#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/times.h>
#include <unistd.h>
#include <mkl_types.h>

#ifndef MIN_M
#define MIN_M 1000
#endif

#ifndef MIN_N
#define MIN_N 1000
#endif

#ifndef MAX_M
#define MAX_M 10000
#endif

#ifndef MAX_N
#define MAX_N 10000
#endif

#ifndef INCX
#define INCX 1
#endif

#ifndef INCY
#define INCY 1
#endif

#ifndef ALPHA
#define ALPHA 1.5
#endif

#ifndef BETA
#define BETA 1.5
#endif

#ifndef T_MIN
#define T_MIN 1
#endif


double A[MAX_M*MAX_N];
double X[MAX_N*INCX];
double Y[MAX_M*INCY];
double Y1[MAX_M*INCY];
double Y2[MAX_M*INCY];
double Y3[MAX_M*INCY];
double Y4[MAX_M*INCY];
double Y5[MAX_M*INCY];

double
walltime()
{
   struct tms    ts;
   static double ClockTick=0.0;

   if (ClockTick==0.0) {
        ClockTick = 1.0 / ((double) sysconf(_SC_CLK_TCK));
   }
   return ((double) times(&ts)) * ClockTick;
}

void
initMatrix(long m, long n, double *A, long incRowA, long incColA)
{
    int i, j;
    for (j=0; j<n; ++j) {
        for (i=0; i<m; ++i) {
            A[i*incRowA+j*incColA] = ((double)rand() - RAND_MAX/2)*200/RAND_MAX;
        }
    }
}

void
copyMatrix(long m, long n,
           const double *A, long incRowA, long incColA,
           double *B, long incRowB, long incColB)
{
    int i, j;
    for (j=0; j<n; ++j) {
        for (i=0; i<m; ++i) {
            B[i*incRowB+j*incColB] = A[i*incRowA+j*incColA];
        }
    }
}

double
asumDiffMatrix(long m, long n,
               const double *A, long incRowA, long incColA,
               double *B, long incRowB, long incColB)
{
    int i, j;

    double asum = 0;

    for (j=0; j<n; ++j) {
        for (i=0; i<m; ++i) {
            asum += fabs(B[i*incRowB+j*incColB] - A[i*incRowA+j*incColA]);
        }
    }
    return asum;
}

//------------------------------------------------------------------------------

void
dgemv(const char *trans,
      const MKL_INT *m, const MKL_INT *n, const double *alpha,
      const double *A, const MKL_INT *ldA, const double *x,
      const MKL_INT *incX,
      const double *beta, double *y, const MKL_INT *incY);

void
dgemv_mkl(MKL_INT m, MKL_INT n,
          double alpha,
          const double *A, MKL_INT incRowA, MKL_INT incColA,
          const double *x, MKL_INT incX,
          double beta,
          double *y, MKL_INT incY)
{
    MKL_INT ldA   = (incRowA==1) ? incColA : incRowA;
    char    trans = (incRowA==1) ? 'N' : 'T';
    MKL_INT M     = (incRowA==1) ? m : n;
    MKL_INT N     = (incRowA==1) ? n : m;

    dgemv(&trans, &M, &N, &alpha, A, &ldA, x, &incX, &beta, y, &incY);
}

//------------------------------------------------------------------------------

void
dgemv_ulm(long m, long n,
          double alpha,
          const double *A, long incRowA, long incColA,
          const double *x, long incX,
          double beta,
          double *y, long incY)
{
    long i, j;

    if (beta!=1.0) {
        for (i=0; i<m; ++i) {
            y[i*incY] *= beta;
        }
    }
    if (incRowA > incColA) {
        for (i=0; i<m; ++i) {
            for (j=0; j<n; ++j) {
                y[i*incY] += alpha*A[i*incRowA+j*incColA]*x[j*incX];
            }
        }
    } else  {
        for (j=0; j<n; ++j) {
            for (i=0; i<m; ++i) {
                y[i*incY] += alpha*A[i*incRowA+j*incColA]*x[j*incX];
            }
        }
    }
}

//------------------------------------------------------------------------------

#ifndef COLMAJOR
//#define COLMAJOR 1
#define COLMAJOR 0
#endif

int
main()
{
    long runs, i, m, n, incRowA, incColA;
    double t0, t1, t2;
    double diff2;
    double alpha = ALPHA;
    double beta  = BETA;

    initMatrix(MAX_M, MAX_N, A, 1, MAX_M);
    initMatrix(MAX_N, 1, X, INCX, 1);
    initMatrix(MAX_M, 1, Y, INCY, 1);

    printf("# COLMAJOR    = %d\n", COLMAJOR);
    printf("# T_MIN       = %d\n", T_MIN);
    printf("#RUN    M     N  INCROW  INCCOL");
    printf("    GEMV_MKL    GEMV_ULM");
    printf("    GEMV_MKL    GEMV_ULM");
    printf("       DIFF2");
    printf("\n");
    printf("#                              ");
    printf("    (t in s)    (t in s)");
    printf("    (MFLOPS)    (MFLOPS)");
    printf("           ");
    printf("\n");

    for (i=0, m=MIN_M, n=MIN_N; m<=MAX_M && n<=MAX_N; ++i, m+=100, n+=100) {

        if (COLMAJOR) {
            incRowA = 1;
            incColA = m;
        } else {
            incRowA = n;
            incColA = 1;
        }

        t1   = 0;
        runs = 0;
        do {
            copyMatrix(MAX_M, 1, Y, INCY, 1, Y1, INCY, 1);
            t0 = walltime();
            dgemv_mkl(m, n, alpha,
                      A, incRowA, incColA,
                      X, INCX,
                      beta,
                      Y1, INCY);
            t1 += walltime() - t0;
            ++runs;
        } while (t1<T_MIN);
        t1 /= runs;

        t2   = 0;
        runs = 0;
        do {
            copyMatrix(MAX_M, 1, Y, INCY, 1, Y2, INCY, 1);
            t0 = walltime();
            dgemv_ulm(m, n, alpha,
                      A, incRowA, incColA,
                      X, INCX,
                      beta,
                      Y2, INCY);
            t2 += walltime() - t0;
            ++runs;
        } while (t2<T_MIN);
        t2 /= runs;
        diff2 = asumDiffMatrix(m, 1, Y1, INCY, 1, Y2, INCY, 1);

        printf("%3ld %5ld %5ld %7ld %7ld ", i, m, n, incRowA, incColA);
        printf("%11.4lf %11.4lf ", t1, t2);
        printf("%11.4lf ", 2*(m/1000.0)*(n/1000.0)/t1);
        printf("%11.4lf ", 2*(m/1000.0)*(n/1000.0)/t2);
        printf("%11.4lf ", diff2);
        printf("\n");
    }

    return 0;
}