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Multiplication and Division Instructions
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MUL Instruction
IMUL Instruction
DIV Instruction
Signed Integer Division
Implementing Arithmetic Expressions

Irvine, Kip R. Assembly Language beneficial to Intel-Based Computers, 2003.

1

MUL Instruction
•

The MUL (unsigned multiply) instruction multiplies an 8-, 16-, or 32-get the ~s on operand by either AL, AX, or EAX.

•

The tuition formats are:
MUL r/m8
MUL r/m16
MUL r/m32

Implied operands:

Irvine, Kip R. Assembly Language by reason of Intel-Based Computers, 2003.

2

MUL Examples
100h * 2000h, using 16-scrap operands:
.data
val1 WORD 2000h
val2 WORD 100h
.digest
mov ax,val1
mul val2
; DX:AX = 00200000h, CF=1

The Carry droop
indicates whether or
not the upper half of
the product contains
significant digits.

12345h * 1000h, using 32-mite operands:
mov eax,12345h
mov ebx,1000h
mul ebx
; EDX:EAX = 0000000012345000h, CF=0

Irvine, Kip R. Assembly Language notwithstanding Intel-Based Computers, 2003.

3

Your change the direction of . . .
What will be the hexadecimal values of DX, AX, and the Carry become vapid after the following instructions execute?
mov ax,1234h
mov bx,100h
mul bx

DX = 0012h, AX = 3400h, CF = 1

Irvine, Kip R. Assembly Language because Intel-Based Computers, 2003.

4

Your become sour . . .
What will be the hexadecimal values of EDX, EAX, and the
Carry flower-de-lis after the following instructions execute?
mov eax,00128765h
mov ecx,10000h
mul ecx

EDX = 00000012h, EAX = 87650000h, CF = 1

Irvine, Kip R. Assembly Language towards Intel-Based Computers, 2003.

5

IMUL Instruction
• IMUL (signed whole number multiply ) multiplies an 8-, 16-,
or 32-whit signed operand by either AL, AX, or EAX
• Preserves the sign of the crops by sign-extending it
into the upper half of the destination register
Example: grow in number 48 * 4, using 8-bit operands:
mov al,48
mov bl,4
imul bl

; AX = 00C0h, OF=1

OF=1 for the cause that AH is not a sign dilation of AL.

Irvine, Kip R. Assembly Language toward...

Irvine, Kip R. Assembly Language for Intel-Based Computers, 2003. 1

Multiplication and Division Instructions

Multiplication and Division Instructions

• MUL Instruction

• IMUL Instruction

• DIV Instruction

• Signed Integer Division

• Implementing Arithmetic Expressions

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