countLeadingZeros64
shiftCount = countLeadingZeros64( zSig0 ) - 15;
shiftCount = countLeadingZeros64( absA ) - 40;
shiftCount = countLeadingZeros64( absA );
shiftCount = countLeadingZeros64( absA ) + 49;
shiftCount = countLeadingZeros64( aSig ) - 11;
shiftCount = countLeadingZeros64( zSig ) - 1;
shiftCount = countLeadingZeros64( aSig );
shiftCount = countLeadingZeros64( zSig0 );
shiftCount = countLeadingZeros64( aSig1 ) - 15;
shiftCount = countLeadingZeros64( aSig0 ) - 15;