More i386 optimizations (use edx register as well).

Moved the interleave check outside mix_areas() routine.

diff --git a/src/pcm/pcm_dmix.c b/src/pcm/pcm_dmix.c
index f32f91303a948eea70ec68f361cb2c280ddb0eee..86306ef68bba755e426a4ea3f3e764f4bfe315cb 100644 (file)
--- a/src/pcm/pcm_dmix.c
+++ b/src/pcm/pcm_dmix.c
@@ -120,6 +120,7 @@ typedef struct {
        int server_fd;
        pid_t server_pid;
        snd_timer_t *timer; /* timer used as poll_fd */
+       int interleaved; /* we have interleaved buffer */
 } snd_pcm_dmix_t;
 
 /*
@@ -531,6 +532,30 @@ static int client_discard(snd_pcm_dmix_t *dmix)
  *  ring buffer operation
  */
 
+static int check_interleave(snd_pcm_dmix_t *dmix)
+{
+       unsigned int chn, channels;
+       int interleaved = 1;
+       const snd_pcm_channel_area_t *dst_areas;
+
+       channels = dmix->shmptr->s.channels;
+       dst_areas = snd_pcm_mmap_areas(dmix->spcm);
+       for (chn = 1; chn < channels; chn++) {
+               if (dst_areas[chn-1].addr != dst_areas[chn].addr) {
+                       interleaved = 0;
+                       break;
+               }
+       }
+       for (chn = 0; chn < channels; chn++) {
+               if (dst_areas[chn].first != sizeof(signed short) * chn * 8 ||
+                   dst_areas[chn].step != channels * sizeof(signed short) * 8) {
+                       interleaved = 0;
+                       break;
+               }
+       }
+       return dmix->interleaved = interleaved;
+}
+
 /*
  *  the main function of this plugin: mixing
  *  FIXME: optimize it for different architectures
@@ -549,13 +574,15 @@ static void mix_areas1(unsigned int size,
         *  EBX - sum
         *  ECX - old sample
         *  EAX - sample / temporary
+        *  EDX - size
         */
        __asm__ __volatile__ (
                "\n"
 
                /*
-                *  initialization, load ESI, EDI, EBX registers
+                *  initialization, load EDX, ESI, EDI, EBX registers
                 */
+               "\tmovl %0, %%edx\n"
                "\tmovl %1, %%edi\n"
                "\tmovl %2, %%esi\n"
                "\tmovl %3, %%ebx\n"
@@ -563,7 +590,7 @@ static void mix_areas1(unsigned int size,
                /*
                 * while (size-- > 0) {
                 */
-               "\tcmp $0, %0\n"
+               "\tcmp $0, %%edx\n"
                "jz 6f\n"
 
                "1:"
@@ -576,12 +603,12 @@ static void mix_areas1(unsigned int size,
                 */
                "\tmovw $0, %%ax\n"
                "\tmovw $1, %%cx\n"
-               "\tlock cmpxchgw %%cx, (%%edi)\n"
+               "\tlock; cmpxchgw %%cx, (%%edi)\n"
                "\tmovswl (%%esi), %%ecx\n"
                "\tjnz 2f\n"
                "\tsubl (%%ebx), %%ecx\n"
                "2:"
-               "\tlock addl %%ecx, (%%ebx)\n"
+               "\tlock; addl %%ecx, (%%ebx)\n"
 
                /*
                 *   do {
@@ -607,7 +634,7 @@ static void mix_areas1(unsigned int size,
                "\tadd %4, %%edi\n"
                "\tadd %5, %%esi\n"
                "\tadd %6, %%ebx\n"
-               "\tdecl %0\n"
+               "\tdecl %%edx\n"
                "\tjnz 1b\n"
                "\tjmp 6f\n"
 
@@ -623,7 +650,7 @@ static void mix_areas1(unsigned int size,
                "\tadd %4, %%edi\n"
                "\tadd %5, %%esi\n"
                "\tadd %6, %%ebx\n"
-               "\tdecl %0\n"
+               "\tdecl %%edx\n"
                "\tjnz 1b\n"
                "\tjmp 6f\n"
 
@@ -639,7 +666,7 @@ static void mix_areas1(unsigned int size,
                "\tadd %4, %%edi\n"
                "\tadd %5, %%esi\n"
                "\tadd %6, %%ebx\n"
-               "\tdecl %0\n"
+               "\tdecl %%edx\n"
                "\tjnz 1b\n"
                // "\tjmp 6f\n"
                
@@ -647,7 +674,7 @@ static void mix_areas1(unsigned int size,
 
                : /* no output regs */
                : "m" (size), "m" (dst), "m" (src), "m" (sum), "m" (dst_step), "m" (src_step), "m" (sum_step)
-               : "esi", "edi", "ecx", "ebx", "eax"
+               : "esi", "edi", "edx", "ecx", "ebx", "eax"
        );
 }
 #endif
@@ -683,43 +710,29 @@ static void mix_areas1(unsigned int size,
 }
 #endif
 
-static void mix_areas(const snd_pcm_channel_area_t *src_areas,
+static void mix_areas(snd_pcm_dmix_t *dmix,
+                     const snd_pcm_channel_area_t *src_areas,
                      const snd_pcm_channel_area_t *dst_areas,
-                     unsigned int channels,
                      snd_pcm_uframes_t src_ofs,
                      snd_pcm_uframes_t dst_ofs,
-                     snd_pcm_uframes_t size,
-                     void *sum_buffer)
+                     snd_pcm_uframes_t size)
 {
        signed short *src;
        volatile signed short *dst;
        volatile signed int *sum;
        unsigned int src_step, dst_step;
-       unsigned int chn;
-       int interleaved = 1;
+       unsigned int chn, channels;
        
-       for (chn = 1; chn < channels; chn++) {
-               if (dst_areas[chn-1].addr != dst_areas[chn].addr) {
-                       interleaved = 0;
-                       break;
-               }
-       }
-       for (chn = 0; chn < channels; chn++) {
-               if (dst_areas[chn].first != sizeof(signed short) * chn * 8 ||
-                   dst_areas[chn].step != channels * sizeof(signed short) * 8) {
-                       interleaved = 0;
-                       break;
-               }
-       }
-       if (interleaved) {
+       channels = dmix->shmptr->s.channels;
+       if (dmix->interleaved) {
                /*
-                * process the area in one loop
+                * process the all areas in one loop
                 * it optimizes the memory accesses for this case
                 */
                mix_areas1(size * channels,
                           ((signed short *)dst_areas[0].addr) + (dst_ofs * channels),
                           ((signed short *)src_areas[0].addr) + (src_ofs * channels),
-                          ((signed int *)sum_buffer) + (dst_ofs * channels),
+                          dmix->sum_buffer + (dst_ofs * channels),
                           sizeof(signed short),
                           sizeof(signed short),
                           sizeof(signed int));
@@ -730,7 +743,7 @@ static void mix_areas(const snd_pcm_channel_area_t *src_areas,
                dst_step = dst_areas[chn].step / 8;
                src = (signed short *)(((char *)src_areas[chn].addr + src_areas[chn].first / 8) + (src_ofs * src_step));
                dst = (signed short *)(((char *)dst_areas[chn].addr + dst_areas[chn].first / 8) + (dst_ofs * dst_step));
-               sum = (signed int *)sum_buffer + channels * dst_ofs + chn;
+               sum = dmix->sum_buffer + channels * dst_ofs + chn;
                mix_areas1(size, dst, src, sum, dst_step, src_step, channels * sizeof(signed int));
        }
 }
@@ -759,7 +772,7 @@ static void snd_pcm_dmix_sync_area(snd_pcm_t *pcm, snd_pcm_uframes_t size)
                transfer = appl_ptr + size > pcm->buffer_size ? pcm->buffer_size - appl_ptr : size;
                transfer = slave_appl_ptr + transfer > dmix->shmptr->s.buffer_size ? dmix->shmptr->s.buffer_size - slave_appl_ptr : transfer;
                size -= transfer;
-               mix_areas(src_areas, dst_areas, pcm->channels, appl_ptr, slave_appl_ptr, transfer, dmix->sum_buffer);
+               mix_areas(dmix, src_areas, dst_areas, appl_ptr, slave_appl_ptr, transfer);
                slave_appl_ptr += transfer;
                slave_appl_ptr %= dmix->shmptr->s.buffer_size;
                appl_ptr += transfer;
@@ -1593,6 +1606,8 @@ int snd_pcm_dmix_open(snd_pcm_t **pcmp, const char *name,
                SNDERR("unable to initialize poll_fd\n");
                goto _err;
        }
+
+       check_interleave(dmix);
                
        pcm->poll_fd = dmix->poll_fd;
        pcm->poll_events = POLLIN;      /* it's different than other plugins */