src/x8-zip/x4-neon.c

// Copyright (c) Facebook, Inc. and its affiliates.
// All rights reserved.
//
// Copyright 2019 Google LLC
//
// This source code is licensed under the BSD-style license found in the
// LICENSE file in the root directory of this source tree.

#include <arm_neon.h>

#include <xnnpack/zip.h>


void xnn_x8_zip_x4_ukernel__neon(
    size_t n,
    const uint8_t* input,
    uint8_t* output)
{
  const uint8_t* x = input;
  const uint8_t* y = (const uint8_t*) ((uintptr_t) x + n);
  const uint8_t* z = (const uint8_t*) ((uintptr_t) y + n);
  const uint8_t* w = (const uint8_t*) ((uintptr_t) z + n);
  uint8_t* o = output;

  if (n >= 8) {
    do {
      uint8x8x4_t vxyzw;
      vxyzw.val[0] = vld1_u8(x); x += 8;
      vxyzw.val[1] = vld1_u8(y); y += 8;
      vxyzw.val[2] = vld1_u8(z); z += 8;
      vxyzw.val[3] = vld1_u8(w); w += 8;
      vst4_u8(o, vxyzw); o += 32;
      n -= 8;
    } while (n >= 8);
    if (n != 0) {
      const size_t address_increment = n - 8;
      uint8x8x4_t vxyzw;
      vxyzw.val[0] = vld1_u8(x + address_increment);
      vxyzw.val[1] = vld1_u8(y + address_increment);
      vxyzw.val[2] = vld1_u8(z + address_increment);
      vxyzw.val[3] = vld1_u8(w + address_increment);
      vst4_u8((uint8_t*) ((uintptr_t) o + address_increment * 4), vxyzw);
    }
  } else {
    do {
      const uint8_t vx = *x++;
      const uint8_t vy = *y++;
      const uint8_t vz = *z++;
      const uint8_t vw = *w++;
      o[0] = vx;
      o[1] = vy;
      o[2] = vz;
      o[3] = vw;
      o += 4;
    } while (--n != 0);
  }
}