kc3-lang/gnulib/lib/sqrtl.c

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• Hash : 57fdfd3f
  Author :
  Date : 2007-10-07T19:14:58
  

  Change copyright notice from GPLv2+ to GPLv3+.
  

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• lib/sqrtl.c

• /* Emulation for sqrtl.
     Contributed by Paolo Bonzini
  
     Copyright 2002, 2003, 2007 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>
  #include "isnanl.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;
  }
  

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