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/GNU Fortran 7

9.79 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, DATE_AND_TIME

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Licensed under the GNU Free Documentation License, Version 1.3.
https://gcc.gnu.org/onlinedocs/gcc-7.1.0/gfortran/CPU_005fTIME.html