What is CMP instruction in arm?
The CMP instruction subtracts the value of Operand2 from the value in Rn . This is the same as a SUBS instruction, except that the result is discarded. This is the same as an ADDS instruction, except that the result is discarded. In certain circumstances, the assembler can substitute CMN for CMP , or CMP for CMN .
What is the meaning of the instruction CMP A?
COMPARE is an important instruction widely used in 8085 microprocessor. The 8085 instruction set has two types of Compare operations: Compare with accumulator (CMP) and Compare immediate with accumulator (CPI).
What are the arithmetic instructions of ARM?
The arithmetic instructions are further classified into binary, decimal, logical, shift/rotate, and bit/byte manipulation instructions….Binary Operations.
| Instruction Mnemonic | Example | Description |
|---|---|---|
| ADC | ADC EAX, EAX | Add with carry |
| SUB | SUB EAX, 0002h | Subtract the 2 from the register |
What does CMP mean in assembly?
Operands
Compare Two Operands (cmp) (IA-32 Assembly Language Reference Manual)
Which flags are affected by CMP instruction?
CMP and TEST instructions affect flags only and do not store a result (these instruction are used to make decisions during program execution). These instructions affect these flags only: CF, ZF, SF, OF, PF, AF.
What is RSB in arm?
The RSB instruction subtracts the value in Rn from the value of Operand2 . This is useful because of the wide range of options for Operand2 . In certain circumstances, the assembler can substitute one instruction for another.
What is the use of DAA instruction?
The DAA instruction is only useful when it follows an ADD instruction that adds (binary addition) two 2-digit, packed BCD values and stores a byte result in the AL register. The DAA instruction then adjusts the contents of the AL register to contain the correct 2-digit, packed BCD result.
What is the function of RSB instruction?
The RSB instruction subtracts the value in Rn from the value of Operand2 . This is useful because of the wide range of options for Operand2 . Use ADC and SBC to synthesize multiword arithmetic, see Multiword arithmetic examples.
How many operands does DEC instruction have?
The dec instruction decrements the contents of its operand by one. dec eax — subtract one from the contents of EAX. The imul instruction has two basic formats: two-operand (first two syntax listings above) and three-operand (last two syntax listings above).
Is cmp instruction signed?
Performs a comparison operation between arg1 and arg2. The comparison is performed by a (signed) subtraction of arg2 from arg1, the results of which can be called Temp.
Which two flags are affected after executing CMP instruction?
While CMP B instruction executes, microprocessor compares the contents of register B with the contents of the accumulator. The comparison is shown by setting all the flags. The flags S, P, AC are modified and flag Z and CY reflects the result of the operation. So, all flags will be affected.
What is difference between CMP and test instruction?
The TEST instruction performs an implied AND operation between corresponding bits in the two operands and sets the flags without modifying either operand. reg, mem, and immed can be 8, 16, or 32 bits. The CMP instruction sets the flags as if it had performed subtraction on the operand.