// Copyright 2020 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.

$assert CHANNEL_TILE % 8 == 0
$assert KERNEL_TILE >= 2
$assert ACCUMULATORS >= 1
$ABC = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"
#include <assert.h>

#include <arm_neon.h>

#include <xnnpack/dwconv.h>


void xnn_f16_dwconv_minmax_ukernel_${KERNEL_TILE}p${CHANNEL_TILE}c__neonfp16arith${"" if ACCUMULATORS == 1 else "_acc%d" % ACCUMULATORS}(
    size_t channels,
    size_t output_width,
    const void** input,
    const void* weights,
    void* output_ptr,
    intptr_t input_stride,
    size_t output_increment,
    size_t input_offset,
    const void* zero,
    const union xnn_f16_minmax_params params[restrict XNN_MIN_ELEMENTS(1)]) XNN_OOB_READS
{
  assert(channels != 0);
  assert(output_width != 0);

  uint16_t* output = (uint16_t*) output_ptr;
  const float16x8_t vmin = vreinterpretq_f16_u16(vld1q_dup_u16(&params->fp16arith.min));
  const float16x8_t vmax = vreinterpretq_f16_u16(vld1q_dup_u16(&params->fp16arith.max));
  do {
    $for K in range(KERNEL_TILE):
      const uint16_t* i${K} = (const uint16_t*) input[${K}];
      assert(i${K} != NULL);
      if XNN_UNPREDICTABLE(i${K} != (const uint16_t*) zero) {
        i${K} = (const uint16_t*) ((uintptr_t) i${K} + input_offset);
      }

    input = (const void**) ((uintptr_t) input + input_stride);

    size_t c = channels;
    const uint16_t* w = (const uint16_t*) weights;
    for (; c >= ${CHANNEL_TILE}; c -= ${CHANNEL_TILE}) {
      $for C in range(0, CHANNEL_TILE, 8):
        float16x8_t vacc${ABC[C:C+8]}p0 = vreinterpretq_f16_u16(vld1q_u16(w)); w += 8;

      $for K in range(KERNEL_TILE):

        $for C in range(0, CHANNEL_TILE, 8):
          const float16x8_t vi${K}x${ABC[C:C+8]} = vreinterpretq_f16_u16(vld1q_u16(i${K})); i${K} += 8;
        $for C in range(0, CHANNEL_TILE, 8):
          const float16x8_t vk${K}x${ABC[C:C+8]} = vreinterpretq_f16_u16(vld1q_u16(w)); w += 8;
        $for C in range(0, CHANNEL_TILE, 8):
          $if 1 <= K < ACCUMULATORS:
            float16x8_t vacc${ABC[C:C+8]}p${K} = vmulq_f16(vi${K}x${ABC[C:C+8]}, vk${K}x${ABC[C:C+8]});
          $else:
            vacc${ABC[C:C+8]}p${K % ACCUMULATORS} = vfmaq_f16(vacc${ABC[C:C+8]}p${K % ACCUMULATORS}, vi${K}x${ABC[C:C+8]}, vk${K}x${ABC[C:C+8]});

      $if ACCUMULATORS > 1:
        // Add up all accumulators to vacc${ABC[0:CHANNEL_TILE]}p0
        $ACC_STEP = 1
        $while ACC_STEP < ACCUMULATORS:
          $for A in range(0, ACCUMULATORS, ACC_STEP * 2):
            $if A + ACC_STEP < ACCUMULATORS:
              $for C in range(0, CHANNEL_TILE, 8):
                vacc${ABC[C:C+8]}p${A} = vaddq_f16(vacc${ABC[C:C+8]}p${A}, vacc${ABC[C:C+8]}p${A + ACC_STEP});
          $ACC_STEP *= 2

      $for C in range(0, CHANNEL_TILE, 8):
        float16x8_t vacc${ABC[C:C+8]} = vmaxq_f16(vacc${ABC[C:C+8]}p0, vmin);
      $for C in range(0, CHANNEL_TILE, 8):
        vacc${ABC[C:C+8]} = vminq_f16(vacc${ABC[C:C+8]}, vmax);

      $for C in range(0, CHANNEL_TILE, 8):
        vst1q_u16(output, vreinterpretq_u16_f16(vacc${ABC[C:C+8]})); output += 8;
    }
    $if CHANNEL_TILE > 8:
      for (; c >= 8; c -= 8) {
        float16x8_t vacc01234567p0 = vreinterpretq_f16_u16(vld1q_u16(w)); w += 8;

        $for K in range(KERNEL_TILE):

          const float16x8_t vi${K}x01234567 = vreinterpretq_f16_u16(vld1q_u16(i${K})); i${K} += 8;
          const float16x8_t vk${K}x01234567 = vreinterpretq_f16_u16(vld1q_u16(w + ${(K + 1) * CHANNEL_TILE - 8}));
          $if 1 <= K < ACCUMULATORS:
            float16x8_t vacc01234567p${K} = vmulq_f16(vi${K}x01234567, vk${K}x01234567);
          $else:
            vacc01234567p${K % ACCUMULATORS} = vfmaq_f16(vacc01234567p${K % ACCUMULATORS}, vi${K}x01234567, vk${K}x01234567);

        $if ACCUMULATORS > 1:
          // Add up all accumulators to vacc01234567p0
          $ACC_STEP = 1
          $while ACC_STEP < ACCUMULATORS:
            $for A in range(0, ACCUMULATORS, ACC_STEP * 2):
              $if A + ACC_STEP < ACCUMULATORS:
                vacc01234567p${A} = vaddq_f16(vacc01234567p${A}, vacc01234567p${A + ACC_STEP});
            $ACC_STEP *= 2

        float16x8_t vacc01234567 = vmaxq_f16(vacc01234567p0, vmin);
        vacc01234567 = vminq_f16(vacc01234567, vmax);

        vst1q_u16(output, vreinterpretq_u16_f16(vacc01234567)); output += 8;
      }
    if XNN_UNLIKELY(c != 0) {
      $if CHANNEL_TILE == 8:
        float16x8_t vacc01234567p0 = vreinterpretq_f16_u16(vld1q_u16(w)); w += 8;
      $else:
        float16x8_t vacc01234567p0 = vreinterpretq_f16_u16(vld1q_u16(w));

      $for K in range(KERNEL_TILE):

        const float16x8_t vi${K}x01234567 = vreinterpretq_f16_u16(vld1q_u16(i${K}));
        $if CHANNEL_TILE == 8:
          const float16x8_t vk${K}x01234567 = vreinterpretq_f16_u16(vld1q_u16(w)); w += 8;
        $else:
          const float16x8_t vk${K}x01234567 = vreinterpretq_f16_u16(vld1q_u16(w + ${(K + 1) * CHANNEL_TILE}));
        $if 1 <= K < ACCUMULATORS:
          float16x8_t vacc01234567p${K} = vmulq_f16(vi${K}x01234567, vk${K}x01234567);
        $else:
          vacc01234567p${K % ACCUMULATORS} = vfmaq_f16(vacc01234567p${K % ACCUMULATORS}, vi${K}x01234567, vk${K}x01234567);

      $if ACCUMULATORS > 1:
        // Add up all accumulators to vacc01234567p0
        $ACC_STEP = 1
        $while ACC_STEP < ACCUMULATORS:
          $for A in range(0, ACCUMULATORS, ACC_STEP * 2):
            $if A + ACC_STEP < ACCUMULATORS:
              vacc01234567p${A} = vaddq_f16(vacc01234567p${A}, vacc01234567p${A + ACC_STEP});
          $ACC_STEP *= 2

      float16x8_t vacc01234567 = vmaxq_f16(vacc01234567p0, vmin);
      vacc01234567 = vminq_f16(vacc01234567, vmax);

      float16x4_t vacc0123 = vget_low_f16(vacc01234567);
      if (c & 4) {
        vst1_u16(output, vreinterpret_u16_f16(vacc0123)); output += 4;
        vacc0123 = vget_high_f16(vacc01234567);
      }
      if (c & 2) {
        vst1_lane_u32((void*) output, vreinterpret_u32_f16(vacc0123), 0); output += 2;
        vacc0123 = vext_f16(vacc0123, vacc0123, 2);
      }
      if (c & 1) {
        vst1_lane_u16(output, vreinterpret_u16_f16(vacc0123), 0); output += 1;
      }
    }

    output = (uint16_t*) ((uintptr_t) output + output_increment);
  } while (--output_width != 0);
}