text: // 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/maxpool.h>
  
  
  void xnn_f32_maxpool_minmax_ukernel_9p8x__neon_c4(
      size_t output_pixels,
      size_t kernel_elements,
      size_t channels,
      const float** input,
      size_t input_offset,
      float* output,
      size_t input_increment,
      size_t output_increment,
      const union xnn_f32_minmax_params params[restrict XNN_MIN_ELEMENTS(1)]) XNN_DISABLE_TSAN
  {
    assert(output_pixels != 0);
    assert(kernel_elements != 0);
    assert(channels != 0);
  
    const float32x4_t voutput_max = vld1q_dup_f32(&params->scalar.max);
    const float32x4_t voutput_min = vld1q_dup_f32(&params->scalar.min);
    do {
      float* o = output;
      {
        const float* i0 = *input++;
        const float* i1 = *input++;
        const float* i2 = *input++;
        const float* i3 = *input++;
        const float* i4 = *input++;
        const float* i5 = *input++;
        const float* i6 = *input++;
        const float* i7 = *input++;
        const float* i8 = *input++;
        i0 = (const float*) ((uintptr_t) i0 + input_offset);
        i1 = (const float*) ((uintptr_t) i1 + input_offset);
        i2 = (const float*) ((uintptr_t) i2 + input_offset);
        i3 = (const float*) ((uintptr_t) i3 + input_offset);
        i4 = (const float*) ((uintptr_t) i4 + input_offset);
        i5 = (const float*) ((uintptr_t) i5 + input_offset);
        i6 = (const float*) ((uintptr_t) i6 + input_offset);
        i7 = (const float*) ((uintptr_t) i7 + input_offset);
        i8 = (const float*) ((uintptr_t) i8 + input_offset);
        if (kernel_elements < 2) {
          i1 = i0;
        }
        if (kernel_elements <= 2) {
          i2 = i0;
        }
        if (kernel_elements < 4) {
          i3 = i0;
        }
        if (kernel_elements <= 4) {
          i4 = i0;
        }
        if (kernel_elements < 6) {
          i5 = i0;
        }
        if (kernel_elements <= 6) {
          i6 = i0;
        }
        if (kernel_elements < 8) {
          i7 = i0;
        }
        if (kernel_elements <= 8) {
          i8 = i0;
        }
  
        size_t c = channels;
        for (; c >= 4; c -= 4) {
          const float32x4_t vi0 = vld1q_f32(i0);
          i0 += 4;
          const float32x4_t vi1 = vld1q_f32(i1);
          i1 += 4;
          const float32x4_t vi2 = vld1q_f32(i2);
          i2 += 4;
          const float32x4_t vi3 = vld1q_f32(i3);
          i3 += 4;
          const float32x4_t vi4 = vld1q_f32(i4);
          i4 += 4;
          const float32x4_t vi5 = vld1q_f32(i5);
          i5 += 4;
          const float32x4_t vi6 = vld1q_f32(i6);
          i6 += 4;
          const float32x4_t vi7 = vld1q_f32(i7);
          i7 += 4;
          const float32x4_t vi8 = vld1q_f32(i8);
          i8 += 4;
  
          const float32x4_t vmax018 = vmaxq_f32(vmaxq_f32(vi0, vi1), vi8);
          const float32x4_t vmax23 = vmaxq_f32(vi2, vi3);
          const float32x4_t vmax45 = vmaxq_f32(vi4, vi5);
          const float32x4_t vmax67 = vmaxq_f32(vi6, vi7);
  
          const float32x4_t vmax2345 = vmaxq_f32(vmax23, vmax45);
          const float32x4_t vmax01678 = vmaxq_f32(vmax018, vmax67);
          const float32x4_t vmax = vmaxq_f32(vmax2345, vmax01678);
          const float32x4_t vout = vmaxq_f32(vminq_f32(vmax, voutput_max), voutput_min);
  
          vst1q_f32(o, vout);
          o += 4;
        }
        if (c != 0) {
          const float32x4_t vi0 = vld1q_f32(i0);
          i0 += 4;
          const float32x4_t vi1 = vld1q_f32(i1);
          i1 += 4;
          const float32x4_t vi2 = vld1q_f32(i2);
          i2 += 4;
          const float32x4_t vi3 = vld1q_f32(i3);
          i3 += 4;
          const float32x4_t vi4 = vld1q_f32(i4);
          i4 += 4;
          const float32x4_t vi5 = vld1q_f32(i5);
          i5 += 4;
          const float32x4_t vi6 = vld1q_f32(i6);
          i6 += 4;
          const float32x4_t vi7 = vld1q_f32(i7);
          i7 += 4;
          const float32x4_t vi8 = vld1q_f32(i8);
          i8 += 4;
  
          const float32x4_t vmax018 = vmaxq_f32(vmaxq_f32(vi0, vi1), vi8);
          const float32x4_t vmax23 = vmaxq_f32(vi2, vi3);
          const float32x4_t vmax45 = vmaxq_f32(vi4, vi5);
          const float32x4_t vmax67 = vmaxq_f32(vi6, vi7);
  
          const float32x4_t vmax2345 = vmaxq_f32(vmax23, vmax45);
          const float32x4_t vmax01678 = vmaxq_f32(vmax018, vmax67);
          const float32x4_t vmax = vmaxq_f32(vmax2345, vmax01678);
          float32x4_t vout = vmaxq_f32(vminq_f32(vmax, voutput_max), voutput_min);
  
          float32x2_t vout_lo = vget_low_f32(vout);
          if (c & 2) {
            vst1_f32(o, vout_lo);
            vout_lo = vget_high_f32(vout);
            o += 2;
          }
          if (c & 1) {
            vst1_lane_f32(o, vout_lo, 0);
            o += 1;
          }
        }
      }
  
      for (ptrdiff_t k = (ptrdiff_t) kernel_elements - 9; k > 0; k -= 8) {
        const float* i0 = *input++;
        const float* i1 = *input++;
        const float* i2 = *input++;
        const float* i3 = *input++;
        const float* i4 = *input++;
        const float* i5 = *input++;
        const float* i6 = *input++;
        const float* i7 = *input++;
        i0 = (const float*) ((uintptr_t) i0 + input_offset);
        i1 = (const float*) ((uintptr_t) i1 + input_offset);
        i2 = (const float*) ((uintptr_t) i2 + input_offset);
        i3 = (const float*) ((uintptr_t) i3 + input_offset);
        i4 = (const float*) ((uintptr_t) i4 + input_offset);
        i5 = (const float*) ((uintptr_t) i5 + input_offset);
        i6 = (const float*) ((uintptr_t) i6 + input_offset);
        i7 = (const float*) ((uintptr_t) i7 + input_offset);
        if (k < 2) {
          i1 = i0;
        }
        if (k <= 2) {
          i2 = i0;
        }
        if (k < 4) {
          i3 = i0;
        }
        if (k <= 4) {
          i4 = i0;
        }
        if (k < 6) {
          i5 = i0;
        }
        if (k <= 6) {
          i6 = i0;
        }
        if (k < 8) {
          i7 = i0;
        }
  
        o = output;
        size_t c = channels;
        for (; c >= 4; c -= 4) {
          const float32x4_t vi0 = vld1q_f32(i0);
          i0 += 4;
          const float32x4_t vi1 = vld1q_f32(i1);
          i1 += 4;
          const float32x4_t vi2 = vld1q_f32(i2);
          i2 += 4;
          const float32x4_t vi3 = vld1q_f32(i3);
          i3 += 4;
          const float32x4_t vi4 = vld1q_f32(i4);
          i4 += 4;
          const float32x4_t vi5 = vld1q_f32(i5);
          i5 += 4;
          const float32x4_t vi6 = vld1q_f32(i6);
          i6 += 4;
          const float32x4_t vi7 = vld1q_f32(i7);
          i7 += 4;
          const float32x4_t vo = vld1q_f32(o);
  
          const float32x4_t vmax01 = vmaxq_f32(vmaxq_f32(vi0, vi1), vo);
          const float32x4_t vmax23 = vmaxq_f32(vi2, vi3);
          const float32x4_t vmax45 = vmaxq_f32(vi4, vi5);
          const float32x4_t vmax67 = vmaxq_f32(vi6, vi7);
  
          const float32x4_t vmax2345 = vmaxq_f32(vmax23, vmax45);
          const float32x4_t vmax0167 = vmaxq_f32(vmax01, vmax67);
          const float32x4_t vmax = vmaxq_f32(vmax2345, vmax0167);
          const float32x4_t vout = vmaxq_f32(vminq_f32(vmax, voutput_max), voutput_min);
  
          vst1q_f32(o, vout);
          o += 4;
        }
        if (c != 0) {
          const float32x4_t vi0 = vld1q_f32(i0);
          const float32x4_t vi1 = vld1q_f32(i1);
          const float32x4_t vi2 = vld1q_f32(i2);
          const float32x4_t vi3 = vld1q_f32(i3);
          const float32x4_t vi4 = vld1q_f32(i4);
          const float32x4_t vi5 = vld1q_f32(i5);
          const float32x4_t vi6 = vld1q_f32(i6);
          const float32x4_t vi7 = vld1q_f32(i7);
          const float32x4_t vo = vld1q_f32(o);
  
          const float32x4_t vmax01 = vmaxq_f32(vmaxq_f32(vi0, vi1), vo);
          const float32x4_t vmax23 = vmaxq_f32(vi2, vi3);
          const float32x4_t vmax45 = vmaxq_f32(vi4, vi5);
          const float32x4_t vmax67 = vmaxq_f32(vi6, vi7);
  
          const float32x4_t vmax2345 = vmaxq_f32(vmax23, vmax45);
          const float32x4_t vmax0167 = vmaxq_f32(vmax01, vmax67);
          const float32x4_t vmax = vmaxq_f32(vmax2345, vmax0167);
          float32x4_t vout = vmaxq_f32(vminq_f32(vmax, voutput_max), voutput_min);
  
          float32x2_t vout_lo = vget_low_f32(vout);
          if (c & 2) {
            vst1_f32(o, vout_lo);
            vout_lo = vget_high_f32(vout);
            o += 2;
          }
          if (c & 1) {
            vst1_lane_f32(o, vout_lo, 0);
            o += 1;
          }
        }
      }
      input = (const float**) ((uintptr_t) input + input_increment);
      output = (float*) ((uintptr_t) o + output_increment);
    } while (--output_pixels != 0);
  }
  