--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/libm/k_sin.c	Mon Sep 15 06:33:23 2008 +0000
@@ -0,0 +1,86 @@
+/* @(#)k_sin.c 5.1 93/09/24 */
+/*
+ * ====================================================
+ * 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.
+ * ====================================================
+ */
+
+#if defined(LIBM_SCCS) && !defined(lint)
+static char rcsid[] = "$NetBSD: k_sin.c,v 1.8 1995/05/10 20:46:31 jtc Exp $";
+#endif
+
+/* __kernel_sin( x, y, iy)
+ * kernel sin function on [-pi/4, pi/4], pi/4 ~ 0.7854
+ * Input x is assumed to be bounded by ~pi/4 in magnitude.
+ * Input y is the tail of x.
+ * Input iy indicates whether y is 0. (if iy=0, y assume to be 0).
+ *
+ * Algorithm
+ *	1. Since sin(-x) = -sin(x), we need only to consider positive x.
+ *	2. if x < 2^-27 (hx<0x3e400000 0), return x with inexact if x!=0.
+ *	3. sin(x) is approximated by a polynomial of degree 13 on
+ *	   [0,pi/4]
+ *		  	         3            13
+ *	   	sin(x) ~ x + S1*x + ... + S6*x
+ *	   where
+ *
+ * 	|sin(x)         2     4     6     8     10     12  |     -58
+ * 	|----- - (1+S1*x +S2*x +S3*x +S4*x +S5*x  +S6*x   )| <= 2
+ * 	|  x 					           |
+ *
+ *	4. sin(x+y) = sin(x) + sin'(x')*y
+ *		    ~ sin(x) + (1-x*x/2)*y
+ *	   For better accuracy, let
+ *		     3      2      2      2      2
+ *		r = x *(S2+x *(S3+x *(S4+x *(S5+x *S6))))
+ *	   then                   3    2
+ *		sin(x) = x + (S1*x + (x *(r-y/2)+y))
+ */
+
+#include "math.h"
+#include "math_private.h"
+
+#ifdef __STDC__
+static const double
+#else
+static double
+#endif
+  half = 5.00000000000000000000e-01,    /* 0x3FE00000, 0x00000000 */
+    S1 = -1.66666666666666324348e-01,   /* 0xBFC55555, 0x55555549 */
+    S2 = 8.33333333332248946124e-03,    /* 0x3F811111, 0x1110F8A6 */
+    S3 = -1.98412698298579493134e-04,   /* 0xBF2A01A0, 0x19C161D5 */
+    S4 = 2.75573137070700676789e-06,    /* 0x3EC71DE3, 0x57B1FE7D */
+    S5 = -2.50507602534068634195e-08,   /* 0xBE5AE5E6, 0x8A2B9CEB */
+    S6 = 1.58969099521155010221e-10;    /* 0x3DE5D93A, 0x5ACFD57C */
+
+#ifdef __STDC__
+double attribute_hidden
+__kernel_sin(double x, double y, int iy)
+#else
+double attribute_hidden
+__kernel_sin(x, y, iy)
+     double x, y;
+     int iy;                    /* iy=0 if y is zero */
+#endif
+{
+    double z, r, v;
+    int32_t ix;
+    GET_HIGH_WORD(ix, x);
+    ix &= 0x7fffffff;           /* high word of x */
+    if (ix < 0x3e400000) {      /* |x| < 2**-27 */
+        if ((int) x == 0)
+            return x;
+    }                           /* generate inexact */
+    z = x * x;
+    v = z * x;
+    r = S2 + z * (S3 + z * (S4 + z * (S5 + z * S6)));
+    if (iy == 0)
+        return x + v * (S1 + z * r);
+    else
+        return x - ((z * (half * y - v * r) - y) - v * S1);
+}