| | |
| | | /* @(#)k_cos.c 5.1 93/09/24 */ |
| | | /* |
| | | * ==================================================== |
| | | * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. |
| | |
| | | * is preserved. |
| | | * ==================================================== |
| | | */ |
| | | |
| | | #if defined(LIBM_SCCS) && !defined(lint) |
| | | static const char rcsid[] = |
| | | "$NetBSD: k_cos.c,v 1.8 1995/05/10 20:46:22 jtc Exp $"; |
| | | #endif |
| | | |
| | | /* |
| | | * __kernel_cos( x, y ) |
| | |
| | | #include "math_libm.h" |
| | | #include "math_private.h" |
| | | |
| | | #ifdef __STDC__ |
| | | static const double |
| | | #else |
| | | static double |
| | | #endif |
| | | 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 */ |
| | | 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 */ |
| | | |
| | | #ifdef __STDC__ |
| | | double attribute_hidden |
| | | __kernel_cos(double x, double y) |
| | | #else |
| | | double attribute_hidden |
| | | __kernel_cos(x, y) |
| | | double x, y; |
| | | #endif |
| | | double attribute_hidden __kernel_cos(double x, double y) |
| | | { |
| | | double a, hz, z, r, qx; |
| | | int32_t ix; |
| | | GET_HIGH_WORD(ix, x); |
| | | ix &= 0x7fffffff; /* ix = |x|'s high word */ |
| | | if (ix < 0x3e400000) { /* if x < 2**27 */ |
| | | if (((int) x) == 0) |
| | | return one; /* generate inexact */ |
| | | } |
| | | z = x * x; |
| | | r = z * (C1 + z * (C2 + z * (C3 + z * (C4 + z * (C5 + z * C6))))); |
| | | if (ix < 0x3FD33333) /* if |x| < 0.3 */ |
| | | return one - (0.5 * z - (z * r - x * y)); |
| | | else { |
| | | if (ix > 0x3fe90000) { /* x > 0.78125 */ |
| | | qx = 0.28125; |
| | | } else { |
| | | INSERT_WORDS(qx, ix - 0x00200000, 0); /* x/4 */ |
| | | } |
| | | hz = 0.5 * z - qx; |
| | | a = one - qx; |
| | | return a - (hz - (z * r - x * y)); |
| | | } |
| | | double a,hz,z,r,qx; |
| | | int32_t ix; |
| | | GET_HIGH_WORD(ix,x); |
| | | ix &= 0x7fffffff; /* ix = |x|'s high word*/ |
| | | if(ix<0x3e400000) { /* if x < 2**27 */ |
| | | if(((int)x)==0) return one; /* generate inexact */ |
| | | } |
| | | z = x*x; |
| | | r = z*(C1+z*(C2+z*(C3+z*(C4+z*(C5+z*C6))))); |
| | | if(ix < 0x3FD33333) /* if |x| < 0.3 */ |
| | | return one - (0.5*z - (z*r - x*y)); |
| | | else { |
| | | if(ix > 0x3fe90000) { /* x > 0.78125 */ |
| | | qx = 0.28125; |
| | | } else { |
| | | INSERT_WORDS(qx,ix-0x00200000,0); /* x/4 */ |
| | | } |
| | | hz = 0.5*z-qx; |
| | | a = one-qx; |
| | | return a - (hz - (z*r-x*y)); |
| | | } |
| | | } |