newlib-cygwin/newlib/libm/mathfp/sf_asinh.c

67 lines
1.5 KiB
C

/* sf_asinh.c -- float version of s_asinh.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.
* ====================================================
*/
#include "fdlibm.h"
#ifdef __STDC__
static const float
#else
static float
#endif
one = 1.0000000000e+00, /* 0x3F800000 */
ln2 = 6.9314718246e-01, /* 0x3f317218 */
huge= 1.0000000000e+30;
#ifdef __STDC__
float asinhf(float x)
#else
float asinhf(x)
float x;
#endif
{
float t,w;
__int32_t hx,ix;
GET_FLOAT_WORD(hx,x);
ix = hx&0x7fffffff;
if(ix>=0x7f800000) return x+x; /* x is inf or NaN */
if(ix< 0x31800000) { /* |x|<2**-28 */
if(huge+x>one) return x; /* return x inexact except 0 */
}
if(ix>0x4d800000) { /* |x| > 2**28 */
w = logf(fabsf(x))+ln2;
} else if (ix>0x40000000) { /* 2**28 > |x| > 2.0 */
t = fabsf(x);
w = logf((float)2.0*t+one/(sqrtf(x*x+one)+t));
} else { /* 2.0 > |x| > 2**-28 */
t = x*x;
w =log1pf(fabsf(x)+t/(one+sqrtf(one+t)));
}
if(hx>0) return w; else return -w;
}
#ifdef _DOUBLE_IS_32BITS
#ifdef __STDC__
double asinh(double x)
#else
double asinh(x)
double x;
#endif
{
return (double) asinhf((float) x);
}
#endif /* defined(_DOUBLE_IS_32BITS) */