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Teehee



Joined: 05 Aug 2009
Posts: 570
Location: Brazil
Teehee
Question: How many instructions are executed at once by the CPU?

EDIT by DOS386: split from: http://board.flatassembler.net/topic.php?t=10984

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Sorry if bad english.
Post 29 May 2010, 17:28
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mindcooler



Joined: 01 Dec 2009
Posts: 423
Location: Västerås, Sweden
mindcooler
Nowadays you can't really know that. Depends on the architechture, the code and today's air pressure.
Post 29 May 2010, 17:51
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Teehee



Joined: 05 Aug 2009
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Location: Brazil
Teehee
Lets suppose a Intel PIII and IV, 32bits.
Post 29 May 2010, 17:54
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baldr



Joined: 19 Mar 2008
Posts: 1651
baldr
Teehee,

Agner Fog's optimization manuals contain quite detailed information about microarchitecture of Intel, AMD and VIA CPUs. Not an easy reading though, but you'll understand that your question has no real-life meaning even for PPro (if you're not really into spherical horses' races in vacuum Wink).
Post 29 May 2010, 18:19
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revolution
When all else fails, read the source


Joined: 24 Aug 2004
Posts: 17715
Location: In your JS exploiting you and your system
revolution
Teehee wrote:
Question: How many instructions are executed at once by the CPU?
IIRC it is currently something like 72. I can't be bothered to look it up to confirm the figure of 72, but basically the CPU can hold many instructions in various stages of completion in various computational units and staging buffers.

To even try to measure, or predict, how much of a piece of code is currently in-flight would be almost impossible without extreme amounts of patience and effort.
Post 29 May 2010, 23:56
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Teehee



Joined: 05 Aug 2009
Posts: 570
Location: Brazil
Teehee
so align code (like data [eg. align 4]) makes no sense, right?
Post 30 May 2010, 12:30
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baldr



Joined: 19 Mar 2008
Posts: 1651
baldr
Teehee,

Read those optimization manuals. Code alignment may or may not have sense, that depends.
Post 30 May 2010, 12:39
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