1 /* Copyright (C) 2003-2021 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library. If not, see
16 <https://www.gnu.org/licenses/>. */
17
18 #include <math.h>
19
20 long double
__frexpl(long double value,int * expptr)21 __frexpl (long double value, int *expptr)
22 {
23 long double mantissa, exponent;
24 int iexponent;
25 unsigned long fpsr;
26
27 __asm ("ftst%.x %1\n"
28 "fmove%.l %/fpsr, %0"
29 : "=dm" (fpsr) : "f" (value));
30 if (fpsr & (7 << 24))
31 {
32 /* Not finite or zero. */
33 *expptr = 0;
34 return value;
35 }
36 __asm ("fgetexp%.x %1, %0" : "=f" (exponent) : "f" (value));
37 iexponent = (int) exponent + 1;
38 *expptr = iexponent;
39 /* Unnormalized numbers must be handled specially, otherwise fscale
40 results in overflow. */
41 if (iexponent <= -16384)
42 {
43 value *= 0x1p16383L;
44 iexponent += 16383;
45 }
46 else if (iexponent >= 16384)
47 {
48 value *= 0x1p-16383L;
49 iexponent -= 16383;
50 }
51
52 __asm ("fscale%.l %2, %0"
53 : "=f" (mantissa)
54 : "0" (value), "dmi" (-iexponent));
55 return mantissa;
56 }
57
58 weak_alias (__frexpl, frexpl)
59