43 lines
783 B
C
43 lines
783 B
C
|
/* _FCosh function */
|
||
|
|
#include "wctype.h"
|
||
|
|
#include "xmath.h"
|
||
|
|
_STD_BEGIN
|
||
|
|
|
||
|
|
_CRTIMP2 float __cdecl _FCosh(float x, float y)
|
||
|
|
{ /* compute y * cosh(x), |y| <= 1 */
|
||
|
|
switch (_FDtest(&x))
|
||
|
|
{ /* test for special codes */
|
||
|
|
case NAN:
|
||
|
|
errno = EDOM;
|
||
|
|
return (x);
|
||
|
|
case INF:
|
||
|
|
if (y == 0)
|
||
|
|
return (0);
|
||
|
|
errno = ERANGE;
|
||
|
|
return (_FInf._F);
|
||
|
|
case 0:
|
||
|
|
return (y);
|
||
|
|
default: /* finite */
|
||
|
|
if (x < 0)
|
||
|
|
x = -x;
|
||
|
|
if (x < _FXbig)
|
||
|
|
{ /* worth adding in exp(-x) */
|
||
|
|
_FExp(&x, 1, -1);
|
||
|
|
return (y * (x + 0.25 / x));
|
||
|
|
}
|
||
|
|
if (0 <= _FExp(&x, y, -1))
|
||
|
|
errno = ERANGE; /* x large */
|
||
|
|
return (x);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
_STD_END
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Copyright (c) 1994 by P.J. Plauger. ALL RIGHTS RESERVED.
|
||
|
|
* Consult your license regarding permissions and restrictions.
|
||
|
|
*/
|
||
|
|
|
||
|
|
/*
|
||
|
|
941029 pjp: added _STD machinery
|
||
|
|
*/
|