blsmsk

Get Mask Up to Lowest Set Bit

BLSMSK r32, r/m32

Creates mask up to lowest set bit (x ^ (x-1)).

Details

The Get Mask Up to Lowest Set Bit instruction creates mask up to lowest set bit (x ^ (x-1)).

Pseudocode Operation

// Creates mask up to lowest set bit (x ^ (x-1))

Example

BLSMSK eax, ebx

Encoding

Binary Layout
VEX
+0
opcode
+3
ModRM
+4
 
Format VEX
Opcode C4 ... F3 /2
Extension BMI1

Operands

  • dest
    32-bit general-purpose register (e.g. EAX)
  • src
    32-bit register or memory