/* e_coshf.c -- float version of e_cosh.c.

 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.

 * Optimizations by Ulrich Drepper <drepper@gmail.com>, 2011

 */

/*

 * ====================================================

 * 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 <math.h>

#include <math-narrow-eval.h>

#include <math_private.h>

static const float huge = 1.0e30;

static const float one = 1.0, half=0.5;

float

__ieee754_coshf (float x)

{

	float t,w;

	int32_t ix;

	GET_FLOAT_WORD(ix,x);

	ix &= 0x7fffffff;

    /* |x| in [0,22] */

	if (ix < 0x41b00000) {

	    /* |x| in [0,0.5*ln2], return 1+expm1(|x|)^2/(2*exp(|x|)) */

		if(ix<0x3eb17218) {

		    if (ix<0x24000000) return one;	/* cosh(tiny) = 1 */

		    t = __expm1f(fabsf(x));

		    w = one+t;

		    return one+(t*t)/(w+w);

		}

	    /* |x| in [0.5*ln2,22], return (exp(|x|)+1/exp(|x|)/2; */

		t = __ieee754_expf(fabsf(x));

		return half*t+half/t;

	}

    /* |x| in [22, log(maxdouble)] return half*exp(|x|) */

	if (ix < 0x42b17180)  return half*__ieee754_expf(fabsf(x));

    /* |x| in [log(maxdouble), overflowthresold] */

	if (ix<=0x42b2d4fc) {

	    w = __ieee754_expf(half*fabsf(x));

	    t = half*w;

	    return t*w;

	}

    /* x is INF or NaN */

	if(ix>=0x7f800000) return x*x;

    /* |x| > overflowthresold, cosh(x) overflow */

	return math_narrow_eval (huge*huge);

}

strong_alias (__ieee754_coshf, __coshf_finite)