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0e45984fa0
The internal function SDL_EGL_LoadLibrary() did not delete and remove a mostly uninitialized data structure if loading the library first failed. A later try to use EGL then skipped initialization and assumed it was previously successful because the data structure now already existed. This led to at least one crash in the internal function SDL_EGL_ChooseConfig() because a NULL pointer was dereferenced to make a call to eglBindAPI().
101 lines
3.3 KiB
C
101 lines
3.3 KiB
C
/* @(#)k_cos.c 5.1 93/09/24 */
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/*
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* ====================================================
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* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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*
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* Developed at SunPro, a Sun Microsystems, Inc. business.
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* Permission to use, copy, modify, and distribute this
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* software is freely granted, provided that this notice
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* is preserved.
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* ====================================================
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*/
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#if defined(LIBM_SCCS) && !defined(lint)
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static const char rcsid[] =
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"$NetBSD: k_cos.c,v 1.8 1995/05/10 20:46:22 jtc Exp $";
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#endif
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/*
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* __kernel_cos( x, y )
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* kernel cos function on [-pi/4, pi/4], pi/4 ~ 0.785398164
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* Input x is assumed to be bounded by ~pi/4 in magnitude.
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* Input y is the tail of x.
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*
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* Algorithm
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* 1. Since cos(-x) = cos(x), we need only to consider positive x.
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* 2. if x < 2^-27 (hx<0x3e400000 0), return 1 with inexact if x!=0.
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* 3. cos(x) is approximated by a polynomial of degree 14 on
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* [0,pi/4]
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* 4 14
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* cos(x) ~ 1 - x*x/2 + C1*x + ... + C6*x
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* where the remez error is
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*
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* | 2 4 6 8 10 12 14 | -58
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* |cos(x)-(1-.5*x +C1*x +C2*x +C3*x +C4*x +C5*x +C6*x )| <= 2
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* | |
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*
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* 4 6 8 10 12 14
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* 4. let r = C1*x +C2*x +C3*x +C4*x +C5*x +C6*x , then
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* cos(x) = 1 - x*x/2 + r
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* since cos(x+y) ~ cos(x) - sin(x)*y
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* ~ cos(x) - x*y,
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* a correction term is necessary in cos(x) and hence
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* cos(x+y) = 1 - (x*x/2 - (r - x*y))
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* For better accuracy when x > 0.3, let qx = |x|/4 with
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* the last 32 bits mask off, and if x > 0.78125, let qx = 0.28125.
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* Then
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* cos(x+y) = (1-qx) - ((x*x/2-qx) - (r-x*y)).
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* Note that 1-qx and (x*x/2-qx) is EXACT here, and the
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* magnitude of the latter is at least a quarter of x*x/2,
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* thus, reducing the rounding error in the subtraction.
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*/
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#include "math_libm.h"
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#include "math_private.h"
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#ifdef __STDC__
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static const double
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#else
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static double
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#endif
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one = 1.00000000000000000000e+00, /* 0x3FF00000, 0x00000000 */
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C1 = 4.16666666666666019037e-02, /* 0x3FA55555, 0x5555554C */
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C2 = -1.38888888888741095749e-03, /* 0xBF56C16C, 0x16C15177 */
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C3 = 2.48015872894767294178e-05, /* 0x3EFA01A0, 0x19CB1590 */
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C4 = -2.75573143513906633035e-07, /* 0xBE927E4F, 0x809C52AD */
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C5 = 2.08757232129817482790e-09, /* 0x3E21EE9E, 0xBDB4B1C4 */
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C6 = -1.13596475577881948265e-11; /* 0xBDA8FAE9, 0xBE8838D4 */
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#ifdef __STDC__
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double attribute_hidden
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__kernel_cos(double x, double y)
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#else
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double attribute_hidden
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__kernel_cos(x, y)
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double x, y;
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#endif
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{
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double a, hz, z, r, qx;
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int32_t ix;
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GET_HIGH_WORD(ix, x);
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ix &= 0x7fffffff; /* ix = |x|'s high word */
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if (ix < 0x3e400000) { /* if x < 2**27 */
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if (((int) x) == 0)
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return one; /* generate inexact */
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}
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z = x * x;
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r = z * (C1 + z * (C2 + z * (C3 + z * (C4 + z * (C5 + z * C6)))));
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if (ix < 0x3FD33333) /* if |x| < 0.3 */
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return one - (0.5 * z - (z * r - x * y));
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else {
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if (ix > 0x3fe90000) { /* x > 0.78125 */
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qx = 0.28125;
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} else {
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INSERT_WORDS(qx, ix - 0x00200000, 0); /* x/4 */
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}
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hz = 0.5 * z - qx;
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a = one - qx;
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return a - (hz - (z * r - x * y));
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}
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}
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