+++ /dev/null
-/* @(#)k_sin.c 5.1 93/09/24 */\r
-/*\r
- * ====================================================\r
- * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.\r
- *\r
- * Developed at SunPro, a Sun Microsystems, Inc. business.\r
- * Permission to use, copy, modify, and distribute this\r
- * software is freely granted, provided that this notice\r
- * is preserved.\r
- * ====================================================\r
- */\r
-#include <LibConfig.h>\r
-#include <sys/EfiCdefs.h>\r
-#if defined(LIBM_SCCS) && !defined(lint)\r
-__RCSID("$NetBSD: k_sin.c,v 1.11 2002/05/26 22:01:53 wiz Exp $");\r
-#endif\r
-\r
-/* __kernel_sin( x, y, iy)\r
- * kernel sin function on [-pi/4, pi/4], pi/4 ~ 0.7854\r
- * Input x is assumed to be bounded by ~pi/4 in magnitude.\r
- * Input y is the tail of x.\r
- * Input iy indicates whether y is 0. (if iy=0, y assume to be 0).\r
- *\r
- * Algorithm\r
- * 1. Since sin(-x) = -sin(x), we need only to consider positive x.\r
- * 2. if x < 2^-27 (hx<0x3e400000 0), return x with inexact if x!=0.\r
- * 3. sin(x) is approximated by a polynomial of degree 13 on\r
- * [0,pi/4]\r
- * 3 13\r
- * sin(x) ~ x + S1*x + ... + S6*x\r
- * where\r
- *\r
- * |sin(x) 2 4 6 8 10 12 | -58\r
- * |----- - (1+S1*x +S2*x +S3*x +S4*x +S5*x +S6*x )| <= 2\r
- * | x |\r
- *\r
- * 4. sin(x+y) = sin(x) + sin'(x')*y\r
- * ~ sin(x) + (1-x*x/2)*y\r
- * For better accuracy, let\r
- * 3 2 2 2 2\r
- * r = x *(S2+x *(S3+x *(S4+x *(S5+x *S6))))\r
- * then 3 2\r
- * sin(x) = x + (S1*x + (x *(r-y/2)+y))\r
- */\r
-\r
-#include "math.h"\r
-#include "math_private.h"\r
-\r
-static const double\r
-half = 5.00000000000000000000e-01, /* 0x3FE00000, 0x00000000 */\r
-S1 = -1.66666666666666324348e-01, /* 0xBFC55555, 0x55555549 */\r
-S2 = 8.33333333332248946124e-03, /* 0x3F811111, 0x1110F8A6 */\r
-S3 = -1.98412698298579493134e-04, /* 0xBF2A01A0, 0x19C161D5 */\r
-S4 = 2.75573137070700676789e-06, /* 0x3EC71DE3, 0x57B1FE7D */\r
-S5 = -2.50507602534068634195e-08, /* 0xBE5AE5E6, 0x8A2B9CEB */\r
-S6 = 1.58969099521155010221e-10; /* 0x3DE5D93A, 0x5ACFD57C */\r
-\r
-double\r
-__kernel_sin(double x, double y, int iy)\r
-{\r
- double z,r,v;\r
- int32_t ix;\r
- GET_HIGH_WORD(ix,x);\r
- ix &= 0x7fffffff; /* high word of x */\r
- if(ix<0x3e400000) /* |x| < 2**-27 */\r
- {if((int)x==0) return x;} /* generate inexact */\r
- z = x*x;\r
- v = z*x;\r
- r = S2+z*(S3+z*(S4+z*(S5+z*S6)));\r
- if(iy==0) return x+v*(S1+z*r);\r
- else return x-((z*(half*y-v*r)-y)-v*S1);\r
-}\r