lib/libm/src/w_sqrt.c

   1 /* @(#)w_sqrt.c 5.1 93/09/24 */
   2 /*
   3  * ====================================================
   4  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
   5  *
   6  * Developed at SunPro, a Sun Microsystems, Inc. business.
   7  * Permission to use, copy, modify, and distribute this
   8  * software is freely granted, provided that this notice
   9  * is preserved.
  10  * ====================================================
  11  */
  12
  13 #include <sys/cdefs.h>
  14 #if defined(LIBM_SCCS) && !defined(lint)
  15 __RCSID("$NetBSD: w_sqrt.c,v 1.10 2013/11/19 19:24:34 joerg Exp $");
  16 #endif
  17
  18 /*
  19  * wrapper sqrt(x)
  20  */
  21
  22 #include "namespace.h"
  23 #include "math.h"
  24 #include "math_private.h"
  25
  26 #ifndef __HAVE_LONG_DOUBLE
  27 __strong_alias(_sqrtl, sqrt)
  28 __weak_alias(sqrtl, _sqrtl)
  29 #endif
  30
  31 double
  32 sqrt(double x)          /* wrapper sqrt */
  33 {
  34 #ifdef _IEEE_LIBM
  35         return __ieee754_sqrt(x);
  36 #else
  37         double z;
  38         z = __ieee754_sqrt(x);
  39         if(_LIB_VERSION == _IEEE_ || isnan(x)) return z;
  40         if(x<0.0) {
  41             return __kernel_standard(x,x,26); /* sqrt(negative) */
  42         } else
  43             return z;
  44 #endif
  45 }