Intel ITANIUM ARCHITECTURE - SOFTWARE DEVELOPERS MANUAL VOLUME 1 REV 2.3 Manual page 1599

MUL—Unsigned Multiplication of AL, AX, or EAX
Opcode
F6 /4
F7 /4
F7 /4
Description
Performs an unsigned multiplication of the first operand (destination operand) and the
second operand (source operand) and stores the result in the destination operand. The
destination operand is an implied operand located in register AL, AX or EAX (depending
on the size of the operand); the source operand is located in a general-purpose register
or a memory location. The action of this instruction and the location of the result
depends on the opcode and the operand size as shown in the following table.
:
Byte
Word
Doubleword
The AH, DX, or EDX registers (depending on the operand size) contain the high-order
bits of the product. If the contents of one of these registers are 0, the CF and OF flags
are cleared; otherwise, the flags are set.
Operation
IF byte operation
THEN
AX  AL  SRC
ELSE (* word or doubleword operation *)
IF OperandSize = 16
FI;
FI;
Flags Affected
The OF and CF flags are cleared to 0 if the upper half of the result is 0; otherwise, they
are set to 1. The SF, ZF, AF, and PF flags are undefined.
Additional Itanium System Environment Exceptions
Itanium Reg Faults NaT Register Consumption Abort.
Itanium Mem FaultsVHPT Data Fault, Nested TLB Fault, Data TLB Fault, Alternate Data
Volume 4: Base IA-32 Instruction Reference
Instruction
MUL r/m8
MUL r/m16
MUL r/m32
Operand Size
AL
AX
EAX
THEN
DX:AX  AX  SRC
ELSE (* OperandSize = 32 *)
EDX:EAX  EAX  SRC
TLB Fault, Data Page Not Present Fault, Data NaT Page Consumption
Abort, Data Key Miss Fault, Data Key Permission Fault, Data Access
Rights Fault, Data Access Bit Fault, Data Dirty Bit Fault
Description
Unsigned multiply (AX  AL  r/m8 )
Unsigned multiply (DX:AX  AX  r/m16 )
Unsigned multiply (EDX:EAX  EAX  r/m32 )
Source 1 Source 2
r/m8
r/m16
r/m32
Destination
AX
DX:AX
EDX:EAX
4:297