Basic HTML version of Foils prepared 17 Sept 1996

Foil 20 Fortran77 is part of Fortran90

From New CPS615HPF and Fortran90 Discussion Sept 17 96 Basic Simulation Track for Computational Science CPS615 -- Fall Semester 96. by Geoffrey C. Fox, Tom Haupt
A=B or more interestingly
WHERE( B > 0. ) A = B
ELSEWHERE A=0.
END WHERE
can be written
DO I = n1,n2
DO J = m1,m2
IF(B(I,J) >0.) THEN A(I,J) = B(I,J)
ELSE A(i,J) = 0.
END IF
END DO
END DO
Now a good HPF compiler will recognize the DO loops can be parallelized and give the same answer for Fortran90 and Fortran77 forms but often the detection of parallelism is not clear
Note FORALL is guaranteed to be parallelizeable as by definition no side effects.

© on Tue Oct 7 1997