src/events/default_cursor.h
author Sam Lantinga
Wed, 03 Jun 2009 04:37:27 +0000
changeset 3162 dc1eb82ffdaa
parent 2859 99210400e8b9
child 3697 f7b03b6838cb
permissions -rw-r--r--
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
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/*
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    SDL - Simple DirectMedia Layer
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    Copyright (C) 1997-2009 Sam Lantinga
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    This library is free software; you can redistribute it and/or
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    modify it under the terms of the GNU Lesser General Public
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    License as published by the Free Software Foundation; either
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    version 2.1 of the License, or (at your option) any later version.
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    This library is distributed in the hope that it will be useful,
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    but WITHOUT ANY WARRANTY; without even the implied warranty of
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    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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    Lesser General Public License for more details.
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    You should have received a copy of the GNU Lesser General Public
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    License along with this library; if not, write to the Free Software
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    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
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    Sam Lantinga
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    slouken@libsdl.org
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*/
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/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * 
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 * Default cursor - it happens to be the Mac cursor, but could be anything   */
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#define DEFAULT_CWIDTH	16
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#define DEFAULT_CHEIGHT	16
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#define DEFAULT_CHOTX	0
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#define DEFAULT_CHOTY	0
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/* Added a real MacOS cursor, at the request of Luc-Olivier de Charrière */
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#define USE_MACOS_CURSOR
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#ifdef USE_MACOS_CURSOR
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static const unsigned char default_cdata[] = {
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    0x00, 0x00,
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    0x40, 0x00,
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    0x60, 0x00,
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    0x70, 0x00,
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    0x78, 0x00,
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    0x7C, 0x00,
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    0x7E, 0x00,
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    0x7F, 0x00,
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    0x7F, 0x80,
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    0x7C, 0x00,
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    0x6C, 0x00,
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    0x46, 0x00,
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    0x06, 0x00,
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    0x03, 0x00,
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    0x03, 0x00,
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    0x00, 0x00
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};
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static const unsigned char default_cmask[] = {
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    0xC0, 0x00,
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    0xE0, 0x00,
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    0xF0, 0x00,
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    0xF8, 0x00,
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    0xFC, 0x00,
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    0xFE, 0x00,
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    0xFF, 0x00,
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    0xFF, 0x80,
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    0xFF, 0xC0,
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    0xFF, 0xE0,
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    0xFE, 0x00,
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    0xEF, 0x00,
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    0xCF, 0x00,
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    0x87, 0x80,
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    0x07, 0x80,
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    0x03, 0x00
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};
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#else
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static const unsigned char default_cdata[] = {
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    0x00, 0x00,
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    0x40, 0x00,
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    0x60, 0x00,
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    0x70, 0x00,
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    0x78, 0x00,
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    0x7C, 0x00,
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    0x7E, 0x00,
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    0x7F, 0x00,
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    0x7F, 0x80,
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    0x7C, 0x00,
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    0x6C, 0x00,
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    0x46, 0x00,
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    0x06, 0x00,
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    0x03, 0x00,
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    0x03, 0x00,
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    0x00, 0x00
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};
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static const unsigned char default_cmask[] = {
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    0x40, 0x00,
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    0xE0, 0x00,
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    0xF0, 0x00,
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    0xF8, 0x00,
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    0xFC, 0x00,
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    0xFE, 0x00,
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    0xFF, 0x00,
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    0xFF, 0x80,
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    0xFF, 0xC0,
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    0xFF, 0x80,
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    0xFE, 0x00,
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    0xEF, 0x00,
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    0x4F, 0x00,
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    0x07, 0x80,
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    0x07, 0x80,
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    0x03, 0x00
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};
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#endif /* TRUE_MACINTOSH_CURSOR */
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/* vi: set ts=4 sw=4 expandtab: */