view src/thread/SDL_systhread.h @ 2752:edd2839b36f7

http://sources.redhat.com/ml/newlib/2002/msg00230.html Stephen L Moshier wrote: > > pow(x,y) returns 0 when x is very close to -1.0 and y is very large. > The following test program prints > > pow(1.0000000000000002e+00 4.5035996273704970e+15) = 2.7182818284590455e+00 > pow(-1.0000000000000002e+00 4.5035996273704970e+15) =0.0000000000000000e+00 > pow(9.9999999999999978e-01 4.5035996273704970e+15) = 3.6787944117144222e-01 > pow(-9.9999999999999978e-01 4.5035996273704970e+15) = 0.0000000000000000e+00 > > which is incorrect for the negative arguments raised to an odd integer > power. > > ----- > double pow (double, double); > > int > main () > { > double x, y, z; > > x = 1.0 + pow (2.0, -52.0); > y = 1.0 + pow (2.0, 52.0); > z = pow (x, y); > printf ("pow(%.16e %.16e) = %.16e\n", x, y, z); > x = -x; > z = pow (x, y); > printf ("pow(%.16e %.16e) = %.16e\n", x, y, z); > x = 1.0 - pow (2.0, -52.0); > z = pow (x, y); > printf ("pow(%.16e %.16e) = %.16e\n", x, y, z); > x = -x; > z = pow (x, y); > printf ("pow(%.16e %.16e) = %.16e\n", x, y, z); > } > ----- > > Here is a patch for newlib/libm/math/epow.c: Patch checked in and duplicated for ef_pow.c. Thanks. -- Jeff J.
author Sam Lantinga <slouken@libsdl.org>
date Mon, 15 Sep 2008 04:31:30 +0000
parents c121d94672cb
children 4436464c4f51
line wrap: on
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/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2006 Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Sam Lantinga
    slouken@libsdl.org
*/
#include "SDL_config.h"

/* These are functions that need to be implemented by a port of SDL */

#ifndef _SDL_systhread_h
#define _SDL_systhread_h

#include "SDL_thread.h"

/* This function creates a thread, passing args to SDL_RunThread(),
   saves a system-dependent thread id in thread->id, and returns 0
   on success.
*/
#ifdef SDL_PASSED_BEGINTHREAD_ENDTHREAD
extern int SDL_SYS_CreateThread(SDL_Thread * thread, void *args,
                                pfnSDL_CurrentBeginThread pfnBeginThread,
                                pfnSDL_CurrentEndThread pfnEndThread);
#else
extern int SDL_SYS_CreateThread(SDL_Thread * thread, void *args);
#endif

/* This function does any necessary setup in the child thread */
extern void SDL_SYS_SetupThread(void);

/* This function waits for the thread to finish and frees any data
   allocated by SDL_SYS_CreateThread()
 */
extern void SDL_SYS_WaitThread(SDL_Thread * thread);

/* This function kills the thread and returns */
extern void SDL_SYS_KillThread(SDL_Thread * thread);

#endif /* _SDL_systhread_h */
/* vi: set ts=4 sw=4 expandtab: */