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git.ipfire.org Git - thirdparty/glibc.git/blob - sysdeps/m68k/m680x0/fpu/e_pow.c
1 /* Copyright (C) 1997-2017 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
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.
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.
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 <http://www.gnu.org/licenses/>. */
19 #include <math_private.h>
26 #define float_type double
29 #define CONCATX(a,b) __CONCAT(a,b)
30 #define s(name) CONCATX(name,SUFF)
31 #define m81(func) __m81_u(s(func))
34 s(__ieee754_pow
) (float_type x
, float_type y
)
38 unsigned long x_cond
, y_cond
;
40 y_cond
= __m81_test (y
);
41 if (y_cond
& __M81_COND_ZERO
)
43 if (y_cond
& __M81_COND_NAN
)
44 return x
== 1.0 ? x
: x
+ y
;
46 x_cond
= __m81_test (x
);
47 if (x_cond
& __M81_COND_NAN
)
50 if (y_cond
& __M81_COND_INF
)
56 return y_cond
& __M81_COND_NEG
? 0 : y
;
58 return y_cond
& __M81_COND_NEG
? -y
: 0;
61 if (s(fabs
) (y
) == 1.0)
62 return y_cond
& __M81_COND_NEG
? 1 / x
: x
;
66 if (y
== 0.5 && !(x_cond
& __M81_COND_NEG
))
67 return m81(__ieee754_sqrt
) (x
);
71 __asm ("ftentox%.x %1, %0" : "=f" (z
) : "f" (y
));
76 __asm ("ftwotox%.x %1, %0" : "=f" (z
) : "f" (y
));
81 if (x_cond
& (__M81_COND_INF
| __M81_COND_ZERO
) || ax
== 1.0)
84 if (y_cond
& __M81_COND_NEG
)
86 if (x_cond
& __M81_COND_NEG
)
88 if (y
!= m81(__rint
) (y
))
91 z
= (z
- z
) / (z
- z
);
99 if (x_cond
& __M81_COND_NEG
)
101 if (y
== m81(__rint
) (y
))
103 z
= m81(__ieee754_exp
) (y
* m81(__ieee754_log
) (-x
));
105 /* We always use the long double format, since y is already in
106 this format and rounding won't change the result. */
110 GET_LDOUBLE_WORDS (exponent
, i0
, i1
, y
);
111 exponent
= (exponent
& 0x7fff) - 0x3fff;
113 ? i0
& (1 << (31 - exponent
))
115 && i1
& (1 << (63 - exponent
))))
120 z
= (y
- y
) / (y
- y
);
123 z
= m81(__ieee754_exp
) (y
* m81(__ieee754_log
) (x
));
126 strong_alias (s(__ieee754_pow
), CONCATX (s(__pow
), _finite
))