax < 0x1p31f) | |
| 40 | xr = (long long int) (long int) x; | |
| 41 | else if (!(ax < 0x1p55f)) | |
| 42 | xr = (long long int) (long int) (x * 0x1p-32f) << 32; | |
| 43 | else | |
| 44 | { | |
| 45 | uint32_t i0; | |
| 46 | GET_FLOAT_WORD (i0, x); | |
| 47 | int exponent = ((i0 >> 23) & 0xff) - 0x7f; | |
| 48 | unsigned long long int mant = (i0 & 0x7fffff) | 0x800000; | |
| 49 | mant <<= exponent - 23; | |
| 50 | xr = (long long int) ((i0 & 0x80000000) != 0 ? -mant : mant); | |
| 51 | } | |
| 52 | } | |
| 53 | /* Avoid spurious "inexact" converting LLONG_MAX to float, and from | |
| 54 | subtraction when the result is out of range, by returning early | |
| 55 | for arguments large enough that no rounding is needed. */ | |
| 56 | if (!(fabsf (x) < 0x1p23f)) | |
| 57 | return xr; | |
| da13146d AM |
58 | float xrf = (float) xr; |
| 59 | ||
| b9b49b44 | 60 | if (x >= 0.0) |
| da13146d AM |
61 | { |
| 62 | if (x - xrf >= 0.5) | |
| 63 | xr += (long long) ((unsigned long long) xr + 1) > 0; | |
| 64 | } | |
| b9b49b44 | 65 | else |
| da13146d AM |
66 | { |
| 67 | if (xrf - x >= 0.5) | |
| 68 | xr -= (long long) ((unsigned long long) xr - 1) < 0; | |
| 69 | } | |
| 70 | return xr; | |
| b9b49b44 UD |
71 | } |
| 72 | weak_alias (__llroundf, llroundf) |