matrix-hl.c

Go to the documentation of this file.

/****************************************************************************
 *C     
 *C     matrix-hl.f
 *C     An example of matrix-matrix multiplication and using PAPI high level
 *C     to look at the performance. written by Kevin London
 *C     March 2000
 *C     Added to c tests to check stop
 *C****************************************************************************
 */
#include "papi_test.h"
#include <stdlib.h>

int
main( int argc, char **argv )
{

#define NROWS1 175
#define NCOLS1 225
#define NROWS2 NCOLS1
#define NCOLS2 150
    double p[NROWS1][NCOLS1], q[NROWS2][NCOLS2], r[NROWS1][NCOLS2];
    int i, j, k, num_events, retval;
    /*     PAPI standardized event to be monitored */
    int event[2];
    /*     PAPI values of the counters */
    long long values[2], tmp;
    extern int TESTS_QUIET;

    tests_quiet( argc, argv );

    /*     Setup default values */
    num_events = 0;

    /*     See how many hardware events at one time are supported
     *     This also initializes the PAPI library */
    num_events = PAPI_num_counters(  );
    if ( num_events < 2 ) {
        printf( "This example program requries the architecture to "
                "support 2 simultaneous hardware events...shutting down.\n" );
        test_skip( __FILE__, __LINE__, "PAPI_num_counters", 1 );
    }

    if ( !TESTS_QUIET )
        printf( "Number of hardware counters supported: %d\n", num_events );

    if ( PAPI_query_event( PAPI_FP_OPS ) == PAPI_OK )
        event[0] = PAPI_FP_OPS;
    else if ( PAPI_query_event( PAPI_FP_INS ) == PAPI_OK )
        event[0] = PAPI_FP_INS;
    else
        event[0] = PAPI_TOT_INS;

    /*     Time used */
    event[1] = PAPI_TOT_CYC;

    /*     matrix 1: read in the matrix values */
    for ( i = 0; i < NROWS1; i++ )
        for ( j = 0; j < NCOLS1; j++ )
            p[i][j] = i * j * 1.0;

    for ( i = 0; i < NROWS2; i++ )
        for ( j = 0; j < NCOLS2; j++ )
            q[i][j] = i * j * 1.0;

    for ( i = 0; i < NROWS1; i++ )
        for ( j = 0; j < NCOLS2; j++ )
            r[i][j] = i * j * 1.0;

    /*     Set up the counters */
    num_events = 2;
    retval = PAPI_start_counters( event, num_events );
    if ( retval != PAPI_OK )
        test_fail( __FILE__, __LINE__, "PAPI_start_counters", retval );

    /*     Clear the counter values */
    retval = PAPI_read_counters( values, num_events );
    if ( retval != PAPI_OK )
        test_fail( __FILE__, __LINE__, "PAPI_read_counters", retval );

    /*     Compute the matrix-matrix multiplication  */
    for ( i = 0; i < NROWS1; i++ )
        for ( j = 0; j < NCOLS2; j++ )
            for ( k = 0; k < NCOLS1; k++ )
                r[i][j] = r[i][j] + p[i][k] * q[k][j];

    /*     Stop the counters and put the results in the array values  */
    retval = PAPI_stop_counters( values, num_events );
    if ( retval != PAPI_OK )
        test_fail( __FILE__, __LINE__, "PAPI_stop_counters", retval );

    /*  Make sure the compiler does not optimize away the multiplication
     *  with dummy(r);
     */
    dummy( r );

    if ( !TESTS_QUIET ) {
        if ( event[0] == PAPI_TOT_INS ) {
            printf( TAB1, "TOT Instructions:", values[0] );
        } else {
            printf( TAB1, "FP Instructions:", values[0] );
        }
        printf( TAB1, "Cycles:", values[1] );
    }

    /*  
     *  Intel Core overreports flops by 50% when using -O
     *  Use -O2 or -O3 to produce the expected # of flops
     */

    if ( event[0] == PAPI_FP_INS ) {
        /*     Compare measured FLOPS to expected value */
        tmp =
            2 * ( long long ) ( NROWS1 ) * ( long long ) ( NCOLS2 ) *
            ( long long ) ( NCOLS1 );
        if ( abs( ( int ) values[0] - ( int ) tmp ) > ( double ) tmp * 0.05 ) {
            /*     Maybe we are counting FMAs? */
            tmp = tmp / 2;
            if ( abs( ( int ) values[0] - ( int ) tmp ) >
                 ( double ) tmp * 0.05 ) {
                printf( "\n" TAB1, "Expected operation count: ", 2 * tmp );
                printf( TAB1, "Or possibly (using FMA):  ", tmp );
                printf( TAB1, "Instead I got:            ", values[0] );
                test_fail( __FILE__, __LINE__,
                           "Unexpected FLOP count (check vector operations)",
                           1 );
            }
        }
    }
    test_pass( __FILE__, 0, 0 );
    return ( PAPI_EMISC );
}