📄 idct_mmx.c
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movq_m2r (*table, mm3); // mm3 = C6 C4 C2 C4
pslld_i2r (16, mm1); // mm1 = y7 0 y5 0
movq_m2r (*(table+4), mm4); // mm4 = -C2 -C4 C6 C4
por_r2r (mm1, mm7); // mm7 = y7 y6 y5 y4
movq_m2r (*(table+8), mm1); // mm1 = -C7 C3 C3 C1
punpckhdq_r2r (mm2, mm2); // mm2 = x6 x4 x6 x4
movq_r2m (mm7, *(row+store+4)); // save y7 y6 y5 y4
pmaddwd_r2r (mm0, mm3); // mm3 = C4*x0+C6*x2 C4*x0+C2*x2
}
#if 0
// C column IDCT - it is just here to document the MMXEXT and MMX versions
static inline void idct_col (int16_t * col, int offset)
{
/* multiplication - as implemented on mmx */
#define F(c,x) (((c) * (x)) >> 16)
/* saturation - it helps us handle torture test cases */
#define S(x) (((x)>32767) ? 32767 : ((x)<-32768) ? -32768 : (x))
int16_t x0, x1, x2, x3, x4, x5, x6, x7;
int16_t y0, y1, y2, y3, y4, y5, y6, y7;
int16_t a0, a1, a2, a3, b0, b1, b2, b3;
int16_t u04, v04, u26, v26, u17, v17, u35, v35, u12, v12;
col += offset;
x0 = col[0*8];
x1 = col[1*8];
x2 = col[2*8];
x3 = col[3*8];
x4 = col[4*8];
x5 = col[5*8];
x6 = col[6*8];
x7 = col[7*8];
u04 = S (x0 + x4);
v04 = S (x0 - x4);
u26 = S (F (T2, x6) + x2);
v26 = S (F (T2, x2) - x6);
a0 = S (u04 + u26);
a1 = S (v04 + v26);
a2 = S (v04 - v26);
a3 = S (u04 - u26);
u17 = S (F (T1, x7) + x1);
v17 = S (F (T1, x1) - x7);
u35 = S (F (T3, x5) + x3);
v35 = S (F (T3, x3) - x5);
b0 = S (u17 + u35);
b3 = S (v17 - v35);
u12 = S (u17 - u35);
v12 = S (v17 + v35);
u12 = S (2 * F (C4, u12));
v12 = S (2 * F (C4, v12));
b1 = S (u12 + v12);
b2 = S (u12 - v12);
y0 = S (a0 + b0) >> COL_SHIFT;
y1 = S (a1 + b1) >> COL_SHIFT;
y2 = S (a2 + b2) >> COL_SHIFT;
y3 = S (a3 + b3) >> COL_SHIFT;
y4 = S (a3 - b3) >> COL_SHIFT;
y5 = S (a2 - b2) >> COL_SHIFT;
y6 = S (a1 - b1) >> COL_SHIFT;
y7 = S (a0 - b0) >> COL_SHIFT;
col[0*8] = y0;
col[1*8] = y1;
col[2*8] = y2;
col[3*8] = y3;
col[4*8] = y4;
col[5*8] = y5;
col[6*8] = y6;
col[7*8] = y7;
}
#endif
// MMX column IDCT
static inline void idct_col (int16_t * col, int offset)
{
#define T1 13036
#define T2 27146
#define T3 43790
#define C4 23170
static const short _T1[] ATTR_ALIGN(8) = {T1,T1,T1,T1};
static const short _T2[] ATTR_ALIGN(8) = {T2,T2,T2,T2};
static const short _T3[] ATTR_ALIGN(8) = {T3,T3,T3,T3};
static const short _C4[] ATTR_ALIGN(8) = {C4,C4,C4,C4};
/* column code adapted from peter gubanov */
/* http://www.elecard.com/peter/idct.shtml */
movq_m2r (*_T1, mm0); // mm0 = T1
movq_m2r (*(col+offset+1*8), mm1); // mm1 = x1
movq_r2r (mm0, mm2); // mm2 = T1
movq_m2r (*(col+offset+7*8), mm4); // mm4 = x7
pmulhw_r2r (mm1, mm0); // mm0 = T1*x1
movq_m2r (*_T3, mm5); // mm5 = T3
pmulhw_r2r (mm4, mm2); // mm2 = T1*x7
movq_m2r (*(col+offset+5*8), mm6); // mm6 = x5
movq_r2r (mm5, mm7); // mm7 = T3-1
movq_m2r (*(col+offset+3*8), mm3); // mm3 = x3
psubsw_r2r (mm4, mm0); // mm0 = v17
movq_m2r (*_T2, mm4); // mm4 = T2
pmulhw_r2r (mm3, mm5); // mm5 = (T3-1)*x3
paddsw_r2r (mm2, mm1); // mm1 = u17
pmulhw_r2r (mm6, mm7); // mm7 = (T3-1)*x5
/* slot */
movq_r2r (mm4, mm2); // mm2 = T2
paddsw_r2r (mm3, mm5); // mm5 = T3*x3
pmulhw_m2r (*(col+offset+2*8), mm4);// mm4 = T2*x2
paddsw_r2r (mm6, mm7); // mm7 = T3*x5
psubsw_r2r (mm6, mm5); // mm5 = v35
paddsw_r2r (mm3, mm7); // mm7 = u35
movq_m2r (*(col+offset+6*8), mm3); // mm3 = x6
movq_r2r (mm0, mm6); // mm6 = v17
pmulhw_r2r (mm3, mm2); // mm2 = T2*x6
psubsw_r2r (mm5, mm0); // mm0 = b3
psubsw_r2r (mm3, mm4); // mm4 = v26
paddsw_r2r (mm6, mm5); // mm5 = v12
movq_r2m (mm0, *(col+offset+3*8)); // save b3 in scratch0
movq_r2r (mm1, mm6); // mm6 = u17
paddsw_m2r (*(col+offset+2*8), mm2);// mm2 = u26
paddsw_r2r (mm7, mm6); // mm6 = b0
psubsw_r2r (mm7, mm1); // mm1 = u12
movq_r2r (mm1, mm7); // mm7 = u12
movq_m2r (*(col+offset+0*8), mm3); // mm3 = x0
paddsw_r2r (mm5, mm1); // mm1 = u12+v12
movq_m2r (*_C4, mm0); // mm0 = C4/2
psubsw_r2r (mm5, mm7); // mm7 = u12-v12
movq_r2m (mm6, *(col+offset+5*8)); // save b0 in scratch1
pmulhw_r2r (mm0, mm1); // mm1 = b1/2
movq_r2r (mm4, mm6); // mm6 = v26
pmulhw_r2r (mm0, mm7); // mm7 = b2/2
movq_m2r (*(col+offset+4*8), mm5); // mm5 = x4
movq_r2r (mm3, mm0); // mm0 = x0
psubsw_r2r (mm5, mm3); // mm3 = v04
paddsw_r2r (mm5, mm0); // mm0 = u04
paddsw_r2r (mm3, mm4); // mm4 = a1
movq_r2r (mm0, mm5); // mm5 = u04
psubsw_r2r (mm6, mm3); // mm3 = a2
paddsw_r2r (mm2, mm5); // mm5 = a0
paddsw_r2r (mm1, mm1); // mm1 = b1
psubsw_r2r (mm2, mm0); // mm0 = a3
paddsw_r2r (mm7, mm7); // mm7 = b2
movq_r2r (mm3, mm2); // mm2 = a2
movq_r2r (mm4, mm6); // mm6 = a1
paddsw_r2r (mm7, mm3); // mm3 = a2+b2
psraw_i2r (COL_SHIFT, mm3); // mm3 = y2
paddsw_r2r (mm1, mm4); // mm4 = a1+b1
psraw_i2r (COL_SHIFT, mm4); // mm4 = y1
psubsw_r2r (mm1, mm6); // mm6 = a1-b1
movq_m2r (*(col+offset+5*8), mm1); // mm1 = b0
psubsw_r2r (mm7, mm2); // mm2 = a2-b2
psraw_i2r (COL_SHIFT, mm6); // mm6 = y6
movq_r2r (mm5, mm7); // mm7 = a0
movq_r2m (mm4, *(col+offset+1*8)); // save y1
psraw_i2r (COL_SHIFT, mm2); // mm2 = y5
movq_r2m (mm3, *(col+offset+2*8)); // save y2
paddsw_r2r (mm1, mm5); // mm5 = a0+b0
movq_m2r (*(col+offset+3*8), mm4); // mm4 = b3
psubsw_r2r (mm1, mm7); // mm7 = a0-b0
psraw_i2r (COL_SHIFT, mm5); // mm5 = y0
movq_r2r (mm0, mm3); // mm3 = a3
movq_r2m (mm2, *(col+offset+5*8)); // save y5
psubsw_r2r (mm4, mm3); // mm3 = a3-b3
psraw_i2r (COL_SHIFT, mm7); // mm7 = y7
paddsw_r2r (mm0, mm4); // mm4 = a3+b3
movq_r2m (mm5, *(col+offset+0*8)); // save y0
psraw_i2r (COL_SHIFT, mm3); // mm3 = y4
movq_r2m (mm6, *(col+offset+6*8)); // save y6
psraw_i2r (COL_SHIFT, mm4); // mm4 = y3
movq_r2m (mm7, *(col+offset+7*8)); // save y7
movq_r2m (mm3, *(col+offset+4*8)); // save y4
movq_r2m (mm4, *(col+offset+3*8)); // save y3
#undef T1
#undef T2
#undef T3
#undef C4
}
static const int32_t rounder0[] ATTR_ALIGN(8) =
rounder ((1 << (COL_SHIFT - 1)) - 0.5);
static const int32_t rounder4[] ATTR_ALIGN(8) = rounder (0);
static const int32_t rounder1[] ATTR_ALIGN(8) =
rounder (1.25683487303); /* C1*(C1/C4+C1+C7)/2 */
static const int32_t rounder7[] ATTR_ALIGN(8) =
rounder (-0.25); /* C1*(C7/C4+C7-C1)/2 */
static const int32_t rounder2[] ATTR_ALIGN(8) =
rounder (0.60355339059); /* C2 * (C6+C2)/2 */
static const int32_t rounder6[] ATTR_ALIGN(8) =
rounder (-0.25); /* C2 * (C6-C2)/2 */
static const int32_t rounder3[] ATTR_ALIGN(8) =
rounder (0.087788325588); /* C3*(-C3/C4+C3+C5)/2 */
static const int32_t rounder5[] ATTR_ALIGN(8) =
rounder (-0.441341716183); /* C3*(-C5/C4+C5-C3)/2 */
#undef COL_SHIFT
#undef ROW_SHIFT
#define declare_idct(idct,table,idct_row_head,idct_row,idct_row_tail,idct_row_mid) \
void idct (int16_t * block) \
{ \
static const int16_t table04[] ATTR_ALIGN(16) = \
table (22725, 21407, 19266, 16384, 12873, 8867, 4520); \
static const int16_t table17[] ATTR_ALIGN(16) = \
table (31521, 29692, 26722, 22725, 17855, 12299, 6270); \
static const int16_t table26[] ATTR_ALIGN(16) = \
table (29692, 27969, 25172, 21407, 16819, 11585, 5906); \
static const int16_t table35[] ATTR_ALIGN(16) = \
table (26722, 25172, 22654, 19266, 15137, 10426, 5315); \
\
idct_row_head (block, 0*8, table04); \
idct_row (table04, rounder0); \
idct_row_mid (block, 0*8, 4*8, table04); \
idct_row (table04, rounder4); \
idct_row_mid (block, 4*8, 1*8, table17); \
idct_row (table17, rounder1); \
idct_row_mid (block, 1*8, 7*8, table17); \
idct_row (table17, rounder7); \
idct_row_mid (block, 7*8, 2*8, table26); \
idct_row (table26, rounder2); \
idct_row_mid (block, 2*8, 6*8, table26); \
idct_row (table26, rounder6); \
idct_row_mid (block, 6*8, 3*8, table35); \
idct_row (table35, rounder3); \
idct_row_mid (block, 3*8, 5*8, table35); \
idct_row (table35, rounder5); \
idct_row_tail (block, 5*8); \
\
idct_col (block, 0); \
idct_col (block, 4); \
}
void ff_mmx_idct(DCTELEM *block);
void ff_mmxext_idct(DCTELEM *block);
declare_idct (ff_mmxext_idct, mmxext_table,
mmxext_row_head, mmxext_row, mmxext_row_tail, mmxext_row_mid)
declare_idct (ff_mmx_idct, mmx_table,
mmx_row_head, mmx_row, mmx_row_tail, mmx_row_mid)
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