/// direct method: "stack" without loop
unsigned rbN6 (unsigned arg)
{
  __asm
  {
    mov edx, arg
    mov ecx, 32
   
    align 16    // didn't help, however
NEXTBIT:
    shr edx, 1  // pop cf from edx
    rcl eax, 1  // push cf into eax
    sub ecx, 1
    jnz NEXTBIT
  }
}