64 lines
1.6 KiB
C
64 lines
1.6 KiB
C
|
/* ef_sinh.c -- float version of e_sinh.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 __STDC__
|
||
|
|
static const float one = 1.0, shuge = 1.0e37;
|
||
|
|
#else
|
||
|
|
static float one = 1.0, shuge = 1.0e37;
|
||
|
|
#endif
|
||
|
|
|
||
|
|
#ifdef __STDC__
|
||
|
|
float __ieee754_sinhf(float x)
|
||
|
|
#else
|
||
|
|
float __ieee754_sinhf(x)
|
||
|
|
float x;
|
||
|
|
#endif
|
||
|
|
{
|
||
|
|
float t,w,h;
|
||
|
|
__int32_t ix,jx;
|
||
|
|
|
||
|
|
GET_FLOAT_WORD(jx,x);
|
||
|
|
ix = jx&0x7fffffff;
|
||
|
|
|
||
|
|
/* x is INF or NaN */
|
||
|
|
if(!FLT_UWORD_IS_FINITE(ix)) return x+x;
|
||
|
|
|
||
|
|
h = 0.5;
|
||
|
|
if (jx<0) h = -h;
|
||
|
|
/* |x| in [0,22], return sign(x)*0.5*(E+E/(E+1))) */
|
||
|
|
if (ix < 0x41b00000) { /* |x|<22 */
|
||
|
|
if (ix<0x31800000) /* |x|<2**-28 */
|
||
|
|
if(shuge+x>one) return x;/* sinh(tiny) = tiny with inexact */
|
||
|
|
t = expm1f(fabsf(x));
|
||
|
|
if(ix<0x3f800000) return h*((float)2.0*t-t*t/(t+one));
|
||
|
|
return h*(t+t/(t+one));
|
||
|
|
}
|
||
|
|
|
||
|
|
/* |x| in [22, log(maxdouble)] return 0.5*exp(|x|) */
|
||
|
|
if (ix<=FLT_UWORD_LOG_MAX) return h*__ieee754_expf(fabsf(x));
|
||
|
|
|
||
|
|
/* |x| in [log(maxdouble), overflowthresold] */
|
||
|
|
if (ix<=FLT_UWORD_LOG_2MAX) {
|
||
|
|
w = __ieee754_expf((float)0.5*fabsf(x));
|
||
|
|
t = h*w;
|
||
|
|
return t*w;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* |x| > overflowthresold, sinh(x) overflow */
|
||
|
|
return x*shuge;
|
||
|
|
}
|