Xref: utzoo comp.lang.c:34618 comp.lang.fortran:4354 Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!samsung!think.com!snorkelwacker.mit.edu!ai-lab!life!tmb From: tmb@bambleweenie57.ai.mit.edu (Thomas M. Breuel) Newsgroups: comp.lang.c,comp.lang.fortran Subject: alternatives to "noalias"? Message-ID: Date: 10 Dec 90 08:58:36 GMT References: <221@validgh.com> <1990Dec9.003028.13424@zoo.toronto.edu> Sender: news@ai.mit.edu Organization: MIT Artificial Intelligence Lab Lines: 12 In-reply-to: henry@zoo.toronto.edu's message of 9 Dec 90 00:30:28 GMT Many optimizations that are possible because the compiler can assume that two different names don't refer to the same location can be expressed portably introducing explicit temporaries. Vectorization and parallelization requires a declaration (or separate looping construct) that states to the compiler that there are no (or "harmless") sequential dependencies in a loop body. What I would like to ask: ignoring programming style, can you think of any optimizations that a FORTRAN compiler can carry out that cannot be expressed portably using temporaries and one or two compiler directives declaring absence of sequential dependencies in a loop body?