Description Jeffrey Overbey 2010-06-24 12:22:50 EDT

In Unroll Loop and Align/Fuse Loops, Ashley needs to replace uses of a loop's index variable with expressions.  E.g.,

DO I = 1,4
    PRINT *, I
END DO

unrolls to

DO I = 1,4,2
    PRINT *, I
    PRINT *, I+1    ! Use of I replaced with I+1
END DO

Replacing the variable with an expression is not legal (and thus the refactoring should fail) when
(1) the variable is passed by reference to a subprogram
(2) the variable is assigned via a READ or WRITE statement
(any others?)

Also it should not be replaced when it is used as the index variable in an implied DO loop, although the implied-DO index variable has its own scope, so the refactoring should still succeed.

This information will be available after we have du-chains available.