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e53df1de | 1 | /* Implement frexp for m68k. |
2b778ceb | 2 | Copyright (C) 1996-2021 Free Software Foundation, Inc. |
e53df1de JM |
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 | |
5a82c748 | 17 | <https://www.gnu.org/licenses/>. */ |
e53df1de JM |
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) |