[Coco] lwtools assembler difference

Dave Philipsen dave at davebiz.com
Wed Sep 2 03:14:01 EDT 2015


Just out of curiosity, does EDTASM do anything differently with this?

         org    $0000
Symbol  rmb    1

         ldb    Symbol,x

To me, the most logical way to handle that would be to assume that you 
want the machine code optimized for zero offset indexed addressing 
instead of the 5-bit.  I can see how a program in a very rare case might 
want to force the 5-bit offset for timing issues but most likely the 
desired outcome of the example above would be for the assembler to 
automatically translate it to ldb  ,x.  The idea of forcing it to the 
5-bit offset when the programmer uses ldb  0,x is probably a good one as 
most programmers would not code it that way unless there was a good reason.

Dave Philipsen

> EDTASM will give you the following results:
>
>  ldb ,x
> get
>  $E6 $84
>
>  ldb 0,x
> get
>  $E6 $00
>
> Robert
>
>


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