CMP (immediate) Compare (immediate) Compare (immediate) subtracts an immediate value from a register value. It updates the condition flags based on the result, and discards the result. For more information about the constrained unpredictable behavior, see Architectural Constraints on UNPREDICTABLE behaviors. If CPSR.DIT is 1, this instruction has passed its condition execution check, and does not use R15 as either its source or destination: The execution time of this instruction is independent of:The values of the data supplied in any of its registers.The values of the NZCV flags. The response of this instruction to asynchronous exceptions does not vary based on:The values of the data supplied in any of its registers.The values of the NZCV flags. It has encodings from the following instruction sets: A32 ( A1 ) and T32 ( T1 and T2 ) . != 1111 0 0 1 1 0 1 0 1 (0) (0) (0) (0) CMP{<c>}{<q>} <Rn>, #<const> n = UInt(Rn); imm32 = A32ExpandImm(imm12); 0 0 1 0 1 CMP{<c>}{<q>} <Rn>, #<imm8> n = UInt(Rn); imm32 = ZeroExtend(imm8, 32); 1 1 1 1 0 0 1 1 0 1 1 0 1 1 1 1 CMP{<c>}.W <Rn>, #<const> CMP{<c>}{<q>} <Rn>, #<const> n = UInt(Rn); imm32 = T32ExpandImm(i:imm3:imm8); if n == 15 then UNPREDICTABLE; <c> See Standard assembler syntax fields. <q> See Standard assembler syntax fields. <Rn> For encoding A1: is the general-purpose source register, encoded in the "Rn" field. The PC can be used, but this is deprecated. <Rn> For encoding T1: is a general-purpose source register, encoded in the "Rn" field. <Rn> For encoding T2: is the general-purpose source register, encoded in the "Rn" field. <imm8> Is a 8-bit unsigned immediate, in the range 0 to 255, encoded in the "imm8" field. <const> For encoding A1: an immediate value. See Modified immediate constants in A32 instructions for the range of values. <const> For encoding T2: an immediate value. See Modified immediate constants in T32 instructions for the range of values. if ConditionPassed() then EncodingSpecificOperations(); (result, nzcv) = AddWithCarry(R[n], NOT(imm32), '1'); PSTATE.<N,Z,C,V> = nzcv;