Alias verification for Fortran code optimization

Abstract: Alias analysis for Fortran is less complicated than for programming languages with pointers but many real Fortran programs violate the standard: a formal parameter or a common variable that is aliased with another formal parameter is modified. Compilers, assuming standard-conforming programs, consider that an assignment to one variable will not change the value of any other variable, allowing optimizations involving the aliased variables. Higher performance results but anything may happen: the program may appear to run normally, or produce incorrect answers, or behave unpredictably. The results may depend on the compiler and the optimization level. To guarantee the standard conformance of programs in order to make program analyses exact and program optimizations safe, precise alias information, i.e the determination of overlaps among arrays is studied in this paper. Static analyses and code instrumentation are used to find all violations of the aliasing rules in Fortran code....

• Type: Journal
• Year: 2002
• Where: ENTCS
• Authors: Thi Viet Nga Nguyen, François Irigoin
• Keywords: Alias Analysis, ENTCS 2002, Formal Parameter, Programming Languages