/*

 * Copyright © 2013 Soren Sandmann Pedersen

 * Copyright © 2013 Red Hat, Inc.

 *

 * Permission is hereby granted, free of charge, to any person obtaining a

 * copy of this software and associated documentation files (the "Software"),

 * to deal in the Software without restriction, including without limitation

 * the rights to use, copy, modify, merge, publish, distribute, sublicense,

 * and/or sell copies of the Software, and to permit persons to whom the

 * Software is furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice (including the next

 * paragraph) shall be included in all copies or substantial portions of the

 * Software.

 * 

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL

 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING

 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER

 * DEALINGS IN THE SOFTWARE.

 *

 * Author: Soren Sandmann (soren.sandmann@gmail.com)

 */

#ifdef HAVE_CONFIG_H

#include <config.h>

#endif

#include <stdlib.h>

#include <mmintrin.h>

#include <xmmintrin.h>

#include <emmintrin.h>

#include <tmmintrin.h>

#include "pixman-private.h"

#include "pixman-inlines.h"

typedef struct

{

    int		y;

    uint64_t *	buffer;

} line_t;

typedef struct

{

    line_t		lines[2];

    pixman_fixed_t	y;

    pixman_fixed_t	x;

    uint64_t		data[1];

} bilinear_info_t;

static void

ssse3_fetch_horizontal (bits_image_t *image, line_t *line,

			int y, pixman_fixed_t x, pixman_fixed_t ux, int n)

{

    uint32_t *bits = image->bits + y * image->rowstride;

    __m128i vx = _mm_set_epi16 (

	- (x + 1), x, - (x + 1), x,

	- (x + ux + 1), x + ux,  - (x + ux + 1), x + ux);

    __m128i vux = _mm_set_epi16 (

	- 2 * ux, 2 * ux, - 2 * ux, 2 * ux,

	- 2 * ux, 2 * ux, - 2 * ux, 2 * ux);

    __m128i vaddc = _mm_set_epi16 (1, 0, 1, 0, 1, 0, 1, 0);

    __m128i *b = (__m128i *)line->buffer;

    __m128i vrl0, vrl1;

    while ((n -= 2) >= 0)

    {

	__m128i vw, vr, s;

	vrl1 = _mm_loadl_epi64 (

	    (__m128i *)(bits + pixman_fixed_to_int (x + ux)));

	/* vrl1: R1, L1 */

    final_pixel:

	vrl0 = _mm_loadl_epi64 (

	    (__m128i *)(bits + pixman_fixed_to_int (x)));

	/* vrl0: R0, L0 */

	/* The weights are based on vx which is a vector of 

	 *

	 *    - (x + 1), x, - (x + 1), x,

	 *          - (x + ux + 1), x + ux, - (x + ux + 1), x + ux

	 *

	 * so the 16 bit weights end up like this:

	 *

	 *    iw0, w0, iw0, w0, iw1, w1, iw1, w1

	 *

	 * and after shifting and packing, we get these bytes:

	 *

	 *    iw0, w0, iw0, w0, iw1, w1, iw1, w1,

	 *        iw0, w0, iw0, w0, iw1, w1, iw1, w1,

	 *

	 * which means the first and the second input pixel 

	 * have to be interleaved like this:

	 *

	 *    la0, ra0, lr0, rr0, la1, ra1, lr1, rr1,

	 *        lg0, rg0, lb0, rb0, lg1, rg1, lb1, rb1

	 *

	 * before maddubsw can be used.

	 */

	vw = _mm_add_epi16 (

	    vaddc, _mm_srli_epi16 (vx, 16 - BILINEAR_INTERPOLATION_BITS));

	/* vw: iw0, w0, iw0, w0, iw1, w1, iw1, w1

	 */

	vw = _mm_packus_epi16 (vw, vw);

	/* vw: iw0, w0, iw0, w0, iw1, w1, iw1, w1,

	 *         iw0, w0, iw0, w0, iw1, w1, iw1, w1

	 */

	vx = _mm_add_epi16 (vx, vux);

	x += 2 * ux;

	vr = _mm_unpacklo_epi16 (vrl1, vrl0);

	/* vr: rar0, rar1, rgb0, rgb1, lar0, lar1, lgb0, lgb1 */

	s = _mm_shuffle_epi32 (vr, _MM_SHUFFLE (1, 0, 3, 2));

	/* s:  lar0, lar1, lgb0, lgb1, rar0, rar1, rgb0, rgb1 */

	vr = _mm_unpackhi_epi8 (vr, s);

	/* vr: la0, ra0, lr0, rr0, la1, ra1, lr1, rr1,

	 *         lg0, rg0, lb0, rb0, lg1, rg1, lb1, rb1

	 */

	vr = _mm_maddubs_epi16 (vr, vw);

	/* When the weight is 0, the inverse weight is

	 * 128 which can't be represented in a signed byte.

	 * As a result maddubsw computes the following:

	 *

	 *     r = l * -128 + r * 0

	 *

	 * rather than the desired

	 *

	 *     r = l * 128 + r * 0

	 *

	 * We fix this by taking the absolute value of the

	 * result.

	 */

	vr = _mm_abs_epi16 (vr);

	/* vr: A0, R0, A1, R1, G0, B0, G1, B1 */

	_mm_store_si128 (b++, vr);

    }

    if (n == -1)

    {

	vrl1 = _mm_setzero_si128();

	goto final_pixel;

    }

    line->y = y;

}

static uint32_t *

ssse3_fetch_bilinear_cover (pixman_iter_t *iter, const uint32_t *mask)

{

    pixman_fixed_t fx, ux;

    bilinear_info_t *info = iter->data;

    line_t *line0, *line1;

    int y0, y1;

    int32_t dist_y;

    __m128i vw;

    int i;

    fx = info->x;

    ux = iter->image->common.transform->matrix[0][0];

    y0 = pixman_fixed_to_int (info->y);

    y1 = y0 + 1;

    line0 = &info->lines[y0 & 0x01];

    line1 = &info->lines[y1 & 0x01];

    if (line0->y != y0)

    {

	ssse3_fetch_horizontal (

	    &iter->image->bits, line0, y0, fx, ux, iter->width);

    }

    if (line1->y != y1)

    {

	ssse3_fetch_horizontal (

	    &iter->image->bits, line1, y1, fx, ux, iter->width);

    }

    dist_y = pixman_fixed_to_bilinear_weight (info->y);

    dist_y <<= (16 - BILINEAR_INTERPOLATION_BITS);

    vw = _mm_set_epi16 (

	dist_y, dist_y, dist_y, dist_y, dist_y, dist_y, dist_y, dist_y);

    for (i = 0; i + 3 < iter->width; i += 4)

    {

	__m128i top0 = _mm_load_si128 ((__m128i *)(line0->buffer + i));

	__m128i bot0 = _mm_load_si128 ((__m128i *)(line1->buffer + i));

	__m128i top1 = _mm_load_si128 ((__m128i *)(line0->buffer + i + 2));

	__m128i bot1 = _mm_load_si128 ((__m128i *)(line1->buffer + i + 2));

	__m128i r0, r1, tmp, p;

	r0 = _mm_mulhi_epu16 (

	    _mm_sub_epi16 (bot0, top0), vw);

	tmp = _mm_cmplt_epi16 (bot0, top0);

	tmp = _mm_and_si128 (tmp, vw);

	r0 = _mm_sub_epi16 (r0, tmp);

	r0 = _mm_add_epi16 (r0, top0);

	r0 = _mm_srli_epi16 (r0, BILINEAR_INTERPOLATION_BITS);

	/* r0:  A0 R0 A1 R1 G0 B0 G1 B1 */

	r0 = _mm_shuffle_epi32 (r0, _MM_SHUFFLE (2, 0, 3, 1));

	/* r0:  A1 R1 G1 B1 A0 R0 G0 B0 */

	r1 = _mm_mulhi_epu16 (

	    _mm_sub_epi16 (bot1, top1), vw);

	tmp = _mm_cmplt_epi16 (bot1, top1);

	tmp = _mm_and_si128 (tmp, vw);

	r1 = _mm_sub_epi16 (r1, tmp);

	r1 = _mm_add_epi16 (r1, top1);

	r1 = _mm_srli_epi16 (r1, BILINEAR_INTERPOLATION_BITS);

	r1 = _mm_shuffle_epi32 (r1, _MM_SHUFFLE (2, 0, 3, 1));

	/* r1: A3 R3 G3 B3 A2 R2 G2 B2 */

	p = _mm_packus_epi16 (r0, r1);

	_mm_storeu_si128 ((__m128i *)(iter->buffer + i), p);

    }

    while (i < iter->width)

    {

	__m128i top0 = _mm_load_si128 ((__m128i *)(line0->buffer + i));

	__m128i bot0 = _mm_load_si128 ((__m128i *)(line1->buffer + i));

	__m128i r0, tmp, p;

	r0 = _mm_mulhi_epu16 (

	    _mm_sub_epi16 (bot0, top0), vw);

	tmp = _mm_cmplt_epi16 (bot0, top0);

	tmp = _mm_and_si128 (tmp, vw);

	r0 = _mm_sub_epi16 (r0, tmp);

	r0 = _mm_add_epi16 (r0, top0);

	r0 = _mm_srli_epi16 (r0, BILINEAR_INTERPOLATION_BITS);

	/* r0:  A0 R0 A1 R1 G0 B0 G1 B1 */

	r0 = _mm_shuffle_epi32 (r0, _MM_SHUFFLE (2, 0, 3, 1));

	/* r0:  A1 R1 G1 B1 A0 R0 G0 B0 */

	p = _mm_packus_epi16 (r0, r0);

	if (iter->width - i == 1)

	{

	    *(uint32_t *)(iter->buffer + i) = _mm_cvtsi128_si32 (p);

	    i++;

	}

	else

	{

	    _mm_storel_epi64 ((__m128i *)(iter->buffer + i), p);

	    i += 2;

	}

    }

    info->y += iter->image->common.transform->matrix[1][1];

    return iter->buffer;

}

static void

ssse3_bilinear_cover_iter_fini (pixman_iter_t *iter)

{

    free (iter->data);

}

static void

ssse3_bilinear_cover_iter_init (pixman_iter_t *iter, const pixman_iter_info_t *iter_info)

{

    int width = iter->width;

    bilinear_info_t *info;

    pixman_vector_t v;

    /* Reference point is the center of the pixel */

    v.vector[0] = pixman_int_to_fixed (iter->x) + pixman_fixed_1 / 2;

    v.vector[1] = pixman_int_to_fixed (iter->y) + pixman_fixed_1 / 2;

    v.vector[2] = pixman_fixed_1;

    if (!pixman_transform_point_3d (iter->image->common.transform, &v))

	goto fail;

    info = malloc (sizeof (*info) + (2 * width - 1) * sizeof (uint64_t) + 64);

    if (!info)

	goto fail;

    info->x = v.vector[0] - pixman_fixed_1 / 2;

    info->y = v.vector[1] - pixman_fixed_1 / 2;

#define ALIGN(addr)							\

    ((void *)((((uintptr_t)(addr)) + 15) & (~15)))

    /* It is safe to set the y coordinates to -1 initially

     * because COVER_CLIP_BILINEAR ensures that we will only

     * be asked to fetch lines in the [0, height) interval

     */

    info->lines[0].y = -1;

    info->lines[0].buffer = ALIGN (&(info->data[0]));

    info->lines[1].y = -1;

    info->lines[1].buffer = ALIGN (info->lines[0].buffer + width);

    iter->get_scanline = ssse3_fetch_bilinear_cover;

    iter->fini = ssse3_bilinear_cover_iter_fini;

    iter->data = info;

    return;

fail:

    /* Something went wrong, either a bad matrix or OOM; in such cases,

     * we don't guarantee any particular rendering.

     */

    _pixman_log_error (

	FUNC, "Allocation failure or bad matrix, skipping rendering\n");

    iter->get_scanline = _pixman_iter_get_scanline_noop;

    iter->fini = NULL;

}

static const pixman_iter_info_t ssse3_iters[] = 

{

    { PIXMAN_a8r8g8b8,

      (FAST_PATH_STANDARD_FLAGS			|

       FAST_PATH_SCALE_TRANSFORM		|

       FAST_PATH_BILINEAR_FILTER		|

       FAST_PATH_SAMPLES_COVER_CLIP_BILINEAR),

      ITER_NARROW | ITER_SRC,

      ssse3_bilinear_cover_iter_init,

      NULL, NULL

    },

    { PIXMAN_null },

};

static const pixman_fast_path_t ssse3_fast_paths[] =

{

    { PIXMAN_OP_NONE },

};

pixman_implementation_t *

_pixman_implementation_create_ssse3 (pixman_implementation_t *fallback)

{

    pixman_implementation_t *imp =

	_pixman_implementation_create (fallback, ssse3_fast_paths);

    imp->iter_info = ssse3_iters;

    return imp;

}