C****************************************************************************

C     

C     fmatrixpapi.f

C     An example of matrix-matrix multiplication and using PAPI high level to 

C     look at the performance. written by Kevin London

C     March 2000

C****************************************************************************

#include "fpapi_test.h"

      program fmatrixpapi

      IMPLICIT integer (p)

      INTEGER ncols1,nrows1,ncols2,nrows2

      PARAMETER(nrows1=175,ncols1=225,nrows2=ncols1,ncols2=150)

      INTEGER i,j,k,num_events,retval

C     PAPI standardized event to be monitored

      INTEGER event(2)

C     PAPI values of the counters

      INTEGER*8 values(2)

      REAL*8 p(nrows1,ncols1),q(nrows2,ncols2),

     &     r(nrows1,ncols2),tmp

      integer tests_quiet, get_quiet

      external get_quiet

      tests_quiet = get_quiet()

C     Setup default values

      num_events=0

C     Open matrix file number 1 for reading

C     OPEN(UNIT=1,FILE='fmt1',STATUS='OLD')

C     Open matrix file number 2 for reading

C     OPEN(UNIT=2,FILE='fmt2',STATUS='OLD')

C     See how many hardware events at one time are supported

C     This also initializes the PAPI library

      call PAPIf_num_counters( num_events )

      if ( num_events .LT. 2 ) then

        print *,'This example program requries the architecture to ',

     .       'support 2 simultaneous hardware events...shutting down.'

        call ftest_skip(__FILE__, __LINE__,

     *       'too few counters', num_events)

      end if

      if (tests_quiet .EQ. 0) then

        print *, 'Number of hardware counters supported: ', num_events

      end if

      call PAPIf_query_event(PAPI_FP_INS, retval)

      if (retval .NE. PAPI_OK) then

        event(1) = PAPI_TOT_INS

      else

C     Total floating point operations

        event(1) = PAPI_FP_INS

      end if

C     Time used

      event(2) = PAPI_TOT_CYC

C     matrix 1: read in the matrix values

      do i=1, nrows1

        do j=1,ncols1

          p(i,j) = i*j*1.0

        end do

      end do

C     matrix 2: read in the matrix values

      do i=1, nrows2

        do j=1,ncols2

          q(i,j) = i*j*1.0

        end do

      end do

C     Initialize the result matrix 

      do i=1,nrows1

        do j=1, ncols2

          r(i,j) = i*j*1.0

        end do

      end do

C     Set up the counters

      num_events = 2

      call PAPIf_start_counters( event, num_events, retval)

      if ( retval .NE. PAPI_OK ) then

        call ftest_fail(__FILE__, __LINE__, 

     *       'PAPIf_start_counters', retval)

      end if

C     Clear the counter values

      call PAPIf_read_counters(values, num_events,retval)

      if ( retval .NE. PAPI_OK ) then

        call ftest_fail(__FILE__, __LINE__, 

     *       'PAPIf_read_counters', retval)

      end if

C     Compute the matrix-matrix multiplication

      do i=1,nrows1

        do j=1,ncols2

          do k=1,ncols1

            r(i,j)=r(i,j) + p(i,k)*q(k,j)

          end do

        end do

      end do

C     Stop the counters and put the results in the array values 

      call PAPIf_stop_counters(values,num_events,retval)

      if ( retval .NE. PAPI_OK ) then

        call ftest_fail(__FILE__, __LINE__, 

     *       'PAPIf_stop_counters', retval)

      end if

C     Make sure the compiler does not optimize away the multiplication

      call dummy(r)

      if (tests_quiet .EQ. 0) then

        if (event(1) .EQ. PAPI_TOT_INS) then

          print *, 'TOT Instructions:  ',values(1)

        else

          print *, 'FP Instructions:  ',values(1)

        end if

        print *, 'Cycles: ',values(2)

        if (event(1) .EQ. PAPI_FP_INS) then

          write(*,'(a,f9.6)') ' Efficiency (flops/cycles):',

     &         real(values(1))/real(values(2))

C     Compare measured FLOPS to expected value

          tmp=2.0*real(nrows1)*real(ncols2)*real(ncols1)

          if(abs(values(1)-tmp).gt.tmp*0.05)then

C     Maybe we are counting FMAs?

            tmp=tmp/2.0

            if(abs(values(1)-tmp).gt.tmp*0.05)then

              print *,'Expected operation count:',2.0*tmp

              print *,'Or possibly (using FMA): ',tmp

              print *,'Instead I got:           ',values(1)

              call ftest_fail(__FILE__, __LINE__, 

     *             'Unexpected FLOP count (check vector operations)', 1)

            end if

          end if

        end if

      end if

      call ftests_pass(__FILE__)

      end