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ffmpeg/libavcodec/i386/mpegvideo_mmx.c

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/*
* The simplest mpeg encoder (well, it was the simplest!)
* Copyright (c) 2000,2001 Gerard Lantau.
*
* 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 program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* Optimized for ia32 cpus by Nick Kurshev <nickols_k@mail.ru>
*/
#include "../dsputil.h"
#include "../mpegvideo.h"
#if 0
/* XXX: GL: I don't understand why this function needs optimization
(it is called only once per frame!), so I disabled it */
void MPV_frame_start(MpegEncContext *s)
{
if (s->pict_type == B_TYPE) {
__asm __volatile(
"movl (%1), %%eax\n\t"
"movl 4(%1), %%edx\n\t"
"movl 8(%1), %%ecx\n\t"
"movl %%eax, (%0)\n\t"
"movl %%edx, 4(%0)\n\t"
"movl %%ecx, 8(%0)\n\t"
:
:"r"(s->current_picture), "r"(s->aux_picture)
:"eax","edx","ecx","memory");
} else {
/* swap next and last */
__asm __volatile(
"movl (%1), %%eax\n\t"
"movl 4(%1), %%edx\n\t"
"movl 8(%1), %%ecx\n\t"
"xchgl (%0), %%eax\n\t"
"xchgl 4(%0), %%edx\n\t"
"xchgl 8(%0), %%ecx\n\t"
"movl %%eax, (%1)\n\t"
"movl %%edx, 4(%1)\n\t"
"movl %%ecx, 8(%1)\n\t"
"movl %%eax, (%2)\n\t"
"movl %%edx, 4(%2)\n\t"
"movl %%ecx, 8(%2)\n\t"
:
:"r"(s->last_picture), "r"(s->next_picture), "r"(s->current_picture)
:"eax","edx","ecx","memory");
}
}
#endif
static const unsigned long long int mm_wabs __attribute__ ((aligned(8))) = 0xffffffffffffffffULL;
static const unsigned long long int mm_wone __attribute__ ((aligned(8))) = 0x0001000100010001ULL;
/*
NK:
Note: looking at PARANOID:
"enable all paranoid tests for rounding, overflows, etc..."
#ifdef PARANOID
if (level < -2048 || level > 2047)
fprintf(stderr, "unquant error %d %d\n", i, level);
#endif
We can suppose that result of two multiplications can't be greate of 0xFFFF
i.e. is 16-bit, so we use here only PMULLW instruction and can avoid
a complex multiplication.
=====================================================
Full formula for multiplication of 2 integer numbers
which are represent as high:low words:
input: value1 = high1:low1
value2 = high2:low2
output: value3 = value1*value2
value3=high3:low3 (on overflow: modulus 2^32 wrap-around)
this mean that for 0x123456 * 0x123456 correct result is 0x766cb0ce4
but this algorithm will compute only 0x66cb0ce4
this limited by 16-bit size of operands
---------------------------------
tlow1 = high1*low2
tlow2 = high2*low1
tlow1 = tlow1 + tlow2
high3:low3 = low1*low2
high3 += tlow1
*/
static void dct_unquantize_mpeg1_mmx(MpegEncContext *s,
DCTELEM *block, int n, int qscale)
{
int i, level;
const UINT16 *quant_matrix;
if (s->mb_intra) {
if (n < 4)
block[0] = block[0] * s->y_dc_scale;
else
block[0] = block[0] * s->c_dc_scale;
if (s->out_format == FMT_H263) {
i = 1;
goto unquant_even;
}
/* XXX: only mpeg1 */
quant_matrix = s->intra_matrix;
i=1;
/* Align on 4 elements boundary */
while(i&3)
{
level = block[i];
if (level) {
if (level < 0) level = -level;
level = (int)(level * qscale * quant_matrix[i]) >> 3;
level = (level - 1) | 1;
if (block[i] < 0) level = -level;
block[i] = level;
}
i++;
}
__asm __volatile(
"movd %0, %%mm6\n\t" /* mm6 = qscale | 0 */
"punpckldq %%mm6, %%mm6\n\t" /* mm6 = qscale | qscale */
"movq %2, %%mm4\n\t"
"movq %%mm6, %%mm7\n\t"
"movq %1, %%mm5\n\t"
"packssdw %%mm6, %%mm7\n\t" /* mm7 = qscale | qscale | qscale | qscale */
"pxor %%mm6, %%mm6\n\t"
::"g"(qscale),"m"(mm_wone),"m"(mm_wabs):"memory");
for(;i<64;i+=4) {
__asm __volatile(
"movq %1, %%mm0\n\t"
"movq %%mm7, %%mm1\n\t"
"movq %%mm0, %%mm2\n\t"
"movq %%mm0, %%mm3\n\t"
"pcmpgtw %%mm6, %%mm2\n\t"
"pmullw %2, %%mm1\n\t"
"pandn %%mm4, %%mm2\n\t"
"por %%mm5, %%mm2\n\t"
"pmullw %%mm2, %%mm0\n\t" /* mm0 = abs(block[i]). */
"pcmpeqw %%mm6, %%mm3\n\t"
"pmullw %%mm0, %%mm1\n\t"
"psraw $3, %%mm1\n\t"
"psubw %%mm5, %%mm1\n\t" /* block[i] --; */
"pandn %%mm4, %%mm3\n\t" /* fake of pcmpneqw : mm0 != 0 then mm1 = -1 */
"por %%mm5, %%mm1\n\t" /* block[i] |= 1 */
"pmullw %%mm2, %%mm1\n\t" /* change signs again */
"pand %%mm3, %%mm1\n\t" /* nullify if was zero */
"movq %%mm1, %0"
:"=m"(block[i])
:"m"(block[i]), "m"(quant_matrix[i])
:"memory");
}
} else {
i = 0;
unquant_even:
quant_matrix = s->non_intra_matrix;
/* Align on 4 elements boundary */
while(i&3)
{
level = block[i];
if (level) {
if (level < 0) level = -level;
level = (((level << 1) + 1) * qscale *
((int) quant_matrix[i])) >> 4;
level = (level - 1) | 1;
if(block[i] < 0) level = -level;
block[i] = level;
}
i++;
}
__asm __volatile(
"movd %0, %%mm6\n\t" /* mm6 = qscale | 0 */
"punpckldq %%mm6, %%mm6\n\t" /* mm6 = qscale | qscale */
"movq %2, %%mm4\n\t"
"movq %%mm6, %%mm7\n\t"
"movq %1, %%mm5\n\t"
"packssdw %%mm6, %%mm7\n\t" /* mm7 = qscale | qscale | qscale | qscale */
"pxor %%mm6, %%mm6\n\t"
::"g"(qscale),"m"(mm_wone),"m"(mm_wabs):"memory");
for(;i<64;i+=4) {
__asm __volatile(
"movq %1, %%mm0\n\t"
"movq %%mm7, %%mm1\n\t"
"movq %%mm0, %%mm2\n\t"
"movq %%mm0, %%mm3\n\t"
"pcmpgtw %%mm6, %%mm2\n\t"
"pmullw %2, %%mm1\n\t"
"pandn %%mm4, %%mm2\n\t"
"por %%mm5, %%mm2\n\t"
"pmullw %%mm2, %%mm0\n\t" /* mm0 = abs(block[i]). */
"psllw $1, %%mm0\n\t" /* block[i] <<= 1 */
"paddw %%mm5, %%mm0\n\t" /* block[i] ++ */
"pmullw %%mm0, %%mm1\n\t"
"psraw $4, %%mm1\n\t"
"pcmpeqw %%mm6, %%mm3\n\t"
"psubw %%mm5, %%mm1\n\t" /* block[i] --; */
"pandn %%mm4, %%mm3\n\t" /* fake of pcmpneqw : mm0 != 0 then mm1 = -1 */
"por %%mm5, %%mm1\n\t" /* block[i] |= 1 */
"pmullw %%mm2, %%mm1\n\t" /* change signs again */
"pand %%mm3, %%mm1\n\t" /* nullify if was zero */
"movq %%mm1, %0"
:"=m"(block[i])
:"m"(block[i]), "m"(quant_matrix[i])
:"memory");
}
}
}
void MPV_common_init_mmx(MpegEncContext *s)
{
if (mm_flags & MM_MMX) {
/* XXX: should include h263 optimization too. It would go even
faster! */
s->dct_unquantize = dct_unquantize_mpeg1_mmx;
}
}
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