Specifications

Intel
®
64 and IA-32 Architectures Software Developer’s Manual Documentation Changes 27
Documentation Changes
BW/CWDE/CDQE—Convert Byte to Word/Convert Word to Doubleword/
Convert Doubleword to Quadword
Instruction Operand Encoding
...
CLC—Clear Carry Flag
Instruction Operand Encoding
...
CLD—Clear Direction Flag
Instruction Operand Encoding
...
Opcode Instruction Op/
En
64-bit
Mode
Compat/
Leg Mode
Description
98 CBW A Valid Valid AX ← sign-extend of AL.
98 CWDE A Valid Valid EAX ← sign-extend of AX.
REX.W + 98 CDQE A Valid N.E. RAX ← sign-extend of EAX.
Op/En Operand 1 Operand 2 Operand 3 Operand 4
ANA NA NA NA
Opcode Instruction Op/
En
64-bit
Mode
Compat/
Leg Mode
Description
F8 CLC A Valid Valid Clear CF flag.
Op/En Operand 1 Operand 2 Operand 3 Operand 4
ANA NA NA NA
Opcode Instruction Op/
En
64-bit
Mode
Compat/
Leg Mode
Description
FC CLD A Valid Valid Clear DF flag.
Op/En Operand 1 Operand 2 Operand 3 Operand 4
ANA NA NA NA