AMD 4.4.5 DEC reg/mem8, DEC reg/mem16, DEC reg/mem32, DEC reg/mem64, DEC reg16, DEC reg32

AMD Confidential

November 21st, 2008

User Manual

Instruction

Supported

Mnemonic

Opcode

Description

Compare EDX:EAX register to 64-bit

memory location. If equal, set the

zero

flag

(ZF)

to

1

and

copy

the

CMPXCHG8B

0F C7 /1 m64

ECX:EBX

register

to

the

memory

location. Otherwise, copy the memory

location

to EDX:EAX and clear the

zero flag.

CPUID

0F A2

Executes

the

CPUID

function

whose

number is in the EAX register.

DAA

27

Decimal adjust AL.

DAS

2F

Decimal adjusts AL after subtraction.

DEC reg/mem8

FE /1

Decrement

the

contents

of

an

8-bit

register or memory location by 1.

DEC reg/mem16

FF /1

Decrement

the

contents

of

a

16-bit

register or memory location by 1.

DEC reg/mem32

FF /1

Decrement

the

contents

of

a

32-bit

register or memory location by 1.

DEC reg/mem64

FF /1

Decrement

the

contents

of

a

64-bit

register or memory location by 1.

DEC reg16

48 +rw

Decrement

the

contents

of

a

16-bit

register by 1.

DEC reg32

48 +rd

Decrement

the

contents

of

a

32-bit

register by 1.

Perform

unsigned

division

of

AX

by

the contents of an 8-bit register or

DIV reg/mem8

F6 /6

memory

location

and

store

the

quotient in AL and the remainder in

AH.

Perform unsigned division of DX:AX by

the contents of a 16-bit register or

DIV reg/mem16

F7 /6

memory

location

and

store

the

quotient in AX and the remainder in

DX.

Perform unsigned division of EDX:EAX

by the contents of a 32-bit register

DIV reg/mem32

F7 /6

or

memory

location

and

store

the

quotient in EAX and the remainder in

EDX.

Perform unsigned division of RDX:RAX

by the contents of a 64-bit register

DIV reg/mem64

F7 /6

or

memory

location

and

store

the

quotient in RAX and the remainder in

RDX.

ENTER imm16,0

CB iw 00

Create a procedure stack frame.

ENTER imm16,1

CB iw 01

Create

a

nested

stack

frame

for

a

procedure.

ENTER imm16,imm8

CB iw ib

Create

a

nested

stack

frame

for

a

procedure.

Perform signed division of AX by the

contents

of an 8-bit register or

IDIV reg/mem8

F6 /7

memory

location

and

store

the

quotient in AL and the remainder in

AH.

Perform signed division of DX:AX by

the contents of a 16-bit register or

IDIV reg/mem16

F7 /7

memory

location

and

store

the

quotient in AX and the remainder in

DX.

Perform signed division of EDX:EAX by

the contents of a 32-bit register or

IDIV reg/mem32

F7 /7

memory

location

and

store

the

quotient in EAX and the remainder in

EDX.

196 Appendix A