1 /* e_coshf.c -- float version of e_cosh.c.
2 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
6 * ====================================================
7 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
9 * Developed at SunPro, a Sun Microsystems, Inc. business.
10 * Permission to use, copy, modify, and distribute this
11 * software is freely granted, provided that this notice
13 * ====================================================
15 * $NetBSD: e_coshf.c,v 1.9 2002/05/26 22:01:49 wiz Exp $
16 * $DragonFly: src/lib/libm/src/e_coshf.c,v 1.1 2005/07/26 21:15:20 joerg Exp $
20 #include "math_private.h"
22 static const float huge
= 1.0e30
;
23 static const float one
= 1.0, half
=0.5;
35 if(ix
>=0x7f800000) return x
*x
;
37 /* |x| in [0,0.5*ln2], return 1+expm1(|x|)^2/(2*exp(|x|)) */
41 if (ix
<0x24000000) return w
; /* cosh(tiny) = 1 */
42 return one
+(t
*t
)/(w
+w
);
45 /* |x| in [0.5*ln2,22], return (exp(|x|)+1/exp(|x|)/2; */
46 if (ix
< 0x41b00000) {
51 /* |x| in [22, log(maxdouble)] return half*exp(|x|) */
52 if (ix
< 0x42b17180) return half
*expf(fabsf(x
));
54 /* |x| in [log(maxdouble), overflowthresold] */
56 w
= expf(half
*fabsf(x
));
61 /* |x| > overflowthresold, cosh(x) overflow */