projects / thirdparty / glibc.git / blame
| Commit | Line | Data |
|---|---|---|
| 688903eb | 1 | /* Copyright (C) 2007-2018 Free Software Foundation, Inc. |
| f878f0bb RH |
2 | This file is part of the GNU C Library. |
| 3 | Contributed by Richard Henderson. | |
| 4 | ||
| 5 | The GNU C Library is free software; you can redistribute it and/or | |
| 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. | |
| 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 | |
| 13 | Lesser General Public License for more details. | |
| 14 | ||
| 15 | You should have received a copy of the GNU Lesser General Public | |
| ab84e3ff PE |
16 | License along with the GNU C Library. If not, see |
| 17 | <http://www.gnu.org/licenses/>. */ | |
| f878f0bb RH |
18 | |
| 19 | #include <math.h> | |
| 20 | #include <math_ldbl_opt.h> | |
| 5de60638 | 21 | #include <libm-alias-double.h> |
| f878f0bb RH |
22 | |
| 23 | ||
| 24 | /* Use the chopped rounding mode conversion instructions to implement trunc. */ | |
| 25 | ||
| 26 | double | |
| 27 | __trunc (double x) | |
| 28 | { | |
| 29 | double two52 = copysign (0x1.0p52, x); | |
| 30 | double r, tmp; | |
| 5556231d | 31 | |
| b74d259f AJ |
32 | if (isgreaterequal (fabs (x), 0x1.0p52)) |
| 33 | return x; | |
| 34 | ||
| f878f0bb | 35 | __asm ( |
| f878f0bb | 36 | "addt/suc %2, %3, %1\n\tsubt/suc %1, %3, %0" |
| f878f0bb RH |
37 | : "=&f"(r), "=&f"(tmp) |
| 38 | : "f"(x), "f"(two52)); | |
| 39 | ||
| 40 | /* trunc(-0) == -0, and in general we'll always have the same | |
| 41 | sign as our input. */ | |
| 42 | return copysign (r, x); | |
| 43 | } | |
| 44 | ||
| 5de60638 | 45 | libm_alias_double (__trunc, trunc) |