Scalar Variables

Unless explicitly mapped, scalar variables are generally replicated, in other words, every processor has a copy of the variable.

These copies must be kept up-to date (by the compiler). Consider,

     REAL, DIMENSION(100,100) :: X
     REAL                     :: Scal
!HPF$ DISTRIBUTE (BLOCK,BLOCK) :: X
       ....
      Scal = X(i,j)
       ....

The processor that owns X(i,j) updates its copy of Scal and then broadcasts its new value to all other processors.

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