Re: SIMPLE assembly question...

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#6158

From: Stig Venaas
Date: Tue, 22 Dec 1992 09:47

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In article <rol-221292092834@90.222.1.80> rol@grasp1.univ-lyon1.fr (Paul Rolland) writes:
>In article <gn#@byu.edu>, $dougn@sasb.byu.edu (Douglas R. Nebeker -
>MIS_SAS) wrote:
>> 
>> is there ANY difference between  MOV ES,AX
>> 
>> and                              PUSH AX
>>                                  POP ES
>>  
>
>I think there are two major differences between the two forms :
>   - Execution time (only important if your program is time critical, and
>     this piece of code is inside a loop) : first solution is faster,
>   - the flags are set in the first case, but not in the second (well, I'm
>     not absolutely sure, but I really think so...)
>
>Paul Rolland
>
>A bug can be changed to a feature by documenting it. Developpers know !

The flags will be unchanged in both cases. The only difference between
them is speed. MOV will use only 2 cycles while PUSH-POP uses 7.
That's quite a difference. They both use only 2 bytes.

Stig

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Message-ID: <1992Dec22.094718.16178@ugle.unit.no>

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References: <gn#@byu.edu> <rol-221292092834@90.222.1.80>

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Path: arc1-ca.pugleaf.net!sparky!uunet!pipex!bnr.co.uk!uknet!mcsun!sunic!ugle.unit.no!flipper.pvv.unit.no!venaas
From: venaas@flipper.pvv.unit.no (Stig Venaas)
Newsgroups: comp.os.msdos.programmer
Subject: Re: SIMPLE assembly question...
Message-ID: <1992Dec22.094718.16178@ugle.unit.no>
Date: 22 Dec 92 09:47:18 GMT
References: <gn#@byu.edu> <rol-221292092834@90.222.1.80>
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Organization: ProgramVareVerkstedet - UNIT
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