[Feature]add MT2731_MP2_MR2_SVN388 baseline version
Change-Id: Ief04314834b31e27effab435d3ca8ba33b499059
diff --git a/src/bsp/lk/lib/libm/k_cos.c b/src/bsp/lk/lib/libm/k_cos.c
new file mode 100644
index 0000000..b6412bf
--- /dev/null
+++ b/src/bsp/lk/lib/libm/k_cos.c
@@ -0,0 +1,79 @@
+
+/* @(#)k_cos.c 1.3 95/01/18 */
+/*
+ * ====================================================
+ * 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.
+ * ====================================================
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+/*
+ * __kernel_cos( x, y )
+ * kernel cos function on [-pi/4, pi/4], pi/4 ~ 0.785398164
+ * Input x is assumed to be bounded by ~pi/4 in magnitude.
+ * Input y is the tail of x.
+ *
+ * Algorithm
+ * 1. Since cos(-x) = cos(x), we need only to consider positive x.
+ * 2. if x < 2^-27 (hx<0x3e400000 0), return 1 with inexact if x!=0.
+ * 3. cos(x) is approximated by a polynomial of degree 14 on
+ * [0,pi/4]
+ * 4 14
+ * cos(x) ~ 1 - x*x/2 + C1*x + ... + C6*x
+ * where the remez error is
+ *
+ * | 2 4 6 8 10 12 14 | -58
+ * |cos(x)-(1-.5*x +C1*x +C2*x +C3*x +C4*x +C5*x +C6*x )| <= 2
+ * | |
+ *
+ * 4 6 8 10 12 14
+ * 4. let r = C1*x +C2*x +C3*x +C4*x +C5*x +C6*x , then
+ * cos(x) ~ 1 - x*x/2 + r
+ * since cos(x+y) ~ cos(x) - sin(x)*y
+ * ~ cos(x) - x*y,
+ * a correction term is necessary in cos(x) and hence
+ * cos(x+y) = 1 - (x*x/2 - (r - x*y))
+ * For better accuracy, rearrange to
+ * cos(x+y) ~ w + (tmp + (r-x*y))
+ * where w = 1 - x*x/2 and tmp is a tiny correction term
+ * (1 - x*x/2 == w + tmp exactly in infinite precision).
+ * The exactness of w + tmp in infinite precision depends on w
+ * and tmp having the same precision as x. If they have extra
+ * precision due to compiler bugs, then the extra precision is
+ * only good provided it is retained in all terms of the final
+ * expression for cos(). Retention happens in all cases tested
+ * under FreeBSD, so don't pessimize things by forcibly clipping
+ * any extra precision in w.
+ */
+
+#include "math.h"
+#include "math_private.h"
+
+static const double
+one = 1.00000000000000000000e+00, /* 0x3FF00000, 0x00000000 */
+C1 = 4.16666666666666019037e-02, /* 0x3FA55555, 0x5555554C */
+C2 = -1.38888888888741095749e-03, /* 0xBF56C16C, 0x16C15177 */
+C3 = 2.48015872894767294178e-05, /* 0x3EFA01A0, 0x19CB1590 */
+C4 = -2.75573143513906633035e-07, /* 0xBE927E4F, 0x809C52AD */
+C5 = 2.08757232129817482790e-09, /* 0x3E21EE9E, 0xBDB4B1C4 */
+C6 = -1.13596475577881948265e-11; /* 0xBDA8FAE9, 0xBE8838D4 */
+
+double
+__kernel_cos(double x, double y)
+{
+ double hz,z,r,w;
+
+ z = x*x;
+ w = z*z;
+ r = z*(C1+z*(C2+z*C3)) + w*w*(C4+z*(C5+z*C6));
+ hz = 0.5*z;
+ w = one-hz;
+ return w + (((one-w)-hz) + (z*r-x*y));
+}