compiler/stdc/math/s_asinhf.c

   1 /* s_asinhf.c -- float version of s_asinh.c.
   2  * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@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 #ifndef lint
  17 static char rcsid[] = "$FreeBSD: src/lib/msun/src/s_asinhf.c,v 1.8 2002/05/28 18:15:04 alfred Exp $";
  18 #endif
  19
  20 #include "math.h"
  21 #include "math_private.h"
  22
  23 static const float
  24 one =  1.0000000000e+00, /* 0x3F800000 */
  25 ln2 =  6.9314718246e-01, /* 0x3f317218 */
  26 huge=  1.0000000000e+30;
  27
  28 float
  29 asinhf(float x)
  30 {
  31         float t,w;
  32         int32_t hx,ix;
  33         GET_FLOAT_WORD(hx,x);
  34         ix = hx&0x7fffffff;
  35         if(ix>=0x7f800000) return x+x;  /* x is inf or NaN */
  36         if(ix< 0x31800000) {    /* |x|<2**-28 */
  37             if(huge+x>one) return x;    /* return x inexact except 0 */
  38         }
  39         if(ix>0x4d800000) {     /* |x| > 2**28 */
  40             w = __ieee754_logf(fabsf(x))+ln2;
  41         } else if (ix>0x40000000) {     /* 2**28 > |x| > 2.0 */
  42             t = fabsf(x);
  43             w = __ieee754_logf((float)2.0*t+one/(__ieee754_sqrtf(x*x+one)+t));
  44         } else {                /* 2.0 > |x| > 2**-28 */
  45             t = x*x;
  46             w =log1pf(fabsf(x)+t/(one+__ieee754_sqrtf(one+t)));
  47         }
  48         if(hx>0) return w; else return -w;
  49 }