0,0 → 1,66 |
/* 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(!FLT_UWORD_IS_FINITE(ix)) 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 = __ieee754_logf(fabsf(x))+ln2; |
} else if (ix>0x40000000) { /* 2**28 > |x| > 2.0 */ |
t = fabsf(x); |
w = __ieee754_logf((float)2.0*t+one/(__ieee754_sqrtf(x*x+one)+t)); |
} else { /* 2.0 > |x| > 2**-28 */ |
t = x*x; |
w =log1pf(fabsf(x)+t/(one+__ieee754_sqrtf(one+t))); |
} |
if(hx>0) return w; else return -w; |
} |
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#ifdef _DOUBLE_IS_32BITS |
|
#ifdef __STDC__ |
double asinh(double x) |
#else |
double asinh(x) |
double x; |
#endif |
{ |
return (double) asinhf((float) x); |
} |
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#endif /* defined(_DOUBLE_IS_32BITS) */ |