rockbox/firmware/asm/m68k/pcm-mixer.c
2012-01-22 18:46:45 +01:00

134 lines
4.9 KiB
C

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2011 by Michael Sevakis
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#define MIXER_OPTIMIZED_MIX_SAMPLES
#define MIXER_OPTIMIZED_WRITE_SAMPLES
static struct emac_context
{
unsigned long r[4];
} emac_context IBSS_ATTR;
/* Save emac context affected in ISR */
static FORCE_INLINE void save_emac_context(void)
{
asm volatile (
"move.l %%macsr, %%d0 \n"
"move.l %%accext01, %%d1 \n"
"movclr.l %%acc0, %%a0 \n"
"movclr.l %%acc1, %%a1 \n"
"movem.l %%d0-%%d1/%%a0-%%a1, (%0) \n"
:
: "a"(&emac_context)
: "d0", "d1", "a0", "a1");
}
/* Restore emac context affected in ISR */
static FORCE_INLINE void restore_emac_context(void)
{
asm volatile (
"movem.l (%0), %%d0-%%d1/%%a0-%%a1 \n"
"move.l %%a1, %%acc1 \n"
"move.l %%a0, %%acc0 \n"
"move.l %%d1, %%accext01 \n"
"move.l %%d0, %%macsr \n"
:
: "a"(&emac_context)
: "d0", "d1", "a0", "a1");
}
/* Mix channels' samples and apply gain factors */
static FORCE_INLINE void mix_samples(void *out,
void *src0,
int32_t src0_amp,
void *src1,
int32_t src1_amp,
size_t size)
{
uint32_t s0, s1, s2, s3;
save_emac_context();
coldfire_set_macsr(EMAC_ROUND | EMAC_SATURATE);
asm volatile (
"move.l (%1)+, %5 \n"
"1: \n"
"movea.w %5, %4 \n"
"asr.l %10, %5 \n"
"mac.l %4, %8, %%acc0 \n"
"mac.l %5, %8, (%2)+, %5, %%acc1 \n"
"movea.w %5, %4 \n"
"asr.l %10, %5 \n"
"mac.l %4, %9, %%acc0 \n"
"mac.l %5, %9, (%1)+, %5, %%acc1 \n"
"movclr.l %%acc0, %6 \n"
"movclr.l %%acc1, %7 \n"
"swap.w %6 \n"
"move.w %6, %7 \n"
"move.l %7, (%0)+ \n"
"subq.l #4, %3 \n"
"bhi.b 1b \n"
: "+a"(out), "+a"(src0), "+a"(src1), "+d"(size),
"=&a"(s0), "=&d"(s1), "=&d"(s2), "=&d"(s3)
: "r"(src0_amp), "r"(src1_amp), "d"(16)
);
restore_emac_context();
}
/* Write channel's samples and apply gain factor */
static FORCE_INLINE void write_samples(void *out,
void *src,
int32_t amp,
size_t size)
{
if (LIKELY(amp == MIX_AMP_UNITY))
{
/* Channel is unity amplitude */
memcpy(out, src, size);
}
else
{
/* Channel needs amplitude cut */
uint32_t s0, s1, s2, s3;
save_emac_context();
coldfire_set_macsr(EMAC_ROUND | EMAC_SATURATE);
asm volatile (
"move.l (%1)+, %4 \n"
"1: \n"
"movea.w %4, %3 \n"
"asr.l %8, %4 \n"
"mac.l %3, %7, %%acc0 \n"
"mac.l %4, %7, (%1)+, %4, %%acc1 \n"
"movclr.l %%acc0, %5 \n"
"movclr.l %%acc1, %6 \n"
"swap.w %5 \n"
"move.w %5, %6 \n"
"move.l %6, (%0)+ \n"
"subq.l #4, %2 \n"
"bhi.b 1b \n"
: "+a"(out), "+a"(src), "+d"(size),
"=&a"(s0), "=&d"(s1), "=&d"(s2), "=&d"(s3)
: "r"(amp), "d"(16)
);
restore_emac_context();
}
}