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OF and CF flags, difference
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aramt
  Posted: Mar 8 2005, 16:50

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Joined: February 4, 2004

Hello.

Can anyone tell me the difference between the OF and CF flags of EFLAGS CPU register ?
 
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abyss
Posted: Mar 9 2005, 00:14

Challenger

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Member No.: 29

Joined: March 9, 2003

from intel's manual
QUOTE

Some arithmetic instructions (such as the ADD and SUB) perform both signed and unsigned
arithmetic. These instructions set the OF and CF flags in the EFLAGS register to indicate signed
overflow and unsigned overflow, respectively. When performing arithmetic on signed operands,
the OF flag can be tested directly or the INTO instruction can be used. The benefit of using the
INTO instruction is that if the overflow exception is detected, an exception handler can be called
automatically to handle the overflow condition.



--------------------
[x]-=-[ ]-=-[x]
 
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aramt
Posted: Mar 9 2005, 01:19

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Abyss.
I didn't know what is signed overflow, I already found it out.
Thanks.
 
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arnix
Posted: Mar 9 2005, 01:28

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Joined: July 31, 2004

держи этот документ, там всё на блюдочке..

User Attached Image Download attachment
CR_CF.zip ( Number of downloads: 362 )


 
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aramt
Posted: Mar 9 2005, 02:32

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QUOTE (In the immortal words of arnix, since Mar 9 2005, 01:28...)
держи этот документ, там всё на блюдочке..

Arnix.
Срасибо за ценную инфо. smile.gif

Ото читаю учебник Юрова и ни черта не понимаю, столько противоречии... wacko.gif
 
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arnix
Posted: Mar 12 2005, 04:26

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Group: Moderator
Member No.: 869

Joined: July 31, 2004

QUOTE (In the immortal words of BlackCode, since Mar 9 2005, 02:32)
Arnix.
Срасибо за ценную инфо. smile.gif

Ото читаю учебник Юрова и ни черта не понимаю, столько противоречии... wacko.gif

Пожалуйста smile.gif

P.S.
Пожалуй Юров сам не всё нормально понимал loool
 
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