1 | /* Implement frexp for m68k. |
2 | Copyright (C) 1996-2024 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 | |
21 | FLOAT |
22 | M_DECL_FUNC (__frexp) (FLOAT value, int *expptr) |
23 | { |
24 | FLOAT mantissa, exponent; |
25 | int iexponent; |
26 | unsigned long fpsr; |
27 | |
28 | __asm ("ftst%.x %1\n" |
29 | "fmove%.l %/fpsr, %0" |
30 | : "=dm" (fpsr) : "f" (value)); |
31 | if (fpsr & (7 << 24)) |
32 | { |
33 | /* Not finite or zero. */ |
34 | *expptr = 0; |
35 | return value; |
36 | } |
37 | __asm ("fgetexp%.x %1, %0" : "=f" (exponent) : "f" (value)); |
38 | iexponent = (int) exponent + 1; |
39 | *expptr = iexponent; |
40 | __asm ("fscale%.l %2, %0" |
41 | : "=f" (mantissa) |
42 | : "0" (value), "dmi" (-iexponent)); |
43 | return mantissa; |
44 | } |
45 | declare_mgen_alias (__frexp, frexp) |
46 | |