Update to Arguments for PAPIF_flops_rate, PAPIF_flips_rate, PAPIF_epc

[Treece-Burgess]

Pull Request Description

This PR updates the PAPI Fortran wrappers for: PAPIF_flops_rate, PAPIF_flips_rate, and PAPIF_epc. All three of the aforementioned functions had a first argument of int event. However, setting int event equal to events such as PAPI_FP_OPS for PAPIF_flops_rate, PAPI_FP_INS for PAPIF_flips_rate, and PAPI_TOT_INS for PAPIF_epc would result in an error being output, specifically -7. Which means the "Hardware event does not exist". This is not the correct behavior due to the events existing and the associated C low-level functions running correctly given the same input.

To fix this issue, int event was changed to int *EventCode for PAPIF_flops_rate, PAPIF_flips_rate, and PAPIF_epc. As well as *EventCode being passed to the C function calls within the wrappers.

Two other minor updates are:

• Updated documentation for PAPIF_flops_rate, PAPIF_flips_rate, and PAPIF_epc within the papi_fwrappers.c source file.
• Changed argument name from event to EventCode, the idea with this change is to keep the argument naming scheme similar to other PAPI functions such as PAPIF_event_code_to_name.

Example code for PAPIF_flops_rate with the changes mentioned above:

#include "fpapi.h"    
      program main
          use iso_c_binding
          integer(c_int) EventCode, check, retval
          real(c_float) real_time, proc_time, mflops, nfact
          integer(c_long_long) flpops

          EventCode = PAPI_FP_OPS

          retval = PAPI_VER_CURRENT
          call PAPIf_library_init(retval)
          if ( retval.NE.PAPI_VER_CURRENT) then
            write(*,*) retval
          end if

          call PAPIF_flops_rate(EventCode, real_time, proc_time,
     & flpops, mflops, check) 
          if ( check.NE.PAPI_OK) then
            write(*,*) check
          end if

          ! do some arbitrary work
          do n = 1, 10000
              nfact = (1.1 + 100)/n
          end do

          call PAPIF_flops_rate(EventCode, real_time, proc_time,
     & flpops, mflops, check) 
          if ( check.NE.PAPI_OK) then
              write(*,*) check
          end if

      end program main

Possible output is from running the above script on Guyot:

Real Time: 3.79999983E-05
Proc Time: 3.70000016E-05
Flpops: 10000
Mflops:  270.270264    
Error Check: 0

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