1/* Implement __kernel_standard_l.
2 Copyright (C) 2012-2021 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 Parts based on k_standard.c from fdlibm: */
20
21/* @(#)k_standard.c 5.1 93/09/24 */
22/*
23 * ====================================================
24 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
25 *
26 * Developed at SunPro, a Sun Microsystems, Inc. business.
27 * Permission to use, copy, modify, and distribute this
28 * software is freely granted, provided that this notice
29 * is preserved.
30 * ====================================================
31 */
32
33#include <math.h>
34#include <math-barriers.h>
35#include <math-svid-compat.h>
36#include <fenv.h>
37#include <float.h>
38#include <errno.h>
39
40
41#if LIBM_SVID_COMPAT
42
43static double zero = 0.0;
44
45/* Handle errors for a libm function as specified by TYPE (see
46 comments in k_standard.c for details), with arguments X and Y,
47 returning the appropriate return value for that function. */
48
49long double
50__kernel_standard_l (long double x, long double y, int type)
51{
52 double dx, dy;
53 struct exception exc;
54 fenv_t env;
55
56 feholdexcept (&env);
57 dx = x;
58 dy = y;
59 math_force_eval (dx);
60 math_force_eval (dy);
61 fesetenv (&env);
62
63 switch (type)
64 {
65 case 221:
66 /* powl (x, y) overflow. */
67 exc.arg1 = dx;
68 exc.arg2 = dy;
69 exc.type = OVERFLOW;
70 exc.name = (char *) "powl";
71 if (_LIB_VERSION == _SVID_)
72 {
73 exc.retval = HUGE;
74 y *= 0.5;
75 if (x < zero && rintl (y) != y)
76 exc.retval = -HUGE;
77 }
78 else
79 {
80 exc.retval = HUGE_VAL;
81 y *= 0.5;
82 if (x < zero && rintl (y) != y)
83 exc.retval = -HUGE_VAL;
84 }
85 if (_LIB_VERSION == _POSIX_)
86 __set_errno (ERANGE);
87 else if (!matherr (&exc))
88 __set_errno (ERANGE);
89 return exc.retval;
90
91 case 222:
92 /* powl (x, y) underflow. */
93 exc.arg1 = dx;
94 exc.arg2 = dy;
95 exc.type = UNDERFLOW;
96 exc.name = (char *) "powl";
97 exc.retval = zero;
98 y *= 0.5;
99 if (x < zero && rintl (y) != y)
100 exc.retval = -zero;
101 if (_LIB_VERSION == _POSIX_)
102 __set_errno (ERANGE);
103 else if (!matherr (&exc))
104 __set_errno (ERANGE);
105 return exc.retval;
106
107 default:
108 return __kernel_standard (dx, dy, type);
109 }
110}
111#endif
112