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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 4973 | right-hear | 1 | /* Copyright (C) 1994 DJ Delorie, see COPYING.DJ for details */ |
| 2 | /* e_atanhf.c -- float version of e_atanh.c. |
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| 3 | * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. |
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| 4 | */ |
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| 5 | |||
| 6 | /* |
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| 7 | * ==================================================== |
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| 8 | * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. |
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| 9 | * |
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| 10 | * Developed at SunPro, a Sun Microsystems, Inc. business. |
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| 11 | * Permission to use, copy, modify, and distribute this |
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| 12 | * software is freely granted, provided that this notice |
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| 13 | * is preserved. |
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| 14 | * ==================================================== |
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| 15 | */ |
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| 16 | |||
| 17 | #if defined(LIBM_SCCS) && !defined(lint) |
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| 18 | static char rcsid[] = "$Id: e_atanhf.c,v 1.2 1994/08/18 23:05:14 jtc Exp $"; |
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| 19 | #endif |
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| 20 | |||
| 21 | #include "math.h" |
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| 22 | #include "math_private.h" |
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| 23 | |||
| 24 | #ifdef __STDC__ |
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| 25 | static const float one = 1.0, huge = 1e30; |
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| 26 | #else |
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| 27 | static float one = 1.0, huge = 1e30; |
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| 28 | #endif |
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| 29 | |||
| 30 | #ifdef __STDC__ |
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| 31 | static const float zero = 0.0; |
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| 32 | #else |
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| 33 | static float zero = 0.0; |
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| 34 | #endif |
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| 35 | |||
| 36 | #ifdef __STDC__ |
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| 37 | float __ieee754_atanhf(float x) |
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| 38 | #else |
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| 39 | float __ieee754_atanhf(x) |
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| 40 | float x; |
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| 41 | #endif |
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| 42 | { |
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| 43 | float t; |
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| 44 | int32_t hx,ix; |
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| 45 | GET_FLOAT_WORD(hx,x); |
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| 46 | ix = hx&0x7fffffff; |
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| 47 | if (ix>0x3f800000) /* |x|>1 */ |
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| 48 | return (x-x)/(x-x); |
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| 49 | if(ix==0x3f800000) |
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| 50 | return x/zero; |
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| 51 | if(ix<0x31800000&&(huge+x)>zero) return x; /* x<2**-28 */ |
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| 52 | SET_FLOAT_WORD(x,ix); |
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| 53 | if(ix<0x3f000000) { /* x < 0.5 */ |
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| 54 | t = x+x; |
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| 55 | t = (float)0.5*log1pf(t+t*x/(one-x)); |
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| 56 | } else |
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| 57 | t = (float)0.5*log1pf((x+x)/(one-x)); |
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| 58 | if(hx>=0) return t; else return -t; |
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| 59 | } |