VMS Help FORTRAN, Error Messages, Vectorization Errors  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  The following errors identify when vectorization was inhibited and
  attempt to identify why it was inhibited.  These messages are
  generated if the /VECTOR/SHOW=DATA_DEPENDENCES/DIAGNOSTICS
  qualifiers are specified.  These errors are only generated to the
  diagnostic file, not to the listing file or terminal.

  Unknown dependence using xxxx
    The compiler has analyzed the dependences between array
    references and is unable to determine the order in which the
    references must occur.  Many times this is caused by not knowing
    the range of values possible for an expression used as part of
    the array index.

  Nonuniform dependence
    The compiler has detected that the relative order of references
    to common memory locations, for two array references in the loop,
    are not uniform for all such locations.  For example:

       A(I) = B(I) * A(N-I)

    Some locations are accessed first by A(I) and others by A(N-I).

  Outer level vectorization inhibited
    The compiler has analyzed the dependences between array
    references at different DO-loop levels and is unable to determine
    the order in which the references must occur.

  These errors relate to assertion declarations.  See Section 6.2.1
  in your performance guide for information on how to handle these
  errors.

  Within LSE, you can use Review Mode to apply suggested assertions
  to handle these errors.  To do so, move the cursor to the
  suggestion that you wish to use and press Ctrl/G.  This instructs
  LSE to apply the suggestion to the source file.  LSE then prompts
  for a confirmation that this change is desirable.  If it is, answer
  YES and the suggestion will be inserted.