countLeadingZeros32
shiftCount = countLeadingZeros32( aSig ) - 8;
shiftCount = countLeadingZeros32( zSig ) - 1;
shiftCount = countLeadingZeros32( absA ) + 21;
shiftCount = countLeadingZeros32( absA ) + 32;
shiftCount += countLeadingZeros32(a);
shiftCount = countLeadingZeros32(zSig) - 1;
shiftCount = countLeadingZeros32(aSig) - 8;
static int8 countLeadingZeros32(bits32 a);