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glibc  2.9
w_sqrt.c
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00001 /* Double-precision floating point square root wrapper.
00002    Copyright (C) 2004 Free Software Foundation, Inc.
00003    This file is part of the GNU C Library.
00004 
00005    The GNU C Library is free software; you can redistribute it and/or
00006    modify it under the terms of the GNU Lesser General Public
00007    License as published by the Free Software Foundation; either
00008    version 2.1 of the License, or (at your option) any later version.
00009 
00010    The GNU C Library is distributed in the hope that it will be useful,
00011    but WITHOUT ANY WARRANTY; without even the implied warranty of
00012    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00013    Lesser General Public License for more details.
00014 
00015    You should have received a copy of the GNU Lesser General Public
00016    License along with the GNU C Library; if not, write to the Free
00017    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
00018    02111-1307 USA.  */
00019 
00020 #include "math.h"
00021 #include "math_private.h"
00022 #include <fenv_libc.h>
00023 
00024 #ifdef __STDC__
00025 double
00026 __sqrt (double x)           /* wrapper sqrt */
00027 #else
00028 double
00029 __sqrt (x)                  /* wrapper sqrt */
00030      double x;
00031 #endif
00032 {
00033 #ifdef _IEEE_LIBM
00034   return __ieee754_sqrt (x);
00035 #else
00036   double z;
00037   z = __ieee754_sqrt (x);
00038   if (_LIB_VERSION == _IEEE_ || (x != x))
00039     return z;
00040 
00041   if (x < 0.0)
00042     return __kernel_standard (x, x, 26);  /* sqrt(negative) */
00043   else
00044     return z;
00045 #endif
00046 }
00047 
00048 weak_alias (__sqrt, sqrt)
00049 #ifdef NO_LONG_DOUBLE
00050   strong_alias (__sqrt, __sqrtl) weak_alias (__sqrt, sqrtl)
00051 #endif