MixerFunctions_SIMD_SSE2.hpp

#pragma once

#include "SystemDefines.hpp"

#ifdef X64_SIMD_AVAILABLE

#if (defined(__GNUC__) || defined(__clang__))
__attribute__((target("sse2")))
#endif
int dotProductSimdSse2(const short* const t, const short* const w, int n) {
  __m128i sum = _mm_setzero_si128();

  while ((n -= 8) >= 0) {
    __m128i tmp = _mm_madd_epi16(*(__m128i*) & t[n], *(__m128i*) & w[n]);
    tmp = _mm_srai_epi32(tmp, 8);
    sum = _mm_add_epi32(sum, tmp);
  }

  sum = _mm_add_epi32(sum, _mm_srli_si128(sum, 8));
  sum = _mm_add_epi32(sum, _mm_srli_si128(sum, 4));
  return _mm_cvtsi128_si32(sum);
}

#if (defined(__GNUC__) || defined(__clang__))
__attribute__((target("sse2")))
#endif
void trainSimdSse2(const short* const t, short* const w, int n, const int e) {
  const __m128i one = _mm_set1_epi16(1);
  const __m128i err = _mm_set1_epi16(short(e));

  while ((n -= 8) >= 0) {
    __m128i tmp = _mm_adds_epi16(*(__m128i*) & t[n], *(__m128i*) & t[n]);
    tmp = _mm_mulhi_epi16(tmp, err);
    tmp = _mm_adds_epi16(tmp, one);
    tmp = _mm_srai_epi16(tmp, 1);
    tmp = _mm_adds_epi16(tmp, *reinterpret_cast<__m128i*>(&w[n]));
    *reinterpret_cast<__m128i*>(&w[n]) = tmp;
  }
}

#endif // X64_SIMD_AVAILABLE