blcfill

Fill From Lowest Clear Bit

BLCFILL r32, r/m32

Sets all bits below the lowest clear bit (x & (x+1)).

Details

The Fill From Lowest Clear Bit instruction sets all bits below the lowest clear bit (x & (x+1)).

Pseudocode Operation

// Sets all bits below the lowest clear bit (x & (x+1))

Example

BLCFILL eax, ebx

Encoding

Binary Layout
VEX
+0
opcode
+3
ModRM
+4
 
Format TBM
Opcode 8F ... 01
Extension TBM

Operands

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