view include/SDL_platform.h @ 3162:dc1eb82ffdaa

Von: Thomas Zimmermann Betreff: [SDL] [PATCH] Make static variables const Datum: Tue, 19 May 2009 19:45:37 +0200 Hi, this is a set of simple changes which make some of SDL's internal static arrays constant. The purpose is to shrink the number of write-able static bytes and thus increase the number of memory pages shared between SDL applications. The patch set is against trunk@4513. Each of the attached patch files is specific to a sub-system. The set is completed by a second mail, because of the list's 40 KiB limit. The files readelf-r4513.txt and readelf-const-patch.txt where made by calling 'readelf -S libSDL.so'. They show the difference in ELF sections without and with the patch. Some numbers measured on my x86-64: Before [13] .rodata PROGBITS 00000000000eaaa0 000eaaa0 0000000000008170 0000000000000000 A 0 0 32 [19] .data.rel.ro PROGBITS 00000000003045e0 001045e0 00000000000023d0 0000000000000000 WA 0 0 32 [23] .data PROGBITS 00000000003076e0 001076e0 0000000000004988 0000000000000000 WA 0 0 32 After [13] .rodata PROGBITS 00000000000eaaa0 000eaaa0 0000000000009a50 0000000000000000 A 0 0 32 [19] .data.rel.ro PROGBITS 0000000000306040 00106040 0000000000002608 0000000000000000 WA 0 0 32 [23] .data PROGBITS 0000000000309360 00109360 0000000000002e88 0000000000000000 WA 0 0 32 The size of the write-able data section decreased considerably. Some entries became const-after-relocation, while most of its content went straight into the read-only data section. Best regards, Thomas
author Sam Lantinga <slouken@libsdl.org>
date Wed, 03 Jun 2009 04:37:27 +0000
parents cf09447f3d3c
children 245a7d79577c
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/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2009 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
*/

/* Try to get a standard set of platform defines */

#ifndef _SDL_platform_h
#define _SDL_platform_h

#if defined(_AIX)
#undef __AIX__
#define __AIX__		1
#endif
#if defined(__BEOS__)
#undef __BEOS__
#define __BEOS__	1
#endif
#if defined(bsdi) || defined(__bsdi) || defined(__bsdi__)
#undef __BSDI__
#define __BSDI__	1
#endif
#if defined(_arch_dreamcast)
#undef __DREAMCAST__
#define __DREAMCAST__	1
#endif
#if defined(__FreeBSD__) || defined(__DragonFly__)
#undef __FREEBSD__
#define __FREEBSD__	1
#endif
#if defined(hpux) || defined(__hpux) || defined(__hpux__)
#undef __HPUX__
#define __HPUX__	1
#endif
#if defined(sgi) || defined(__sgi) || defined(__sgi__) || defined(_SGI_SOURCE)
#undef __IRIX__
#define __IRIX__	1
#endif
#if defined(linux) || defined(__linux) || defined(__linux__)
#undef __LINUX__
#define __LINUX__	1
#endif

#if defined(__APPLE__)
/* lets us know what version of Mac OS X we're compiling on */
#include "AvailabilityMacros.h"
#ifdef MAC_OS_X_VERSION_10_3
#include "TargetConditionals.h" /* this header is in 10.3 or later */
#if TARGET_OS_IPHONE
/* if compiling for iPhone */
#undef __IPHONEOS__
#define __IPHONEOS__ 1
#undef __MACOSX__
#else
/* if not compiling for iPhone */
#undef __MACOSX__
#define __MACOSX__	1
#endif /* TARGET_OS_IPHONE */
#else
/* if earlier verion of Mac OS X than version 10.3 */
#undef __MACOSX__
#define __MACOSX__	1
#endif

#endif /* defined(__APPLE__) */

#if defined(__NetBSD__)
#undef __NETBSD__
#define __NETBSD__	1
#endif
#if defined(__OpenBSD__)
#undef __OPENBSD__
#define __OPENBSD__	1
#endif
#if defined(__OS2__)
#undef __OS2__
#define __OS2__		1
#endif
#if defined(osf) || defined(__osf) || defined(__osf__) || defined(_OSF_SOURCE)
#undef __OSF__
#define __OSF__		1
#endif
#if defined(__QNXNTO__)
#undef __QNXNTO__
#define __QNXNTO__	1
#endif
#if defined(riscos) || defined(__riscos) || defined(__riscos__)
#undef __RISCOS__
#define __RISCOS__	1
#endif
#if defined(__SVR4)
#undef __SOLARIS__
#define __SOLARIS__	1
#endif
#if defined(WIN32) || defined(_WIN32)
#undef __WIN32__
#define __WIN32__	1
#endif

#if defined(__NDS__)
#undef __NINTENDODS__
#define __NINTENDODS__	1
#endif

#endif /* _SDL_platform_h */