// Copyright (c) 2019-2021, The rav1e contributors. All rights reserved
//
// This source code is subject to the terms of the BSD 2 Clause License and
// the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
// was not distributed with this source code in the LICENSE file, you can
// obtain it at www.aomedia.org/license/software. If the Alliance for Open
// Media Patent License 1.0 was not distributed with this source code in the
// PATENTS file, you can obtain it at www.aomedia.org/license/patent.

use crate::cpu_features::CpuFeatureLevel;
use crate::frame::*;
use crate::mc::FilterMode::*;
use crate::mc::*;
use crate::tiling::*;
use crate::util::*;

type PutFn = unsafe extern fn(
  dst: *mut u8,
  dst_stride: isize,
  src: *const u8,
  src_stride: isize,
  width: i32,
  height: i32,
  col_frac: i32,
  row_frac: i32,
);

type PutHBDFn = unsafe extern fn(
  dst: *mut u16,
  dst_stride: isize,
  src: *const u16,
  src_stride: isize,
  width: i32,
  height: i32,
  col_frac: i32,
  row_frac: i32,
  bitdepth_max: i32,
);

type PrepFn = unsafe extern fn(
  tmp: *mut i16,
  src: *const u8,
  src_stride: isize,
  width: i32,
  height: i32,
  col_frac: i32,
  row_frac: i32,
);

type PrepHBDFn = unsafe extern fn(
  tmp: *mut i16,
  src: *const u16,
  src_stride: isize,
  width: i32,
  height: i32,
  col_frac: i32,
  row_frac: i32,
  bitdepth_max: i32,
);

type AvgFn = unsafe extern fn(
  dst: *mut u8,
  dst_stride: isize,
  tmp1: *const i16,
  tmp2: *const i16,
  width: i32,
  height: i32,
);

type AvgHBDFn = unsafe extern fn(
  dst: *mut u16,
  dst_stride: isize,
  tmp1: *const i16,
  tmp2: *const i16,
  width: i32,
  height: i32,
  bitdepth_max: i32,
);

// gets an index that can be mapped to a function for a pair of filter modes
#[inline]
const fn get_2d_mode_idx(mode_x: FilterMode, mode_y: FilterMode) -> usize {
  (mode_x as usize + 4 * (mode_y as usize)) & 15
}

#[inline(always)]
pub fn put_8tap<T: Pixel>(
  dst: &mut PlaneRegionMut<'_, T>, src: PlaneSlice<'_, T>, width: usize,
  height: usize, col_frac: i32, row_frac: i32, mode_x: FilterMode,
  mode_y: FilterMode, bit_depth: usize, cpu: CpuFeatureLevel,
) {
  let call_rust = |dst: &mut PlaneRegionMut<'_, T>| {
    rust::put_8tap(
      dst, src, width, height, col_frac, row_frac, mode_x, mode_y, bit_depth,
      cpu,
    );
  };
  #[cfg(feature = "check_asm")]
  let ref_dst = {
    let mut copy = dst.scratch_copy();
    call_rust(&mut copy.as_region_mut());
    copy
  };
  match T::type_enum() {
    PixelType::U8 => {
      match PUT_FNS[cpu.as_index()][get_2d_mode_idx(mode_x, mode_y)] {
        Some(func) => unsafe {
          (func)(
            dst.data_ptr_mut() as *mut _,
            T::to_asm_stride(dst.plane_cfg.stride),
            src.as_ptr() as *const _,
            T::to_asm_stride(src.plane.cfg.stride),
            width as i32,
            height as i32,
            col_frac,
            row_frac,
          );
        },
        None => call_rust(dst),
      }
    }
    PixelType::U16 => {
      match PUT_HBD_FNS[cpu.as_index()][get_2d_mode_idx(mode_x, mode_y)] {
        Some(func) => unsafe {
          (func)(
            dst.data_ptr_mut() as *mut _,
            T::to_asm_stride(dst.plane_cfg.stride),
            src.as_ptr() as *const _,
            T::to_asm_stride(src.plane.cfg.stride),
            width as i32,
            height as i32,
            col_frac,
            row_frac,
            (1 << bit_depth) - 1,
          );
        },
        None => call_rust(dst),
      }
    }
  }
  #[cfg(feature = "check_asm")]
  {
    for (dst_row, ref_row) in
      dst.rows_iter().zip(ref_dst.as_region().rows_iter())
    {
      for (dst, reference) in dst_row.iter().zip(ref_row) {
        assert_eq!(*dst, *reference);
      }
    }
  }
}

#[inline(always)]
pub fn prep_8tap<T: Pixel>(
  tmp: &mut [i16], src: PlaneSlice<'_, T>, width: usize, height: usize,
  col_frac: i32, row_frac: i32, mode_x: FilterMode, mode_y: FilterMode,
  bit_depth: usize, cpu: CpuFeatureLevel,
) {
  let call_rust = |tmp: &mut [i16]| {
    rust::prep_8tap(
      tmp, src, width, height, col_frac, row_frac, mode_x, mode_y, bit_depth,
      cpu,
    );
  };
  #[cfg(feature = "check_asm")]
  let ref_tmp = {
    let mut copy = vec![0; width * height];
    copy[..].copy_from_slice(&tmp[..width * height]);
    call_rust(&mut copy);
    copy
  };
  match T::type_enum() {
    PixelType::U8 => {
      match PREP_FNS[cpu.as_index()][get_2d_mode_idx(mode_x, mode_y)] {
        Some(func) => unsafe {
          (func)(
            tmp.as_mut_ptr(),
            src.as_ptr() as *const _,
            T::to_asm_stride(src.plane.cfg.stride),
            width as i32,
            height as i32,
            col_frac,
            row_frac,
          );
        },
        None => call_rust(tmp),
      }
    }
    PixelType::U16 if bit_depth > 8 => {
      match PREP_HBD_FNS[cpu.as_index()][get_2d_mode_idx(mode_x, mode_y)] {
        Some(func) => unsafe {
          (func)(
            tmp.as_mut_ptr() as *mut _,
            src.as_ptr() as *const _,
            T::to_asm_stride(src.plane.cfg.stride),
            width as i32,
            height as i32,
            col_frac,
            row_frac,
            (1 << bit_depth) - 1,
          );
        },
        None => call_rust(tmp),
      }
    }
    _ => call_rust(tmp),
  }
  #[cfg(feature = "check_asm")]
  {
    assert_eq!(&tmp[..width * height], &ref_tmp[..]);
  }
}

pub fn mc_avg<T: Pixel>(
  dst: &mut PlaneRegionMut<'_, T>, tmp1: &[i16], tmp2: &[i16], width: usize,
  height: usize, bit_depth: usize, cpu: CpuFeatureLevel,
) {
  let call_rust = |dst: &mut PlaneRegionMut<'_, T>| {
    rust::mc_avg(dst, tmp1, tmp2, width, height, bit_depth, cpu);
  };
  #[cfg(feature = "check_asm")]
  let ref_dst = {
    let mut copy = dst.scratch_copy();
    call_rust(&mut copy.as_region_mut());
    copy
  };
  match T::type_enum() {
    PixelType::U8 => match AVG_FNS[cpu.as_index()] {
      Some(func) => unsafe {
        (func)(
          dst.data_ptr_mut() as *mut _,
          T::to_asm_stride(dst.plane_cfg.stride),
          tmp1.as_ptr(),
          tmp2.as_ptr(),
          width as i32,
          height as i32,
        );
      },
      None => call_rust(dst),
    },
    PixelType::U16 if bit_depth > 8 => match AVG_HBD_FNS[cpu.as_index()] {
      Some(func) => unsafe {
        (func)(
          dst.data_ptr_mut() as *mut _,
          T::to_asm_stride(dst.plane_cfg.stride),
          tmp1.as_ptr(),
          tmp2.as_ptr(),
          width as i32,
          height as i32,
          (1 << bit_depth) - 1,
        );
      },
      None => call_rust(dst),
    },
    _ => call_rust(dst),
  }
  #[cfg(feature = "check_asm")]
  {
    for (dst_row, ref_row) in
      dst.rows_iter().zip(ref_dst.as_region().rows_iter())
    {
      for (dst, reference) in dst_row.iter().zip(ref_row) {
        assert_eq!(*dst, *reference);
      }
    }
  }
}

macro_rules! decl_mc_fns {
  ($(($mode_x:expr, $mode_y:expr, $func_name:ident)),+) => {
    paste::item! {
      extern {
        $(
          fn [<$func_name _ssse3>](
            dst: *mut u8, dst_stride: isize, src: *const u8, src_stride: isize,
            w: i32, h: i32, mx: i32, my: i32
          );

          fn [<$func_name _avx2>](
            dst: *mut u8, dst_stride: isize, src: *const u8, src_stride: isize,
            w: i32, h: i32, mx: i32, my: i32
          );
        )*
      }

      static PUT_FNS_SSSE3: [Option<PutFn>; 16] = {
        let mut out: [Option<PutFn>; 16] = [None; 16];
        $(
          out[get_2d_mode_idx($mode_x, $mode_y)] = Some([<$func_name _ssse3>]);
        )*
        out
      };

      static PUT_FNS_AVX2: [Option<PutFn>; 16] = {
        let mut out: [Option<PutFn>; 16] = [None; 16];
        $(
          out[get_2d_mode_idx($mode_x, $mode_y)] = Some([<$func_name _avx2>]);
        )*
        out
      };
    }
  }
}

decl_mc_fns!(
  (REGULAR, REGULAR, rav1e_put_8tap_regular),
  (REGULAR, SMOOTH, rav1e_put_8tap_regular_smooth),
  (REGULAR, SHARP, rav1e_put_8tap_regular_sharp),
  (SMOOTH, REGULAR, rav1e_put_8tap_smooth_regular),
  (SMOOTH, SMOOTH, rav1e_put_8tap_smooth),
  (SMOOTH, SHARP, rav1e_put_8tap_smooth_sharp),
  (SHARP, REGULAR, rav1e_put_8tap_sharp_regular),
  (SHARP, SMOOTH, rav1e_put_8tap_sharp_smooth),
  (SHARP, SHARP, rav1e_put_8tap_sharp),
  (BILINEAR, BILINEAR, rav1e_put_bilin)
);

cpu_function_lookup_table!(
  PUT_FNS: [[Option<PutFn>; 16]],
  default: [None; 16],
  [SSSE3, AVX2]
);

macro_rules! decl_mc_hbd_fns {
  ($(($mode_x:expr, $mode_y:expr, $func_name:ident)),+) => {
    paste::item! {
      extern {
        $(
          fn [<$func_name _ssse3>](
            dst: *mut u16, dst_stride: isize, src: *const u16, src_stride: isize,
            w: i32, h: i32, mx: i32, my: i32, bitdepth_max: i32,
          );

          fn [<$func_name _avx2>](
            dst: *mut u16, dst_stride: isize, src: *const u16, src_stride: isize,
            w: i32, h: i32, mx: i32, my: i32, bitdepth_max: i32,
          );
        )*
      }

      static PUT_HBD_FNS_SSSE3: [Option<PutHBDFn>; 16] = {
        let mut out: [Option<PutHBDFn>; 16] = [None; 16];
        $(
          out[get_2d_mode_idx($mode_x, $mode_y)] = Some([<$func_name _ssse3>]);
        )*
        out
      };

      static PUT_HBD_FNS_AVX2: [Option<PutHBDFn>; 16] = {
        let mut out: [Option<PutHBDFn>; 16] = [None; 16];
        $(
          out[get_2d_mode_idx($mode_x, $mode_y)] = Some([<$func_name _avx2>]);
        )*
        out
      };
    }
  }
}

decl_mc_hbd_fns!(
  (REGULAR, REGULAR, rav1e_put_8tap_regular_16bpc),
  (REGULAR, SMOOTH, rav1e_put_8tap_regular_smooth_16bpc),
  (REGULAR, SHARP, rav1e_put_8tap_regular_sharp_16bpc),
  (SMOOTH, REGULAR, rav1e_put_8tap_smooth_regular_16bpc),
  (SMOOTH, SMOOTH, rav1e_put_8tap_smooth_16bpc),
  (SMOOTH, SHARP, rav1e_put_8tap_smooth_sharp_16bpc),
  (SHARP, REGULAR, rav1e_put_8tap_sharp_regular_16bpc),
  (SHARP, SMOOTH, rav1e_put_8tap_sharp_smooth_16bpc),
  (SHARP, SHARP, rav1e_put_8tap_sharp_16bpc),
  (BILINEAR, BILINEAR, rav1e_put_bilin_16bpc)
);

cpu_function_lookup_table!(
  PUT_HBD_FNS: [[Option<PutHBDFn>; 16]],
  default: [None; 16],
  [SSSE3, AVX2]
);

macro_rules! decl_mct_fns {
  ($(($mode_x:expr, $mode_y:expr, $func_name:ident)),+) => {
    paste::item! {
      extern {
        $(
          fn [<$func_name _ssse3>](
            tmp: *mut i16, src: *const u8, src_stride: libc::ptrdiff_t, w: i32,
            h: i32, mx: i32, my: i32
          );

          fn [<$func_name _avx2>](
            tmp: *mut i16, src: *const u8, src_stride: libc::ptrdiff_t, w: i32,
            h: i32, mx: i32, my: i32
          );

          fn [<$func_name _avx512icl>](
            tmp: *mut i16, src: *const u8, src_stride: libc::ptrdiff_t, w: i32,
            h: i32, mx: i32, my: i32
          );
        )*
      }

      static PREP_FNS_SSSE3: [Option<PrepFn>; 16] = {
        let mut out: [Option<PrepFn>; 16] = [None; 16];
        $(
            out[get_2d_mode_idx($mode_x, $mode_y)] = Some([<$func_name _ssse3>]);
        )*
        out
      };

      static PREP_FNS_AVX2: [Option<PrepFn>; 16] = {
        let mut out: [Option<PrepFn>; 16] = [None; 16];
        $(
            out[get_2d_mode_idx($mode_x, $mode_y)] = Some([<$func_name _avx2>]);
        )*
        out
      };

      static PREP_FNS_AVX512ICL: [Option<PrepFn>; 16] = {
        let mut out: [Option<PrepFn>; 16] = [None; 16];
        $(
            out[get_2d_mode_idx($mode_x, $mode_y)] = Some([<$func_name _avx512icl>]);
        )*
        out
      };
    }
  }
}

decl_mct_fns!(
  (REGULAR, REGULAR, rav1e_prep_8tap_regular),
  (REGULAR, SMOOTH, rav1e_prep_8tap_regular_smooth),
  (REGULAR, SHARP, rav1e_prep_8tap_regular_sharp),
  (SMOOTH, REGULAR, rav1e_prep_8tap_smooth_regular),
  (SMOOTH, SMOOTH, rav1e_prep_8tap_smooth),
  (SMOOTH, SHARP, rav1e_prep_8tap_smooth_sharp),
  (SHARP, REGULAR, rav1e_prep_8tap_sharp_regular),
  (SHARP, SMOOTH, rav1e_prep_8tap_sharp_smooth),
  (SHARP, SHARP, rav1e_prep_8tap_sharp),
  (BILINEAR, BILINEAR, rav1e_prep_bilin)
);

cpu_function_lookup_table!(
  PREP_FNS: [[Option<PrepFn>; 16]],
  default: [None; 16],
  [SSSE3, AVX2, AVX512ICL]
);

macro_rules! decl_mct_hbd_fns {
  ($(($mode_x:expr, $mode_y:expr, $func_name:ident)),+) => {
    paste::item! {
      extern {
        $(
          fn [<$func_name _ssse3>](
            tmp: *mut i16, src: *const u16, src_stride: libc::ptrdiff_t, w: i32,
            h: i32, mx: i32, my: i32, bitdepth_max: i32,
          );

          fn [<$func_name _avx2>](
            tmp: *mut i16, src: *const u16, src_stride: libc::ptrdiff_t, w: i32,
            h: i32, mx: i32, my: i32, bitdepth_max: i32,
          );
        )*
      }

      static PREP_HBD_FNS_SSSE3: [Option<PrepHBDFn>; 16] = {
        let mut out: [Option<PrepHBDFn>; 16] = [None; 16];
        $(
          out[get_2d_mode_idx($mode_x, $mode_y)] = Some([<$func_name _ssse3>]);
        )*
        out
      };

      static PREP_HBD_FNS_AVX2: [Option<PrepHBDFn>; 16] = {
        let mut out: [Option<PrepHBDFn>; 16] = [None; 16];
        $(
          out[get_2d_mode_idx($mode_x, $mode_y)] = Some([<$func_name _avx2>]);
        )*
        out
      };
    }
  }
}

decl_mct_hbd_fns!(
  (REGULAR, REGULAR, rav1e_prep_8tap_regular_16bpc),
  (REGULAR, SMOOTH, rav1e_prep_8tap_regular_smooth_16bpc),
  (REGULAR, SHARP, rav1e_prep_8tap_regular_sharp_16bpc),
  (SMOOTH, REGULAR, rav1e_prep_8tap_smooth_regular_16bpc),
  (SMOOTH, SMOOTH, rav1e_prep_8tap_smooth_16bpc),
  (SMOOTH, SHARP, rav1e_prep_8tap_smooth_sharp_16bpc),
  (SHARP, REGULAR, rav1e_prep_8tap_sharp_regular_16bpc),
  (SHARP, SMOOTH, rav1e_prep_8tap_sharp_smooth_16bpc),
  (SHARP, SHARP, rav1e_prep_8tap_sharp_16bpc),
  (BILINEAR, BILINEAR, rav1e_prep_bilin_16bpc)
);

cpu_function_lookup_table!(
  PREP_HBD_FNS: [[Option<PrepHBDFn>; 16]],
  default: [None; 16],
  [SSSE3, AVX2]
);

extern {
  fn rav1e_avg_ssse3(
    dst: *mut u8, dst_stride: libc::ptrdiff_t, tmp1: *const i16,
    tmp2: *const i16, w: i32, h: i32,
  );

  fn rav1e_avg_avx2(
    dst: *mut u8, dst_stride: libc::ptrdiff_t, tmp1: *const i16,
    tmp2: *const i16, w: i32, h: i32,
  );

  fn rav1e_avg_16bpc_ssse3(
    dst: *mut u16, dst_stride: libc::ptrdiff_t, tmp1: *const i16,
    tmp2: *const i16, w: i32, h: i32, bitdepth_max: i32,
  );

  fn rav1e_avg_16bpc_avx2(
    dst: *mut u16, dst_stride: libc::ptrdiff_t, tmp1: *const i16,
    tmp2: *const i16, w: i32, h: i32, bitdepth_max: i32,
  );
}

cpu_function_lookup_table!(
  AVG_FNS: [Option<AvgFn>],
  default: None,
  [(SSSE3, Some(rav1e_avg_ssse3)), (AVX2, Some(rav1e_avg_avx2))]
);

cpu_function_lookup_table!(
  AVG_HBD_FNS: [Option<AvgHBDFn>],
  default: None,
  [(SSSE3, Some(rav1e_avg_16bpc_ssse3)), (AVX2, Some(rav1e_avg_16bpc_avx2))]
);

#[cfg(test)]
mod test {
  use super::*;
  use rand::random;
  use std::str::FromStr;

  macro_rules! test_put_fns {
    ($(($mode_x:expr, $mode_y:expr, $func_name:ident)),*, $OPT:ident, $OPTLIT:tt, $BD:expr) => {
      $(
        paste::item! {
          #[test]
          fn [<test_ $func_name _bd_ $BD _ $OPT>]() {
            if !is_x86_feature_detected!($OPTLIT) {
              eprintln!("Ignoring {} test, not supported on this machine!", $OPTLIT);
              return;
            }

            let test_mvs = [MotionVector { row: 0, col: 0 }, MotionVector { row: 4, col: 0 }, MotionVector { row: 0, col: 4 }, MotionVector { row: 4, col: 4 }];
            if $BD > 8 {
              // dynamic allocation: test
              let mut src = Plane::from_slice(&vec![0u16; 64 * 64], 64);
              for s in src.data.iter_mut() {
                *s = random::<u8>() as u16 * $BD / 8;
              }
              // dynamic allocation: test
              let mut dst1 = Plane::from_slice(&vec![0u16; 64 * 64], 64);
              // dynamic allocation: test
              let mut dst2 = Plane::from_slice(&vec![0u16; 64 * 64], 64);

              for mv in &test_mvs {
                let (row_frac, col_frac, src) = get_params(&src, PlaneOffset { x: 0, y: 0 }, *mv);
                super::put_8tap(&mut dst1.as_region_mut(), src, 8, 8, col_frac, row_frac, $mode_x, $mode_y, 8, CpuFeatureLevel::from_str($OPTLIT).unwrap());
                super::put_8tap(&mut dst2.as_region_mut(), src, 8, 8, col_frac, row_frac, $mode_x, $mode_y, 8, CpuFeatureLevel::RUST);

                assert_eq!(&*dst1.data, &*dst2.data);
              }
            } else {
              // dynamic allocation: test
              let mut src = Plane::from_slice(&vec![0u8; 64 * 64], 64);
              for s in src.data.iter_mut() {
                *s = random::<u8>();
              }
              // dynamic allocation: test
              let mut dst1 = Plane::from_slice(&vec![0u8; 64 * 64], 64);
              // dynamic allocation: test
              let mut dst2 = Plane::from_slice(&vec![0u8; 64 * 64], 64);

              for mv in &test_mvs {
                let (row_frac, col_frac, src) = get_params(&src, PlaneOffset { x: 0, y: 0 }, *mv);
                super::put_8tap(&mut dst1.as_region_mut(), src, 8, 8, col_frac, row_frac, $mode_x, $mode_y, 8, CpuFeatureLevel::from_str($OPTLIT).unwrap());
                super::put_8tap(&mut dst2.as_region_mut(), src, 8, 8, col_frac, row_frac, $mode_x, $mode_y, 8, CpuFeatureLevel::RUST);

                assert_eq!(&*dst1.data, &*dst2.data);
              }
            };
          }
        }
      )*
    }
  }

  test_put_fns!(
    (REGULAR, REGULAR, rav1e_put_8tap_regular),
    (REGULAR, SMOOTH, rav1e_put_8tap_regular_smooth),
    (REGULAR, SHARP, rav1e_put_8tap_regular_sharp),
    (SMOOTH, REGULAR, rav1e_put_8tap_smooth_regular),
    (SMOOTH, SMOOTH, rav1e_put_8tap_smooth),
    (SMOOTH, SHARP, rav1e_put_8tap_smooth_sharp),
    (SHARP, REGULAR, rav1e_put_8tap_sharp_regular),
    (SHARP, SMOOTH, rav1e_put_8tap_sharp_smooth),
    (SHARP, SHARP, rav1e_put_8tap_sharp),
    (BILINEAR, BILINEAR, rav1e_put_bilin),
    ssse3,
    "ssse3",
    8
  );

  test_put_fns!(
    (REGULAR, REGULAR, rav1e_put_8tap_regular),
    (REGULAR, SMOOTH, rav1e_put_8tap_regular_smooth),
    (REGULAR, SHARP, rav1e_put_8tap_regular_sharp),
    (SMOOTH, REGULAR, rav1e_put_8tap_smooth_regular),
    (SMOOTH, SMOOTH, rav1e_put_8tap_smooth),
    (SMOOTH, SHARP, rav1e_put_8tap_smooth_sharp),
    (SHARP, REGULAR, rav1e_put_8tap_sharp_regular),
    (SHARP, SMOOTH, rav1e_put_8tap_sharp_smooth),
    (SHARP, SHARP, rav1e_put_8tap_sharp),
    (BILINEAR, BILINEAR, rav1e_put_bilin),
    avx2,
    "avx2",
    8
  );

  macro_rules! test_prep_fns {
    ($(($mode_x:expr, $mode_y:expr, $func_name:ident)),*, $OPT:ident, $OPTLIT:tt, $BD:expr) => {
      $(
        paste::item! {
          #[test]
          fn [<test_ $func_name _bd_ $BD _ $OPT>]() {
            if !is_x86_feature_detected!($OPTLIT) {
              eprintln!("Ignoring {} test, not supported on this machine!", $OPTLIT);
              return;
            }

            // dynamic allocation: test
            let mut dst1 = Aligned::new([0i16; 128 * 128]);
            // dynamic allocation: test
            let mut dst2 = Aligned::new([0i16; 128 * 128]);
            let test_mvs = [MotionVector { row: 0, col: 0 }, MotionVector { row: 4, col: 0 }, MotionVector { row: 0, col: 4 }, MotionVector { row: 4, col: 4 }];

            if $BD > 8 {
              // dynamic allocation: test
              let mut src = Plane::from_slice(&vec![0u16; 64 * 64], 64);
              for s in src.data.iter_mut() {
                *s = random::<u8>() as u16 * $BD / 8;
              }

              for mv in &test_mvs {
                let (row_frac, col_frac, src) = get_params(&src, PlaneOffset { x: 0, y: 0 }, *mv);
                super::prep_8tap(&mut dst1.data, src, 8, 8, col_frac, row_frac, $mode_x, $mode_y, 8, CpuFeatureLevel::from_str($OPTLIT).unwrap());
                super::prep_8tap(&mut dst2.data, src, 8, 8, col_frac, row_frac, $mode_x, $mode_y, 8, CpuFeatureLevel::RUST);
              }
            } else {
              // dynamic allocation: test
              let mut src = Plane::from_slice(&vec![0u8; 64 * 64], 64);
              for s in src.data.iter_mut() {
                *s = random::<u8>();
              }

              for mv in &test_mvs {
                let (row_frac, col_frac, src) = get_params(&src, PlaneOffset { x: 0, y: 0 }, *mv);
                super::prep_8tap(&mut dst1.data, src, 8, 8, col_frac, row_frac, $mode_x, $mode_y, 8, CpuFeatureLevel::from_str($OPTLIT).unwrap());
                super::prep_8tap(&mut dst2.data, src, 8, 8, col_frac, row_frac, $mode_x, $mode_y, 8, CpuFeatureLevel::RUST);
              }
            };

            assert_eq!(&dst1.data.to_vec(), &dst2.data.to_vec());
          }
        }
      )*
    }
  }

  test_prep_fns!(
    (REGULAR, REGULAR, rav1e_prep_8tap_regular),
    (REGULAR, SMOOTH, rav1e_prep_8tap_regular_smooth),
    (REGULAR, SHARP, rav1e_prep_8tap_regular_sharp),
    (SMOOTH, REGULAR, rav1e_prep_8tap_smooth_regular),
    (SMOOTH, SMOOTH, rav1e_prep_8tap_smooth),
    (SMOOTH, SHARP, rav1e_prep_8tap_smooth_sharp),
    (SHARP, REGULAR, rav1e_prep_8tap_sharp_regular),
    (SHARP, SMOOTH, rav1e_prep_8tap_sharp_smooth),
    (SHARP, SHARP, rav1e_prep_8tap_sharp),
    (BILINEAR, BILINEAR, rav1e_prep_bilin),
    ssse3,
    "ssse3",
    8
  );

  test_prep_fns!(
    (REGULAR, REGULAR, rav1e_prep_8tap_regular),
    (REGULAR, SMOOTH, rav1e_prep_8tap_regular_smooth),
    (REGULAR, SHARP, rav1e_prep_8tap_regular_sharp),
    (SMOOTH, REGULAR, rav1e_prep_8tap_smooth_regular),
    (SMOOTH, SMOOTH, rav1e_prep_8tap_smooth),
    (SMOOTH, SHARP, rav1e_prep_8tap_smooth_sharp),
    (SHARP, REGULAR, rav1e_prep_8tap_sharp_regular),
    (SHARP, SMOOTH, rav1e_prep_8tap_sharp_smooth),
    (SHARP, SHARP, rav1e_prep_8tap_sharp),
    (BILINEAR, BILINEAR, rav1e_prep_bilin),
    avx2,
    "avx2",
    8
  );

  test_prep_fns!(
    (REGULAR, REGULAR, rav1e_prep_8tap_regular),
    (REGULAR, SMOOTH, rav1e_prep_8tap_regular_smooth),
    (REGULAR, SHARP, rav1e_prep_8tap_regular_sharp),
    (SMOOTH, REGULAR, rav1e_prep_8tap_smooth_regular),
    (SMOOTH, SMOOTH, rav1e_prep_8tap_smooth),
    (SMOOTH, SHARP, rav1e_prep_8tap_smooth_sharp),
    (SHARP, REGULAR, rav1e_prep_8tap_sharp_regular),
    (SHARP, SMOOTH, rav1e_prep_8tap_sharp_smooth),
    (SHARP, SHARP, rav1e_prep_8tap_sharp),
    (BILINEAR, BILINEAR, rav1e_prep_bilin),
    avx512icl,
    "avx512vpclmulqdq",
    8
  );

  fn get_params<T: Pixel>(
    rec_plane: &Plane<T>, po: PlaneOffset, mv: MotionVector,
  ) -> (i32, i32, PlaneSlice<T>) {
    let rec_cfg = &rec_plane.cfg;
    let shift_row = 3 + rec_cfg.ydec;
    let shift_col = 3 + rec_cfg.xdec;
    let row_offset = mv.row as i32 >> shift_row;
    let col_offset = mv.col as i32 >> shift_col;
    let row_frac =
      (mv.row as i32 - (row_offset << shift_row)) << (4 - shift_row);
    let col_frac =
      (mv.col as i32 - (col_offset << shift_col)) << (4 - shift_col);
    let qo = PlaneOffset {
      x: po.x + col_offset as isize - 3,
      y: po.y + row_offset as isize - 3,
    };
    (row_frac, col_frac, rec_plane.slice(qo).clamp().subslice(3, 3))
  }
}
