Separate HTML for Basic Foil 56 WHERE (masked array assignment) in HPF

Basic HTML version of Foils prepared 17 Sept 1996

Foil 56 WHERE (masked array assignment) in HPF

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

This is as in CMFortran and Maspar MPFortran with example:

WHERE (A .GT. 0) A = A - 100

Semantics of WHERE statement:

1. evaluate mask (in parallel) and store as a temporary T1
2. for each i that T1(i)=.TRUE. compute T2(i)=A(i) - 100
3. for each i that T1(i)=.TRUE. assign A(i)=T2(1)