> On Tue, Oct 4, 2016 at 4:00 AM, <[email protected]> wrote: > > > > We could still get rid of the tagged pointer type. After some more > > > > > > > thought on the matter, I believe they're mostly worthless. > > > > "They" means tagged pointers? I agree. > > > > I continue to disagree. Tagged pointers make it possible to have > dynamically type-safe or type-dispatched treatment of C objects referred to > by the pointer side. Logically it is equivalent to encapsulate the raw > pointer in a record, but record dereference is much slower than pointer > dereference for whatever reason, so it adds substantial overhead.
"Substantial" may be a bit strong, though the overhead is indeed there. AFAIK, tagged pointers are seldom used. If indeed they were used instead of raw pointers everywhere in the FFI (say, by generally tagging each pointer of a known type), then the situation would be different, of course. I don't feel strong enough to assess this. Any takers? felix _______________________________________________ Chicken-hackers mailing list [email protected] https://lists.nongnu.org/mailman/listinfo/chicken-hackers
