[Coco] Assembler Question???
uhmgawa
uhmgawa at third-harmonic.com
Wed Sep 2 17:52:12 EDT 2009
jdaggett at gate.net wrote:
>> I don't believe that is the case as a subtract
>> operation sets the carry to the inverse of that
>> resulting from an add operation. So in this
>> respect subtraction of x and addition of -x
>> aren't trivially interchangeable.
:
> Yes with subtraction you treat the carry differently. I understand that. What I needed to
> know was when the subtrahend is converted to 2's compliment, at assembly or internally
> in the ALU. I now know that it is internal and all is well.
My point rather was given the disposition of the
carry bit after a subtract operation being
opposite from that of an addition, the data is
being interpreted as unsigned in both operations.
--
uhmgawa at third-harmonic.com
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