Understanding condition code flag setting in assembly

Question

If I have the following table:

Case 1:    x: 42           y: -15           (y-x) = -57 
Case 2:    x: -17          y: -17           (y-x) = 0
Case 3:    x: 0x7ffffffd   y: -67           (y-x) = 2147483584
Case 4:    x: 67           y: -0x7fffffffd  (y-x) = 2147483584

What would the condition code flags set (zero or one, per flag) for ZF SF OF and CF

when considering the instruction: cmp1 %eax %ecx if %eax contains x and %ecx contains y?

I understand that cmp1 ...,... is executed by: cmp1 SRC2,SRC1

which means: "sets condition codes of SRC1 – SRC2"

I understand that the flags represent:

OF = overflow (?)
ZF = zero flag i.e. zero...
CF = carry out from msb
SF - sign flag i.e. negative

For my four cases in the table, I believe the flags would be:

1) ZF = 0 SF = 1 CF = 0 OF = ?
2) ZF = 1 SF = 0 CF = 0 OF = ?
3) ZF = 0 SF = 0 CF = 1 OF = ?
4) ZF = 0 SF = 0 CF = 1 OF = ?

Am I correct? Please explain what CF and OF are and how to determine if either will be set TRUE, and correct any of my flawed understanding. Thank you.

Answer 1

Carry overflow occurs when an arithmetic operation generates a carry that cannot fit into the register. So if you had 8-bit registers, and wanted to add 10000000 and 10000000 (unsigned):

 10000000
 10000000
 --------
100000000

This 1 is the carry from most significant bit, and thus sets CF = 1.

You might also want to check this other answer.