[Openmcl-devel] is (pref *display* ...) supposed to work?
gb at clozure.com
Wed Dec 17 11:42:40 PST 2003
On Wed, 17 Dec 2003, Timothy MOORE wrote:
> A quick question: the offset to %get-signed-long and friends is in
> bytes; how about the array length in (make-record (:array int 42))?
The MAKE-RECORD will ultimately macroexpand into something like
(#_malloc 164) ; 164 = 42 * 4
The only places where bit offsets are used explicitly are when bitfields
are involved. (Field offsets are maintained as bit offsets internally
because that makes bitfields a lot easier to deal with.) The "(/ N 8)" -
where N is a constant and multiple of 8 - shouldn't cause any arithmetic
to happen at runtime; I don't remember whether there's a reason that
the arithmetic isn't done inside of PREF.
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