For an addition, including the comparison instruction CMN, C is set to 1 if the addition produced a carry (that is, an unsigned overflow), and to 0 otherwise.

For a subtraction, including the comparison instruction CMP, C is set to 0 if the subtraction produced a borrow (that is, an unsigned underflow), and to 1 otherwise.

For non-additions/subtractions that incorporate a shift operation, C is set to the last bit shifted out of the value by the shifter.

For other non-additions/subtractions, C is normally left unchanged, but see the individual instruction descriptions for any special cases.

The floating-point compare instructions, VCMP and VCMPE set the C flag and the other condition flags in the FPSCR to the result of the comparison.

For an addition, including the comparison instruction CMN, C is set to 1 if the addition produced a carry (that is, an unsigned overflow), and to 0 otherwise.

For a subtraction, including the comparison instruction CMP and the negate instructions NEGS and NGCS, C is set to 0 if the subtraction produced a borrow (that is, an unsigned underflow), and to 1 otherwise.

For the integer and floating-point conditional compare instructions CCMP, CCMN, FCCMP, and FCCMPE, C and the other condition flags are set either to the result of the comparison, or directly from an immediate value.

For the floating-point compare instructions, FCMP and FCMPE, C and the other condition flags are set to the result of the comparison.

For other instructions, C is normally left unchanged, but see the individual instruction descriptions for any special cases.