Specifications

Intel
®
64 and IA-32 Architectures Software Developer’s Manual Documentation Changes 144
Documentation Changes
Instruction Operand Encoding
...
POPA/POPAD—Pop All General-Purpose Registers
Instruction Operand Encoding
...
POPCNT — Return the Count of Number of Bits Set to 1
Instruction Operand Encoding
...
Op/En Operand 1 Operand 2 Operand 3 Operand 4
A ModRM:r/m (w) NA NA NA
Breg (w) NA NA NA
CNA NA NA NA
Opcode Instruction Op/
En
64-Bit
Mode
Compat/
Leg Mode
Description
61 POPA A Invalid Valid Pop DI, SI, BP, BX, DX, CX,
and AX.
61 POPAD A Invalid Valid Pop EDI, ESI, EBP, EBX, EDX,
ECX, and 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
F3 0F B8 /r POPCNT r16,
r/m16
A Valid Valid POPCNT on r/m16
F3 0F B8 /r POPCNT r32,
r/m32
A Valid Valid POPCNT on r/m32
F3 REX.W 0F B8
/r
POPCNT r64,
r/m64
A Valid N.E. POPCNT on r/m64
Op/En Operand 1 Operand 2 Operand 3 Operand 4
A ModRM:reg (w) ModRM:r/m (r) NA NA