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#include <stdio.h>
#include <stdlib.h>
#include <string.h> // for memset, memcmp
#include "test.h"
#include "erasure_code.h"

#ifndef GT_L3_CACHE
#define GT_L3_CACHE 32 * 1024 * 1024 /* some number > last level cache */
#endif

#if !defined(COLD_TEST) && !defined(TEST_CUSTOM)
// Cached test, loop many times over small dataset
#define TEST_SOURCES  10
#define TEST_LEN      8 * 1024
#define TEST_TYPE_STR "_warm"
#elif defined(COLD_TEST)
// Uncached test.  Pull from large mem base.
#define TEST_SOURCES  10
#define TEST_LEN      (GT_L3_CACHE / TEST_SOURCES)
#define TEST_TYPE_STR "_cold"
#elif defined(TEST_CUSTOM)
#define TEST_TYPE_STR "_cus"
#endif

typedef unsigned char u8;

// Global GF(256) tables
u8 gff[256];
u8 gflog[256];
u8 gf_mul_table[256 * 256];

void
mk_gf_field(void)
{
        int i;
        u8 s = 1;
        gflog[0] = 0;

        for (i = 0; i < 256; i++) {
                gff[i] = s;
                gflog[s] = i;
                s = (s << 1) ^ ((s & 0x80) ? 0x1d : 0); // mult by GF{2}
        }
}

void
mk_gf_mul_table(u8 *table)
{
        // Populate a single table with all multiply combinations for a fast,
        // single-table lookup of GF(2^8) multiply at the expense of memory.
        int i, j;
        for (i = 0; i < 256; i++)
                for (j = 0; j < 256; j++)
                        table[i * 256 + j] = gf_mul(i, j);
}

void
gf_vect_dot_prod_ref(int len, int vlen, u8 *v, u8 **src, u8 *dest)
{
        int i, j;
        u8 s;
        for (i = 0; i < len; i++) {
                s = 0;
                for (j = 0; j < vlen; j++)
                        s ^= gf_mul(src[j][i], v[j]);

                dest[i] = s;
        }
}

void
gf_vect_dot_prod_mult(int len, int vlen, u8 *v, u8 **src, u8 *dest)
{
        int i, j;
        u8 s;
        for (i = 0; i < len; i++) {
                s = 0;
                for (j = 0; j < vlen; j++) {
                        s ^= gf_mul_table[v[j] * 256 + src[j][i]];
                }
                dest[i] = s;
        }
}

int
main(void)
{
        int i, j;
        u8 vec[TEST_SOURCES], *dest1, *dest2;
        u8 *matrix[TEST_SOURCES];
        struct perf start;

        dest1 = (u8 *) malloc(TEST_LEN);
        dest2 = (u8 *) malloc(TEST_LEN);

        if (NULL == dest1 || NULL == dest2) {
                printf("buffer alloc error\n");
                return -1;
        }
        memset(dest1, 0xfe, TEST_LEN);
        memset(dest2, 0xfe, TEST_LEN);

        mk_gf_field();
        mk_gf_mul_table(gf_mul_table);

        // generate random vector and matrix/data
        for (i = 0; i < TEST_SOURCES; i++) {
                vec[i] = rand();

                if (!(matrix[i] = malloc(TEST_LEN))) {
                        fprintf(stderr, "Error failure\n\n");
                        return -1;
                }
                for (j = 0; j < TEST_LEN; j++)
                        matrix[i][j] = rand();
        }

        BENCHMARK(&start, BENCHMARK_TIME,
                  gf_vect_dot_prod_ref(TEST_LEN, TEST_SOURCES, vec, matrix, dest1));
        printf("gf_vect_dot_prod_2tbl" TEST_TYPE_STR ": ");
        perf_print(start, (long long) TEST_LEN * (TEST_SOURCES + 1));

        BENCHMARK(&start, BENCHMARK_TIME,
                  gf_vect_dot_prod_mult(TEST_LEN, TEST_SOURCES, vec, matrix, dest2));
        printf("gf_vect_dot_prod_1tbl" TEST_TYPE_STR ": ");
        perf_print(start, (long long) TEST_LEN * (TEST_SOURCES + 1));

        // Compare with reference function
        if (0 != memcmp(dest1, dest2, TEST_LEN)) {
                printf("Error, different results!\n\n");
                return -1;
        }

        printf("Pass functional test\n");
        return 0;
}