# What is Imul instruction?

## What is Imul instruction?

Description. The single-operand form of imul executes a signed multiply of a byte, word, or long by the contents of the AL, AX, or EAX register and stores the product in the AX, DX:AX or EDX:EAX register respectively.

### What is MUL and Imul in assembly language?

The MUL (Multiply) instruction handles unsigned data and the IMUL (Integer Multiply) handles signed data.

#### What is MUL and Imul in microprocessor?

The MUL instruction multiplies unsigned numbers. IMUL multiplies signed numbers. A nonzero number in the upper half of the result (AH for byte, DX or EDX for word) sets the overflow and carry flags. On the 80186â€“80486 processors, the IMUL instruction supports three additional operand combinations.

How many form does the Imul instruction have?

three forms
The three forms of the IMUL instruction are similar in that the length of the product is calculated to twice the length of the operands. With the one-operand form, the product is stored exactly in the destination.

What is a compare instruction?

Comparison instructions in PLC are used to test pairs of values to condition the logical continuity of a rung. As an example, suppose a LES instruction is presented with two values. If the first value is less than the second, then the comparison instruction is true.

## How does MUL work in assembly?

The mul instruction is used to perform a multiplication. Always multiplies EAX by a value. The result of the multiplication is stored in a 64-bits value accross EDX (most significant 32 bits of the operation) and EAX (least significant 32 bits of the operation).

### What is difference between MUL and Imul?

Explanation: The MUL and IMUL are multiplication instructions. Here, MUL instructions used for multiplying unsigned numbers. On the other hand, IMUL multiplies signed numbers.

#### How do you use compare instruction?

Comparison Instructions in PLC Programming

1. Types of Comparison Instructions.
2. Equal (EQU) Instruction.
3. Not Equal (NEQ) Instruction.
4. Less Than (LES) Instruction.
5. Less Than or Equal (LEQ) Instruction.
6. Greater Than (GRT) Instruction.
7. Greater Than Or Equal (GEQ) Instruction.
8. Masked Comparison for Equal (MEQ)

How do you compare Assembly?

In assembly, all branching is done using two types of instruction:

1. A compare instruction, like “cmp”, compares two values. Internally, it does this by subtracting them.
2. A conditional jump instruction, like “je” (jump-if-equal), does a goto somewhere if the two values satisfy the right condition.

What is the basic difference between Mul and IMUL instruction in 8086?

What is the basic difference between MUL and IMUL instruction in 8086 microprocessor? mul is used for unsigned multiplication whereas imul is used for signed multiplication. Algorithm for both are same, which is as follows: AX = AL * operand. (DX AX) = AX * operand. This entry was posted in Uncategorized. Bookmark the permalink .

## How does the 8086 singed multiplication instruction work?

8086 Singed Multiplication Instruction (IMUL) The IMUL instruction allows the multiplication of two signed operands. The operands can be positive or negative. When the operand is a byte, it is multiplied with AL register and when it is a word, it is multiplied with AX register. The operation of MUL and IMUL instructions are same.

### Which is an example of an Imul instruction?

IMUL Instruction • IMUL (signed integer multiply ) multiplies an 8-, 16-, or 32-bit signed operand by either AL, AX, or EAX • Preserves the sign of the product by sign-extending it into the upper half of the destination register Example: multiply 48 * 4, using 8-bit operands: mov al,48 mov bl,4 imul bl ; AX = 00C0h, OF=1

#### What are the arithmetic instructions for the 8086?

Previous Tutorials in the series are : 8086 Data Transfer Instructions , 8086 Integer Arithmetic Instructions , 8086 Microprocessor Addressing Modes The multiplication instructions include: The MUL instruction deals with the multiplication of two unsigned numbers.