From:	"Bart Alewijnse" <scarfman AT geocities DOT com>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Screen copy
Date:	20 Jun 1999 18:08:09 GMT
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To:	djgpp AT delorie DOT com
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I've been experimenting, but don't quite know all the possibilities yet:
How do you copy a double buffer to the screen the fastest? I'm currently
using mode 13h, i.e. dos memory @ 0xA0000, but am interested in LFB's
as well.. I suppose a simple rep stosl , which should be (I read this, 
correct me if I'm wrong) inlined when a memcpy has a constant 
(when this is determinable at compile time) for its 'amount to move' 
value (in ecx, but anyways)
I :can: use this for dos as well when I use  __djgpp_nearptr_enable()
and  __djgpp_nearptr_disable(), and that works, but it's three promilles
faster than dosmemput(), and I don't like never having any memory
protection... _farnspokel() is a bit iffy as well, at least I think...

Are there any other ways to do this? What's a fast one/the fastest?
I suppose that for the LFB it'd just be memcpy, 'cos djgpp (i think)
has its own align-optimized (move alignes stuff, stick on bytes and
words as necessary) rep-movsl that it inlines it as. Right?

(Am I completely babbling and/or clueless?:)

-Bart

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