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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/s_tan.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/s_tan.c')
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diff --git a/src/MSL_C.PPCEABI.bare.H/s_tan.c b/src/MSL_C.PPCEABI.bare.H/s_tan.c
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+/* @(#)s_tan.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.
+ * ====================================================
+ */
+
+/* tan(x)
+ * Return tangent function of x.
+ *
+ * kernel function:
+ * __kernel_tan ... tangent function on [-pi/4,pi/4]
+ * __ieee754_rem_pio2 ... argument reduction routine
+ *
+ * Method.
+ * Let S,C and T denote the sin, cos and tan respectively on
+ * [-PI/4, +PI/4]. Reduce the argument x to y1+y2 = x-k*pi/2
+ * in [-pi/4 , +pi/4], and let n = k mod 4.
+ * We have
+ *
+ * n sin(x) cos(x) tan(x)
+ * ----------------------------------------------------------
+ * 0 S C T
+ * 1 C -S -1/T
+ * 2 -S -C T
+ * 3 -C S -1/T
+ * ----------------------------------------------------------
+ *
+ * Special cases:
+ * Let trig be any of sin, cos, or tan.
+ * trig(+-INF) is NaN, with signals;
+ * trig(NaN) is that NaN;
+ *
+ * Accuracy:
+ * TRIG(x) returns trig(x) nearly rounded
+ */
+
+#include "fdlibm.h"
+
+#ifdef __STDC__
+double tan(double x)
+#else
+double tan(x)
+double x;
+#endif
+{
+ double y[2], z = 0.0;
+ _INT32 n, ix;
+
+ /* High word of x. */
+ ix = __HI(x);
+
+ /* |x| ~< pi/4 */
+ ix &= 0x7fffffff;
+ if (ix <= 0x3fe921fb)
+ return __kernel_tan(x, z, 1);
+
+ /* tan(Inf or NaN) is NaN */
+ else if (ix >= 0x7ff00000)
+ return x - x; /* NaN */
+
+ /* argument reduction needed */
+ else {
+ n = __ieee754_rem_pio2(x, y);
+ return __kernel_tan(y[0], y[1], 1 - ((n & 1) << 1)); /* 1 -- n even
+ -1 -- n odd */
+ }
+}