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2 | pj | 1 | /* s_asinhf.c -- float version of s_asinh.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: s_asinhf.c,v 1.2 1995/05/30 05:49:19 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 |
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25 | #else |
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26 | static float |
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27 | #endif |
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28 | one = 1.0000000000e+00, /* 0x3F800000 */ |
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29 | ln2 = 6.9314718246e-01, /* 0x3f317218 */ |
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30 | huge= 1.0000000000e+30; |
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31 | |||
32 | #ifdef __STDC__ |
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33 | float asinhf(float x) |
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34 | #else |
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35 | float asinhf(x) |
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36 | float x; |
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37 | #endif |
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38 | { |
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39 | float t,w; |
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40 | int32_t hx,ix; |
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41 | GET_FLOAT_WORD(hx,x); |
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42 | ix = hx&0x7fffffff; |
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43 | if(ix>=0x7f800000) return x+x; /* x is inf or NaN */ |
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44 | if(ix< 0x31800000) { /* |x|<2**-28 */ |
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45 | if(huge+x>one) return x; /* return x inexact except 0 */ |
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46 | } |
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47 | if(ix>0x4d800000) { /* |x| > 2**28 */ |
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48 | w = __ieee754_logf(fabsf(x))+ln2; |
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49 | } else if (ix>0x40000000) { /* 2**28 > |x| > 2.0 */ |
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50 | t = fabsf(x); |
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51 | w = __ieee754_logf((float)2.0*t+one/(sqrtf(x*x+one)+t)); |
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52 | } else { /* 2.0 > |x| > 2**-28 */ |
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53 | t = x*x; |
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54 | w =log1pf(fabsf(x)+t/(one+sqrtf(one+t))); |
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55 | } |
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56 | if(hx>0) return w; else return -w; |
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57 | } |