FFmpeg/libavcodec/alpha/dsputil_alpha.c

/*
 * Alpha optimized DSP utils
 * Copyright (c) 2002 Falk Hueffner <falk@debian.org>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include "asm.h"
#include "../dsputil.h"

void simple_idct_axp(DCTELEM *block);

void put_pixels_axp_asm(uint8_t *block, const uint8_t *pixels,
			int line_size, int h);
void put_pixels_clamped_mvi_asm(const DCTELEM *block, uint8_t *pixels,
				int line_size);
void add_pixels_clamped_mvi_asm(const DCTELEM *block, uint8_t *pixels, 
				int line_size);

#if 0
/* These functions were the base for the optimized assembler routines,
   and remain here for documentation purposes.  */
static void put_pixels_clamped_mvi(const DCTELEM *block, uint8_t *pixels, 
                                   int line_size)
{
    int i = 8;
    uint64_t clampmask = zap(-1, 0xaa); /* 0x00ff00ff00ff00ff */

    ASM_ACCEPT_MVI;

    do {
        uint64_t shorts0, shorts1;

        shorts0 = ldq(block);
        shorts0 = maxsw4(shorts0, 0);
        shorts0 = minsw4(shorts0, clampmask);
        stl(pkwb(shorts0), pixels);

        shorts1 = ldq(block + 4);
        shorts1 = maxsw4(shorts1, 0);
        shorts1 = minsw4(shorts1, clampmask);
        stl(pkwb(shorts1), pixels + 4);

        pixels += line_size;
        block += 8;
    } while (--i);
}

void add_pixels_clamped_mvi(const DCTELEM *block, uint8_t *pixels, 
                            int line_size)
{
    int h = 8;
    /* Keep this function a leaf function by generating the constants
       manually (mainly for the hack value ;-).  */
    uint64_t clampmask = zap(-1, 0xaa); /* 0x00ff00ff00ff00ff */
    uint64_t signmask  = zap(-1, 0x33);
    signmask ^= signmask >> 1;  /* 0x8000800080008000 */

    ASM_ACCEPT_MVI;

    do {
        uint64_t shorts0, pix0, signs0;
        uint64_t shorts1, pix1, signs1;

        shorts0 = ldq(block);
        shorts1 = ldq(block + 4);

        pix0    = unpkbw(ldl(pixels));
        /* Signed subword add (MMX paddw).  */
        signs0  = shorts0 & signmask;
        shorts0 &= ~signmask;
        shorts0 += pix0;
        shorts0 ^= signs0;
        /* Clamp. */
        shorts0 = maxsw4(shorts0, 0);
        shorts0 = minsw4(shorts0, clampmask);   

        /* Next 4.  */
        pix1    = unpkbw(ldl(pixels + 4));
        signs1  = shorts1 & signmask;
        shorts1 &= ~signmask;
        shorts1 += pix1;
        shorts1 ^= signs1;
        shorts1 = maxsw4(shorts1, 0);
        shorts1 = minsw4(shorts1, clampmask);

        stl(pkwb(shorts0), pixels);
        stl(pkwb(shorts1), pixels + 4);

        pixels += line_size;
        block += 8;
    } while (--h);
}
#endif

static void clear_blocks_axp(DCTELEM *blocks) {
    uint64_t *p = (uint64_t *) blocks;
    int n = sizeof(DCTELEM) * 6 * 64;

    do {
        p[0] = 0;
        p[1] = 0;
        p[2] = 0;
        p[3] = 0;
        p[4] = 0;
        p[5] = 0;
        p[6] = 0;
        p[7] = 0;
        p += 8;
        n -= 8 * 8;
    } while (n);
}

static inline uint64_t avg2_no_rnd(uint64_t a, uint64_t b)
{
    return (a & b) + (((a ^ b) & BYTE_VEC(0xfe)) >> 1);
}

static inline uint64_t avg2(uint64_t a, uint64_t b)
{
    return (a | b) - (((a ^ b) & BYTE_VEC(0xfe)) >> 1);    
}

#if 0
/* The XY2 routines basically utilize this scheme, but reuse parts in
   each iteration.  */
static inline uint64_t avg4(uint64_t l1, uint64_t l2, uint64_t l3, uint64_t l4)
{
    uint64_t r1 = ((l1 & ~BYTE_VEC(0x03)) >> 2)
		+ ((l2 & ~BYTE_VEC(0x03)) >> 2)
		+ ((l3 & ~BYTE_VEC(0x03)) >> 2)
		+ ((l4 & ~BYTE_VEC(0x03)) >> 2);
    uint64_t r2 = ((  (l1 & BYTE_VEC(0x03))
		    + (l2 & BYTE_VEC(0x03))
		    + (l3 & BYTE_VEC(0x03))
		    + (l4 & BYTE_VEC(0x03))
		    + BYTE_VEC(0x02)) >> 2) & BYTE_VEC(0x03);
    return r1 + r2;
}
#endif

#define OP(LOAD, STORE)                         \
    do {                                        \
        STORE(LOAD(pixels), block);             \
        pixels += line_size;                    \
        block += line_size;                     \
    } while (--h)

#define OP_X2(LOAD, STORE)                                      \
    do {                                                        \
        uint64_t pix1, pix2;                                    \
                                                                \
        pix1 = LOAD(pixels);                                    \
        pix2 = pix1 >> 8 | ((uint64_t) pixels[8] << 56);        \
        STORE(AVG2(pix1, pix2), block);                         \
        pixels += line_size;                                    \
        block += line_size;                                     \
    } while (--h)

#define OP_Y2(LOAD, STORE)                      \
    do {                                        \
        uint64_t pix = LOAD(pixels);            \
        do {                                    \
            uint64_t next_pix;                  \
                                                \
            pixels += line_size;                \
            next_pix = LOAD(pixels);            \
            STORE(AVG2(pix, next_pix), block);  \
            block += line_size;                 \
            pix = next_pix;                     \
        } while (--h);                          \
    } while (0)

#define OP_XY2(LOAD, STORE)                                                 \
    do {                                                                    \
        uint64_t pix1 = LOAD(pixels);                                       \
        uint64_t pix2 = pix1 >> 8 | ((uint64_t) pixels[8] << 56);           \
        uint64_t pix_l = (pix1 & BYTE_VEC(0x03))                            \
                       + (pix2 & BYTE_VEC(0x03));                           \
        uint64_t pix_h = ((pix1 & ~BYTE_VEC(0x03)) >> 2)                    \
                       + ((pix2 & ~BYTE_VEC(0x03)) >> 2);                   \
                                                                            \
        do {                                                                \
            uint64_t npix1, npix2;                                          \
            uint64_t npix_l, npix_h;                                        \
            uint64_t avg;                                                   \
                                                                            \
            pixels += line_size;                                            \
            npix1 = LOAD(pixels);                                           \
            npix2 = npix1 >> 8 | ((uint64_t) pixels[8] << 56);              \
            npix_l = (npix1 & BYTE_VEC(0x03))                               \
                   + (npix2 & BYTE_VEC(0x03));                              \
            npix_h = ((npix1 & ~BYTE_VEC(0x03)) >> 2)                       \
                   + ((npix2 & ~BYTE_VEC(0x03)) >> 2);                      \
            avg = (((pix_l + npix_l + AVG4_ROUNDER) >> 2) & BYTE_VEC(0x03)) \
                + pix_h + npix_h;                                           \
            STORE(avg, block);                                              \
                                                                            \
            block += line_size;                                             \
            pix_l = npix_l;                                                 \
            pix_h = npix_h;                                                 \
        } while (--h);                                                      \
    } while (0)

#define MAKE_OP(OPNAME, SUFF, OPKIND, STORE)                            \
static void OPNAME ## _pixels ## SUFF ## _axp                           \
        (uint8_t *restrict block, const uint8_t *restrict pixels,       \
         int line_size, int h)                                          \
{                                                                       \
    if ((size_t) pixels & 0x7) {                                        \
        OPKIND(uldq, STORE);                                            \
    } else {                                                            \
        OPKIND(ldq, STORE);                                             \
    }                                                                   \
}

#define PIXOP(OPNAME, STORE)                    \
    MAKE_OP(OPNAME, ,     OP,     STORE)        \
    MAKE_OP(OPNAME, _x2,  OP_X2,  STORE)        \
    MAKE_OP(OPNAME, _y2,  OP_Y2,  STORE)        \
    MAKE_OP(OPNAME, _xy2, OP_XY2, STORE)

/* Rounding primitives.  */
#define AVG2 avg2
#define AVG4 avg4
#define AVG4_ROUNDER BYTE_VEC(0x02)
#define STORE(l, b) stq(l, b)
PIXOP(put, STORE);

#undef STORE
#define STORE(l, b) stq(AVG2(l, ldq(b)), b);
PIXOP(avg, STORE);

/* Not rounding primitives.  */
#undef AVG2
#undef AVG4
#undef AVG4_ROUNDER
#undef STORE
#define AVG2 avg2_no_rnd
#define AVG4 avg4_no_rnd
#define AVG4_ROUNDER BYTE_VEC(0x01)
#define STORE(l, b) stq(l, b)
PIXOP(put_no_rnd, STORE);

#undef STORE
#define STORE(l, b) stq(AVG2(l, ldq(b)), b);
PIXOP(avg_no_rnd, STORE);

void dsputil_init_alpha(void)
{
    put_pixels_tab[0] = put_pixels_axp_asm;
    put_pixels_tab[1] = put_pixels_x2_axp;
    put_pixels_tab[2] = put_pixels_y2_axp;
    put_pixels_tab[3] = put_pixels_xy2_axp;

    put_no_rnd_pixels_tab[0] = put_pixels_axp_asm;
    put_no_rnd_pixels_tab[1] = put_no_rnd_pixels_x2_axp;
    put_no_rnd_pixels_tab[2] = put_no_rnd_pixels_y2_axp;
    put_no_rnd_pixels_tab[3] = put_no_rnd_pixels_xy2_axp;

    avg_pixels_tab[0] = avg_pixels_axp;
    avg_pixels_tab[1] = avg_pixels_x2_axp;
    avg_pixels_tab[2] = avg_pixels_y2_axp;
    avg_pixels_tab[3] = avg_pixels_xy2_axp;

    avg_no_rnd_pixels_tab[0] = avg_no_rnd_pixels_axp;
    avg_no_rnd_pixels_tab[1] = avg_no_rnd_pixels_x2_axp;
    avg_no_rnd_pixels_tab[2] = avg_no_rnd_pixels_y2_axp;
    avg_no_rnd_pixels_tab[3] = avg_no_rnd_pixels_xy2_axp;

    clear_blocks = clear_blocks_axp;

    /* amask clears all bits that correspond to present features.  */
    if (amask(AMASK_MVI) == 0) {
        put_pixels_clamped = put_pixels_clamped_mvi_asm;
        add_pixels_clamped = add_pixels_clamped_mvi_asm;
    }
}