// Auto-generated file. Do not edit!
//   Template: src/f32-raddstoreexpminusmax/neon-lut64-p2.c.in
//   Generator: tools/xngen
//
// 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.

#include <assert.h>

#include <arm_neon.h>

#include <xnnpack/common.h>
#include <xnnpack/raddstoreexpminusmax.h>


extern XNN_INTERNAL const float xnn_table_exp2_k_over_64[64];

void xnn_f32_raddstoreexpminusmax_ukernel__neon_rr2_lut64_p2_x4(
    size_t elements,
    const float* input,
    const float* max,
    float* output,
    float* sum,
    const union xnn_f32_expminus_params params[restrict XNN_MIN_ELEMENTS(1)]) XNN_OOB_READS
{
  assert(elements % sizeof(float) == 0);

  const float32x4_t vi_max = vld1q_dup_f32(max);
  const float32x4_t vlog2e = vld1q_dup_f32(&params->neon_rr2_lut64_p2.log2e);
  const float32x4_t vmagic_bias = vld1q_dup_f32(&params->neon_rr2_lut64_p2.magic_bias);
  const int32x4_t vindex_mask = vmovq_n_s32(INT32_C(0x3F));
  const float32x4_t vminus_ln2_hi = vld1q_dup_f32(&params->neon_rr2_lut64_p2.minus_ln2_hi);
  const float32x4_t vminus_ln2_lo = vld1q_dup_f32(&params->neon_rr2_lut64_p2.minus_ln2_lo);
  const float32x4_t vc2 = vld1q_dup_f32(&params->neon_rr2_lut64_p2.c2);
  const float32x4_t vdenorm_cutoff = vld1q_dup_f32(&params->neon_rr2_lut64_p2.denorm_cutoff);

  float32x4_t vacc = vmovq_n_f32(0.0f);
  for (; elements >= 4 * sizeof(float); elements -= 4 * sizeof(float)) {
    const float32x4_t vi = vld1q_f32(input); input += 4;

    const float32x4_t vx = vsubq_f32(vi, vi_max);

    float32x4_t vn = vmlaq_f32(vmagic_bias, vx, vlog2e);

    const int32x4_t ve = vshlq_n_s32(vbicq_s32(vreinterpretq_s32_f32(vn), vmovq_n_s32(INT32_C(0x3F))), 17);

    const uint64x2_t vidx = vreinterpretq_u64_s32(vandq_s32(vreinterpretq_s32_f32(vn), vindex_mask));
    const uint64_t vidx_lo = vgetq_lane_u64(vidx, 0);
    const uint64_t vidx_hi = vgetq_lane_u64(vidx, 1);
    float32x2_t vl_lo = vld1_dup_f32(&xnn_table_exp2_k_over_64[(uint32_t) vidx_lo]);
    float32x2_t vl_hi = vld1_dup_f32(&xnn_table_exp2_k_over_64[(uint32_t) vidx_hi]);
    vl_lo = vld1_lane_f32(&xnn_table_exp2_k_over_64[(uint32_t) (vidx_lo >> 32)], vl_lo, 1);
    vl_hi = vld1_lane_f32(&xnn_table_exp2_k_over_64[(uint32_t) (vidx_hi >> 32)], vl_hi, 1);
    const float32x4_t vl = vcombine_f32(vl_lo, vl_hi);
    const float32x4_t vs = vreinterpretq_f32_s32(vaddq_s32(vreinterpretq_s32_f32(vl), ve));

    vn = vsubq_f32(vn, vmagic_bias);

    float32x4_t vt = vmlaq_f32(vx, vn, vminus_ln2_hi);
    vt = vmlaq_f32(vt, vn, vminus_ln2_lo);

    float32x4_t vp = vmulq_f32(vt, vc2);
    vp = vmlaq_f32(vt, vt, vp);

    float32x4_t vf = vmlaq_f32(vs, vs, vp);

    vf = vreinterpretq_f32_u32(vbicq_u32(vreinterpretq_u32_f32(vf), vcltq_f32(vx, vdenorm_cutoff)));

    vst1q_f32(output, vf); output += 4;

    vacc = vaddq_f32(vacc, vf);
  }
#if XNN_ARCH_ARM64
  float vacc_lo = vaddvq_f32(vacc);
#else
  float32x2_t vacc_lo = vadd_f32(vget_high_f32(vacc), vget_low_f32(vacc));
#endif
  if (elements != 0) {
    assert(elements >= 1 * sizeof(float));
    assert(elements <= 3 * sizeof(float));
    const float32x4_t vi = vld1q_f32(input); input += 4;

    const float32x4_t vx = vsubq_f32(vi, vi_max);

    float32x4_t vn = vmlaq_f32(vmagic_bias, vx, vlog2e);

    const int32x4_t ve = vshlq_n_s32(vbicq_s32(vreinterpretq_s32_f32(vn), vmovq_n_s32(INT32_C(0x3F))), 17);

    const uint64x2_t vidx = vreinterpretq_u64_s32(vandq_s32(vreinterpretq_s32_f32(vn), vindex_mask));
    const uint64_t vidx_lo = vgetq_lane_u64(vidx, 0);
    const uint64_t vidx_hi = vgetq_lane_u64(vidx, 1);
    float32x2_t vl_lo = vld1_dup_f32(&xnn_table_exp2_k_over_64[(uint32_t) vidx_lo]);
    float32x2_t vl_hi = vld1_dup_f32(&xnn_table_exp2_k_over_64[(uint32_t) vidx_hi]);
    vl_lo = vld1_lane_f32(&xnn_table_exp2_k_over_64[(uint32_t) (vidx_lo >> 32)], vl_lo, 1);
    vl_hi = vld1_lane_f32(&xnn_table_exp2_k_over_64[(uint32_t) (vidx_hi >> 32)], vl_hi, 1);
    const float32x4_t vl = vcombine_f32(vl_lo, vl_hi);
    const float32x4_t vs = vreinterpretq_f32_s32(vaddq_s32(vreinterpretq_s32_f32(vl), ve));

    vn = vsubq_f32(vn, vmagic_bias);

    float32x4_t vt = vmlaq_f32(vx, vn, vminus_ln2_hi);
    vt = vmlaq_f32(vt, vn, vminus_ln2_lo);

    float32x4_t vp = vmulq_f32(vt, vc2);
    vp = vmlaq_f32(vt, vt, vp);

    float32x4_t vf = vmlaq_f32(vs, vs, vp);

    vf = vreinterpretq_f32_u32(vbicq_u32(vreinterpretq_u32_f32(vf), vcltq_f32(vx, vdenorm_cutoff)));

    float32x2_t vf_lo = vget_low_f32(vf);
    if (elements & (2 * sizeof(float))) {
      vst1_f32(output, vf_lo); output += 2;

      #if XNN_ARCH_ARM64
        vacc_lo += vaddv_f32(vf_lo);
      #else
        vacc_lo = vadd_f32(vacc_lo, vf_lo);
      #endif

      vf_lo = vget_high_f32(vf);
    }
    if (elements & (1 * sizeof(float))) {
      vst1_lane_f32(output, vf_lo, 0);

      #if XNN_ARCH_ARM64
        vacc_lo += vget_lane_f32(vf_lo, 0);
      #else
        vacc_lo = vadd_f32(vacc_lo, vreinterpret_f32_u64(vshl_n_u64(vreinterpret_u64_f32(vf_lo), 32)));
      #endif
    }
  }
#if XNN_ARCH_ARM64
  *sum = vacc_lo;
#else
  vst1_lane_f32(sum, vpadd_f32(vacc_lo, vacc_lo), 0);
#endif
}