popcnt

Population Count

POPCNT r, r/m

Counts number of bits set to 1.

Details

The Population Count instruction counts number of bits set to 1.

Pseudocode Operation

DEST <- count of set bits in SRC

Example

POPCNT rax, rbx

Encoding

Binary Layout
F3
+0
0F
+1
B8
+2
 
Format VEX
Opcode F3 0F B8
Extension SSE4.2

Operands

  • dest
    General-purpose register
  • src
    Register or memory operand