My Question is regarding the assembly Language programming for a project i am going to deliver to Professor Aghazarian ... There goes the Question: Why is it that the Increment and/or the Decrement instructions have no change nor effect over the carry flag ?!
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3Already answered here: http://stackoverflow.com/questions/13435142/why-the-inc-and-dec-instructions-do-not-affect-the-carry-flag – Alan Wolfe May 17 '15 at 16:50
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1This is simply by design, and is useful when writing loops for carrying out arbitrary precision arithmetic. – Daniel Kamil Kozar May 17 '15 at 17:43
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Think of it like this, you wish to add two binary values together:
1111
1111
This if you add these together it will trigger the carry flag, as adding two 1's together in a register will write a 0 at the registers position and will carry over a 1. Thus setting the carry flag to 1.
Inc/Dec instructions will just increment and decrement a value stored in a register.
Unless an overflow occurs from the incrementing, this will also set the carry flag.
Rami
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1Which - if I'm not mistaken - can also overflow and logically should also set the carry flag. So unless I'm mistaken that cannot be the complete answer, can it? – David van Driessche May 17 '15 at 16:54
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