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Analysis of Distribution Directives

The first phase semantically analyzes all Fortran 90D/HPF directives and stores the resulting information on decomposition, distribution, alignment, and processor arrangements in the array descriptor portion of the symbol table. This information is used throughout compilation. For variables that are not explicitly mapped (and compiler-created temporaries), the compiler chooses a default distribution and alignment. Figure shows a typical sequence of Fortran 90D/HPF directives used to align and distribute arrays. The compiler identifies alignment chains and determines that no PROCESSORS directive is present. In the absence of a PROCESSORS directive, the compiler generates code to dynamically determine the number of available processors and uses a default one-dimensional processor arrangement.

The compiler stores the distribution information as in Figure . It creates a default template for array and collapses all alignments to into alignments to . is distributed by default onto , the default processor arrangement.


zbozkus@
Thu Jul 6 21:09:19 EDT 1995