cvd_src/faster_corner_utilities.h

#ifndef CVD_INTERNAL_INC_FAST_CORNER_UTILITIES_H
#define CVD_INTERNAL_INC_FAST_CORNER_UTILITIES_H

#include <emmintrin.h>

namespace CVD
{

  struct Less 
  { 
    template <class T1, class T2> static bool eval(const T1 a, const T2 b) 
    {
    return a < b; 
    }
    static int prep_t(int pixel_val, int barrier)
    {
      return pixel_val - barrier;
    }
  };
  struct Greater 
  {
    template <class T1, class T2> static bool eval(const T1 a, const T2 b) 
    {
      return a > b; 
    }
    static int prep_t(int pixel_val, int barrier)
    {
      return pixel_val + barrier;
    }
  };
  
#define CHECK_BARRIER(lo, hi, other, flags)             \
    {                                   \
    __m128i diff = _mm_subs_epu8(lo, other);            \
    __m128i diff2 = _mm_subs_epu8(other, hi);           \
    __m128i z = _mm_setzero_si128();                \
    diff = _mm_cmpeq_epi8(diff, z);                 \
    diff2 = _mm_cmpeq_epi8(diff2, z);               \
    flags = ~(_mm_movemask_epi8(diff) | (_mm_movemask_epi8(diff2) << 16)); \
    }
     
    template <bool Aligned> inline __m128i load_si128(const void* addr) { return _mm_loadu_si128((const __m128i*)addr); }
    template <> inline __m128i load_si128<true>(const void* addr) { return _mm_load_si128((const __m128i*)addr); }

}
#endif