view src/libm/e_log.c @ 4447:947201caa46e

Added automated test to Xcode project plus needed changes to SDL_RWFromFile to be OS X bundle aware. The Mac OS X project has a new target called testsdl which builds the automated test. I looked at using Xcode's native unit test support, but the impedance mismatch between the existing automated test structure and Apple's was more than I could handle. As such, the testsdl application is a full blown proper OS X application, which means it is a self-contained .app bundle. This immediately revealed some problems from the automated test. The largest problem was the assumption about the current working directory and where to find resources. (I suspect Windows may have a similar problem depending on circumstance.) To open resources, the test was looking in directories relative to the SDL source directory, but this will not work well with self-contained .app bundles and Xcode which can place its built applications almost anywhere. And for real-world situations, this is pretty useless anyway. So I modified SDL_RWFromFile to do special things on OS X. First, it will look for a file in the .app bundle. If not found, it will fallback and just call fopen as it used to do. I also had to modify the automated test itself because it had a contrieved test which called fopen directly to do read from an existing FILE pointer. In addition, there was a write test. Since a .app bundle is likely going to be read-only, I added a special case for OS X to write to NSTemporaryDirectory. I expect these changes should work for both Mac and iPhone OS (which includes iPad). I will update the iPhone Xcode project next. Finally, FYI, the X11 automated test seems to be failing. Below is my output. Pending breakpoint 4 - "-[NSException raise]" resolved Platform : All tests successful (2) SDL_RWops : All tests successful (5) Rect : All tests successful (1) SDL_Surface : All tests successful (6) Rendering with cocoa driver : All tests successful (3) Assert Failed! Blit output not the same. Test Case 'Renderer x11' Test Suite 'Rendering with x11 driver' Last SDL error '' Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSGetSurfaceBounds Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorFailure: Set a breakpoint @ CGErrorBreakpoint() to catch errors as they are logged. Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSBindSurface: Invalid window 0xa150 Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSBindSurface: Invalid window 0xa150 Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSBindSurface: Invalid window 0xa150 Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSGetWindowBounds Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSGetSurfaceBounds Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSBindSurface: Invalid window 0xa150 Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSBindSurface: Invalid window 0xa150 Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSBindSurface: Invalid window 0xa150 Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSGetWindowBounds Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSGetSurfaceBounds Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSBindSurface: Invalid window 0xa150 Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSBindSurface: Invalid window 0xa150 Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSBindSurface: Invalid window 0xa150 Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSGetWindowBounds Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSGetSurfaceBounds Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSBindSurface: Invalid window 0xa150 Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSBindSurface: Invalid window 0xa150 Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSBindSurface: Invalid window 0xa150 Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSGetWindowBounds Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSGetSurfaceBounds Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSBindSurface: Invalid window 0xa150 Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSBindSurface: Invalid window 0xa150 Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSBindSurface: Invalid window 0xa150 Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSGetWindowBounds Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSGetSurfaceBounds Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSBindSurface: Invalid window 0xa150 Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSBindSurface: Invalid window 0xa150 Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSBindSurface: Invalid window 0xa150 Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSGetWindowBounds Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSGetSurfaceBounds Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSBindSurface: Invalid window 0xa150 Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSBindSurface: Invalid window 0xa150 Sat May 8 00:30:34 iMacAL.local testsdl[71586] <Error>: kCGErrorIllegalArgument: CGSBindSurface: Invalid window 0xa150 Rendering with x11 driver : Failed 1 out of 4 testcases! Rendering with dummy driver : All tests successful (3) SDL_Audio : All tests successful (1) Tests run with SDL 1.3.0 revision 1095906 System is running Mac OS X and is little endian
author Eric Wing <ewing . public |-at-| gmail . com>
date Sat, 08 May 2010 00:54:22 -0700
parents dc1eb82ffdaa
children
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/* @(#)e_log.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 const char rcsid[] =
    "$NetBSD: e_log.c,v 1.8 1995/05/10 20:45:49 jtc Exp $";
#endif

/* __ieee754_log(x)
 * Return the logrithm of x
 *
 * Method :
 *   1. Argument Reduction: find k and f such that
 *			x = 2^k * (1+f),
 *	   where  sqrt(2)/2 < 1+f < sqrt(2) .
 *
 *   2. Approximation of log(1+f).
 *	Let s = f/(2+f) ; based on log(1+f) = log(1+s) - log(1-s)
 *		 = 2s + 2/3 s**3 + 2/5 s**5 + .....,
 *	     	 = 2s + s*R
 *      We use a special Reme algorithm on [0,0.1716] to generate
 * 	a polynomial of degree 14 to approximate R The maximum error
 *	of this polynomial approximation is bounded by 2**-58.45. In
 *	other words,
 *		        2      4      6      8      10      12      14
 *	    R(z) ~ Lg1*s +Lg2*s +Lg3*s +Lg4*s +Lg5*s  +Lg6*s  +Lg7*s
 *  	(the values of Lg1 to Lg7 are listed in the program)
 *	and
 *	    |      2          14          |     -58.45
 *	    | Lg1*s +...+Lg7*s    -  R(z) | <= 2
 *	    |                             |
 *	Note that 2s = f - s*f = f - hfsq + s*hfsq, where hfsq = f*f/2.
 *	In order to guarantee error in log below 1ulp, we compute log
 *	by
 *		log(1+f) = f - s*(f - R)	(if f is not too large)
 *		log(1+f) = f - (hfsq - s*(hfsq+R)).	(better accuracy)
 *
 *	3. Finally,  log(x) = k*ln2 + log(1+f).
 *			    = k*ln2_hi+(f-(hfsq-(s*(hfsq+R)+k*ln2_lo)))
 *	   Here ln2 is split into two floating point number:
 *			ln2_hi + ln2_lo,
 *	   where n*ln2_hi is always exact for |n| < 2000.
 *
 * Special cases:
 *	log(x) is NaN with signal if x < 0 (including -INF) ;
 *	log(+INF) is +INF; log(0) is -INF with signal;
 *	log(NaN) is that NaN with no signal.
 *
 * Accuracy:
 *	according to an error analysis, the error is always less than
 *	1 ulp (unit in the last place).
 *
 * Constants:
 * The hexadecimal values are the intended ones for the following
 * constants. The decimal values may be used, provided that the
 * compiler will convert from decimal to binary accurately enough
 * to produce the hexadecimal values shown.
 */

#include "math.h"
#include "math_private.h"

#ifdef __STDC__
static const double
#else
static double
#endif
  ln2_hi = 6.93147180369123816490e-01,  /* 3fe62e42 fee00000 */
    ln2_lo = 1.90821492927058770002e-10,        /* 3dea39ef 35793c76 */
    two54 = 1.80143985094819840000e+16, /* 43500000 00000000 */
    Lg1 = 6.666666666666735130e-01,     /* 3FE55555 55555593 */
    Lg2 = 3.999999999940941908e-01,     /* 3FD99999 9997FA04 */
    Lg3 = 2.857142874366239149e-01,     /* 3FD24924 94229359 */
    Lg4 = 2.222219843214978396e-01,     /* 3FCC71C5 1D8E78AF */
    Lg5 = 1.818357216161805012e-01,     /* 3FC74664 96CB03DE */
    Lg6 = 1.531383769920937332e-01,     /* 3FC39A09 D078C69F */
    Lg7 = 1.479819860511658591e-01;     /* 3FC2F112 DF3E5244 */

#ifdef __STDC__
static const double zero = 0.0;
#else
static double zero = 0.0;
#endif

#ifdef __STDC__
double attribute_hidden
__ieee754_log(double x)
#else
double attribute_hidden
__ieee754_log(x)
     double x;
#endif
{
    double hfsq, f, s, z, R, w, t1, t2, dk;
    int32_t k, hx, i, j;
    u_int32_t lx;

    EXTRACT_WORDS(hx, lx, x);

    k = 0;
    if (hx < 0x00100000) {      /* x < 2**-1022  */
        if (((hx & 0x7fffffff) | lx) == 0)
            return -two54 / zero;       /* log(+-0)=-inf */
        if (hx < 0)
            return (x - x) / zero;      /* log(-#) = NaN */
        k -= 54;
        x *= two54;             /* subnormal number, scale up x */
        GET_HIGH_WORD(hx, x);
    }
    if (hx >= 0x7ff00000)
        return x + x;
    k += (hx >> 20) - 1023;
    hx &= 0x000fffff;
    i = (hx + 0x95f64) & 0x100000;
    SET_HIGH_WORD(x, hx | (i ^ 0x3ff00000));    /* normalize x or x/2 */
    k += (i >> 20);
    f = x - 1.0;
    if ((0x000fffff & (2 + hx)) < 3) {  /* |f| < 2**-20 */
        if (f == zero) {
            if (k == 0)
                return zero;
            else {
                dk = (double) k;
                return dk * ln2_hi + dk * ln2_lo;
            }
        }
        R = f * f * (0.5 - 0.33333333333333333 * f);
        if (k == 0)
            return f - R;
        else {
            dk = (double) k;
            return dk * ln2_hi - ((R - dk * ln2_lo) - f);
        }
    }
    s = f / (2.0 + f);
    dk = (double) k;
    z = s * s;
    i = hx - 0x6147a;
    w = z * z;
    j = 0x6b851 - hx;
    t1 = w * (Lg2 + w * (Lg4 + w * Lg6));
    t2 = z * (Lg1 + w * (Lg3 + w * (Lg5 + w * Lg7)));
    i |= j;
    R = t2 + t1;
    if (i > 0) {
        hfsq = 0.5 * f * f;
        if (k == 0)
            return f - (hfsq - s * (hfsq + R));
        else
            return dk * ln2_hi - ((hfsq - (s * (hfsq + R) + dk * ln2_lo)) -
                                  f);
    } else {
        if (k == 0)
            return f - s * (f - R);
        else
            return dk * ln2_hi - ((s * (f - R) - dk * ln2_lo) - f);
    }
}