🚀 go-pugleaf

Robert AH Prins kirjoitti viestiss� <7naolk$5j$1@nnrp1.deja.com>...
>To avoid having to load pointers over and over again, the program
uses a
>GETMEM'ed array, I use BASM, and this works without a glitch,
until...
>I had to change the size of the elements from 8 to 16 and didn't
realize
>that I also needed to change a "shl  cx, 3" into "shl  cx, 4". I
spend
>ages trying to find out what was wrong - the equivalent code in
Pascal
>continued to work, be it rather more slowly.
>
>Does anyone know, short of what I've done now, adding a constant with
>the required shift value, if there is a way to get the base-2 log of
>sizes of datastructures in BASM. (Obviously restricted to sizes that
are
>powers of 2...)

I don't understand perfectly your question, I figure that you haven't
written the assembler code for yourself.

Anyhow, it seems that the instruction is part of the code that
calculates the memory address offset out of the array index.  It
simply multiplied the index by 8 and now by 16.  If the element size
had not been a power of two, the code would have been a little more
complex.


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Raimo Suonio
raimo.suonio@qdlc.fi (remove spam preventing q)