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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 2 | pj | 1 | /* e_atanhf.c -- float version of e_atanh.c. |
| 2 | * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. |
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| 3 | */ |
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| 4 | |||
| 5 | /* |
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| 6 | * ==================================================== |
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| 7 | * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. |
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| 8 | * |
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| 9 | * Developed at SunPro, a Sun Microsystems, Inc. business. |
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| 10 | * Permission to use, copy, modify, and distribute this |
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| 11 | * software is freely granted, provided that this notice |
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| 12 | * is preserved. |
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| 13 | * ==================================================== |
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| 14 | */ |
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| 15 | |||
| 16 | #ifndef lint |
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| 17 | static char rcsid[] = "$\Id: e_atanhf.c,v 1.2 1995/05/30 05:48:04 rgrimes Exp $"; |
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| 18 | #endif |
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| 19 | |||
| 20 | #include "math.h" |
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| 21 | #include "math_private.h" |
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| 22 | |||
| 23 | #ifdef __STDC__ |
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| 24 | static const float one = 1.0, huge = 1e30; |
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| 25 | #else |
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| 26 | static float one = 1.0, huge = 1e30; |
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| 27 | #endif |
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| 28 | |||
| 29 | #ifdef __STDC__ |
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| 30 | static const float zero = 0.0; |
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| 31 | #else |
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| 32 | static float zero = 0.0; |
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| 33 | #endif |
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| 34 | |||
| 35 | #ifdef __STDC__ |
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| 36 | float __ieee754_atanhf(float x) |
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| 37 | #else |
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| 38 | float __ieee754_atanhf(x) |
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| 39 | float x; |
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| 40 | #endif |
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| 41 | { |
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| 42 | float t; |
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| 43 | int32_t hx,ix; |
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| 44 | GET_FLOAT_WORD(hx,x); |
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| 45 | ix = hx&0x7fffffff; |
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| 46 | if (ix>0x3f800000) /* |x|>1 */ |
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| 47 | return (x-x)/(x-x); |
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| 48 | if(ix==0x3f800000) |
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| 49 | return x/zero; |
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| 50 | if(ix<0x31800000&&(huge+x)>zero) return x; /* x<2**-28 */ |
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| 51 | SET_FLOAT_WORD(x,ix); |
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| 52 | if(ix<0x3f000000) { /* x < 0.5 */ |
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| 53 | t = x+x; |
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| 54 | t = (float)0.5*log1pf(t+t*x/(one-x)); |
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| 55 | } else |
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| 56 | t = (float)0.5*log1pf((x+x)/(one-x)); |
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| 57 | if(hx>=0) return t; else return -t; |
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| 58 | } |