papi_br_ins.c

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/* This file attempts to test the retired branches instruction  */
/* performance counter PAPI_BR_INS              */

/* by Vince Weaver, <vincent.weaver@maine.edu>          */

/* This test seems to work on:      */
/* + x86                */
/* + ARMv6 (Raspberry Pi)       */
/* It is known to not work on:      */
/* + ARMv7 (Pi2 CortexA7 Panda CortexA9 */
/*   failure is odd, 1/3 missing but not consistent */
/*   something weird with event 0xC PC_WRITE ?      */


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

#include "papi.h"
#include "papi_test.h"

#include "display_error.h"
#include "testcode.h"


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

    int num_runs=100,i;
    long long high=0,low=0,average=0,expected=1500000;
    double error;

    long long count,total=0;
    int quiet=0,retval,ins_result;
    int eventset=PAPI_NULL;

    quiet=tests_quiet(argc,argv);

    if (!quiet) {
        printf("\nTesting the PAPI_BR_INS event.\n");
    }

    /* Init the PAPI library */
    retval = PAPI_library_init( PAPI_VER_CURRENT );
    if ( retval != PAPI_VER_CURRENT ) {
        test_fail( __FILE__, __LINE__, "PAPI_library_init", retval );
    }

    retval=PAPI_create_eventset(&eventset);
    if (retval!=PAPI_OK) {
        test_fail( __FILE__, __LINE__, "PAPI_create_eventset", retval );
    }

    retval=PAPI_add_named_event(eventset,"PAPI_BR_INS");
    if (retval!=PAPI_OK) {
        test_skip( __FILE__, __LINE__, "adding PAPI_BR_INS", retval );
    }

    if (!quiet) {
        printf("Testing a loop with %lld branches (%d times):\n",
            expected,num_runs);
    }

    for(i=0;i<num_runs;i++) {
        PAPI_reset(eventset);
        PAPI_start(eventset);

        ins_result=branches_testcode();

        retval=PAPI_stop(eventset,&count);

        if (ins_result==CODE_UNIMPLEMENTED) {
            fprintf(stderr,"\tCode unimplemented\n");
            test_skip( __FILE__, __LINE__, "unimplemented", 0);
        }

        if (retval!=PAPI_OK) {
            test_fail( __FILE__, __LINE__,
                "reading PAPI_TOT_INS", retval );
        }

        if (count>high) high=count;
        if ((low==0) || (count<low)) low=count;
        total+=count;
    }

    average=(total/num_runs);

    error=display_error(average,high,low,expected,quiet);

    if ((error > 1.0) || (error<-1.0)) {
        if (!quiet) printf("Instruction count off by more than 1%%\n");
        test_fail( __FILE__, __LINE__, "Error too high", 1 );
    }

    if (!quiet) printf("\n");

    test_pass( __FILE__ );

    PAPI_shutdown();

    return 0;
}