Unsigned Integer Addition With Overflow Flag

Encoding

Description

The ADCX instruction adds the source operand, the destination operand, and the overflow flag. The result is stored in the destination operand. Only the overflow flag is affected.

This instruction is designed for use in multibyte additions such as in arbitrary precision arithmetic. The difference between this instruction and ADC (Add with Carry) is that this one allows the creation of two "carry chains" – one using OF (this one) and one using CF (ADCX (Unsigned Integer Addition with Carry Flag)).

Operation

public void ADOX(ref U32 dest, U32 src)
{
    dest += src + EFLAGS.OF;
}

public void ADOX(ref U64 dest, U64 src)
{
    dest += src + EFLAGS.OF;
}

Flags Affected

CF (carry flag)

Unmodified.

PF (parity flag)

Unmodified.

AF (auxiliary flag)

Unmodified.

ZF (zero flag)

Unmodified.

SF (sign flag)

Unmodified.

OF (overflow flag)

Set if an unsigned overflow occurs. Cleared otherwise.

Intrinsics

uint8_t _addcarryx_u32(uint8_t c_in, uint32_t src1, uint32_t src2, uint32_t *sum_out)
uint8_t _addcarryx_u64(uint8_t c_in, uint64_t src1, uint64_t src2, uint64_t *sum_out)

Exceptions