From:	"PETER NORDLANDER" <peter DOT nordlander AT mbox301 DOT swipnet DOT se>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Inline assembly question
Date:	12 Dec 1997 16:07:27 GMT
Organization:	-
Lines:	26
Message-ID:	<01bd0717$ffc6c1e0$3ca1f482@default>
NNTP-Posting-Host:	dialup161-1-60.swipnet.se
NNTP-Posting-User:	s-323400
To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp

I've been coding in DJGPP for quite a while now. I've written all my GFX
functions, like put_pixel etc in inline assembly. The qestion is now,
please look at the fraction of code
provided in this message, is it a fast way to plot a pixel or could I
optimize it more by
using __djgpp_nearptr_enable and then use direct acces to videomem.
(SCREEN[offset]=col). 

put_pixel (int x,int y,unsigned char col)
{
asm ("
movw _dos_page,%%es			(dos_page is preloaded with _dos_ds)
movl $0xa0000,%%edi
addl %%ebx,%%edi
stosb
:
:"a"(col),"b"((y<<8)+(y<<6)+x)
:"%eax,"%ebx",%edi"
}

It this way of plotting a pixel the same as the farpokeb (...) version??

Thanks in advance
/Peter Nordlander

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