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Article #6558Re: SIMPLE assembly question...
From: D'Arcy J.M. Cain
Date: Sat, 19 Dec 1992 12:31
Date: Sat, 19 Dec 1992 12:31
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$dougn@sasb.byu.edu (Douglas R. Nebeker - MIS_SAS) writes: >is there ANY difference between MOV ES,AX > >and PUSH AX > POP ES The biggest difference is that the second form takes two separate memory accesses while the first takes none. The "MOV ES, AX" takes 2 clocks on a 386. The "PUSH AX" takes 2 clocks and "POP ES" takes 7. (The numbers are 18, 2 and 21 under protected mode.) This doesn't include wait states for the PUSH/POP if your system adds them. Wait states don't apply to the MOV method (I am ignoring the access for the instructions themselves.) Sorry, I don't have the figures for 8088/86/286. >Does this affect ANY flags? The effect on the flags is the same in both cases - none. -- D'Arcy J.M. Cain (darcy@druid.com) | D'Arcy Cain Consulting | There's no government Toronto, Ontario, Canada | like no government! +1 416 424 2871 DoD#0082 |
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Newsgroups: comp.os.msdos.programmer Path: arc1-ca.pugleaf.net!sparky!uunet!uunet.ca!geac!lethe!druid!darcy From: darcy@druid.uucp (D'Arcy J.M. Cain) Subject: Re: SIMPLE assembly question... Message-ID: <1992Dec19.123132.14222@druid.uucp> Date: Sat, 19 Dec 1992 12:31:32 GMT References: <gn#@byu.edu> Organization: D'Arcy Cain Consulting Keywords: assembly mov asm Lines: 25