oliveria@engin.umich.edu (ROQUE DONIZETE DE OLIVEIRA) (09/18/90)
How to correctly calculate cpu usage in fortran on the IBM RS/6000 ? I tried the following program ( h.f ) : C----------------------------------------------------------------------- REAL*8 T , T1 , T2 , X CALL TIME(T1) X = 1. DO 10 I=1,100000 X = X + 10. 10 CONTINUE WRITE(6,50) X 50 FORMAT('X=',D14.7) CALL TIME(T2) T=T2 -T1 WRITE(6,100) T 100 FORMAT('T=',D14.7) STOP END C----------------------------------------------------------------------- SUBROUTINE TIME(T) REAL*8 T I1 = MCLOCK( ) T = 60*I1 RETURN END C----------------------------------------------------------------------- xlf -o h.exe h.f ** main === End of Compilation 1 === ** time === End of Compilation 2 === 1501-510 Compilation successful for file h.f. xanadu% h.exe X= .1000001D+07 T= .4800000D+03 STOP xanadu% time h.exe X= .1000001D+07 T= .4200000D+03 STOP 1.8900u 1.1900s 0:00 91666% 0+0k 0+0io 0pf+0w As you can see the output T=480 seconds is wrong (it took about a second to run). It is probably a mistake in my sample program above. Can someone point it out to me ? I wished ETIME was available in this system. Thanks. Roque Oliveira oliveria@caen.engin.umich.edu