//**************************************************************************
// Multi-threaded Matrix Multiply benchmark
//--------------------------------------------------------------------------
// TA     : Christopher Celio
// Student:
//
//
// This benchmark multiplies two 2-D arrays together and writes the results to
// a third vector. The input data (and reference data) should be generated
// using the matmul_gendata.pl perl script and dumped to a file named
// dataset.h.


// print out arrays, etc.
//#define DEBUG

//--------------------------------------------------------------------------
// Includes

#include <string.h>
#include <stdlib.h>
#include <stdio.h>


//--------------------------------------------------------------------------
// Input/Reference Data

typedef float data_t;
#include "dataset.h"


//--------------------------------------------------------------------------
// Basic Utilities and Multi-thread Support

__thread unsigned long coreid;
unsigned long ncores;

#include "util.h"

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


//--------------------------------------------------------------------------
// Helper functions

void printArray( char name[], int n, data_t arr[] )
{
    int i;
    if (coreid != 0)
        return;
    
    printf( " %10s :", name );
    for ( i = 0; i < n; i++ )
        printf( " %3ld ", (long) arr[i] );
    printf( "\n" );
}

void __attribute__((noinline)) verify(size_t n, const data_t* test, const data_t* correct)
{
    if (coreid != 0)
        return;
    
    size_t i;
    for (i = 0; i < n; i++)
    {
        if (test[i] != correct[i])
        {
            printf("FAILED test[%d]= %3ld, correct[%d]= %3ld\n",
                   i, (long)test[i], i, (long)correct[i]);
            exit(-1);
        }
    }
    
    return;
}

//--------------------------------------------------------------------------
// matmul function

// single-thread, naive version
void __attribute__((noinline)) matmul_naive(const int lda,  const data_t A[], const data_t B[], data_t C[] )
{
    int i, j, k;
    
    if (coreid > 0)
        return;
    
    for ( i = 0; i < lda; i++ )
        for ( j = 0; j < lda; j++ )
        {
            for ( k = 0; k < lda; k++ )
            {
                C[i + j*lda] += A[j*lda + k] * B[k*lda + i];
            }
        }
    
}



void __attribute__((noinline)) matmul(const int lda,  const data_t A[], const data_t B[], data_t C[] )
{    
    int i, j, k;
    
    for ( i = 0; i < lda; i+=2 )
    {
        for (k = 0; k < lda; k+=4)
        {
            int d0 = B[k*lda + i];
            int c0 = B[k*lda + i + 1];
            int d1 = B[(k+1)*lda + i];
            int c1 = B[(k+1)*lda + i + 1];
            int d2 = B[(k+2)*lda + i];
            int c2 = B[(k+2)*lda + i + 1];
            int d3 = B[(k+3)*lda + i];
            int c3 = B[(k+3)*lda + i + 1];
            
            for ( j = coreid*(lda/ncores); j < (coreid+1)*(lda/ncores); j+=4)
            {
                
                int sum = A[j*lda + k] * d0;
                sum += A[j*lda + k + 1] * d1;
                sum += A[j*lda + k + 2] * d2;
                sum += A[j*lda + k + 3] * d3;
                C[j*lda +i] += sum;
                
                sum = A[j*lda + k] * c0;
                sum += A[j*lda + k + 1] * c1;
                sum += A[j*lda + k + 2] * c2;
                sum += A[j*lda + k + 3] * c3;
                C[j*lda + i + 1] += sum;
                
                sum = A[(j+1)*lda + k] * d0;
                sum += A[(j+1)*lda + k + 1] * d1;
                sum += A[(j+1)*lda + k + 2] * d2;
                sum += A[(j+1)*lda + k + 3] * d3;
                C[(j+1)*lda +i] += sum;
                
                sum = A[(j+1)*lda + k] * c0;
                sum += A[(j+1)*lda + k + 1] * c1;
                sum += A[(j+1)*lda + k + 2] * c2;
                sum += A[(j+1)*lda + k + 3] * c3;
                C[(j+1)*lda + i + 1] += sum;
                
                sum = A[(j+2)*lda + k] * d0;
                sum += A[(j+2)*lda + k + 1] * d1;
                sum += A[(j+2)*lda + k + 2] * d2;
                sum += A[(j+2)*lda + k + 3] * d3;
                C[(j+2)*lda +i] += sum;
                
                sum = A[(j+2)*lda + k] * c0;
                sum += A[(j+2)*lda + k + 1] * c1;
                sum += A[(j+2)*lda + k + 2] * c2;
                sum += A[(j+2)*lda + k + 3] * c3;
                C[(j+2)*lda + i + 1] += sum;
                
                sum = A[(j+3)*lda + k] * d0;
                sum += A[(j+3)*lda + k + 1] * d1;
                sum += A[(j+3)*lda + k + 2] * d2;
                sum += A[(j+3)*lda + k + 3] * d3;
                C[(j+3)*lda +i] += sum;
                
                sum = A[(j+3)*lda + k] * c0;
                sum += A[(j+3)*lda + k + 1] * c1;
                sum += A[(j+3)*lda + k + 2] * c2;
                sum += A[(j+3)*lda + k + 3] * c3;
                C[(j+3)*lda + i + 1] += sum;
                
            }
            barrier();
        }
    }
}

//--------------------------------------------------------------------------
// Main
//
// all threads start executing thread_entry(). Use their "coreid" to
// differentiate between threads (each thread is running on a separate core).

void thread_entry(int cid, int nc)
{
    coreid = cid;
    ncores = nc;
    
    // static allocates data in the binary, which is visible to both threads
    static data_t results_data[ARRAY_SIZE];
    
    
//    // Execute the provided, naive matmul
//    barrier();
//    stats(matmul_naive(DIM_SIZE, input1_data, input2_data, results_data); barrier());
//    
//    
//    // verify
//    verify(ARRAY_SIZE, results_data, verify_data);
//    
//    // clear results from the first trial
//    size_t i;
//    if (coreid == 0) 
//        for (i=0; i < ARRAY_SIZE; i++)
//            results_data[i] = 0;
//    barrier();
    
    
    // Execute your faster matmul
    barrier();
    stats(matmul(DIM_SIZE, input1_data, input2_data, results_data); barrier());
    
#ifdef DEBUG
    printArray("results:", ARRAY_SIZE, results_data);
    printArray("verify :", ARRAY_SIZE, verify_data);
#endif
    
    // verify
    verify(ARRAY_SIZE, results_data, verify_data);
    barrier();
    
    exit(0);
}