1 /* Copyright (C) 2011-2022 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 #include <math_private.h>
20 #include <math-svid-compat.h>
21 #include <libm-alias-double.h>
22 
23 
24 #if LIBM_SVID_COMPAT && (SHLIB_COMPAT (libm, GLIBC_2_0, GLIBC_2_29) \
25 			 || defined NO_LONG_DOUBLE \
26 			 || defined LONG_DOUBLE_COMPAT)
27 /* wrapper pow */
28 double
__pow_compat(double x,double y)29 __pow_compat (double x, double y)
30 {
31   double z = __ieee754_pow (x, y);
32   if (__glibc_unlikely (!isfinite (z)))
33     {
34       if (_LIB_VERSION != _IEEE_)
35 	{
36 	  if (isfinite (x) && isfinite (y))
37 	    {
38 	      if (isnan (z))
39 		/* pow neg**non-int */
40 		return __kernel_standard (x, y, 24);
41 	      else if (x == 0.0 && y < 0.0)
42 		{
43 		  if (signbit (x) && signbit (z))
44 		    /* pow(-0.0,negative) */
45 		    return __kernel_standard (x, y, 23);
46 		  else
47 		    /* pow(+0.0,negative) */
48 		    return __kernel_standard (x, y, 43);
49 		}
50 	      else
51 		/* pow overflow */
52 		return __kernel_standard (x, y, 21);
53 	    }
54 	}
55     }
56   else if (__builtin_expect (z == 0.0, 0)
57 	   && isfinite (x) && x != 0 && isfinite (y)
58 	   && _LIB_VERSION != _IEEE_)
59     /* pow underflow */
60     return __kernel_standard (x, y, 22);
61 
62   return z;
63 }
64 # if SHLIB_COMPAT (libm, GLIBC_2_0, GLIBC_2_29)
65 compat_symbol (libm, __pow_compat, pow, GLIBC_2_0);
66 # endif
67 # ifdef NO_LONG_DOUBLE
68 weak_alias (__pow_compat, powl)
69 # endif
70 # ifdef LONG_DOUBLE_COMPAT
71 /* Work around gas bug "multiple versions for symbol".  */
72 weak_alias (__pow_compat, __pow_compat_alias)
73 
74 LONG_DOUBLE_COMPAT_CHOOSE_libm_powl (
75   compat_symbol (libm, __pow_compat_alias, powl, FIRST_VERSION_libm_powl), );
76 # endif
77 #endif
78