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      1 /* s_asinhf.c -- float version of s_asinh.c.
      2  * Conversion to float by Ian Lance Taylor, Cygnus Support, ian (at) cygnus.com.
      3  */
      4 
      5 /*
      6  * ====================================================
      7  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
      8  *
      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
     12  * is preserved.
     13  * ====================================================
     14  */
     15 
     16 #include <sys/cdefs.h>
     17 #if defined(LIBM_SCCS) && !defined(lint)
     18 __RCSID("$NetBSD: s_asinhf.c,v 1.8 2002/05/26 22:01:54 wiz Exp $");
     19 #endif
     20 
     21 #include "math.h"
     22 #include "math_private.h"
     23 
     24 static const float
     25 one =  1.0000000000e+00, /* 0x3F800000 */
     26 ln2 =  6.9314718246e-01, /* 0x3f317218 */
     27 huge=  1.0000000000e+30;
     28 
     29 float
     30 asinhf(float x)
     31 {
     32 	float t,w;
     33 	int32_t hx,ix;
     34 	GET_FLOAT_WORD(hx,x);
     35 	ix = hx&0x7fffffff;
     36 	if(ix>=0x7f800000) return x+x;	/* x is inf or NaN */
     37 	if(ix< 0x31800000) {	/* |x|<2**-28 */
     38 	    if(huge+x>one) return x;	/* return x inexact except 0 */
     39 	}
     40 	if(ix>0x4d800000) {	/* |x| > 2**28 */
     41 	    w = __ieee754_logf(fabsf(x))+ln2;
     42 	} else if (ix>0x40000000) {	/* 2**28 > |x| > 2.0 */
     43 	    t = fabsf(x);
     44 	    w = __ieee754_logf((float)2.0*t+one/(__ieee754_sqrtf(x*x+one)+t));
     45 	} else {		/* 2.0 > |x| > 2**-28 */
     46 	    t = x*x;
     47 	    w =log1pf(fabsf(x)+t/(one+__ieee754_sqrtf(one+t)));
     48 	}
     49 	if(hx>0) return w; else return -w;
     50 }
     51