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/* origin: FreeBSD /usr/src/lib/msun/src/e_sinhf.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 "libm.h"
static const float one = 1.0, huge = 1.0e37;
float sinhf(float x)
{
float t, 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 [0,9], return sign(x)*0.5*(E+E/(E+1))) */
if (ix < 0x41100000) { /* |x|<9 */
if (ix < 0x39800000) /* |x|<2**-12 */
/* raise inexact, return x */
if (huge+x > one)
return x;
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 [9, logf(maxfloat)] return 0.5*exp(|x|) */
if (ix < 0x42b17217)
return h*expf(fabsf(x));
/* |x| in [logf(maxfloat), overflowthresold] */
if (ix <= 0x42b2d4fc)
return h * 2.0f * __expo2f(fabsf(x)); /* h is for sign only */
/* |x| > overflowthresold, sinh(x) overflow */
return x*huge;
}
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