1 | /* Round a float value to a long long in the current rounding mode. |
2 | Copyright (C) 1997-2024 Free Software Foundation, Inc. |
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 |
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 |
16 | License along with the GNU C Library; if not, see |
17 | <https://www.gnu.org/licenses/>. */ |
18 | |
19 | #include <math.h> |
20 | #include <math_private.h> |
21 | #include <stdint.h> |
22 | #include <libm-alias-float.h> |
23 | |
24 | long long int |
25 | __llrintf (float x) |
26 | { |
27 | #ifdef _ARCH_PWR4 |
28 | /* Assume powerpc64 instructions availability. */ |
29 | long long int ret; |
30 | __asm__ ("fctid %0, %1" : "=d" (ret) : "d" (x)); |
31 | return ret; |
32 | #else |
33 | float rx = rintf (x); |
34 | if (HAVE_PPC_FCTIDZ || rx != x) |
35 | return (long long int) rx; |
36 | else |
37 | { |
38 | float arx = fabsf (x: rx); |
39 | /* Avoid incorrect exceptions from libgcc conversions (as of GCC |
40 | 5): <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59412>. */ |
41 | if (arx < 0x1p31f) |
42 | return (long long int) (long int) rx; |
43 | else if (!(arx < 0x1p55f)) |
44 | return (long long int) (long int) (rx * 0x1p-32f) << 32; |
45 | uint32_t i0; |
46 | GET_FLOAT_WORD (i0, rx); |
47 | int exponent = ((i0 >> 23) & 0xff) - 0x7f; |
48 | unsigned long long int mant = (i0 & 0x7fffff) | 0x800000; |
49 | mant <<= exponent - 23; |
50 | return (long long int) ((i0 & 0x80000000) != 0 ? -mant : mant); |
51 | } |
52 | #endif |
53 | } |
54 | libm_alias_float (__llrint, llrint) |
55 | |