計算時間を計測するmodule

たまにはソースを．完全に以下のサイトのパクリですが．
http://www.nag-j.co.jp/fortran/tips/tips_PortableWayToTime.html

    MODULE RecordTime
        IMPLICIT NONE
        INTEGER(4), PRIVATE :: t1, t2, t_rate, t_max, diff
        REAL(8), PRIVATE :: cput1, cput2
        PUBLIC RecordTime_Start, RecordTime_End
    CONTAINS
        SUBROUTINE RecordTime_Start
            CALL system_clock(t1)
            CALL cpu_time(cput1)
        END SUBROUTINE RecordTime_Start

        SUBROUTINE RecordTime_End
            CALL system_clock(t2, t_rate, t_max)
            IF ( t2 < t1 ) THEN
                diff = (t_max - t1) + t2 + 1
            ELSE
                diff = t2 - t1
            END IF
            CALL cpu_time(cput2)
            OPEN(20,FILE="Cal_Time.txt",STATUS='REPLACE')
            WRITE(20, "(A, F10.3)"), "time it took was(sec):", diff/DBLE(t_rate)
            WRITE(20, "(A, F10.3)"), "cpu time(sec):", cput2-cput1
            CLOSE(20)
        END SUBROUTINE RecordTime_End
    END MODULE RecordTime

計算開始時に

CALL RecordTime_Start

終了時に

CALL RecordTime_End

で

OKです．

書いていて思いましたが，もうちょっと複雑なもので，
MODULE文，INTERFACE文の総称，CONTAINS文を使えば，
FORTRANでもカプセル化とかポリモーフィズムが書けますね．