PM Programming Language

When a program is running over multiple processors or processing cores then it is important to be able to map where data are flowing. One way in which data flows can be translated into programming language semantics is though argument passing to subroutines. In the absence of global variables, data transfer to and from a subroutine straightforwardly can be directly related to communication to and from another processor. In PM, the emphasis is on data parallelism through the for statement. for index in array do index=process(index) endfor      So what are the rules governing data flow into and out of this statement? These are primarily based around variable locality. x:= 1 for index in array do y:=func(index) index=process(x,y) endfor Here x is relatively global to the for statement and y is local to it (a variables scope only extends to the end of the statement block in which it is defined).  There are two ways t...