pic-scale 0.7.8

/*
 * Copyright (c) Radzivon Bartoshyk. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * 1.  Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer.
 *
 * 2.  Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 *
 * 3.  Neither the name of the copyright holder nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

use crate::filter_weights::FilterWeights;
use crate::neon::utils::{load_3b_as_u16x4, vxmlal_high_lane_s16, vxmlal_lane_s16, vxmlal_s16};
use crate::support::PRECISION;
use std::arch::aarch64::*;

#[must_use]
#[inline(always)]
fn conv_horiz_rgb_4_u8<const D: bool>(
    start_x: usize,
    src: &[u8],
    weights: int16x4_t,
    store: int32x4_t,
    shuffle: uint8x16_t,
) -> int32x4_t {
    unsafe {
        const CN: usize = 3;
        let src_ptr = src.get_unchecked((start_x * CN)..);

        let mut rgb_pixel = vcombine_u8(vld1_u8(src_ptr.as_ptr()), vdup_n_u8(0));
        rgb_pixel = vreinterpretq_u8_u32(vld1q_lane_u32::<2>(
            src_ptr.get_unchecked(8..).as_ptr().cast(),
            vreinterpretq_u32_u8(rgb_pixel),
        ));

        rgb_pixel = vqtbl1q_u8(rgb_pixel, shuffle);
        let hi = vreinterpretq_s16_u16(vmovl_high_u8(rgb_pixel));
        let lo = vreinterpretq_s16_u16(vmovl_u8(vget_low_u8(rgb_pixel)));

        let acc = vxmlal_high_lane_s16::<D, 3>(store, hi, weights);
        let acc = vxmlal_lane_s16::<D, 2>(acc, vget_low_s16(hi), weights);
        let acc = vxmlal_high_lane_s16::<D, 1>(acc, lo, weights);
        vxmlal_lane_s16::<D, 0>(acc, vget_low_s16(lo), weights)
    }
}

#[must_use]
#[inline(always)]
fn conv_horiz_rgba_2_u8<const D: bool>(
    start_x: usize,
    src: &[u8],
    weights: int16x4_t,
    store: int32x4_t,
    shuffle: uint8x8_t,
) -> int32x4_t {
    unsafe {
        const CN: usize = 3;
        let src_ptr = src.get_unchecked((start_x * CN)..);
        let mut rgb_pixel = vld1_lane_u32::<0>(src_ptr.as_ptr().cast(), vdup_n_u32(0));
        rgb_pixel = vreinterpret_u32_u16(vld1_lane_u16::<2>(
            src_ptr.get_unchecked(4..).as_ptr().cast(),
            vreinterpret_u16_u32(rgb_pixel),
        ));

        rgb_pixel = vreinterpret_u32_u8(vtbl1_u8(vreinterpret_u8_u32(rgb_pixel), shuffle));

        let wide = vreinterpretq_s16_u16(vmovl_u8(vreinterpret_u8_u32(rgb_pixel)));

        let acc = vxmlal_high_lane_s16::<D, 1>(store, wide, weights);
        vxmlal_lane_s16::<D, 0>(acc, vget_low_s16(wide), weights)
    }
}

#[must_use]
#[inline(always)]
fn conv_horiz_rgba_1_u8<const D: bool>(
    start_x: usize,
    src: &[u8],
    w0: int16x4_t,
    store: int32x4_t,
) -> int32x4_t {
    unsafe {
        const CN: usize = 3;
        let src_ptr = src.get_unchecked((start_x * CN)..);
        let rgb_pixel = load_3b_as_u16x4(src_ptr.as_ptr());
        let lo = vreinterpret_s16_u16(rgb_pixel);
        vxmlal_s16::<D>(store, lo, w0)
    }
}

#[inline(always)]
fn write_accumulator_u8<const PRECISION: i32>(store: int32x4_t, dst: &mut [u8]) {
    unsafe {
        let store_16 = vqshrun_n_s32::<PRECISION>(store);
        let store_16_8 = vqmovn_u16(vcombine_u16(store_16, store_16));
        vst1_lane_u16::<0>(
            dst.as_mut_ptr() as *mut u16,
            vreinterpret_u16_u8(store_16_8),
        );
        vst1_lane_u8::<2>(dst.as_mut_ptr().add(2), store_16_8);
    }
}

pub(crate) fn convolve_horizontal_rgb_neon_rows_4(
    src: &[u8],
    src_stride: usize,
    dst: &mut [u8],
    dst_stride: usize,
    filter_weights: &FilterWeights<i16>,
    _: u32,
) {
    convolve_horizontal_rgb_neon_rows_4_impl::<false, PRECISION>(
        src,
        src_stride,
        dst,
        dst_stride,
        filter_weights,
    );
}

fn convolve_horizontal_rgb_neon_rows_4_impl<const D: bool, const PRECISION: i32>(
    src: &[u8],
    src_stride: usize,
    dst: &mut [u8],
    dst_stride: usize,
    filter_weights: &FilterWeights<i16>,
) {
    unsafe {
        let shuf_table_1: [u8; 8] = [0, 1, 2, 255, 3, 4, 5, 255];
        let shuffle_1 = vld1_u8(shuf_table_1.as_ptr());
        let shuf_table_2: [u8; 8] = [6, 7, 8, 255, 9, 10, 11, 255];
        let shuffle_2 = vld1_u8(shuf_table_2.as_ptr());
        let shuffle = vcombine_u8(shuffle_1, shuffle_2);

        // (r0 g0 b0 r1) (g2 b2 r3 g3) (b3 r4 g4 b4) (r5 g5 b5 r6)

        let rnd_const: i32 = 1 << (PRECISION - 1);

        const CN: usize = 3;
        let init = vdupq_n_s32(rnd_const);
        let (row0_ref, rest) = dst.split_at_mut(dst_stride);
        let (row1_ref, rest) = rest.split_at_mut(dst_stride);
        let (row2_ref, row3_ref) = rest.split_at_mut(dst_stride);

        let iter_row0 = row0_ref.as_chunks_mut::<CN>().0;
        let iter_row1 = row1_ref.as_chunks_mut::<CN>().0;
        let iter_row2 = row2_ref.as_chunks_mut::<CN>().0;
        let iter_row3 = row3_ref.as_chunks_mut::<CN>().0;

        for (((((chunk0, chunk1), chunk2), chunk3), &bounds), weights) in iter_row0
            .iter_mut()
            .zip(iter_row1.iter_mut())
            .zip(iter_row2.iter_mut())
            .zip(iter_row3.iter_mut())
            .zip(filter_weights.bounds.iter())
            .zip(
                filter_weights
                    .weights
                    .chunks_exact(filter_weights.aligned_size),
            )
        {
            let mut jx = 0usize;
            let mut store_0 = init;
            let mut store_1 = init;
            let mut store_2 = init;
            let mut store_3 = init;

            let src0 = src;
            let src1 = src0.get_unchecked(src_stride..);
            let src2 = src1.get_unchecked(src_stride..);
            let src3 = src2.get_unchecked(src_stride..);

            while jx + 4 <= bounds.size {
                let bounds_start = bounds.start + jx;
                let w_ptr = weights.get_unchecked(jx..);
                let weights = vld1_s16(w_ptr.as_ptr());
                store_0 = conv_horiz_rgb_4_u8::<D>(bounds_start, src0, weights, store_0, shuffle);
                store_1 = conv_horiz_rgb_4_u8::<D>(bounds_start, src1, weights, store_1, shuffle);
                store_2 = conv_horiz_rgb_4_u8::<D>(bounds_start, src2, weights, store_2, shuffle);
                store_3 = conv_horiz_rgb_4_u8::<D>(bounds_start, src3, weights, store_3, shuffle);
                jx += 4;
            }

            while jx + 2 <= bounds.size {
                let w_ptr = weights.get_unchecked(jx..);
                let bnds = bounds.start + jx;
                let mut v_weight = vld1_dup_s16(w_ptr.as_ptr());
                v_weight = vld1_lane_s16::<1>(w_ptr.as_ptr().add(1), v_weight);
                store_0 = conv_horiz_rgba_2_u8::<D>(bnds, src0, v_weight, store_0, shuffle_1);
                store_1 = conv_horiz_rgba_2_u8::<D>(bnds, src1, v_weight, store_1, shuffle_1);
                store_2 = conv_horiz_rgba_2_u8::<D>(bnds, src2, v_weight, store_2, shuffle_1);
                store_3 = conv_horiz_rgba_2_u8::<D>(bnds, src3, v_weight, store_3, shuffle_1);
                jx += 2;
            }

            while jx < bounds.size {
                let w_ptr = weights.get_unchecked(jx..);
                let bnds = bounds.start + jx;
                let weight0 = vld1_dup_s16(w_ptr.as_ptr());
                store_0 = conv_horiz_rgba_1_u8::<D>(bnds, src0, weight0, store_0);
                store_1 = conv_horiz_rgba_1_u8::<D>(bnds, src1, weight0, store_1);
                store_2 = conv_horiz_rgba_1_u8::<D>(bnds, src2, weight0, store_2);
                store_3 = conv_horiz_rgba_1_u8::<D>(bnds, src3, weight0, store_3);
                jx += 1;
            }

            write_accumulator_u8::<PRECISION>(store_0, chunk0);
            write_accumulator_u8::<PRECISION>(store_1, chunk1);
            write_accumulator_u8::<PRECISION>(store_2, chunk2);
            write_accumulator_u8::<PRECISION>(store_3, chunk3);
        }
    }
}

pub(crate) fn convolve_horizontal_rgb_neon_row_one(
    src: &[u8],
    dst: &mut [u8],
    filter_weights: &FilterWeights<i16>,
    _: u32,
) {
    convolve_horizontal_rgb_neon_row_one_impl::<false, PRECISION>(src, dst, filter_weights);
}

fn convolve_horizontal_rgb_neon_row_one_impl<const D: bool, const PRECISION: i32>(
    src: &[u8],
    dst: &mut [u8],
    filter_weights: &FilterWeights<i16>,
) {
    unsafe {
        const CN: usize = 3;

        let shuf_table_1: [u8; 8] = [0, 1, 2, 255, 3, 4, 5, 255];
        let shuffle_1 = vld1_u8(shuf_table_1.as_ptr());
        let shuf_table_2: [u8; 8] = [6, 7, 8, 255, 9, 10, 11, 255];
        let shuffle_2 = vld1_u8(shuf_table_2.as_ptr());
        let shuffle = vcombine_u8(shuffle_1, shuffle_2);

        let rnd_const: i32 = 1i32 << (PRECISION - 1);

        for ((dst, bounds), weights) in dst
            .as_chunks_mut::<CN>()
            .0
            .iter_mut()
            .zip(filter_weights.bounds.iter())
            .zip(
                filter_weights
                    .weights
                    .chunks_exact(filter_weights.aligned_size),
            )
        {
            let bounds_size = bounds.size;

            let mut jx = 0usize;
            let mut store = vdupq_n_s32(rnd_const);

            while jx + 4 <= bounds_size {
                let bounds_start = bounds.start + jx;
                let w_ptr = weights.get_unchecked(jx..);
                let weights = vld1_s16(w_ptr.as_ptr());
                store = conv_horiz_rgb_4_u8::<D>(bounds_start, src, weights, store, shuffle);
                jx += 4;
            }

            while jx + 2 <= bounds_size {
                let w_ptr = weights.get_unchecked(jx..);
                let bounds_start = bounds.start + jx;
                let v_weight = vreinterpret_s16_s32(vld1_dup_s32(w_ptr.as_ptr() as *const _));
                store = conv_horiz_rgba_2_u8::<D>(bounds_start, src, v_weight, store, shuffle_1);
                jx += 2;
            }

            while jx < bounds_size {
                let w_ptr = weights.get_unchecked(jx..);
                let weight0 = vld1_dup_s16(w_ptr.as_ptr());
                let bnds = bounds.start + jx;
                store = conv_horiz_rgba_1_u8::<D>(bnds, src, weight0, store);
                jx += 1;
            }

            write_accumulator_u8::<PRECISION>(store, dst);
        }
    }
}