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Diffstat (limited to 'lib/mlibc/options/ansi/musl-generic-math/atan2.c')
| -rw-r--r-- | lib/mlibc/options/ansi/musl-generic-math/atan2.c | 107 |
1 files changed, 0 insertions, 107 deletions
diff --git a/lib/mlibc/options/ansi/musl-generic-math/atan2.c b/lib/mlibc/options/ansi/musl-generic-math/atan2.c deleted file mode 100644 index 5a1903c..0000000 --- a/lib/mlibc/options/ansi/musl-generic-math/atan2.c +++ /dev/null @@ -1,107 +0,0 @@ -/* origin: FreeBSD /usr/src/lib/msun/src/e_atan2.c */ -/* - * ==================================================== - * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. - * - * Developed at SunSoft, a Sun Microsystems, Inc. business. - * Permission to use, copy, modify, and distribute this - * software is freely granted, provided that this notice - * is preserved. - * ==================================================== - * - */ -/* atan2(y,x) - * Method : - * 1. Reduce y to positive by atan2(y,x)=-atan2(-y,x). - * 2. Reduce x to positive by (if x and y are unexceptional): - * ARG (x+iy) = arctan(y/x) ... if x > 0, - * ARG (x+iy) = pi - arctan[y/(-x)] ... if x < 0, - * - * Special cases: - * - * ATAN2((anything), NaN ) is NaN; - * ATAN2(NAN , (anything) ) is NaN; - * ATAN2(+-0, +(anything but NaN)) is +-0 ; - * ATAN2(+-0, -(anything but NaN)) is +-pi ; - * ATAN2(+-(anything but 0 and NaN), 0) is +-pi/2; - * ATAN2(+-(anything but INF and NaN), +INF) is +-0 ; - * ATAN2(+-(anything but INF and NaN), -INF) is +-pi; - * ATAN2(+-INF,+INF ) is +-pi/4 ; - * ATAN2(+-INF,-INF ) is +-3pi/4; - * ATAN2(+-INF, (anything but,0,NaN, and INF)) is +-pi/2; - * - * 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 -pi = 3.1415926535897931160E+00, /* 0x400921FB, 0x54442D18 */ -pi_lo = 1.2246467991473531772E-16; /* 0x3CA1A626, 0x33145C07 */ - -double atan2(double y, double x) -{ - double z; - uint32_t m,lx,ly,ix,iy; - - if (isnan(x) || isnan(y)) - return x+y; - EXTRACT_WORDS(ix, lx, x); - EXTRACT_WORDS(iy, ly, y); - if ((ix-0x3ff00000 | lx) == 0) /* x = 1.0 */ - return atan(y); - m = ((iy>>31)&1) | ((ix>>30)&2); /* 2*sign(x)+sign(y) */ - ix = ix & 0x7fffffff; - iy = iy & 0x7fffffff; - - /* when y = 0 */ - if ((iy|ly) == 0) { - switch(m) { - case 0: - case 1: return y; /* atan(+-0,+anything)=+-0 */ - case 2: return pi; /* atan(+0,-anything) = pi */ - case 3: return -pi; /* atan(-0,-anything) =-pi */ - } - } - /* when x = 0 */ - if ((ix|lx) == 0) - return m&1 ? -pi/2 : pi/2; - /* when x is INF */ - if (ix == 0x7ff00000) { - if (iy == 0x7ff00000) { - switch(m) { - case 0: return pi/4; /* atan(+INF,+INF) */ - case 1: return -pi/4; /* atan(-INF,+INF) */ - case 2: return 3*pi/4; /* atan(+INF,-INF) */ - case 3: return -3*pi/4; /* atan(-INF,-INF) */ - } - } else { - switch(m) { - case 0: return 0.0; /* atan(+...,+INF) */ - case 1: return -0.0; /* atan(-...,+INF) */ - case 2: return pi; /* atan(+...,-INF) */ - case 3: return -pi; /* atan(-...,-INF) */ - } - } - } - /* |y/x| > 0x1p64 */ - if (ix+(64<<20) < iy || iy == 0x7ff00000) - return m&1 ? -pi/2 : pi/2; - - /* z = atan(|y/x|) without spurious underflow */ - if ((m&2) && iy+(64<<20) < ix) /* |y/x| < 0x1p-64, x<0 */ - z = 0; - else - z = atan(fabs(y/x)); - switch (m) { - case 0: return z; /* atan(+,+) */ - case 1: return -z; /* atan(-,+) */ - case 2: return pi - (z-pi_lo); /* atan(+,-) */ - default: /* case 3 */ - return (z-pi_lo) - pi; /* atan(-,-) */ - } -} |