minix/lib/libm/src/e_sinhf.c

62 lines
1.6 KiB
C
Raw Normal View History

/* e_sinhf.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 <sys/cdefs.h>
#if defined(LIBM_SCCS) && !defined(lint)
__RCSID("$NetBSD: e_sinhf.c,v 1.7 2002/05/26 22:01:52 wiz Exp $");
#endif
#include "math.h"
#include "math_private.h"
static const float one = 1.0, shuge = 1.0e37;
float
__ieee754_sinhf(float x)
{
float t,w,h;
int32_t ix,jx;
GET_FLOAT_WORD(jx,x);
ix = jx&0x7fffffff;
/* x is INF or NaN */
if(ix>=0x7f800000) 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 < 0x42b17180) return h*__ieee754_expf(fabsf(x));
/* |x| in [log(maxdouble), overflowthresold] */
if (ix<=0x42b2d4fc) {
w = __ieee754_expf((float)0.5*fabsf(x));
t = h*w;
return t*w;
}
/* |x| > overflowthresold, sinh(x) overflow */
return x*shuge;
}