Return the position of the leftmost set bit in a 64bit value.
Source position: systemh.inc line 1253
function BsrQWord( 
const AValue: QWord 
):Cardinal; 
BsfQWord scans the QWord AValue, starting at the leftmost position and working towards position 0, and returns the index of the first set bit. The position is measured from the 0th, rightmost bit.
When the input is 0, the result is 255 (unsigned equivalent of 1).

Return the position of the rightmost set bit in an 8bit value. 


Return the position of the rightmost set bit in a 16bit value. 


Return the position of the rightmost set bit in a 32bit value. 


Return the position of the leftmost set bit in a 64bit value. 