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authormrb0nk500 <b0nk@b0nk.xyz>2023-02-02 17:29:19 -0400
committermrb0nk500 <b0nk@b0nk.xyz>2023-02-03 13:27:06 -0400
commitf2eabdb6257c09cf2890dac5e9737912728542af (patch)
tree3b46f6787185d65605651a0f48776dc9779ce648 /src/MSL_C.PPCEABI.bare.H/e_atan2.c
parenteef1dd840b7cecac28c2e6b0574707b90a37d4e7 (diff)
global: Add rest of Dolphin SDK proper, add MSL, and MetroTRK
Finally, it links properly.
Diffstat (limited to 'src/MSL_C.PPCEABI.bare.H/e_atan2.c')
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+/* @(#)e_atan2.c 1.2 95/01/04 */
+/*
+ * ====================================================
+ * 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.
+ * ====================================================
+ *
+ */
+
+/* __ieee754_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 "fdlibm.h"
+
+#ifdef __STDC__
+static const double
+#else
+static double
+#endif
+ tiny = 1.0e-300,
+ zero = 0.0, pi_o_4 = 7.8539816339744827900E-01, /* 0x3FE921FB, 0x54442D18 */
+ pi_o_2 = 1.5707963267948965580E+00, /* 0x3FF921FB, 0x54442D18 */
+ pi = 3.1415926535897931160E+00, /* 0x400921FB, 0x54442D18 */
+ pi_lo = 1.2246467991473531772E-16; /* 0x3CA1A626, 0x33145C07 */
+
+#ifdef __STDC__
+double __ieee754_atan2(double y, double x)
+#else
+double __ieee754_atan2(y, x)
+double y, x;
+#endif
+{
+ double z;
+ _INT32 k, m, hx, hy, ix, iy;
+ _UINT32 lx, ly;
+
+ hx = __HI(x);
+ ix = hx & 0x7fffffff;
+ lx = __LO(x);
+ hy = __HI(y);
+ iy = hy & 0x7fffffff;
+ ly = __LO(y);
+ if (((ix | ((lx | -lx) >> 31)) > 0x7ff00000) ||
+ ((iy | ((ly | -ly) >> 31)) > 0x7ff00000)) /* x or y is NaN */
+ return x + y;
+ if ((hx - 0x3ff00000 | lx) == 0)
+ return atan(y); /* x=1.0 */
+ m = ((hy >> 31) & 1) | ((hx >> 30) & 2); /* 2*sign(x)+sign(y) */
+
+ /* when y = 0 */
+ if ((iy | ly) == 0) {
+ switch (m) {
+ case 0:
+ case 1:
+ return y; /* atan(+-0,+anything)=+-0 */
+ case 2:
+ return pi + tiny; /* atan(+0,-anything) = pi */
+ case 3:
+ return -pi - tiny; /* atan(-0,-anything) =-pi */
+ }
+ }
+ /* when x = 0 */
+ if ((ix | lx) == 0)
+ return (hy < 0) ? -pi_o_2 - tiny : pi_o_2 + tiny;
+
+ /* when x is INF */
+ if (ix == 0x7ff00000) {
+ if (iy == 0x7ff00000) {
+ switch (m) {
+ case 0:
+ return pi_o_4 + tiny; /* atan(+INF,+INF) */
+ case 1:
+ return -pi_o_4 - tiny; /* atan(-INF,+INF) */
+ case 2:
+ return 3.0 * pi_o_4 + tiny; /*atan(+INF,-INF)*/
+ case 3:
+ return -3.0 * pi_o_4 - tiny; /*atan(-INF,-INF)*/
+ }
+ } else {
+ switch (m) {
+ case 0:
+ return zero; /* atan(+...,+INF) */
+ case 1:
+ return -zero; /* atan(-...,+INF) */
+ case 2:
+ return pi + tiny; /* atan(+...,-INF) */
+ case 3:
+ return -pi - tiny; /* atan(-...,-INF) */
+ }
+ }
+ }
+ /* when y is INF */
+ if (iy == 0x7ff00000)
+ return (hy < 0) ? -pi_o_2 - tiny : pi_o_2 + tiny;
+
+ /* compute y/x */
+ k = (iy - ix) >> 20;
+ if (k > 60)
+ z = pi_o_2 + 0.5 * pi_lo; /* |y/x| > 2**60 */
+ else if (hx < 0 && k < -60)
+ z = 0.0; /* |y|/x < -2**60 */
+ else
+ z = atan(fabs(y / x)); /* safe to do y/x */
+ switch (m) {
+ case 0:
+ return z; /* atan(+,+) */
+ case 1:
+ __HI(z) ^= 0x80000000;
+ return z; /* atan(-,+) */
+ case 2:
+ return pi - (z - pi_lo); /* atan(+,-) */
+ default: /* case 3 */
+ return (z - pi_lo) - pi; /* atan(-,-) */
+ }
+}