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Date: Tue, 19 Aug 2003 17:57:00 +0200 From: Stephane Marchesin Subject: Re: [SDL] [patch] MMX alpha blit patches with MMX detection I think everything is correct now. I've done as much testing as I could, but some real-world testing wouldn't hurt, I think. The patch is here : http://icps.u-strasbg.fr/~marchesin/sdl_mmxblit.patch If you do byte-by-byte comparison of the output between C and MMX functions, you'll notice that the results for 555 and 565 RGB alpha blits aren't exactly the same. This is because MMX functions for 555 and 565 RGB have an higher accuracy. If you want the exact same behaviour that's possible by masking the three lower alpha bits in the MMX functions. Just ask ! I removed one MMX function because after I fixed it to match its C equivalent, it revealed to be slower than the C version on a PIII (although a bit faster on an Athlon XP). I've also added MMX and PIII replacements for SDL_memcpy. Those provide some speed up in testvidinfo -benchmark (at least for me, under linux & X11).
author Sam Lantinga <slouken@libsdl.org>
date Fri, 22 Aug 2003 05:51:19 +0000
parents 873c2598f969
children b8d311d90021
line wrap: on
line source

/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002  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
*/

/*
	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