PAPI3:PAPI flops.3
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Contents

NAME

  • PAPI_flips - PAPI High Level: Simplified call to get Mflips/s, real and processor time
  • PAPI_flops - PAPI High Level: Simplified call to get Mflops/s, real and processor time

Synopsis

C Interface

#include <papi.h>
int PAPI_flips( float * rtime, float * ptime, long_long * flpins, float * mflips );
int PAPI_flops( float * rtime, float * ptime, long_long * flpops, float * mflops );

Fortran Interface

#include "fpapi.h"
PAPIF_flips( C_FLOAT  real_time,  C_FLOAT  proc_time,  C_LONG_LONG  flpins,  C_FLOAT  mflips,  C_INT  check )
PAPIF_flops( C_FLOAT  real_time,  C_FLOAT  proc_time,  C_LONG_LONG  flpops,  C_FLOAT  mflops,  C_INT  check )

Description

The first call to PAPI_flips() or PAPI_flops() will initialize the PAPI High Level interface, set up the counters to monitor PAPI_FP_INS or PAPI_FP_OPS and PAPI_TOT_CYC events and start the counters. Subsequent calls will read the counters and return total real time, total process time, total floating point instructions or operations since the start of the measurement and the Mflip/s or Mflop/s rate since latest call to PAPI_flips() or PAPI_flops(). A call to PAPI_stop_counters() will stop the counters from running and then calls such as PAPI_start_counters() can safely be used.

Arguments

*rtime -- total realtime since the first PAPI_flops() call

*ptime -- total process time since the first PAPI_flops() call

*flpins, flpops -- total floating point instructions or operations since the first call

*mflips, *mflops -- Mflip/s or Mflop/s achieved since the previous call

Errors

In addition to the possible errors returned by the various PAPI low level calls, the following errors could also be returned:

PAPI_EINVAL The counters were already started by something other than: PAPI_flips() or PAPI_flops().

PAPI_ENOEVNT The floating point operations, floating point instructions or total cycles event does not exist.

PAPI_ENOMEM Insufficient memory to complete the operation.

Bugs

These functions have no known bugs.

NOTES

Mflip/s, or millions of floating point instructions per second, is defined in this context as the number of instructions issued to the floating point unit per second. It is usually calculated directly from a counter measurement and may be different from platform to platform. Mflop/s, or millions of floating point operations per second, is intended to represent the number of floating point arithmetic operations per second. Attempts are made to massage the counter values to produce the theoreticallly expected value by, for instance, doubling FMA counts or subtracting floating point loads and stores if necessary. CAVEAT EMPTOR


PAPI_flops() and PAPI_flips() may be called by:

  • the user application program

PAPI_flops() contains calls to:

  • PAPI_perror()
  • PAPI_library_init()
  • PAPI_get_hardware_info()
  • PAPI_create_eventset()
  • PAPI_add_event()
  • PAPI_start()
  • PAPI_get_real_usec()
  • PAPI_accum()
  • PAPI_shutdown()

See Also

PAPI_stop_counters(3), PAPI_ipc(3), PAPI_set_opt(3)