Advanced Scalarization of Array Syntax

One task of all Fortran 90 compilers is to scalarize the array syntax statements of a program into equivalent sequential code. Most compilers require multiple passes over the program source to ensure correctness of this translation, since their analysis algorithms only work on the scalarized form. These same compilers then make additional subsequent passes to perform loop optimizations such as loop fusion. In this paper we discuss a strategy that is capable of making advanced scalarization and fusion decisions at the array level. We present an analysis strategy that supports our advanced scalarizer, and we describe the benefits of this methodology compared to the standard practice. Experimental results show that our strategy can significantly improve the runtime performance of compiled code, while at the same time improving the performance of the compiler itself.