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8.79 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 — Time function, DATE_AND_TIME — Date and time subroutine