#if 0

//#if defined(__i386__) || defined(__x86_64__)

#define LOCK_PREFIX "lock ; "

#define ARCH_ADD(p,a)					\

	__asm__ __volatile__(LOCK_PREFIX "addl %1,%0"	\

			     :"=m" (*p)			\

			     :"ir" (a), "m" (*p))

struct __xchg_dummy { unsigned long a[100]; };

#define __xg(x) ((struct __xchg_dummy *)(x))

static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,

				      unsigned long new, int size)

{

	unsigned long prev;

	switch (size) {

	case 1:

		__asm__ __volatile__(LOCK_PREFIX "cmpxchgb %b1,%2"

				     : "=a"(prev)

				     : "q"(new), "m"(*__xg(ptr)), "0"(old)

				     : "memory");

		return prev;

	case 2:

		__asm__ __volatile__(LOCK_PREFIX "cmpxchgw %w1,%2"

				     : "=a"(prev)

				     : "q"(new), "m"(*__xg(ptr)), "0"(old)

				     : "memory");

		return prev;

	case 4:

		__asm__ __volatile__(LOCK_PREFIX "cmpxchgl %1,%2"

				     : "=a"(prev)

				     : "q"(new), "m"(*__xg(ptr)), "0"(old)

				     : "memory");

		return prev;

	}

	return old;

}

#define ARCH_CMPXCHG(ptr,o,n)\

	((__typeof__(*(ptr)))__cmpxchg((ptr),(unsigned long)(o),\

					(unsigned long)(n),sizeof(*(ptr))))

#define IS_CONCURRENT	1	/* check race */

#endif

#ifndef ARCH_ADD

#define ARCH_ADD(p,a) (*(p) += (a))

#define ARCH_CMPXCHG(p,a,b) (*(p)) /* fake */

#define IS_CONCURRENT	0	/* no race check */

#endif

#if IS_CONCURRENT

static void mix_areas_16(unsigned int size,

			 volatile signed short *dst, signed short *src,

			 volatile signed int *sum, size_t dst_step,

			 size_t src_step, size_t sum_step)

{

	register signed int sample, old_sample;

	for (;;) {

		sample = *src;

		old_sample = *sum;

		if (ARCH_CMPXCHG(dst, 0, 1) == 0)

			sample -= old_sample;

		ARCH_ADD(sum, sample);

		do {

			old_sample = *sum;

			if (old_sample > 0x7fff)

				sample = 0x7fff;

			else if (old_sample < -0x8000)

				sample = -0x8000;

			else

				sample = old_sample;

			*dst = sample;

		} while (IS_CONCURRENT && *sum != old_sample);

		if (!--size)

			return;

		src = (signed short *) ((char *)src + src_step);

		dst = (signed short *) ((char *)dst + dst_step);

		sum = (signed int *)   ((char *)sum + sum_step);

	}

}

static void mix_areas_32(unsigned int size,

			 volatile signed int *dst, signed int *src,

			 volatile signed int *sum, size_t dst_step,

			 size_t src_step, size_t sum_step)

{

	register signed int sample, old_sample;

	for (;;) {

		sample = *src >> 8;

		old_sample = *sum;

		if (ARCH_CMPXCHG(dst, 0, 1) == 0)

			sample -= old_sample;

		ARCH_ADD(sum, sample);

		do {

			old_sample = *sum;

			if (old_sample > 0x7fffff)

				sample = 0x7fffffff;

			else if (old_sample < -0x800000)

				sample = -0x80000000;

			else

				sample = old_sample * 256;

			*dst = sample;

		} while (IS_CONCURRENT && *sum != old_sample);

		if (!--size)

			return;

		src = (signed int *) ((char *)src + src_step);

		dst = (signed int *) ((char *)dst + dst_step);

		sum = (signed int *) ((char *)sum + sum_step);

	}

}

static void mix_select_callbacks(snd_pcm_direct_t *dmix)

{

	dmix->u.dmix.mix_areas_16 = mix_areas_16;

	dmix->u.dmix.mix_areas_32 = mix_areas_32;

}

#else

/* non-concurrent version, supporting both endians */

#define generic_dmix_supported_format \

	((1ULL << SND_PCM_FORMAT_S16_LE) | (1ULL << SND_PCM_FORMAT_S32_LE) |\

	 (1ULL << SND_PCM_FORMAT_S16_BE) | (1ULL << SND_PCM_FORMAT_S32_BE) |\

	 (1ULL << SND_PCM_FORMAT_S24_LE) | (1ULL << SND_PCM_FORMAT_S24_3LE) | \

	 (1ULL << SND_PCM_FORMAT_U8))

#include "bswap.h"

static void generic_mix_areas_16_native(unsigned int size,

					volatile signed short *dst,

					signed short *src,

					volatile signed int *sum,

					size_t dst_step,

					size_t src_step,

					size_t sum_step)

{

	register signed int sample;

	for (;;) {

		sample = *src;

		if (! *dst) {

			*sum = sample;

			*dst = *src;

		} else {

			sample += *sum;

			*sum = sample;

			if (sample > 0x7fff)

				sample = 0x7fff;

			else if (sample < -0x8000)

				sample = -0x8000;

			*dst = sample;

		}

		if (!--size)

			return;

		src = (signed short *) ((char *)src + src_step);

		dst = (signed short *) ((char *)dst + dst_step);

		sum = (signed int *)   ((char *)sum + sum_step);

	}

}

static void generic_remix_areas_16_native(unsigned int size,

					  volatile signed short *dst,

					  signed short *src,

					  volatile signed int *sum,

					  size_t dst_step,

					  size_t src_step,

					  size_t sum_step)

{

	register signed int sample;

	for (;;) {

		sample = *src;

		if (! *dst) {

			*sum = -sample;

			*dst = -sample;

		} else {

			*sum = sample = *sum - sample;

			if (sample > 0x7fff)

				sample = 0x7fff;

			else if (sample < -0x8000)

				sample = -0x8000;

			*dst = sample;

		}

		if (!--size)

			return;

		src = (signed short *) ((char *)src + src_step);

		dst = (signed short *) ((char *)dst + dst_step);

		sum = (signed int *)   ((char *)sum + sum_step);

	}

}

static void generic_mix_areas_32_native(unsigned int size,

					volatile signed int *dst,

					signed int *src,

					volatile signed int *sum,

					size_t dst_step,

					size_t src_step,

					size_t sum_step)

{

	register signed int sample;

	for (;;) {

		sample = *src >> 8;

		if (! *dst) {

			*sum = sample;

			*dst = *src;

		} else {

			sample += *sum;

			*sum = sample;

			if (sample > 0x7fffff)

				sample = 0x7fffffff;

			else if (sample < -0x800000)

				sample = -0x80000000;

			else

				sample *= 256;

			*dst = sample;

		}

		if (!--size)

			return;

		src = (signed int *) ((char *)src + src_step);

		dst = (signed int *) ((char *)dst + dst_step);

		sum = (signed int *) ((char *)sum + sum_step);

	}

}

static void generic_remix_areas_32_native(unsigned int size,

					  volatile signed int *dst,

					  signed int *src,

					  volatile signed int *sum,

					  size_t dst_step,

					  size_t src_step,

					  size_t sum_step)

{

	register signed int sample;

	for (;;) {

		sample = *src >> 8;

		if (! *dst) {

			*sum = -sample;

			*dst = -*src;

		} else {

			*sum = sample = *sum - sample;

			if (sample > 0x7fffff)

				sample = 0x7fffffff;

			else if (sample < -0x800000)

				sample = -0x80000000;

			else

				sample *= 256;

			*dst = sample;

		}

		if (!--size)

			return;

		src = (signed int *) ((char *)src + src_step);

		dst = (signed int *) ((char *)dst + dst_step);

		sum = (signed int *) ((char *)sum + sum_step);

	}

}

static void generic_mix_areas_16_swap(unsigned int size,

				      volatile signed short *dst,

				      signed short *src,

				      volatile signed int *sum,

				      size_t dst_step,

				      size_t src_step,

				      size_t sum_step)

{

	register signed int sample;

	for (;;) {

		sample = (signed short) bswap_16(*src);

		if (! *dst) {

			*sum = sample;

			*dst = *src;

		} else {

			sample += *sum;

			*sum = sample;

			if (sample > 0x7fff)

				sample = 0x7fff;

			else if (sample < -0x8000)

				sample = -0x8000;

			*dst = (signed short) bswap_16((signed short) sample);

		}

		if (!--size)

			return;

		src = (signed short *) ((char *)src + src_step);

		dst = (signed short *) ((char *)dst + dst_step);

		sum = (signed int *)   ((char *)sum + sum_step);

	}

}

static void generic_remix_areas_16_swap(unsigned int size,

				        volatile signed short *dst,

				        signed short *src,

				        volatile signed int *sum,

				        size_t dst_step,

				        size_t src_step,

				        size_t sum_step)

{

	register signed int sample;

	for (;;) {

		sample = (signed short) bswap_16(*src);

		if (! *dst) {

			*sum = -sample;

			*dst = (signed short) bswap_16((signed short) -sample);

		} else {

			*sum = sample = *sum - sample;

			if (sample > 0x7fff)

				sample = 0x7fff;

			else if (sample < -0x8000)

				sample = -0x8000;

			*dst = (signed short) bswap_16((signed short) sample);

		}

		if (!--size)

			return;

		src = (signed short *) ((char *)src + src_step);

		dst = (signed short *) ((char *)dst + dst_step);

		sum = (signed int *)   ((char *)sum + sum_step);

	}

}

static void generic_mix_areas_32_swap(unsigned int size,

				      volatile signed int *dst,

				      signed int *src,

				      volatile signed int *sum,

				      size_t dst_step,

				      size_t src_step,

				      size_t sum_step)

{

	register signed int sample;

	for (;;) {

		sample = bswap_32(*src) >> 8;

		if (! *dst) {

			*sum = sample;

			*dst = *src;

		} else {

			sample += *sum;

			*sum = sample;

			if (sample > 0x7fffff)

				sample = 0x7fffffff;

			else if (sample < -0x800000)

				sample = -0x80000000;

			else

				sample *= 256;

			*dst = bswap_32(sample);

		}

		if (!--size)

			return;

		src = (signed int *) ((char *)src + src_step);

		dst = (signed int *) ((char *)dst + dst_step);

		sum = (signed int *) ((char *)sum + sum_step);

	}

}

static void generic_remix_areas_32_swap(unsigned int size,

				        volatile signed int *dst,

				        signed int *src,

				        volatile signed int *sum,

				        size_t dst_step,

				        size_t src_step,

				        size_t sum_step)

{

	register signed int sample;

	for (;;) {

		sample = bswap_32(*src) >> 8;

		if (! *dst) {

			*sum = -sample;

			*dst = bswap_32(-sample);

		} else {

			*sum = sample = *sum - sample;

			if (sample > 0x7fffff)

				sample = 0x7fffffff;

			else if (sample < -0x800000)

				sample = -0x80000000;

			else

				sample *= 256;

			*dst = bswap_32(sample);

		}

		if (!--size)

			return;

		src = (signed int *) ((char *)src + src_step);

		dst = (signed int *) ((char *)dst + dst_step);

		sum = (signed int *) ((char *)sum + sum_step);

	}

}

/* always little endian */

static void generic_mix_areas_24(unsigned int size,

				 volatile unsigned char *dst,

				 unsigned char *src,

				 volatile signed int *sum,

				 size_t dst_step,

				 size_t src_step,

				 size_t sum_step)

{

	register signed int sample;

	for (;;) {

		sample = src[0] | (src[1] << 8) | (((signed char *)src)[2] << 16);

		if (!(dst[0] | dst[1] | dst[2])) {

			*sum = sample;

		} else {

			sample += *sum;

			*sum = sample;

			if (sample > 0x7fffff)

				sample = 0x7fffff;

			else if (sample < -0x800000)

				sample = -0x800000;

		}

		dst[0] = sample;

		dst[1] = sample >> 8;

		dst[2] = sample >> 16;

		if (!--size)

			return;

		dst += dst_step;

		src += src_step;

		sum = (signed int *) ((char *)sum + sum_step);

	}

}

static void generic_remix_areas_24(unsigned int size,

				   volatile unsigned char *dst,

				   unsigned char *src,

				   volatile signed int *sum,

				   size_t dst_step,

				   size_t src_step,

				   size_t sum_step)

{

	register signed int sample;

	for (;;) {

		sample = src[0] | (src[1] << 8) | (((signed char *)src)[2] << 16);

		if (!(dst[0] | dst[1] | dst[2])) {

			sample = -sample;

			*sum = sample;

		} else {

			*sum = sample = *sum - sample;

			if (sample > 0x7fffff)

				sample = 0x7fffff;

			else if (sample < -0x800000)

				sample = -0x800000;

		}

		dst[0] = sample;

		dst[1] = sample >> 8;

		dst[2] = sample >> 16;

		if (!--size)

			return;

		dst += dst_step;

		src += src_step;

		sum = (signed int *) ((char *)sum + sum_step);

	}

}

static void generic_mix_areas_u8(unsigned int size,

				 volatile unsigned char *dst,

				 unsigned char *src,

				 volatile signed int *sum,

				 size_t dst_step,

				 size_t src_step,

				 size_t sum_step)

{

	for (;;) {

		register int sample = *src - 0x80;

		if (*dst == 0x80) {

			*sum = sample;

		} else {

			sample += *sum;

			*sum = sample;

			if (sample > 0x7f)

				sample = 0x7f;

			else if (sample < -0x80)

				sample = -0x80;

		}

		*dst = sample + 0x80;

		if (!--size)

			return;

		dst += dst_step;

		src += src_step;

		sum = (signed int *) ((char *)sum + sum_step);

	}

}

static void generic_remix_areas_u8(unsigned int size,

				   volatile unsigned char *dst,

				   unsigned char *src,

				   volatile signed int *sum,

				   size_t dst_step,

				   size_t src_step,

				   size_t sum_step)

{

	for (;;) {

		register int sample = *src - 0x80;

		if (*dst == 0x80) {

			sample = -sample;

			*sum = sample;

		} else {

			*sum = sample = *sum - sample;

			if (sample > 0x7f)

				sample = 0x7f;

			else if (sample < -0x80)

				sample = -0x80;

		}

		*dst = sample + 0x80;

		if (!--size)

			return;

		dst += dst_step;

		src += src_step;

		sum = (signed int *) ((char *)sum + sum_step);

	}

}

static void generic_mix_select_callbacks(snd_pcm_direct_t *dmix)

{

	if (snd_pcm_format_cpu_endian(dmix->shmptr->s.format)) {

		dmix->u.dmix.mix_areas_16 = generic_mix_areas_16_native;

		dmix->u.dmix.mix_areas_32 = generic_mix_areas_32_native;

		dmix->u.dmix.remix_areas_16 = generic_remix_areas_16_native;

		dmix->u.dmix.remix_areas_32 = generic_remix_areas_32_native;

	} else {

		dmix->u.dmix.mix_areas_16 = generic_mix_areas_16_swap;

		dmix->u.dmix.mix_areas_32 = generic_mix_areas_32_swap;

		dmix->u.dmix.remix_areas_16 = generic_remix_areas_16_swap;

		dmix->u.dmix.remix_areas_32 = generic_remix_areas_32_swap;

	}

	dmix->u.dmix.mix_areas_24 = generic_mix_areas_24;

	dmix->u.dmix.mix_areas_u8 = generic_mix_areas_u8;

	dmix->u.dmix.remix_areas_24 = generic_remix_areas_24;

	dmix->u.dmix.remix_areas_u8 = generic_remix_areas_u8;

	dmix->u.dmix.use_sem = 1;

}

#endif