static void gmc_mmx(uint8_t *dst, uint8_t *src,

                    int stride, int h, int ox, int oy,

                    int dxx, int dxy, int dyx, int dyy,

                    int shift, int r, int width, int height)

{

    const int w    = 8;

    const int ix   = ox  >> (16 + shift);

    const int iy   = oy  >> (16 + shift);

    const int oxs  = ox  >> 4;

    const int oys  = oy  >> 4;

    const int dxxs = dxx >> 4;

    const int dxys = dxy >> 4;

    const int dyxs = dyx >> 4;

    const int dyys = dyy >> 4;

    const uint16_t r4[4]   = { r, r, r, r };

    const uint16_t dxy4[4] = { dxys, dxys, dxys, dxys };

    const uint16_t dyy4[4] = { dyys, dyys, dyys, dyys };

    const uint64_t shift2  = 2 * shift;

#define MAX_STRIDE 4096U

#define MAX_H 8U

    uint8_t edge_buf[(MAX_H + 1) * MAX_STRIDE];

    int x, y;



    const int dxw = (dxx - (1 << (16 + shift))) * (w - 1);

    const int dyh = (dyy - (1 << (16 + shift))) * (h - 1);

    const int dxh = dxy * (h - 1);

    const int dyw = dyx * (w - 1);

    int need_emu  =  (unsigned) ix >= width  - w ||

                     (unsigned) iy >= height - h;



    if ( // non-constant fullpel offset (3% of blocks)

        ((ox ^ (ox + dxw)) | (ox ^ (ox + dxh)) | (ox ^ (ox + dxw + dxh)) |

         (oy ^ (oy + dyw)) | (oy ^ (oy + dyh)) | (oy ^ (oy + dyw + dyh))) >> (16 + shift) ||

        // uses more than 16 bits of subpel mv (only at huge resolution)

        (dxx | dxy | dyx | dyy) & 15 ||

        (need_emu && (h > MAX_H || stride > MAX_STRIDE))) {

        // FIXME could still use mmx for some of the rows

        ff_gmc_c(dst, src, stride, h, ox, oy, dxx, dxy, dyx, dyy,

                 shift, r, width, height);

        return;

    }



    src += ix + iy * stride;

    if (need_emu) {

        ff_emulated_edge_mc_8(edge_buf, src, stride, stride, w + 1, h + 1, ix, iy, width, height);

        src = edge_buf;

    }



    __asm__ volatile (

        "movd         %0, %%mm6         \n\t"

        "pxor      %%mm7, %%mm7         \n\t"

        "punpcklwd %%mm6, %%mm6         \n\t"

        "punpcklwd %%mm6, %%mm6         \n\t"

        :: "r" (1 << shift));



    for (x = 0; x < w; x += 4) {

        uint16_t dx4[4] = { oxs - dxys + dxxs * (x + 0),

                            oxs - dxys + dxxs * (x + 1),

                            oxs - dxys + dxxs * (x + 2),

                            oxs - dxys + dxxs * (x + 3) };

        uint16_t dy4[4] = { oys - dyys + dyxs * (x + 0),

                            oys - dyys + dyxs * (x + 1),

                            oys - dyys + dyxs * (x + 2),

                            oys - dyys + dyxs * (x + 3) };



        for (y = 0; y < h; y++) {

            __asm__ volatile (

                "movq      %0, %%mm4    \n\t"

                "movq      %1, %%mm5    \n\t"

                "paddw     %2, %%mm4    \n\t"

                "paddw     %3, %%mm5    \n\t"

                "movq   %%mm4, %0       \n\t"

                "movq   %%mm5, %1       \n\t"

                "psrlw    $12, %%mm4    \n\t"

                "psrlw    $12, %%mm5    \n\t"

                : "+m" (*dx4), "+m" (*dy4)

                : "m" (*dxy4), "m" (*dyy4));



            __asm__ volatile (

                "movq      %%mm6, %%mm2 \n\t"

                "movq      %%mm6, %%mm1 \n\t"

                "psubw     %%mm4, %%mm2 \n\t"

                "psubw     %%mm5, %%mm1 \n\t"

                "movq      %%mm2, %%mm0 \n\t"

                "movq      %%mm4, %%mm3 \n\t"

                "pmullw    %%mm1, %%mm0 \n\t" // (s - dx) * (s - dy)

                "pmullw    %%mm5, %%mm3 \n\t" // dx * dy

                "pmullw    %%mm5, %%mm2 \n\t" // (s - dx) * dy

                "pmullw    %%mm4, %%mm1 \n\t" // dx * (s - dy)



                "movd         %4, %%mm5 \n\t"

                "movd         %3, %%mm4 \n\t"

                "punpcklbw %%mm7, %%mm5 \n\t"

                "punpcklbw %%mm7, %%mm4 \n\t"

                "pmullw    %%mm5, %%mm3 \n\t" // src[1, 1] * dx * dy

                "pmullw    %%mm4, %%mm2 \n\t" // src[0, 1] * (s - dx) * dy



                "movd         %2, %%mm5 \n\t"

                "movd         %1, %%mm4 \n\t"

                "punpcklbw %%mm7, %%mm5 \n\t"

                "punpcklbw %%mm7, %%mm4 \n\t"

                "pmullw    %%mm5, %%mm1 \n\t" // src[1, 0] * dx * (s - dy)

                "pmullw    %%mm4, %%mm0 \n\t" // src[0, 0] * (s - dx) * (s - dy)

                "paddw        %5, %%mm1 \n\t"

                "paddw     %%mm3, %%mm2 \n\t"

                "paddw     %%mm1, %%mm0 \n\t"

                "paddw     %%mm2, %%mm0 \n\t"



                "psrlw        %6, %%mm0 \n\t"

                "packuswb  %%mm0, %%mm0 \n\t"

                "movd      %%mm0, %0    \n\t"



                : "=m" (dst[x + y * stride])

                : "m" (src[0]), "m" (src[1]),

                  "m" (src[stride]), "m" (src[stride + 1]),

                  "m" (*r4), "m" (shift2));

            src += stride;

        }

        src += 4 - h * stride;

    }

}
