Mercurial > sdl-ios-xcode

view src/audio/SDL_mixer_m68k.c @ 2318:0c653886cce7

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
HandleEvent() returns done each time it is called. If done was set to 0 the program should quit, but because done is not checked until *all* events are handled a following event can reset done to 1 and prevent the program from terminating when told to. I fixed the while loop that handles events to check for the state of done after handling each event. That could leave some events unhandled when the program exits, but it ensures that the program will exit.
author Bob Pendleton <bob@pendleton.com>
date Wed, 20 Feb 2008 23:27:33 +0000
parents c121d94672cb
children 99210400e8b9
line wrap: on
line source

/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2004 Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either
    version 2 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
    Library General Public License for more details.

    You should have received a copy of the GNU Library General Public
    License along with this library; if not, write to the Free
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

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

/*
	m68k assembly mix routines

	Patrice Mandin
*/

#if defined(__M68000__) && defined(__GNUC__)
void
SDL_MixAudio_m68k_U8(char *dst, char *src, long len, long volume, char *mix8)
{
    __asm__ __volatile__("tstl	%2\n" "	beqs	stoploop_u8\n" "mixloop_u8:\n"
                         /* Mix a sample */
                         "	moveq	#0,%%d0\n" "	moveq	#0,%%d1\n" "	moveb	%1@+,%%d0\n"    /* d0 = *src++ */
                         "	sub	#128,%%d0\n"    /* d0 -= 128 */
                         "	muls	%3,%%d0\n"      /* d0 *= volume (0<=volume<=128) */
                         "	moveb	%0@,%%d1\n"     /* d1 = *dst */
                         "	asr	#7,%%d0\n"      /* d0 /= 128 (SDL_MIX_MAXVOLUME) */
                         "	add	#128,%%d0\n"    /* d0 += 128 */
                         "	add	%%d1,%%d0\n"
                         "	moveb	%4@(%%d0:w),%0@+\n"
                         /* Loop till done */
                         "	subql	#1,%2\n" "	bhis	mixloop_u8\n" "stoploop_u8:\n": /* no return value */
                         :      /* input */
                         "a"(dst), "a"(src), "d"(len), "d"(volume), "a"(mix8):  /* clobbered registers */
                         "d0", "d1", "cc", "memory");
}

void
SDL_MixAudio_m68k_S8(char *dst, char *src, long len, long volume)
{
    __asm__ __volatile__("tstl	%2\n"
                         "	beqs	stoploop_s8\n"
                         "	moveq	#-128,%%d2\n"
                         "	moveq	#127,%%d3\n" "mixloop_s8:\n"
                         /* Mix a sample */
                         "	moveq	#0,%%d0\n" "	moveq	#0,%%d1\n" "	moveb	%1@+,%%d0\n"    /* d0 = *src++ */
                         "	muls	%3,%%d0\n"      /* d0 *= volume (0<=volume<=128) */
                         "	moveb	%0@,%%d1\n"     /* d1 = *dst */
                         "	asr	#7,%%d0\n"      /* d0 /= 128 (SDL_MIX_MAXVOLUME) */
                         "	add	%%d1,%%d0\n"
                         "	cmp	%%d2,%%d0\n"
                         "	bges	lower_limit_s8\n"
                         "	move	%%d2,%%d0\n"
                         "lower_limit_s8:\n"
                         "	cmp	%%d3,%%d0\n"
                         "	bles	upper_limit_s8\n"
                         "	move	%%d3,%%d0\n"
                         "upper_limit_s8:\n" "	moveb	%%d0,%0@+\n"
                         /* Loop till done */
                         "	subql	#1,%2\n" "	bhis	mixloop_s8\n" "stoploop_s8:\n": /* no return value */
                         :      /* input */
                         "a"(dst), "a"(src), "d"(len), "d"(volume):     /* clobbered registers */
                         "d0", "d1", "d2", "d3", "cc", "memory");
}

void
SDL_MixAudio_m68k_S16MSB(short *dst, short *src, long len, long volume)
{
    __asm__ __volatile__("tstl	%2\n"
                         "	beqs	stoploop_s16msb\n"
                         "	movel	#-32768,%%d2\n"
                         "	movel	#32767,%%d3\n"
                         "	lsrl	#1,%2\n" "mixloop_s16msb:\n"
                         /* Mix a sample */
                         "	move	%1@+,%%d0\n"    /* d0 = *src++ */
                         "	muls	%3,%%d0\n"      /* d0 *= volume (0<=volume<=128) */
                         "	move	%0@,%%d1\n"     /* d1 = *dst */
                         "	extl	%%d1\n" /* extend d1 to 32 bits */
                         "	asrl	#7,%%d0\n"      /* d0 /= 128 (SDL_MIX_MAXVOLUME) */
                         "	addl	%%d1,%%d0\n"
                         "	cmpl	%%d2,%%d0\n"
                         "	bges	lower_limit_s16msb\n"
                         "	move	%%d2,%%d0\n"
                         "lower_limit_s16msb:\n"
                         "	cmpl	%%d3,%%d0\n"
                         "	bles	upper_limit_s16msb\n"
                         "	move	%%d3,%%d0\n"
                         "upper_limit_s16msb:\n" "	move	%%d0,%0@+\n"
                         /* Loop till done */
                         "	subql	#1,%2\n" "	bhis	mixloop_s16msb\n" "stoploop_s16msb:\n": /* no return value */
                         :      /* input */
                         "a"(dst), "a"(src), "d"(len), "d"(volume):     /* clobbered registers */
                         "d0", "d1", "d2", "d3", "cc", "memory");
}

void
SDL_MixAudio_m68k_S16LSB(short *dst, short *src, long len, long volume)
{
    __asm__ __volatile__("tstl	%2\n"
                         "	beqs	stoploop_s16lsb\n"
                         "	movel	#-32768,%%d2\n"
                         "	movel	#32767,%%d3\n"
                         "	lsrl	#1,%2\n" "mixloop_s16lsb:\n"
                         /* Mix a sample */
                         "	move	%1@+,%%d0\n"    /* d0 = *src++ */
                         "	rorw	#8,%%d0\n" "	muls	%3,%%d0\n"      /* d0 *= volume (0<=volume<=128) */
                         "	move	%0@,%%d1\n"     /* d1 = *dst */
                         "	rorw	#8,%%d1\n" "	extl	%%d1\n" /* extend d1 to 32 bits */
                         "	asrl	#7,%%d0\n"      /* d0 /= 128 (SDL_MIX_MAXVOLUME) */
                         "	addl	%%d1,%%d0\n"
                         "	cmpl	%%d2,%%d0\n"
                         "	bges	lower_limit_s16lsb\n"
                         "	move	%%d2,%%d0\n"
                         "lower_limit_s16lsb:\n"
                         "	cmpl	%%d3,%%d0\n"
                         "	bles	upper_limit_s16lsb\n"
                         "	move	%%d3,%%d0\n"
                         "upper_limit_s16lsb:\n"
                         "	rorw	#8,%%d0\n" "	move	%%d0,%0@+\n"
                         /* Loop till done */
                         "	subql	#1,%2\n" "	bhis	mixloop_s16lsb\n" "stoploop_s16lsb:\n": /* no return value */
                         :      /* input */
                         "a"(dst), "a"(src), "d"(len), "d"(volume):     /* clobbered registers */
                         "d0", "d1", "d2", "d3", "cc", "memory");
}
#endif
/* vi: set ts=4 sw=4 expandtab: */