diff options
Diffstat (limited to 'lib/mlibc/options/ansi/musl-generic-math/atan.c')
| -rw-r--r-- | lib/mlibc/options/ansi/musl-generic-math/atan.c | 116 |
1 files changed, 0 insertions, 116 deletions
diff --git a/lib/mlibc/options/ansi/musl-generic-math/atan.c b/lib/mlibc/options/ansi/musl-generic-math/atan.c deleted file mode 100644 index 63b0ab2..0000000 --- a/lib/mlibc/options/ansi/musl-generic-math/atan.c +++ /dev/null @@ -1,116 +0,0 @@ -/* origin: FreeBSD /usr/src/lib/msun/src/s_atan.c */ -/* - * ==================================================== - * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. - * - * Developed at SunPro, a Sun Microsystems, Inc. business. - * Permission to use, copy, modify, and distribute this - * software is freely granted, provided that this notice - * is preserved. - * ==================================================== - */ -/* atan(x) - * Method - * 1. Reduce x to positive by atan(x) = -atan(-x). - * 2. According to the integer k=4t+0.25 chopped, t=x, the argument - * is further reduced to one of the following intervals and the - * arctangent of t is evaluated by the corresponding formula: - * - * [0,7/16] atan(x) = t-t^3*(a1+t^2*(a2+...(a10+t^2*a11)...) - * [7/16,11/16] atan(x) = atan(1/2) + atan( (t-0.5)/(1+t/2) ) - * [11/16.19/16] atan(x) = atan( 1 ) + atan( (t-1)/(1+t) ) - * [19/16,39/16] atan(x) = atan(3/2) + atan( (t-1.5)/(1+1.5t) ) - * [39/16,INF] atan(x) = atan(INF) + atan( -1/t ) - * - * Constants: - * The hexadecimal values are the intended ones for the following - * constants. The decimal values may be used, provided that the - * compiler will convert from decimal to binary accurately enough - * to produce the hexadecimal values shown. - */ - - -#include "libm.h" - -static const double atanhi[] = { - 4.63647609000806093515e-01, /* atan(0.5)hi 0x3FDDAC67, 0x0561BB4F */ - 7.85398163397448278999e-01, /* atan(1.0)hi 0x3FE921FB, 0x54442D18 */ - 9.82793723247329054082e-01, /* atan(1.5)hi 0x3FEF730B, 0xD281F69B */ - 1.57079632679489655800e+00, /* atan(inf)hi 0x3FF921FB, 0x54442D18 */ -}; - -static const double atanlo[] = { - 2.26987774529616870924e-17, /* atan(0.5)lo 0x3C7A2B7F, 0x222F65E2 */ - 3.06161699786838301793e-17, /* atan(1.0)lo 0x3C81A626, 0x33145C07 */ - 1.39033110312309984516e-17, /* atan(1.5)lo 0x3C700788, 0x7AF0CBBD */ - 6.12323399573676603587e-17, /* atan(inf)lo 0x3C91A626, 0x33145C07 */ -}; - -static const double aT[] = { - 3.33333333333329318027e-01, /* 0x3FD55555, 0x5555550D */ - -1.99999999998764832476e-01, /* 0xBFC99999, 0x9998EBC4 */ - 1.42857142725034663711e-01, /* 0x3FC24924, 0x920083FF */ - -1.11111104054623557880e-01, /* 0xBFBC71C6, 0xFE231671 */ - 9.09088713343650656196e-02, /* 0x3FB745CD, 0xC54C206E */ - -7.69187620504482999495e-02, /* 0xBFB3B0F2, 0xAF749A6D */ - 6.66107313738753120669e-02, /* 0x3FB10D66, 0xA0D03D51 */ - -5.83357013379057348645e-02, /* 0xBFADDE2D, 0x52DEFD9A */ - 4.97687799461593236017e-02, /* 0x3FA97B4B, 0x24760DEB */ - -3.65315727442169155270e-02, /* 0xBFA2B444, 0x2C6A6C2F */ - 1.62858201153657823623e-02, /* 0x3F90AD3A, 0xE322DA11 */ -}; - -double atan(double x) -{ - double_t w,s1,s2,z; - uint32_t ix,sign; - int id; - - GET_HIGH_WORD(ix, x); - sign = ix >> 31; - ix &= 0x7fffffff; - if (ix >= 0x44100000) { /* if |x| >= 2^66 */ - if (isnan(x)) - return x; - z = atanhi[3] + 0x1p-120f; - return sign ? -z : z; - } - if (ix < 0x3fdc0000) { /* |x| < 0.4375 */ - if (ix < 0x3e400000) { /* |x| < 2^-27 */ - if (ix < 0x00100000) - /* raise underflow for subnormal x */ - FORCE_EVAL((float)x); - return x; - } - id = -1; - } else { - x = fabs(x); - if (ix < 0x3ff30000) { /* |x| < 1.1875 */ - if (ix < 0x3fe60000) { /* 7/16 <= |x| < 11/16 */ - id = 0; - x = (2.0*x-1.0)/(2.0+x); - } else { /* 11/16 <= |x| < 19/16 */ - id = 1; - x = (x-1.0)/(x+1.0); - } - } else { - if (ix < 0x40038000) { /* |x| < 2.4375 */ - id = 2; - x = (x-1.5)/(1.0+1.5*x); - } else { /* 2.4375 <= |x| < 2^66 */ - id = 3; - x = -1.0/x; - } - } - } - /* end of argument reduction */ - z = x*x; - w = z*z; - /* break sum from i=0 to 10 aT[i]z**(i+1) into odd and even poly */ - s1 = z*(aT[0]+w*(aT[2]+w*(aT[4]+w*(aT[6]+w*(aT[8]+w*aT[10]))))); - s2 = w*(aT[1]+w*(aT[3]+w*(aT[5]+w*(aT[7]+w*aT[9])))); - if (id < 0) - return x - x*(s1+s2); - z = atanhi[id] - (x*(s1+s2) - atanlo[id] - x); - return sign ? -z : z; -} |