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Index > Main > the most usefull instruction:

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edfed



Joined: 20 Feb 2006
Posts: 4237
Location: 2018
edfed
i propose some instructions as participants to the most usefull instruction post.

0: adc

1: mov

2: jmp

3: call/ret

4: push/pop

5: feel free to propose your team of most usefull instructions


i made the adc instruction the most usefull because of many reasons.
i think it is possible to emulate a lot of instructions with functions made only with adc...
Post 10 Aug 2011, 00:46
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Overflowz



Joined: 03 Sep 2010
Posts: 1046
Overflowz
lea, shr/shl, ror/rol, add/sub, inc/dec, cmp and int3 Razz jk
Post 10 Aug 2011, 02:05
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Madis731



Joined: 25 Sep 2003
Posts: 2141
Location: Estonia
Madis731
That's a different topic: http://en.wikipedia.org/wiki/One_instruction_set_computer
Yes you can only use a single instruction, but looking at some statistics, http://www.strchr.com/x86_machine_code_statistics mov is the most useful in everyday computing.

Personally I love LEA and if its not the most useful it definitely is the most powerful instruction.

EDIT by DOS386 (2011-08-17) : fixed broken link
Post 10 Aug 2011, 05:33
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AsmGuru62



Joined: 28 Jan 2004
Posts: 1409
Location: Toronto, Canada
AsmGuru62
I like:

SETxx
CMOVxx

These allow for branch-less code.
Post 10 Aug 2011, 12:58
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MHajduk



Joined: 30 Mar 2006
Posts: 6034
Location: Poland
MHajduk
AsmGuru62 wrote:
I like:

SETxx
CMOVxx

These allow for branch-less code.
CMOVxx-like instructions would be truly cool if there was a possibility to move immediate values.
Post 10 Aug 2011, 13:09
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Madis731



Joined: 25 Sep 2003
Posts: 2141
Location: Estonia
Madis731
I agree, CMOVxx could be very useful if it were to allow more options. Shuffling all the registers around makes my head hurt and it doesn't usually give any performance benefits.
Post 10 Aug 2011, 13:16
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cod3b453



Joined: 25 Aug 2004
Posts: 619
cod3b453
My first thought was lea
Post 10 Aug 2011, 19:27
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DOS386



Joined: 08 Dec 2006
Posts: 1901
DOS386
http://board.flatassembler.net/topic.php?t=5249 "top 20"
http://board.flatassembler.net/topic.php?t=13027 "useless"

> the most usefull instruction

LOADALL286 Shocked

> CMOVxx-like instructions would be truly cool if there was a
> possibility to move immediate values.

And even more if added in 80386 or even better in 8086, and if not PageFaulting if condition is false Crying or Very sad
Post 17 Aug 2011, 04:24
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nop



Joined: 01 Sep 2008
Posts: 165
Location: right here left there
nop
of course the most usefull instruction is nop

garanteed to never produce unpredictable results

can sprinkle liberaly through code and replace with single byte interrupt for tracing and debuging
Post 18 Aug 2011, 11:04
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