41 lines
814 B
C
41 lines
814 B
C
|
/* _LCosh function */
|
||
|
|
#include "xmath.h"
|
||
|
|
_STD_BEGIN
|
||
|
|
|
||
|
|
_CRTIMP2 long double __cdecl _LCosh(long double x, long double y)
|
||
|
|
{ /* compute y * cosh(x), |y| <= 1 */
|
||
|
|
switch (_LDtest(&x))
|
||
|
|
{ /* test for special codes */
|
||
|
|
case _NANCODE:
|
||
|
|
case _INFCODE:
|
||
|
|
return (x);
|
||
|
|
case 0:
|
||
|
|
return (y);
|
||
|
|
default: /* finite */
|
||
|
|
if (y == 0.0L)
|
||
|
|
return (y);
|
||
|
|
if (x < 0.0)
|
||
|
|
x = -x;
|
||
|
|
if (x < _LXbig)
|
||
|
|
{ /* worth adding in exp(-x) */
|
||
|
|
_LExp(&x, 1.0L, -1);
|
||
|
|
return (y * (x + 0.25L / x));
|
||
|
|
}
|
||
|
|
switch (_LExp(&x, y, -1))
|
||
|
|
{ /* report over/underflow */
|
||
|
|
case 0:
|
||
|
|
_Feraise(_FE_UNDERFLOW);
|
||
|
|
break;
|
||
|
|
case _INFCODE:
|
||
|
|
_Feraise(_FE_OVERFLOW);
|
||
|
|
}
|
||
|
|
return (x);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
_STD_END
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Copyright (c) 1992-2001 by P.J. Plauger. ALL RIGHTS RESERVED.
|
||
|
|
* Consult your license regarding permissions and restrictions.
|
||
|
|
V3.10:0009 */
|