Mail Archives: djgpp/1998/05/13/05:00:29
On Tue, 12 May 1998, Nate Eldredge wrote:
> the I/O instructions are not particularly slow either.
Actually, the I/O instructions *are* slow: they can take as much as 28
cycles (at least on a 486) in protected mode, depending on the CPL vs
IOPL numbers.
Of course, issuing a real-mode interrupt is much more expensive.
> That said, the only true answer is to benchmark both methods and see. :)
Hear, hear. Far too many people are optimizing in the wrong place
because they *think* they know what's faster.
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