What does CMP mean in assembly?
What does CMP mean in assembly?
Operands
Compare Two Operands (cmp) (IA-32 Assembly Language Reference Manual)
What is JC in assembly language?
In 8085 Instruction set, we are having one mnemonic JC a16, which stands for “Jump if Carry” and “a16” stands for any 16-bit address. This instruction is used to jump to the address a16 as provided in the instruction.
What is the difference between test and CMP?
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.
What is Assembly condition codes?
Condition codes are extra bits kept by a processor that summarize the results of an operation and that affect the execution of later instructions. These bits are often collected together in a single condition or indicator register (CR/IR) or grouped with other status bits into a status register (PSW/PSR).
How does CMP work in ARM assembly?
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 .
Which flag 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.
How does assembly CMP work?
The CMP instruction compares two operands. This instruction basically subtracts one operand from the other for comparing whether the operands are equal or not. It does not disturb the destination or source operands. It is used along with the conditional jump instruction for decision making.
What does JNE mean in assembly?
Description. The jnz (or jne) instruction is a conditional jump that follows a test. It jumps to the specified location if the Zero Flag (ZF) is cleared (0). jnz is commonly used to explicitly test for something not being equal to zero whereas jne is commonly found after a cmp instruction.
Is CMP faster than test?
OF. test is shorter to encode than cmp with immediate 0, in all cases except the cmp al, imm8 special case which is still two bytes.
Which flag register is affected by CMP instruction?
What is the difference between macro and procedure and state their syntax?
Macro is a sequence of instructions that are written within the macro definition to support modular programming. On the other hand, a procedure is a set of instructions that performs a specific task, and a programmer can call it repetitively. Thus, this is the fundamental difference between macro and procedure.
What does CMP mean 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. The CMN instruction adds the value of Operand2 to the value in Rn . This is the same as an ADDS instruction, except that the result is discarded.
What is the difference between CMP and CMN in assembler?
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. The CMN instruction adds the value of Operand2 to the value in Rn . This is the same as an ADDS instruction, except that the result is discarded.
What is the JZ instruction in CMP stack overflow?
jz is “jump if zero”. cmp subtracts its two operands, and sets flags accordingly. (See here for reference.) If the two operands are equal, the subtraction will result in zero and the ZF flag will be set. So in your sample, the jump will be taken if al was 1, not taken otherwise.
What does JG mean in CMP stack overflow?
The command JG simply means: Jump if Greater. The result of the preceding instructions is stored in certain processor flags (in this it would test if ZF=0 and SF=OF) and jump instruction act according to their state. Thanks for contributing an answer to Stack Overflow! Please be sure to answer the question. Provide details and share your research!
How is the CMP instruction used in conditional execution?
The CMP instruction compares two operands. It is generally used in conditional execution. This instruction basically subtracts one operand from the other for comparing whether the operands are equal or not. It does not disturb the destination or source operands.