src/f32-dwconv-chw/5x5s2p2-neonfma.c

// 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 <assert.h>

#include <arm_neon.h>

#include <xnnpack/dwconv.h>
#include <xnnpack/math.h>


void xnn_f32_dwconv_chw_ukernel_5x5s2p2__neonfma(
    size_t input_height,
    size_t input_width,
    const float* input,
    const float* weights,
    const float* zero,
    float* output,
    uint32_t padding_top,
    size_t input_tuple_stride,
    size_t output_tuple_stride,
    size_t input_width_stride,
    size_t output_width_stride,
    const union xnn_f32_chw_params params[restrict XNN_MIN_ELEMENTS(1)])
{
  assert(input_width != 0);
  assert(input_height != 0);
  assert(padding_top >= 1 && padding_top <= 2);

  const size_t padded_input_height = input_height + padding_top + 2 /* padding_bottom */;
  const size_t output_height = (padded_input_height - 5) / 2 + 1;

  const uint32x4_t vmask_even = vld1q_u32(params->neon.mask_even);
  const uint32x4_t vmask_odd = vld1q_u32(params->neon.mask_odd);
  const float32x4_t vmax = vld1q_dup_f32(&params->neon.max);
  const float32x4_t vmin = vld1q_dup_f32(&params->neon.min);

  const size_t input_width_decrement_single = input_tuple_stride * ( (input_width - 1) / 4 + 1);
  const size_t input_width_increment_single = input_width_stride - input_width_decrement_single;
  const size_t input_width_increment_double= input_width_stride * 2 - input_width_decrement_single;
  const size_t output_width_increment_single = output_width_stride - (input_width + 1) / 8 * output_tuple_stride;

  const float* i0;
  const float* i1;
  const float* i2;
  const float* i3;
  const float* i4;

  if (padding_top == 1) {
    i0 = zero;
    i1 = input;
    i2 = (const float*) ((uintptr_t) i1 + input_width_stride);
    i3 = (const float*) ((uintptr_t) i2 + input_width_stride);
    i4 = (const float*) ((uintptr_t) i3 + input_width_stride);
    if (input_height <= 3) {
      i4 = zero;
    }
    if (input_height <= 2) {
      i3 = zero;
    }
    if (input_height == 1) {
      i2 = zero;
    }
  } else {
    i0 = zero;
    i1 = zero;
    i2 = input;
    i3 = (const float*) ((uintptr_t) i2 + input_width_stride);
    i4 = (const float*) ((uintptr_t) i3 + input_width_stride);
    if (input_height <= 2) {
      i4 = zero;
    }
    if (input_height == 1) {
      i3 = zero;
    }
  }

  float* output0 = output;

  const float32x4_t vw0123 = vld1q_f32(weights);
  const float32x4_t vw4567 = vld1q_f32(weights + 4);
  const float32x4_t vw89AB = vld1q_f32(weights + 8);
  const float32x4_t vwCDEF = vld1q_f32(weights + 12);
  const float32x4_t vwGHIJ = vld1q_f32(weights + 16);
  const float32x4_t vwKLMN = vld1q_f32(weights + 20);
  const float32x2_t vwOP   = vld1_f32( weights + 24);

  size_t m = output_height;
  do {
    float32x4_t vi0x0123 = vmovq_n_f32(0.0f);
    float32x4_t vi1x0123 = vmovq_n_f32(0.0f);
    float32x4_t vi2x0123 = vmovq_n_f32(0.0f);
    float32x4_t vi3x0123 = vmovq_n_f32(0.0f);
    float32x4_t vi4x0123 = vmovq_n_f32(0.0f);
    float32x4_t vi0x4567 = vld1q_f32(i0); i0 = (const float*) ((uintptr_t) i0 + input_tuple_stride);
    float32x4_t vi1x4567 = vld1q_f32(i1); i1 = (const float*) ((uintptr_t) i1 + input_tuple_stride);
    float32x4_t vi2x4567 = vld1q_f32(i2); i2 = (const float*) ((uintptr_t) i2 + input_tuple_stride);
    float32x4_t vi3x4567 = vld1q_f32(i3); i3 = (const float*) ((uintptr_t) i3 + input_tuple_stride);
    float32x4_t vi4x4567 = vld1q_f32(i4); i4 = (const float*) ((uintptr_t) i4 + input_tuple_stride);

    size_t k = input_width;
    for (; k > 8; k -= 8) {
      float32x4_t vo468Ap00 = vdupq_laneq_f32(vw0123, 0);

      float32x4_t vi0x89AB;
      float32x4_t vi1x89AB;
      float32x4_t vi2x89AB;
      float32x4_t vi3x89AB;
      float32x4_t vi4x89AB;

      vi0x89AB = vld1q_f32(i0); i0 = (const float*) ((uintptr_t) i0 + input_tuple_stride);
      vi1x89AB = vld1q_f32(i1); i1 = (const float*) ((uintptr_t) i1 + input_tuple_stride);
      vi2x89AB = vld1q_f32(i2); i2 = (const float*) ((uintptr_t) i2 + input_tuple_stride);
      vi3x89AB = vld1q_f32(i3); i3 = (const float*) ((uintptr_t) i3 + input_tuple_stride);
      vi4x89AB = vld1q_f32(i4); i4 = (const float*) ((uintptr_t) i4 + input_tuple_stride);

      float32x4_t vi0xCDEF;
      float32x4_t vi1xCDEF;
      float32x4_t vi2xCDEF;
      float32x4_t vi3xCDEF;
      float32x4_t vi4xCDEF;

      vi0xCDEF = vld1q_f32(i0); i0 = (const float*) ((uintptr_t) i0 + input_tuple_stride);
      vi1xCDEF = vld1q_f32(i1); i1 = (const float*) ((uintptr_t) i1 + input_tuple_stride);
      vi2xCDEF = vld1q_f32(i2); i2 = (const float*) ((uintptr_t) i2 + input_tuple_stride);
      vi3xCDEF = vld1q_f32(i3); i3 = (const float*) ((uintptr_t) i3 + input_tuple_stride);
      vi4xCDEF = vld1q_f32(i4); i4 = (const float*) ((uintptr_t) i4 + input_tuple_stride);

      float32x4_t vi0x468A = vuzp1q_f32(vi0x4567, vi0x89AB);
      float32x4_t vi0x579B = vuzp2q_f32(vi0x4567, vi0x89AB);
      float32x4_t vi1x468A = vuzp1q_f32(vi1x4567, vi1x89AB);
      float32x4_t vi1x579B = vuzp2q_f32(vi1x4567, vi1x89AB);
      float32x4_t vi2x468A = vuzp1q_f32(vi2x4567, vi2x89AB);
      float32x4_t vi2x579B = vuzp2q_f32(vi2x4567, vi2x89AB);
      float32x4_t vi3x468A = vuzp1q_f32(vi3x4567, vi3x89AB);
      float32x4_t vi3x579B = vuzp2q_f32(vi3x4567, vi3x89AB);
      float32x4_t vi4x468A = vuzp1q_f32(vi4x4567, vi4x89AB);
      float32x4_t vi4x579B = vuzp2q_f32(vi4x4567, vi4x89AB);

      // middle tap
      vo468Ap00 = vfmaq_laneq_f32(vo468Ap00, vi0x468A, vw0123, 3);
      float32x4_t vo468Ap01 = vmulq_laneq_f32(vi1x468A, vw89AB, 0);
      vo468Ap00 = vfmaq_laneq_f32(vo468Ap00, vi2x468A, vwCDEF, 1);
      vo468Ap01 = vfmaq_laneq_f32(vo468Ap01, vi3x468A, vwGHIJ, 2);
      vo468Ap00 = vfmaq_laneq_f32(vo468Ap00, vi4x468A, vwKLMN, 3);

      // one left
      const float32x4_t vi0x3579 = vextq_f32(vi0x0123, vi0x579B, 3);
      const float32x4_t vi1x3579 = vextq_f32(vi1x0123, vi1x579B, 3);
      const float32x4_t vi2x3579 = vextq_f32(vi2x0123, vi2x579B, 3);
      const float32x4_t vi3x3579 = vextq_f32(vi3x0123, vi3x579B, 3);
      const float32x4_t vi4x3579 = vextq_f32(vi4x0123, vi4x579B, 3);

      vo468Ap00 = vfmaq_laneq_f32(vo468Ap00, vi0x3579, vw0123, 2);
      vo468Ap01 = vfmaq_laneq_f32(vo468Ap01, vi1x3579, vw4567, 3);
      vo468Ap00 = vfmaq_laneq_f32(vo468Ap00, vi2x3579, vwCDEF, 0);
      vo468Ap01 = vfmaq_laneq_f32(vo468Ap01, vi3x3579, vwGHIJ, 1);
      vo468Ap00 = vfmaq_laneq_f32(vo468Ap00, vi4x3579, vwKLMN, 2);

      // two left
      // getting the vector to use for the far left tap is annoying
      // as we can't ext anything we currently have to get it.
      // To do this, we get a bit ugly.  Interpret the float 32x4
      // vector as int 64x2. Then left shift by 32.  Interpret
      // again as float 32x4.  Now the right most bits are what we
      // want them to be for the following ext.
      const float32x4_t vi0x0012 = vreinterpretq_f32_u64(vshlq_n_u64(vreinterpretq_u64_f32(vi0x0123), 32));
      const float32x4_t vi1x0012 = vreinterpretq_f32_u64(vshlq_n_u64(vreinterpretq_u64_f32(vi1x0123), 32));
      const float32x4_t vi2x0012 = vreinterpretq_f32_u64(vshlq_n_u64(vreinterpretq_u64_f32(vi2x0123), 32));
      const float32x4_t vi3x0012 = vreinterpretq_f32_u64(vshlq_n_u64(vreinterpretq_u64_f32(vi3x0123), 32));
      const float32x4_t vi4x0012 = vreinterpretq_f32_u64(vshlq_n_u64(vreinterpretq_u64_f32(vi4x0123), 32));

      const float32x4_t vi0x2468 = vextq_f32(vi0x0012, vi0x468A, 3);
      const float32x4_t vi1x2468 = vextq_f32(vi1x0012, vi1x468A, 3);
      const float32x4_t vi2x2468 = vextq_f32(vi2x0012, vi2x468A, 3);
      const float32x4_t vi3x2468 = vextq_f32(vi3x0012, vi3x468A, 3);
      const float32x4_t vi4x2468 = vextq_f32(vi4x0012, vi4x468A, 3);

      vo468Ap00 = vfmaq_laneq_f32(vo468Ap00, vi0x2468, vw0123, 1);
      vo468Ap01 = vfmaq_laneq_f32(vo468Ap01, vi1x2468, vw4567, 2);
      vo468Ap00 = vfmaq_laneq_f32(vo468Ap00, vi2x2468, vw89AB, 3);
      vo468Ap01 = vfmaq_laneq_f32(vo468Ap01, vi3x2468, vwGHIJ, 0);
      vo468Ap00 = vfmaq_laneq_f32(vo468Ap00, vi4x2468, vwKLMN, 1);

      vi0x0123 = vi0x89AB;
      vi1x0123 = vi1x89AB;
      vi2x0123 = vi2x89AB;
      vi3x0123 = vi3x89AB;
      vi4x0123 = vi4x89AB;

      // one right
      vo468Ap00 = vfmaq_laneq_f32(vo468Ap00, vi0x579B, vw4567, 0);
      vo468Ap01 = vfmaq_laneq_f32(vo468Ap01, vi1x579B, vw89AB, 1);
      vo468Ap00 = vfmaq_laneq_f32(vo468Ap00, vi2x579B, vwCDEF, 2);
      vo468Ap01 = vfmaq_laneq_f32(vo468Ap01, vi3x579B, vwGHIJ, 3);
      vo468Ap00 = vfmaq_lane_f32( vo468Ap00, vi4x579B, vwOP, 0);

      // two right
      const float32x4_t vi0x68AC = vextq_f32(vi0x468A, vi0xCDEF, 1);
      const float32x4_t vi1x68AC = vextq_f32(vi1x468A, vi1xCDEF, 1);
      const float32x4_t vi2x68AC = vextq_f32(vi2x468A, vi2xCDEF, 1);
      const float32x4_t vi3x68AC = vextq_f32(vi3x468A, vi3xCDEF, 1);
      const float32x4_t vi4x68AC = vextq_f32(vi4x468A, vi4xCDEF, 1);

      vo468Ap00 = vfmaq_laneq_f32(vo468Ap00, vi0x68AC, vw4567, 1);
      vo468Ap01 = vfmaq_laneq_f32(vo468Ap01, vi1x68AC, vw89AB, 2);
      vo468Ap00 = vfmaq_laneq_f32(vo468Ap00, vi2x68AC, vwCDEF, 3);
      vo468Ap01 = vfmaq_laneq_f32(vo468Ap01, vi3x68AC, vwKLMN, 0);
      vo468Ap00 = vfmaq_lane_f32( vo468Ap00, vi4x68AC, vwOP, 1);

      vi0x4567 = vi0xCDEF;
      vi1x4567 = vi1xCDEF;
      vi2x4567 = vi2xCDEF;
      vi3x4567 = vi3xCDEF;
      vi4x4567 = vi4xCDEF;

      float32x4_t vo0 = vaddq_f32(vo468Ap00, vo468Ap01);

      vo0 = vmaxq_f32(vo0, vmin);
      vo0 = vminq_f32(vo0, vmax);

      size_t k_tmp = (k + 1) / 2;
      if XNN_LIKELY(k_tmp >= 4) {
        vst1q_f32(output0, vo0);
        output0 = (float*) ((uintptr_t) output0 + output_tuple_stride);
      } else {
        float* output0_lo = output0;
        float32x2_t vo0_lo = vget_low_f32(vo0);
        if (k_tmp & 2) {
          vst1_f32(output0_lo, vo0_lo); output0_lo += 2;
          vo0_lo = vget_high_f32(vo0);
        }
        if (k_tmp & 1) {
          vst1_lane_f32(output0_lo, vo0_lo, 0);
        }
      }
    }

    {
      float32x4_t vo468Ap00 = vdupq_laneq_f32(vw0123, 0);

      float32x4_t vi0x89AB;
      float32x4_t vi1x89AB;
      float32x4_t vi2x89AB;
      float32x4_t vi3x89AB;
      float32x4_t vi4x89AB;

      if XNN_LIKELY(k > 4) {
        vi0x89AB = vld1q_f32(i0); i0 = (const float*) ((uintptr_t) i0 + input_tuple_stride);
        vi1x89AB = vld1q_f32(i1); i1 = (const float*) ((uintptr_t) i1 + input_tuple_stride);
        vi2x89AB = vld1q_f32(i2); i2 = (const float*) ((uintptr_t) i2 + input_tuple_stride);
        vi3x89AB = vld1q_f32(i3); i3 = (const float*) ((uintptr_t) i3 + input_tuple_stride);
        vi4x89AB = vld1q_f32(i4); i4 = (const float*) ((uintptr_t) i4 + input_tuple_stride);
      } else {
        vi0x89AB = vmovq_n_f32(0.f);
        vi1x89AB = vmovq_n_f32(0.f);
        vi2x89AB = vmovq_n_f32(0.f);
        vi3x89AB = vmovq_n_f32(0.f);
        vi4x89AB = vmovq_n_f32(0.f);
      }

      float32x4_t vi0xCDEF;
      float32x4_t vi1xCDEF;
      float32x4_t vi2xCDEF;
      float32x4_t vi3xCDEF;
      float32x4_t vi4xCDEF;

      if XNN_LIKELY(k > 8) {
        vi0xCDEF = vld1q_f32(i0); i0 = (const float*) ((uintptr_t) i0 + input_tuple_stride);
        vi1xCDEF = vld1q_f32(i1); i1 = (const float*) ((uintptr_t) i1 + input_tuple_stride);
        vi2xCDEF = vld1q_f32(i2); i2 = (const float*) ((uintptr_t) i2 + input_tuple_stride);
        vi3xCDEF = vld1q_f32(i3); i3 = (const float*) ((uintptr_t) i3 + input_tuple_stride);
        vi4xCDEF = vld1q_f32(i4); i4 = (const float*) ((uintptr_t) i4 + input_tuple_stride);
      } else {
        vi0xCDEF = vmovq_n_f32(0.f);
        vi1xCDEF = vmovq_n_f32(0.f);
        vi2xCDEF = vmovq_n_f32(0.f);
        vi3xCDEF = vmovq_n_f32(0.f);
        vi4xCDEF = vmovq_n_f32(0.f);
      }
      float32x4_t vi0x468A = vuzp1q_f32(vi0x4567, vi0x89AB);
      float32x4_t vi0x579B = vuzp2q_f32(vi0x4567, vi0x89AB);
      float32x4_t vi1x468A = vuzp1q_f32(vi1x4567, vi1x89AB);
      float32x4_t vi1x579B = vuzp2q_f32(vi1x4567, vi1x89AB);
      float32x4_t vi2x468A = vuzp1q_f32(vi2x4567, vi2x89AB);
      float32x4_t vi2x579B = vuzp2q_f32(vi2x4567, vi2x89AB);
      float32x4_t vi3x468A = vuzp1q_f32(vi3x4567, vi3x89AB);
      float32x4_t vi3x579B = vuzp2q_f32(vi3x4567, vi3x89AB);
      float32x4_t vi4x468A = vuzp1q_f32(vi4x4567, vi4x89AB);
      float32x4_t vi4x579B = vuzp2q_f32(vi4x4567, vi4x89AB);

      vi0x468A = vreinterpretq_f32_u32(vandq_u32(vmask_even, vreinterpretq_u32_f32(vi0x468A)));
      vi1x468A = vreinterpretq_f32_u32(vandq_u32(vmask_even, vreinterpretq_u32_f32(vi1x468A)));
      vi2x468A = vreinterpretq_f32_u32(vandq_u32(vmask_even, vreinterpretq_u32_f32(vi2x468A)));
      vi3x468A = vreinterpretq_f32_u32(vandq_u32(vmask_even, vreinterpretq_u32_f32(vi3x468A)));
      vi4x468A = vreinterpretq_f32_u32(vandq_u32(vmask_even, vreinterpretq_u32_f32(vi4x468A)));

      vi0x579B = vreinterpretq_f32_u32(vandq_u32(vmask_odd, vreinterpretq_u32_f32(vi0x579B)));
      vi1x579B = vreinterpretq_f32_u32(vandq_u32(vmask_odd, vreinterpretq_u32_f32(vi1x579B)));
      vi2x579B = vreinterpretq_f32_u32(vandq_u32(vmask_odd, vreinterpretq_u32_f32(vi2x579B)));
      vi3x579B = vreinterpretq_f32_u32(vandq_u32(vmask_odd, vreinterpretq_u32_f32(vi3x579B)));
      vi4x579B = vreinterpretq_f32_u32(vandq_u32(vmask_odd, vreinterpretq_u32_f32(vi4x579B)));

      // middle tap
      vo468Ap00 = vfmaq_laneq_f32(vo468Ap00, vi0x468A, vw0123, 3);
      float32x4_t vo468Ap01 = vmulq_laneq_f32(vi1x468A, vw89AB, 0);
      vo468Ap00 = vfmaq_laneq_f32(vo468Ap00, vi2x468A, vwCDEF, 1);
      vo468Ap01 = vfmaq_laneq_f32(vo468Ap01, vi3x468A, vwGHIJ, 2);
      vo468Ap00 = vfmaq_laneq_f32(vo468Ap00, vi4x468A, vwKLMN, 3);

      // one left
      const float32x4_t vi0x3579 = vextq_f32(vi0x0123, vi0x579B, 3);
      const float32x4_t vi1x3579 = vextq_f32(vi1x0123, vi1x579B, 3);
      const float32x4_t vi2x3579 = vextq_f32(vi2x0123, vi2x579B, 3);
      const float32x4_t vi3x3579 = vextq_f32(vi3x0123, vi3x579B, 3);
      const float32x4_t vi4x3579 = vextq_f32(vi4x0123, vi4x579B, 3);

      vo468Ap00 = vfmaq_laneq_f32(vo468Ap00, vi0x3579, vw0123, 2);
      vo468Ap01 = vfmaq_laneq_f32(vo468Ap01, vi1x3579, vw4567, 3);
      vo468Ap00 = vfmaq_laneq_f32(vo468Ap00, vi2x3579, vwCDEF, 0);
      vo468Ap01 = vfmaq_laneq_f32(vo468Ap01, vi3x3579, vwGHIJ, 1);
      vo468Ap00 = vfmaq_laneq_f32(vo468Ap00, vi4x3579, vwKLMN, 2);

      // two left
      // getting the vector to use for the far left tap is annoying
      // as we can't ext anything we currently have to get it.
      // To do this, we get a bit ugly.  Interpret the float 32x4
      // vector as int 64x2. Then left shift by 32.  Interpret
      // again as float 32x4.  Now the right most bits are what we
      // want them to be for the following ext.
      const float32x4_t vi0x0012 = vreinterpretq_f32_u64(vshlq_n_u64(vreinterpretq_u64_f32(vi0x0123), 32));
      const float32x4_t vi1x0012 = vreinterpretq_f32_u64(vshlq_n_u64(vreinterpretq_u64_f32(vi1x0123), 32));
      const float32x4_t vi2x0012 = vreinterpretq_f32_u64(vshlq_n_u64(vreinterpretq_u64_f32(vi2x0123), 32));
      const float32x4_t vi3x0012 = vreinterpretq_f32_u64(vshlq_n_u64(vreinterpretq_u64_f32(vi3x0123), 32));
      const float32x4_t vi4x0012 = vreinterpretq_f32_u64(vshlq_n_u64(vreinterpretq_u64_f32(vi4x0123), 32));

      const float32x4_t vi0x2468 = vextq_f32(vi0x0012, vi0x468A, 3);
      const float32x4_t vi1x2468 = vextq_f32(vi1x0012, vi1x468A, 3);
      const float32x4_t vi2x2468 = vextq_f32(vi2x0012, vi2x468A, 3);
      const float32x4_t vi3x2468 = vextq_f32(vi3x0012, vi3x468A, 3);
      const float32x4_t vi4x2468 = vextq_f32(vi4x0012, vi4x468A, 3);

      vo468Ap00 = vfmaq_laneq_f32(vo468Ap00, vi0x2468, vw0123, 1);
      vo468Ap01 = vfmaq_laneq_f32(vo468Ap01, vi1x2468, vw4567, 2);
      vo468Ap00 = vfmaq_laneq_f32(vo468Ap00, vi2x2468, vw89AB, 3);
      vo468Ap01 = vfmaq_laneq_f32(vo468Ap01, vi3x2468, vwGHIJ, 0);
      vo468Ap00 = vfmaq_laneq_f32(vo468Ap00, vi4x2468, vwKLMN, 1);

      vi0x0123 = vi0x89AB;
      vi1x0123 = vi1x89AB;
      vi2x0123 = vi2x89AB;
      vi3x0123 = vi3x89AB;
      vi4x0123 = vi4x89AB;

      // one right
      vo468Ap00 = vfmaq_laneq_f32(vo468Ap00, vi0x579B, vw4567, 0);
      vo468Ap01 = vfmaq_laneq_f32(vo468Ap01, vi1x579B, vw89AB, 1);
      vo468Ap00 = vfmaq_laneq_f32(vo468Ap00, vi2x579B, vwCDEF, 2);
      vo468Ap01 = vfmaq_laneq_f32(vo468Ap01, vi3x579B, vwGHIJ, 3);
      vo468Ap00 = vfmaq_lane_f32( vo468Ap00, vi4x579B, vwOP, 0);

      // two right
      const float32x4_t vi0x68AC = vextq_f32(vi0x468A, vi0xCDEF, 1);
      const float32x4_t vi1x68AC = vextq_f32(vi1x468A, vi1xCDEF, 1);
      const float32x4_t vi2x68AC = vextq_f32(vi2x468A, vi2xCDEF, 1);
      const float32x4_t vi3x68AC = vextq_f32(vi3x468A, vi3xCDEF, 1);
      const float32x4_t vi4x68AC = vextq_f32(vi4x468A, vi4xCDEF, 1);

      vo468Ap00 = vfmaq_laneq_f32(vo468Ap00, vi0x68AC, vw4567, 1);
      vo468Ap01 = vfmaq_laneq_f32(vo468Ap01, vi1x68AC, vw89AB, 2);
      vo468Ap00 = vfmaq_laneq_f32(vo468Ap00, vi2x68AC, vwCDEF, 3);
      vo468Ap01 = vfmaq_laneq_f32(vo468Ap01, vi3x68AC, vwKLMN, 0);
      vo468Ap00 = vfmaq_lane_f32( vo468Ap00, vi4x68AC, vwOP, 1);

      vi0x4567 = vi0xCDEF;
      vi1x4567 = vi1xCDEF;
      vi2x4567 = vi2xCDEF;
      vi3x4567 = vi3xCDEF;
      vi4x4567 = vi4xCDEF;

      float32x4_t vo0 = vaddq_f32(vo468Ap00, vo468Ap01);

      vo0 = vmaxq_f32(vo0, vmin);
      vo0 = vminq_f32(vo0, vmax);

      size_t k_tmp = (k + 1) / 2;
      if XNN_LIKELY(k_tmp >= 4) {
        vst1q_f32(output0, vo0);
        output0 = (float*) ((uintptr_t) output0 + output_tuple_stride);
      } else {
        float* output0_lo = output0;
        float32x2_t vo0_lo = vget_low_f32(vo0);
        if (k_tmp & 2) {
          vst1_f32(output0_lo, vo0_lo); output0_lo += 2;
          vo0_lo = vget_high_f32(vo0);
        }
        if (k_tmp & 1) {
          vst1_lane_f32(output0_lo, vo0_lo, 0);
        }
      }
    }

    i0 = (const float*) ((uintptr_t) i2 - input_width_decrement_single);
    i1 = (const float*) ((uintptr_t) i2 + input_width_increment_single);
    i2 = (const float*) ((uintptr_t) i2 + input_width_increment_double);
    i3 = (const float*) ((uintptr_t) i3 + input_width_increment_double);
    i4 = (const float*) ((uintptr_t) i4 + input_width_increment_double);
    output0 = (float*) ((uintptr_t) output0 + output_width_increment_single);
    m -= 1;
    if (m == 1) {
      i4 = zero;
      // we mimic the following logic:
      // if (padding_top == 2 && input_height % 2 == 1) {
      //   i3 = zero;
      // } else if (padding_top == 1 && input_height % 2 == 0) {
      //   i3 = zero;
      // }
      // with: padding_top - 1 == input_height % 2
      if (padding_top - 1 == input_height % 2) {
        i3 = zero;
      }
    }
  } while (m > 0);
}