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67 lines
1.5 KiB
C
67 lines
1.5 KiB
C
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/* sf_asinh.c -- float version of s_asinh.c.
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* Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
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*/
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/*
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* ====================================================
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* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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*
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* Developed at SunPro, a Sun Microsystems, Inc. business.
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* Permission to use, copy, modify, and distribute this
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* software is freely granted, provided that this notice
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* is preserved.
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* ====================================================
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*/
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#include "fdlibm.h"
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#ifdef __STDC__
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static const float
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#else
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static float
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#endif
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one = 1.0000000000e+00, /* 0x3F800000 */
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ln2 = 6.9314718246e-01, /* 0x3f317218 */
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huge= 1.0000000000e+30;
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#ifdef __STDC__
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float asinhf(float x)
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#else
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float asinhf(x)
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float x;
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#endif
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{
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float t,w;
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__int32_t hx,ix;
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GET_FLOAT_WORD(hx,x);
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ix = hx&0x7fffffff;
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if(!FLT_UWORD_IS_FINITE(ix)) return x+x; /* x is inf or NaN */
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if(ix< 0x31800000) { /* |x|<2**-28 */
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if(huge+x>one) return x; /* return x inexact except 0 */
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}
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if(ix>0x4d800000) { /* |x| > 2**28 */
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w = __ieee754_logf(fabsf(x))+ln2;
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} else if (ix>0x40000000) { /* 2**28 > |x| > 2.0 */
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t = fabsf(x);
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w = __ieee754_logf((float)2.0*t+one/(__ieee754_sqrtf(x*x+one)+t));
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} else { /* 2.0 > |x| > 2**-28 */
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t = x*x;
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w =log1pf(fabsf(x)+t/(one+__ieee754_sqrtf(one+t)));
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}
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if(hx>0) return w; else return -w;
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}
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#ifdef _DOUBLE_IS_32BITS
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#ifdef __STDC__
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double asinh(double x)
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#else
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double asinh(x)
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double x;
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#endif
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{
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return (double) asinhf((float) x);
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}
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#endif /* defined(_DOUBLE_IS_32BITS) */
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