Next: , Previous: COUNT, Up: Intrinsic Procedures


9.70 CPU_TIME — CPU elapsed time in seconds

Description:
Returns a REAL value representing the elapsed CPU time in seconds. This is useful for testing segments of code to determine execution time.

If a time source is available, time will be reported with microsecond resolution. If no time source is available, TIME is set to -1.0.

Note that TIME may contain a, system dependent, arbitrary offset and may not start with 0.0. For CPU_TIME, the absolute value is meaningless, only differences between subsequent calls to this subroutine, as shown in the example below, should be used.

Standard:
Fortran 95 and later
Class:
Subroutine
Syntax:
CALL CPU_TIME(TIME)
Arguments:

TIME The type shall be REAL with INTENT(OUT).

Return value:
None
Example:
          program test_cpu_time
              real :: start, finish
              call cpu_time(start)
                  ! put code to test here
              call cpu_time(finish)
              print '("Time = ",f6.3," seconds.")',finish-start
          end program test_cpu_time

See also:
SYSTEM_CLOCK, DATE_AND_TIME