#ifndef GFP_HEADER_CUH
#define GFP_HEADER_CUH

#include "../header.cuh"

namespace gfp
{
    using gfp_t = uint32_t;

    static const gfp_t gfprime = 65521;

    static const gfp_t gfp_zero = (gfp_t)0;
    static const gfp_t gfp_one = (gfp_t)1;
    static const gfp_t gfp_fullmask = (gfp_t)0xFF'FF;

    __managed__ gfp_t gfp_inv_table[gfprime];

    void init_inv_table()
    {
        gfp_inv_table[0] = 0;
        gfp_inv_table[1] = 1;
        for (int i = 2; i < gfprime; ++i)
        {
            gfp_inv_table[i] = (gfprime - gfprime / i) * gfp_inv_table[gfprime % i] % gfprime;
        }
    }
    gfp_t gfp_inv(gfp_t a)
    {
        return gfp_inv_table[a];
    }

    __host__ __device__ inline size_t offset4(size_t idx)
    {
        return idx << 2;
    }

    __host__ __device__ inline size_t get4(gfp_t src, size_t idx)
    {
        return (src >> offset4(idx)) & 0xF;
    }

    // 确保set8对应位置的值为0
    __host__ __device__ inline void set4(gfp_t &dst, size_t src, size_t idx)
    {
        dst |= (gfp_t)src << offset4(idx);
    }

}

#endif