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4.4 Data Mapping in MasPar Fortran

It is important to note that in MasPar Fortran, 2-dimensional arrays are mapped, by default, onto the PE grid such that the column of the array is mapped to the row of the grid.

So a 3x2 array A would be mapped to a 4x4 grid as follows:

Cut-and-stack mapping, which is also called canonical mapping, is the default in MasPar Fortran. Consider a 3x6 array B on a 4x4 grid. The default mapping would be

Arrays with more than two dimensions are mapped to the PE grid using the cut-and-stack method for the first two dimensions; subarrays for additional dimensions are stored within a single PE's memory. A 3x2x2 array A would, for example, be stored on a 4x4 PE grid as follows:

Note that A(x,y,1) and A(x,y,2) are stored on the same PE.