kc3-lang/gnulib/lib/sqrtl.c

• Show log

  Commit

• Hash : d60f3b0c
  Author :
  Date : 2011-01-01T20:17:23
  

  maint: update almost all copyright ranges to include 2011
  
  Run the new "make update-copyright" rule.
  

Download

• lib/sqrtl.c

• /* Emulation for sqrtl.
     Contributed by Paolo Bonzini
  
     Copyright 2002-2003, 2007, 2009-2011 Free Software Foundation, Inc.
  
     This file is part of gnulib.
  
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
     the Free Software Foundation; either version 3 of the License, or
     (at your option) any later version.
  
     This program is distributed in the hope that it will be useful,
     but WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     GNU General Public License for more details.
  
     You should have received a copy of the GNU General Public License
     along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  
  #include <config.h>
  
  /* Specification.  */
  #include <math.h>
  
  #include <float.h>
  
  /* A simple Newton-Raphson method. */
  long double
  sqrtl (long double x)
  {
    long double delta, y;
    int exponent;
  
    /* Check for NaN */
    if (isnanl (x))
      return x;
  
    /* Check for negative numbers */
    if (x < 0.0L)
      return (long double) sqrt (-1);
  
    /* Check for zero and infinites */
    if (x + x == x)
      return x;
  
    frexpl (x, &exponent);
    y = ldexpl (x, -exponent / 2);
  
    do
      {
        delta = y;
        y = (y + x / y) * 0.5L;
        delta -= y;
      }
    while (delta != 0.0L);
  
    return y;
  }
  

Download