external/bsd/pcc/dist/pcc-libs/libF77/sinh.c

   1 /*      $Id: sinh.c,v 1.1.1.1 2008/08/24 05:34:47 gmcgarry Exp $        */
   2 /*
   3  * Copyright(C) Caldera International Inc. 2001-2002. All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *
   9  * Redistributions of source code and documentation must retain the above
  10  * copyright notice, this list of conditions and the following disclaimer.
  11  * Redistributions in binary form must reproduce the above copyright
  12  * notice, this list of conditionsand the following disclaimer in the
  13  * documentation and/or other materials provided with the distribution.
  14  * All advertising materials mentioning features or use of this software
  15  * must display the following acknowledgement:
  16  *      This product includes software developed or owned by Caldera
  17  *      International, Inc.
  18  * Neither the name of Caldera International, Inc. nor the names of other
  19  * contributors may be used to endorse or promote products derived from
  20  * this software without specific prior written permission.
  21  *
  22  * USE OF THE SOFTWARE PROVIDED FOR UNDER THIS LICENSE BY CALDERA
  23  * INTERNATIONAL, INC. AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR
  24  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  25  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  26  * DISCLAIMED.  IN NO EVENT SHALL CALDERA INTERNATIONAL, INC. BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OFLIABILITY, WHETHER IN CONTRACT,
  31  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  32  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  33  * POSSIBILITY OF SUCH DAMAGE.
  34  */
  35 /*
  36         sinh(arg) returns the hyperbolic sign of its floating-
  37         point argument.
  38
  39         The exponential function is called for arguments
  40         greater in magnitude than 0.5.
  41         The result overflows and 'huge' is returned for
  42         arguments greater than somewhat.
  43
  44         A series is used for arguments smaller in magnitude than 0.5.
  45         The coeffieients are #2029 from Hart & Cheney. (20.36D)
  46
  47         cosh(arg) is computed from the exponential function for
  48         all arguments.
  49 */
  50
  51 double exp();
  52
  53 static double p0 -0.6307673640497716991184787251e+6;
  54 static double p1 -0.8991272022039509355398013511e+5;
  55 static double p2 -0.2894211355989563807284660366e+4;
  56 static double p3 -0.2630563213397497062819489e+2;
  57 static double q0 -0.6307673640497716991212077277e+6;
  58 static double q1  0.1521517378790019070696485176e+5;
  59 static double q2 -0.173678953558233699533450911e+3;
  60 static double q3  1.0;
  61
  62 double
  63 sinh(arg) double arg; {
  64
  65         double sign, temp, argsq;
  66
  67         sign = 1;
  68         if(arg < 0){
  69                 arg = - arg;
  70                 sign = -1;
  71         }
  72
  73         if(arg > 21.){
  74                 temp = exp(arg)/2;
  75                 return(sign*temp);
  76         }
  77
  78         if(arg > 0.5) {
  79                 temp = (exp(arg) - exp(-arg))/2;
  80                 return(sign*temp);
  81         }
  82
  83         argsq = arg*arg;
  84         temp = (((p3*argsq+p2)*argsq+p1)*argsq+p0)*arg;
  85         temp = temp/(((q3*argsq+q2)*argsq+q1)*argsq+q0);
  86         return(sign*temp);
  87
  88 }
  89
  90 double
  91 cosh(arg) double arg; {
  92
  93         double temp;
  94
  95         if(arg < 0)
  96                 arg = - arg;
  97
  98         if(arg > 21.){
  99                 temp = exp(arg)/2;
 100                 return(temp);
 101         }
 102
 103         temp = (exp(arg) + exp(-arg))/2;
 104         return(temp);
 105 }