sysdeps/ieee754/flt-32/s_asinhf.c

   1 /* s_asinhf.c -- float version of s_asinh.c.
   2  */
   3
   4 /*
   5  * ====================================================
   6  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
   7  *
   8  * Developed at SunPro, a Sun Microsystems, Inc. business.
   9  * Permission to use, copy, modify, and distribute this
  10  * software is freely granted, provided that this notice
  11  * is preserved.
  12  * ====================================================
  13  */
  14
  15 #include <float.h>
  16 #include <math.h>
  17 #include <math_private.h>
  18 #include <math-underflow.h>
  19 #include <libm-alias-float.h>
  20
  21 static const float
  22 one =  1.0000000000e+00, /* 0x3F800000 */
  23 ln2 =  6.9314718246e-01, /* 0x3f317218 */
  24 huge=  1.0000000000e+30;
  25
  26 float
  27 __asinhf(float x)
  28 {
  29         float w;
  30         int32_t hx,ix;
  31         GET_FLOAT_WORD(hx,x);
  32         ix = hx&0x7fffffff;
  33         if(__builtin_expect(ix< 0x38000000, 0)) {       /* |x|<2**-14 */
  34             math_check_force_underflow (x);
  35             if(huge+x>one) return x;    /* return x inexact except 0 */
  36         }
  37         if(__builtin_expect(ix>0x47000000, 0)) {        /* |x| > 2**14 */
  38             if(ix>=0x7f800000) return x+x;      /* x is inf or NaN */
  39             w = __ieee754_logf(fabsf(x))+ln2;
  40         } else {
  41             float xa = fabsf(x);
  42             if (ix>0x40000000) {        /* 2**14 > |x| > 2.0 */
  43                 w = __ieee754_logf(2.0f*xa+one/(sqrtf(xa*xa+one)+xa));
  44             } else {            /* 2.0 > |x| > 2**-14 */
  45                 float t = xa*xa;
  46                 w =__log1pf(xa+t/(one+sqrtf(one+t)));
  47             }
  48         }
  49         return copysignf(w, x);
  50 }
  51 libm_alias_float (__asinh, asinh)