>Yes. To prevent that, I went one step further and wrote a simple
>preprocessor (a Perl script, see below) that allows me to "declare"
>the banked symbols. Whenever an instruction makes a reference to
>such a symbol, this preprocessor inserts Olin's macro call ahead of it.
>
>Even this isn't foolproof -- for example, if you reference one of
>those symbols immediately after a skip instruction and the macro
>inserts something there.

The problem that I have had is as follows: -

        ; unknown banked state
        dbankif bank_x_register
        ; operations using bank_x_registers

label:
        dbankif bank_x_register
        ; more operations using bank_x_registers
        dbankif bank_y_register
        ; operations using bank_y_registers
        bne    label
        ; more operations

The problem arises because the dbankif immediately after the label generates
no code because bank_x is already selected using the macro before the label.
the next dbankif then changes the bank selected, some operations happen,
then branch back to the label. The easiest fix I found was to change the
dbankif after the label to a dbank so the macro inserted code irrespective
of the previous bank.

-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist