Intel Extensible Firmware Interface - Manual (Page 794)

Extensible Firmware Interface Specification
19-20 12/01/02 Version 1.10
CMP
SYNTAX:
CMP[32|64][eq|lte|gte|ulte|ugte] R
1
, {@}R
2
{Index16|Immed16}
DESCRIPTION:
The CMP instruction is used to compare Operand 1 to Operand 2. Supported comparison modes are
=, <=, >=, unsigned <=, and unsigned >=. The comparison size can be 32 bits (CMP32) or 64 bits
(CMP64). The effect of this instruction is to set or clear the condition code bit in the Flags register
per the comparison results. The operands are compared as signed values except for the CMPulte
and CMPugte forms.
OPERATION:
CMPeq: Flags.C <= (Operand 1 == Operand 2)
CMPlte: Flags.C <= (Operand 1 <= Operand 2)
CMPgte: Flags.C <= (Operand 1 >= Operand 2)
CMPulte: Flags.C <= (Operand 1 <= Operand 2) (unsigned)
CMPugte: Flags.C <= (Operand 1>= Operand 2) (unsigned)