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Mail Archives: djgpp/1995/08/10/01:50:43

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From: empty AT sans DOT vuw DOT ac DOT nz (Malcolm Taylor)
Newsgroups: comp.os.msdos.djgpp
Subject: Re: CLI asm instruction
Date: 8 Aug 1995 22:35:17 GMT
Organization: SANS, Student Access Network System
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References: <DCyttJ DOT A0L AT jade DOT mv DOT net> <30275d24 DOT sandmann AT clio DOT rice DOT edu>
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To: djgpp AT sun DOT soe DOT clarkson DOT edu
Dj-Gateway: from newsgroup comp.os.msdos.djgpp

Charles Sandmann (sandmann AT clio DOT rice DOT edu) wrote:
: > buffer gets trashed.  So, I execute a PUSHF; CLI at the beginning of 
: > the loop to turn off interrupts and a POPF at the end of the loop to 

: Okay, this is a BAD THING.  Read the DPMI spec.  It clearly says that
: CLI should be assumed to be very slow.  Problem two: PUSHF is not
: guaranteed to push the virtualized interrupt flag, and POPF may not
: restore it.  Aren't you glad Intel and MS gave us such brain damage?

If CLI is so slow then how are interrupts disabled inside interrupt 
routines normally? Or do they just take the performance hit.

Malcolm

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