/* Copyright 2018 Canaan Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef _BSP_UTIL_H
#define _BSP_UTIL_H

#include <stdint.h>
#if defined(__riscv)
#include "encoding.h"
#endif

#ifdef __cplusplus
extern "C" {
#endif

#if defined(__GNUC__)
#pragma GCC diagnostic ignored "-Wunused-parameter"
#pragma GCC diagnostic ignored "-Wunused-function"
#endif

/**
 * --------------------------------------------------------------------------
 * Macros

 * Set HOST_DEBUG to 1 if you are going to compile this for a host
 * machine (ie Athena/Linux) for debug purposes and set HOST_DEBUG
 * to 0 if you are compiling with the smips-gcc toolchain.
 */

#ifndef HOST_DEBUG
#define HOST_DEBUG 0
#endif

/**
 * Set PREALLOCATE to 1 if you want to preallocate the benchmark
 * function before starting stats. If you have instruction/data
 * caches and you don't want to count the overhead of misses, then
 * you will need to use preallocation.
*/

#ifndef PREALLOCATE
#define PREALLOCATE 0
#endif

#define static_assert(cond){ \
    switch(0){               \
        case 0 : case !!(long)(cond):; } }

#define stringify_1(s) #s
#define stringify(s) stringify_1(s)
#define stats(code, iter)                                                                            \
    do                                                                                               \
    {                                                                                                \
        unsigned long _c = -read_cycle(), _i = -read_csr(minstret);                                  \
        code;                                                                                        \
        _c += read_cycle(), _i += read_csr(minstret);                                                \
        if(cid == 0)                                                                                 \
            printf("\r\n%s: %ld cycles, %ld.%ld cycles/iter, %ld.%ld CPI\r\n",                       \
                   stringify(code), _c, _c / iter, 10 * _c / iter % 10, _c / _i, 10 * _c / _i % 10); \
    } while(0)

/**
 * Set SET_STATS to 1 if you want to carve out the piece that actually
 * does the computation.
 */

#if HOST_DEBUG
#include <stdio.h>
static void setStats(int enable)
{
}
#else
extern void setStats(int enable);
#endif

static void printArray(const char name[], int n, const int arr[])
{
#if HOST_DEBUG
    int i;

    printf(" %10s :", name);
    for(i = 0; i < n; i++)
        printf(" %3d ", arr[i]);
    printf("\r\n");
#endif
}

static void printDoubleArray(const char name[], int n, const double arr[])
{
#if HOST_DEBUG
    int i;

    printf(" %10s :", name);
    for(i = 0; i < n; i++)
        printf(" %g ", arr[i]);
    printf("\r\n");
#endif
}

static int verify(int n, const volatile int *test, const int *verify)
{
    int i;
    /* Unrolled for faster verification */
    for(i = 0; i < n / 2 * 2; i += 2)
    {
        int t0 = test[i], t1 = test[i + 1];
        int v0 = verify[i], v1 = verify[i + 1];

        if(t0 != v0)
            return i + 1;
        if(t1 != v1)
            return i + 2;
    }
    if(n % 2 != 0 && test[n - 1] != verify[n - 1])
        return n;
    return 0;
}

static int verifyDouble(int n, const volatile double *test, const double *verify)
{
    int i;
    /* Unrolled for faster verification */
    for(i = 0; i < n / 2 * 2; i += 2)
    {
        double t0 = test[i], t1 = test[i + 1];
        double v0 = verify[i], v1 = verify[i + 1];
        int eq1 = t0 == v0, eq2 = t1 == v1;

        if(!(eq1 & eq2))
            return i + 1 + eq1;
    }
    if(n % 2 != 0 && test[n - 1] != verify[n - 1])
        return n;
    return 0;
}

static void __attribute__((noinline)) barrier(int ncores)
{
    static volatile int sense = 0;
    static volatile int count = 0;

    static __thread int threadsense;

    __sync_synchronize();

    threadsense = !threadsense;
    if(__sync_fetch_and_add(&count, 1) == ncores - 1)
    {
        count = 0;
        sense = threadsense;
    } else
    {
        while(sense != threadsense)
            ;
    }

    __sync_synchronize();
}

static uint64_t lfsr(uint64_t x)
{
    uint64_t bit = (x ^ (x >> 1)) & 1;

    return (x >> 1) | (bit << 62);
}

#if defined(__GNUC__)
#pragma GCC diagnostic warning "-Wunused-parameter"
#pragma GCC diagnostic warning "-Wunused-function"
#endif

#ifdef __cplusplus
}
#endif

#endif /* _BSP_UTIL_H */