src/core/CL/cl_kernels/warp_helpers_quantized.h

/*
 * Copyright (c) 2018-2021 Arm Limited.
 *
 * SPDX-License-Identifier: MIT
 *
 * 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 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.
 */
#include "helpers_asymm.h"

/** Clamps the given coordinates to the borders according to the border size.
 *
 * @param[in] coords      Vector of 2D coordinates to clamp. Even positions are X coords, odd positions are Y coords.
 * @param[in] width       Width of the image
 * @param[in] height      Height of the image
 * @param[in] border_size Border size of the image
 *
 */
inline const float8 clamp_to_border_with_size_quantized(float8 coords, const float width, const float height, const float border_size)
{
    const float4 clamped_x = clamp(coords.even, 0.0f - border_size, width - 1 + border_size);
    const float4 clamped_y = clamp(coords.odd, 0.0f - border_size, height - 1 + border_size);
    return (float8)(clamped_x.s0, clamped_y.s0, clamped_x.s1, clamped_y.s1, clamped_x.s2, clamped_y.s2, clamped_x.s3, clamped_y.s3);
}

/** Clamps the given coordinates to the borders.
 *
 * @param[in] coords Vector of 2D coordinates to clamp. Even positions are X coords, odd positions are Y coords.
 * @param[in] width  Width of the image
 * @param[in] height Height of the image
 *
 */
inline const float8 clamp_to_border_quantized(float8 coords, const float width, const float height)
{
    return clamp_to_border_with_size_quantized(coords, width, height, 1);
}

/** Given a texel coordinates this function will return the following array of coordinates:
 * [ P, right neighbour, below neighbour, below right neighbour ]
 *
 * @note No checks to see if the coordinates are out of the image are done here.
 *
 * @param[in] coord Input coordinates
 *
 * @return vector of 8 floats with the coordinates, even positions are x and odd y.
 */
inline const float8 get_neighbour_coords_quantized(const float2 coord)
{
    return (float8)(/*tl*/ coord.s0, coord.s1, /*tr*/ coord.s0 + 1, coord.s1, /*bl*/ coord.s0, coord.s1 + 1, /*br*/ coord.s0 + 1, coord.s1 + 1);
}

/** Returns the current thread coordinates. */
inline const float2 get_current_coords_quantized()
{
    return (float2)(get_global_id(0) * 4, get_global_id(1));
}

/** Computes the bilinear interpolation for each set of coordinates in the vector coords and returns the values
 *
 * @param[in] in            Pointer to the source image.
 * @param[in] coords        Vector of four 2D coordinates. Even pos is x and odd y.
 * @param[in] width         Width of the image
 * @param[in] height        Height of the image
 * @param[in] border_size   Border size
 * @param[in] scale         Scale value
 * @param[in] offset_qasymm Offset value
 */
inline const VEC_DATA_TYPE(DATA_TYPE, 4) bilinear_interpolate_with_border_quantized(const Image *in, const float8 coords, const float width, const float height, const float border_size,
                                                                                    const float scale, const int offset_qasymm)
{
    // If any of the 4 texels is out of the image's boundaries we use the border value (REPLICATE or CONSTANT) for any texel out of the image.

    // Sets the 4x4 coordinates for each of the four input texels
    const float8  fc = floor(coords);
    const float16 c1 = (float16)(
                           clamp_to_border_with_size_quantized(get_neighbour_coords_quantized((float2)(fc.s0, fc.s1)), width, height, border_size),
                           clamp_to_border_with_size_quantized(get_neighbour_coords_quantized((float2)(fc.s2, fc.s3)), width, height, border_size));
    const float16 c2 = (float16)(
                           clamp_to_border_with_size_quantized(get_neighbour_coords_quantized((float2)(fc.s4, fc.s5)), width, height, border_size),
                           clamp_to_border_with_size_quantized(get_neighbour_coords_quantized((float2)(fc.s6, fc.s7)), width, height, border_size));

    // Loads the values from the input image
    const int16 t = (int16)(
                        /* tl, tr, bl, br */
                        * ((__global DATA_TYPE *)offset(in, c1.s0, c1.s1)), *((__global DATA_TYPE *)offset(in, c1.s2, c1.s3)),
                        *((__global DATA_TYPE *)offset(in, c1.s4, c1.s5)), *((__global DATA_TYPE *)offset(in, c1.s6, c1.s7)),
                        *((__global DATA_TYPE *)offset(in, c1.s8, c1.s9)), *((__global DATA_TYPE *)offset(in, c1.sa, c1.sb)),
                        *((__global DATA_TYPE *)offset(in, c1.sc, c1.sd)), *((__global DATA_TYPE *)offset(in, c1.se, c1.sf)),
                        *((__global DATA_TYPE *)offset(in, c2.s0, c2.s1)), *((__global DATA_TYPE *)offset(in, c2.s2, c2.s3)),
                        *((__global DATA_TYPE *)offset(in, c2.s4, c2.s5)), *((__global DATA_TYPE *)offset(in, c2.s6, c2.s7)),
                        *((__global DATA_TYPE *)offset(in, c2.s8, c2.s9)), *((__global DATA_TYPE *)offset(in, c2.sa, c2.sb)),
                        *((__global DATA_TYPE *)offset(in, c2.sc, c2.sd)), *((__global DATA_TYPE *)offset(in, c2.se, c2.sf)));

    const float16 inf32 = convert_float16(t - (int16)offset_qasymm) * (float16)scale;

    const float8 a  = coords - fc;
    const float8 b  = ((float8)(1.f)) - a;
    const float4 fr = (float4)(
                          ((inf32.s0 * b.s0 * b.s1) + (inf32.s1 * a.s0 * b.s1) + (inf32.s2 * b.s0 * a.s1) + (inf32.s3 * a.s0 * a.s1)),
                          ((inf32.s4 * b.s2 * b.s3) + (inf32.s5 * a.s2 * b.s3) + (inf32.s6 * b.s2 * a.s3) + (inf32.s7 * a.s2 * a.s3)),
                          ((inf32.s8 * b.s4 * b.s5) + (inf32.s9 * a.s4 * b.s5) + (inf32.sa * b.s4 * a.s5) + (inf32.sb * a.s4 * a.s5)),
                          ((inf32.sc * b.s6 * b.s7) + (inf32.sd * a.s6 * b.s7) + (inf32.se * b.s6 * a.s7) + (inf32.sf * a.s6 * a.s7)));

    const VEC_DATA_TYPE(DATA_TYPE, 4) res = CONVERT_SAT(convert_int4_sat_rtp(fr / scale) + offset_qasymm, VEC_DATA_TYPE(DATA_TYPE, 4));

    return res;
}

/** Computes the bilinear interpolation for each set of coordinates in the vector coords and returns the values
 *
 * @param[in] in            Pointer to the source image.
 * @param[in] coords        Vector of four 2D coordinates. Even pos is x and odd y.
 * @param[in] width         Width of the image
 * @param[in] height        Height of the image
 * @param[in] scale         Scale value
 * @param[in] offset_qasymm Offset value
 */
inline const VEC_DATA_TYPE(DATA_TYPE, 4) bilinear_interpolate_quantized(const Image *in, const float8 coords, const float width, const float height, const float scale, const int offset_qasymm)
{
    return bilinear_interpolate_with_border_quantized(in, coords, width, height, 1, scale, offset_qasymm);
}