dsputil_altivec.c

这是著名的TCPMP播放器在WINDWOWS,和WINCE下编译通过的源程序.笔者对其中的LIBMAD库做了针对ARM MPU的优化. 并增加了词幕功能.

    register vector signed short line0 = vec_add(temp0, temp1);
    register vector signed short line1 = vec_sub(temp0, temp1);
    register vector signed short line2 = vec_add(temp2, temp3);
    register vector signed short line3 = vec_sub(temp2, temp3);
    register vector signed short line4 = vec_add(temp4, temp5);
    register vector signed short line5 = vec_sub(temp4, temp5);
    register vector signed short line6 = vec_add(temp6, temp7);
    register vector signed short line7 = vec_sub(temp6, temp7);
    
    register vector signed short line0B = vec_add(line0, line2);
    register vector signed short line2B = vec_sub(line0, line2);
    register vector signed short line1B = vec_add(line1, line3);
    register vector signed short line3B = vec_sub(line1, line3);
    register vector signed short line4B = vec_add(line4, line6);
    register vector signed short line6B = vec_sub(line4, line6);
    register vector signed short line5B = vec_add(line5, line7);
    register vector signed short line7B = vec_sub(line5, line7);
    
    register vector signed short line0C = vec_add(line0B, line4B);
    register vector signed short line4C = vec_sub(line0B, line4B);
    register vector signed short line1C = vec_add(line1B, line5B);
    register vector signed short line5C = vec_sub(line1B, line5B);
    register vector signed short line2C = vec_add(line2B, line6B);
    register vector signed short line6C = vec_sub(line2B, line6B);
    register vector signed short line3C = vec_add(line3B, line7B);
    register vector signed short line7C = vec_sub(line3B, line7B);
    
    vsum = vec_sum4s(vec_abs(line0C), vec_splat_s32(0));
    vsum = vec_sum4s(vec_abs(line1C), vsum);
    vsum = vec_sum4s(vec_abs(line2C), vsum);
    vsum = vec_sum4s(vec_abs(line3C), vsum);
    vsum = vec_sum4s(vec_abs(line4C), vsum);
    vsum = vec_sum4s(vec_abs(line5C), vsum);
    vsum = vec_sum4s(vec_abs(line6C), vsum);
    vsum = vec_sum4s(vec_abs(line7C), vsum);
    vsum = vec_sums(vsum, (vector signed int)vzero);
    vsum = vec_splat(vsum, 3);
    vec_ste(vsum, 0, &sum);
  }
POWERPC_PERF_STOP_COUNT(altivec_hadamard8_diff8x8_num, 1);
  return sum;
}

/*
  16x8 works with 16 elements ; it allows to avoid replicating
  loads, and give the compiler more rooms for scheduling.
  It's only used from inside hadamard8_diff16_altivec.
  
  Unfortunately, it seems gcc-3.3 is a bit dumb, and
  the compiled code has a LOT of spill code, it seems
  gcc (unlike xlc) cannot keep everything in registers
  by itself. The following code include hand-made
  registers allocation. It's not clean, but on
  a 7450 the resulting code is much faster (best case
  fall from 700+ cycles to 550).
  
  xlc doesn't add spill code, but it doesn't know how to
  schedule for the 7450, and its code isn't much faster than
  gcc-3.3 on the 7450 (but uses 25% less instructions...)
  
  On the 970, the hand-made RA is still a win (arount 690
  vs. around 780), but xlc goes to around 660 on the
  regular C code...
*/

static int hadamard8_diff16x8_altivec(/*MpegEncContext*/ void *s, uint8_t *dst, uint8_t *src, int stride, int h) {
  int sum;
  register vector signed short
    temp0 asm ("v0"),
    temp1 asm ("v1"),
    temp2 asm ("v2"),
    temp3 asm ("v3"),
    temp4 asm ("v4"),
    temp5 asm ("v5"),
    temp6 asm ("v6"),
    temp7 asm ("v7");
  register vector signed short
    temp0S asm ("v8"),
    temp1S asm ("v9"),
    temp2S asm ("v10"),
    temp3S asm ("v11"),
    temp4S asm ("v12"),
    temp5S asm ("v13"),
    temp6S asm ("v14"),
    temp7S asm ("v15");
  register const_vector unsigned char vzero asm ("v31")= (const_vector unsigned char)vec_splat_u8(0);
  {
    register const_vector signed short vprod1 asm ("v16")= (const_vector signed short)AVV( 1,-1, 1,-1, 1,-1, 1,-1);
    register const_vector signed short vprod2 asm ("v17")= (const_vector signed short)AVV( 1, 1,-1,-1, 1, 1,-1,-1);
    register const_vector signed short vprod3 asm ("v18")= (const_vector signed short)AVV( 1, 1, 1, 1,-1,-1,-1,-1);
    register const_vector unsigned char perm1 asm ("v19")= (const_vector unsigned char)
      AVV(0x02, 0x03, 0x00, 0x01,
       0x06, 0x07, 0x04, 0x05,
       0x0A, 0x0B, 0x08, 0x09,
       0x0E, 0x0F, 0x0C, 0x0D);
    register const_vector unsigned char perm2 asm ("v20")= (const_vector unsigned char)
      AVV(0x04, 0x05, 0x06, 0x07,
       0x00, 0x01, 0x02, 0x03,
       0x0C, 0x0D, 0x0E, 0x0F,
       0x08, 0x09, 0x0A, 0x0B);
    register const_vector unsigned char perm3 asm ("v21")= (const_vector unsigned char)
      AVV(0x08, 0x09, 0x0A, 0x0B,
       0x0C, 0x0D, 0x0E, 0x0F,
       0x00, 0x01, 0x02, 0x03,
       0x04, 0x05, 0x06, 0x07);

#define ONEITERBUTTERFLY(i, res1, res2)					\
    {									\
      register vector unsigned char src1 asm ("v22"), src2 asm ("v23"); \
      register vector unsigned char dst1 asm ("v24"), dst2 asm ("v25"); \
      src1 = vec_ld(stride * i, src);					\
      src2 = vec_ld((stride * i) + 16, src);				\
      register vector unsigned char srcO asm ("v22") = vec_perm(src1, src2, vec_lvsl(stride * i, src)); \
      dst1 = vec_ld(stride * i, dst);					\
      dst2 = vec_ld((stride * i) + 16, dst);				\
      register vector unsigned char dstO asm ("v23") = vec_perm(dst1, dst2, vec_lvsl(stride * i, dst)); \
      /* promote the unsigned chars to signed shorts */			\
      register vector signed short srcV asm ("v24") =                   \
	(vector signed short)vec_mergeh((vector signed char)vzero, (vector signed char)srcO); \
      register vector signed short dstV asm ("v25") =                   \
	(vector signed short)vec_mergeh((vector signed char)vzero, (vector signed char)dstO); \
      register vector signed short srcW asm ("v26") =                   \
	(vector signed short)vec_mergel((vector signed char)vzero, (vector signed char)srcO); \
      register vector signed short dstW asm ("v27") =                   \
	(vector signed short)vec_mergel((vector signed char)vzero, (vector signed char)dstO); \
      /* substractions inside the first butterfly */			\
      register vector signed short but0 asm ("v28") = vec_sub(srcV, dstV); \
      register vector signed short but0S asm ("v29") = vec_sub(srcW, dstW); \
      register vector signed short op1 asm ("v30") = vec_perm(but0, but0, perm1); \
      register vector signed short but1 asm ("v22") = vec_mladd(but0, vprod1, op1); \
      register vector signed short op1S asm ("v23") = vec_perm(but0S, but0S, perm1); \
      register vector signed short but1S asm ("v24") = vec_mladd(but0S, vprod1, op1S); \
      register vector signed short op2 asm ("v25") = vec_perm(but1, but1, perm2); \
      register vector signed short but2 asm ("v26") = vec_mladd(but1, vprod2, op2); \
      register vector signed short op2S asm ("v27") = vec_perm(but1S, but1S, perm2); \
      register vector signed short but2S asm ("v28") = vec_mladd(but1S, vprod2, op2S); \
      register vector signed short op3 asm ("v29") = vec_perm(but2, but2, perm3); \
      res1 = vec_mladd(but2, vprod3, op3);				\
      register vector signed short op3S asm ("v30") = vec_perm(but2S, but2S, perm3); \
      res2 = vec_mladd(but2S, vprod3, op3S);				\
    }
    ONEITERBUTTERFLY(0, temp0, temp0S);
    ONEITERBUTTERFLY(1, temp1, temp1S);
    ONEITERBUTTERFLY(2, temp2, temp2S);
    ONEITERBUTTERFLY(3, temp3, temp3S);
    ONEITERBUTTERFLY(4, temp4, temp4S);
    ONEITERBUTTERFLY(5, temp5, temp5S);
    ONEITERBUTTERFLY(6, temp6, temp6S);
    ONEITERBUTTERFLY(7, temp7, temp7S);
  }
#undef ONEITERBUTTERFLY
  {
    register vector signed int vsum;
    register vector signed short line0 = vec_add(temp0, temp1);
    register vector signed short line1 = vec_sub(temp0, temp1);
    register vector signed short line2 = vec_add(temp2, temp3);
    register vector signed short line3 = vec_sub(temp2, temp3);
    register vector signed short line4 = vec_add(temp4, temp5);
    register vector signed short line5 = vec_sub(temp4, temp5);
    register vector signed short line6 = vec_add(temp6, temp7);
    register vector signed short line7 = vec_sub(temp6, temp7);
      
    register vector signed short line0B = vec_add(line0, line2);
    register vector signed short line2B = vec_sub(line0, line2);
    register vector signed short line1B = vec_add(line1, line3);
    register vector signed short line3B = vec_sub(line1, line3);
    register vector signed short line4B = vec_add(line4, line6);
    register vector signed short line6B = vec_sub(line4, line6);
    register vector signed short line5B = vec_add(line5, line7);
    register vector signed short line7B = vec_sub(line5, line7);
      
    register vector signed short line0C = vec_add(line0B, line4B);
    register vector signed short line4C = vec_sub(line0B, line4B);
    register vector signed short line1C = vec_add(line1B, line5B);
    register vector signed short line5C = vec_sub(line1B, line5B);
    register vector signed short line2C = vec_add(line2B, line6B);
    register vector signed short line6C = vec_sub(line2B, line6B);
    register vector signed short line3C = vec_add(line3B, line7B);
    register vector signed short line7C = vec_sub(line3B, line7B);
      
    vsum = vec_sum4s(vec_abs(line0C), vec_splat_s32(0));
    vsum = vec_sum4s(vec_abs(line1C), vsum);
    vsum = vec_sum4s(vec_abs(line2C), vsum);
    vsum = vec_sum4s(vec_abs(line3C), vsum);
    vsum = vec_sum4s(vec_abs(line4C), vsum);
    vsum = vec_sum4s(vec_abs(line5C), vsum);
    vsum = vec_sum4s(vec_abs(line6C), vsum);
    vsum = vec_sum4s(vec_abs(line7C), vsum);

    register vector signed short line0S = vec_add(temp0S, temp1S);
    register vector signed short line1S = vec_sub(temp0S, temp1S);
    register vector signed short line2S = vec_add(temp2S, temp3S);
    register vector signed short line3S = vec_sub(temp2S, temp3S);
    register vector signed short line4S = vec_add(temp4S, temp5S);
    register vector signed short line5S = vec_sub(temp4S, temp5S);
    register vector signed short line6S = vec_add(temp6S, temp7S);
    register vector signed short line7S = vec_sub(temp6S, temp7S);

    register vector signed short line0BS = vec_add(line0S, line2S);
    register vector signed short line2BS = vec_sub(line0S, line2S);
    register vector signed short line1BS = vec_add(line1S, line3S);
    register vector signed short line3BS = vec_sub(line1S, line3S);
    register vector signed short line4BS = vec_add(line4S, line6S);
    register vector signed short line6BS = vec_sub(line4S, line6S);
    register vector signed short line5BS = vec_add(line5S, line7S);
    register vector signed short line7BS = vec_sub(line5S, line7S);

    register vector signed short line0CS = vec_add(line0BS, line4BS);
    register vector signed short line4CS = vec_sub(line0BS, line4BS);
    register vector signed short line1CS = vec_add(line1BS, line5BS);
    register vector signed short line5CS = vec_sub(line1BS, line5BS);
    register vector signed short line2CS = vec_add(line2BS, line6BS);
    register vector signed short line6CS = vec_sub(line2BS, line6BS);
    register vector signed short line3CS = vec_add(line3BS, line7BS);
    register vector signed short line7CS = vec_sub(line3BS, line7BS);

    vsum = vec_sum4s(vec_abs(line0CS), vsum);
    vsum = vec_sum4s(vec_abs(line1CS), vsum);
    vsum = vec_sum4s(vec_abs(line2CS), vsum);
    vsum = vec_sum4s(vec_abs(line3CS), vsum);
    vsum = vec_sum4s(vec_abs(line4CS), vsum);
    vsum = vec_sum4s(vec_abs(line5CS), vsum);
    vsum = vec_sum4s(vec_abs(line6CS), vsum);
    vsum = vec_sum4s(vec_abs(line7CS), vsum);
    vsum = vec_sums(vsum, (vector signed int)vzero);
    vsum = vec_splat(vsum, 3);
    vec_ste(vsum, 0, &sum);
  }
  return sum;
}

int hadamard8_diff16_altivec(/*MpegEncContext*/ void *s, uint8_t *dst, uint8_t *src, int stride, int h){
POWERPC_PERF_DECLARE(altivec_hadamard8_diff16_num, 1);
  int score;
POWERPC_PERF_START_COUNT(altivec_hadamard8_diff16_num, 1);
  score = hadamard8_diff16x8_altivec(s, dst, src, stride, 8);
  if (h==16) {
    dst += 8*stride;
    src += 8*stride;
    score += hadamard8_diff16x8_altivec(s, dst, src, stride, 8);
  }
POWERPC_PERF_STOP_COUNT(altivec_hadamard8_diff16_num, 1);
  return score;
}
#endif //CONFIG_DARWIN

int has_altivec(void)
{
#ifdef __AMIGAOS4__
	ULONG result = 0;
	extern struct ExecIFace *IExec;

	IExec->GetCPUInfoTags(GCIT_VectorUnit, &result, TAG_DONE);
	if (result == VECTORTYPE_ALTIVEC) return 1;
	return 0;
#else /* __AMIGAOS4__ */

#ifdef CONFIG_DARWIN
    int sels[2] = {CTL_HW, HW_VECTORUNIT};
    int has_vu = 0;
    size_t len = sizeof(has_vu);
    int err;

    err = sysctl(sels, 2, &has_vu, &len, NULL, 0);

    if (err == 0) return (has_vu != 0);
#else /* CONFIG_DARWIN */
/* no Darwin, do it the brute-force way */
/* this is borrowed from the libmpeg2 library */
    {
      signal (SIGILL, sigill_handler);
      if (sigsetjmp (jmpbuf, 1)) {
        signal (SIGILL, SIG_DFL);
      } else {
        canjump = 1;
        
        asm volatile ("mtspr 256, %0\n\t"
                      "vand %%v0, %%v0, %%v0"
                      :
                      : "r" (-1));
        
        signal (SIGILL, SIG_DFL);
        return 1;
      }
    }
#endif /* CONFIG_DARWIN */
    return 0;
#endif /* __AMIGAOS4__ */
}

/* next one assumes that ((line_size % 8) == 0) */
void avg_pixels8_xy2_altivec(uint8_t *block, const uint8_t *pixels, int line_size, int h)
{
POWERPC_PERF_DECLARE(altivec_avg_pixels8_xy2_num, 1);
#ifdef ALTIVEC_USE_REFERENCE_C_CODE

    int j;
POWERPC_PERF_START_COUNT(altivec_avg_pixels8_xy2_num, 1);
 for (j = 0; j < 2; j++) {
   int             i;
   const uint32_t  a = (((const struct unaligned_32 *) (pixels))->l);
   const uint32_t  b = (((const struct unaligned_32 *) (pixels + 1))->l);
   uint32_t        l0 = (a & 0x03030303UL) + (b & 0x03030303UL) + 0x02020202UL;
   uint32_t        h0 = ((a & 0xFCFCFCFCUL) >> 2) + ((b & 0xFCFCFCFCUL) >> 2);
   uint32_t        l1, h1;
   pixels += line_size;
   for (i = 0; i < h; i += 2) {
     uint32_t        a = (((const struct unaligned_32 *) (pixels))->l);
     uint32_t        b = (((const struct unaligned_32 *) (pixels + 1))->l);
     l1 = (a & 0x03030303UL) + (b & 0x03030303UL);
     h1 = ((a & 0xFCFCFCFCUL) >> 2) + ((b & 0xFCFCFCFCUL) >> 2);
     *((uint32_t *) block) = rnd_avg32(*((uint32_t *) block), h0 + h1 + (((l0 + l1) >> 2) & 0x0F0F0F0FUL));
     pixels += line_size;
     block += line_size;
     a = (((const struct unaligned_32 *) (pixels))->l);
     b = (((const struct unaligned_32 *) (pixels + 1))->l);
     l0 = (a & 0x03030303UL) + (b & 0x03030303UL) + 0x02020202UL;
     h0 = ((a & 0xFCFCFCFCUL) >> 2) + ((b & 0xFCFCFCFCUL) >> 2);
     *((uint32_t *) block) = rnd_avg32(*((uint32_t *) block), h0 + h1 + (((l0 + l1) >> 2) & 0x0F0F0F0FUL));
     pixels += line_size;
     block += line_size;
   } pixels += 4 - line_size * (h + 1);
   block += 4 - line_size * h;
 }
POWERPC_PERF_STOP_COUNT(altivec_avg_pixels8_xy2_num, 1);
#else /* ALTIVEC_USE_REFERENCE_C_CODE */
   register int i;
   register vector unsigned char
     pixelsv1, pixelsv2,
     pixelsavg;
   register vector unsigned char
     blockv, temp1, temp2, blocktemp;
   register vector unsigned short
     pixelssum1, pixelssum2, temp3;
   register const_vector unsigned char vczero = (const_vector unsigned char)vec_splat_u8(0);
   register const_vector unsigned short vctwo = (const_vector unsigned short)vec_splat_u16(2);
   
   temp1 = vec_ld(0, pixels);
   temp2 = vec_ld(16, pixels);
   pixelsv1 = vec_perm(temp1, temp2, vec_lvsl(0, pixels));
   if ((((unsigned long)pixels) & 0x0000000F) ==  0x0000000F)