mirror of
https://github.com/autc04/Retro68.git
synced 2024-12-12 11:29:30 +00:00
72 lines
1.6 KiB
C
72 lines
1.6 KiB
C
|
/* ef_cosh.c -- float version of e_cosh.c.
|
||
|
|
* Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
|
||
|
|
*/
|
||
|
|
|
||
|
|
/*
|
||
|
|
* ====================================================
|
||
|
|
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
|
||
|
|
*
|
||
|
|
* Developed at SunPro, a Sun Microsystems, Inc. business.
|
||
|
|
* Permission to use, copy, modify, and distribute this
|
||
|
|
* software is freely granted, provided that this notice
|
||
|
|
* is preserved.
|
||
|
|
* ====================================================
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include "fdlibm.h"
|
||
|
|
|
||
|
|
#ifdef __v810__
|
||
|
|
#define const
|
||
|
|
#endif
|
||
|
|
|
||
|
|
#ifdef __STDC__
|
||
|
|
static const float one = 1.0, half=0.5, huge = 1.0e30;
|
||
|
|
#else
|
||
|
|
static float one = 1.0, half=0.5, huge = 1.0e30;
|
||
|
|
#endif
|
||
|
|
|
||
|
|
#ifdef __STDC__
|
||
|
|
float __ieee754_coshf(float x)
|
||
|
|
#else
|
||
|
|
float __ieee754_coshf(x)
|
||
|
|
float x;
|
||
|
|
#endif
|
||
|
|
{
|
||
|
|
float t,w;
|
||
|
|
__int32_t ix;
|
||
|
|
|
||
|
|
GET_FLOAT_WORD(ix,x);
|
||
|
|
ix &= 0x7fffffff;
|
||
|
|
|
||
|
|
/* x is INF or NaN */
|
||
|
|
if(!FLT_UWORD_IS_FINITE(ix)) return x*x;
|
||
|
|
|
||
|
|
/* |x| in [0,0.5*ln2], return 1+expm1(|x|)^2/(2*exp(|x|)) */
|
||
|
|
if(ix<0x3eb17218) {
|
||
|
|
t = expm1f(fabsf(x));
|
||
|
|
w = one+t;
|
||
|
|
if (ix<0x24000000) return w; /* cosh(tiny) = 1 */
|
||
|
|
return one+(t*t)/(w+w);
|
||
|
|
}
|
||
|
|
|
||
|
|
/* |x| in [0.5*ln2,22], return (exp(|x|)+1/exp(|x|)/2; */
|
||
|
|
if (ix < 0x41b00000) {
|
||
|
|
t = __ieee754_expf(fabsf(x));
|
||
|
|
return half*t+half/t;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* |x| in [22, log(maxdouble)] return half*exp(|x|) */
|
||
|
|
if (ix <= FLT_UWORD_LOG_MAX)
|
||
|
|
return half*__ieee754_expf(fabsf(x));
|
||
|
|
|
||
|
|
/* |x| in [log(maxdouble), overflowthresold] */
|
||
|
|
if (ix <= FLT_UWORD_LOG_2MAX) {
|
||
|
|
w = __ieee754_expf(half*fabsf(x));
|
||
|
|
t = half*w;
|
||
|
|
return t*w;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* |x| > overflowthresold, cosh(x) overflow */
|
||
|
|
return huge*huge;
|
||
|
|
}
|