ipiq: Add simple IPI latency measure sysctls (2)
[dragonfly.git] / lib / libm / src / e_asinf.c
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1/* e_asinf.c -- float version of e_asin.c.
2 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
3 */
4
5/*
6 * ====================================================
7 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
8 *
9 * Developed at SunPro, a Sun Microsystems, Inc. business.
10 * Permission to use, copy, modify, and distribute this
11 * software is freely granted, provided that this notice
12 * is preserved.
13 * ====================================================
14 *
6ff43c94 15 * $FreeBSD: head/lib/msun/src/e_asinf.c 181405 2008-08-08 00:21:27Z das $
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16 */
17
6ff43c94 18#include "math.h"
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19#include "math_private.h"
20
21static const float
22one = 1.0000000000e+00, /* 0x3F800000 */
23huge = 1.000e+30,
b34b60bc 24 /* coefficient for R(x^2) */
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25pS0 = 1.6666586697e-01,
26pS1 = -4.2743422091e-02,
27pS2 = -8.6563630030e-03,
28qS1 = -7.0662963390e-01;
29
30static const double
31pio2 = 1.570796326794896558e+00;
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32
33float
6ff43c94 34__ieee754_asinf(float x)
b34b60bc 35{
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36 double s;
37 float t,w,p,q;
b34b60bc 38 int32_t hx,ix;
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39 GET_FLOAT_WORD(hx,x);
40 ix = hx&0x7fffffff;
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41 if(ix>=0x3f800000) { /* |x| >= 1 */
42 if(ix==0x3f800000) /* |x| == 1 */
43 return x*pio2; /* asin(+-1) = +-pi/2 with inexact */
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44 return (x-x)/(x-x); /* asin(|x|>1) is NaN */
45 } else if (ix<0x3f000000) { /* |x|<0.5 */
6ff43c94 46 if(ix<0x39800000) { /* |x| < 2**-12 */
b34b60bc 47 if(huge+x>one) return x;/* return x with inexact if x!=0*/
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48 }
49 t = x*x;
50 p = t*(pS0+t*(pS1+t*pS2));
51 q = one+t*qS1;
52 w = p/q;
53 return x+x*w;
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54 }
55 /* 1> |x|>= 0.5 */
56 w = one-fabsf(x);
57 t = w*(float)0.5;
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58 p = t*(pS0+t*(pS1+t*pS2));
59 q = one+t*qS1;
60 s = sqrt(t);
61 w = p/q;
62 t = pio2-2.0*(s+s*w);
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63 if(hx>0) return t; else return -t;
64}