text: /* e_coshf.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.
   * ====================================================
   *
   * $FreeBSD: head/lib/msun/src/e_coshf.c 226598 2011-10-21 06:28:47Z das $
   */
  
  #include "math.h"
  #include "math_private.h"
  
  static const float one = 1.0, half=0.5, huge = 1.0e30;
  
  float
  __ieee754_coshf(float x)
  {
  	float t,w;
  	int32_t ix;
  
  	GET_FLOAT_WORD(ix,x);
  	ix &= 0x7fffffff;
  
      /* x is INF or NaN */
  	if(ix>=0x7f800000) 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<0x39800000) return one;	/* cosh(tiny) = 1 */
  	    return one+(t*t)/(w+w);
  	}
  
      /* |x| in [0.5*ln2,9], return (exp(|x|)+1/exp(|x|))/2; */
  	if (ix < 0x41100000) {
  		t = __ieee754_expf(fabsf(x));
  		return half*t+half/t;
  	}
  
      /* |x| in [9, log(maxfloat)] return half*exp(|x|) */
  	if (ix < 0x42b17217)  return half*__ieee754_expf(fabsf(x));
  
      /* |x| in [log(maxfloat), overflowthresold] */
  	if (ix<=0x42b2d4fc)
  	    return __ldexp_expf(fabsf(x), -1);
  
      /* |x| > overflowthresold, cosh(x) overflow */
  	return huge*huge;
  }
  