The following ASM code will convert quickly from a floating point value
to a 16.16 fixed point number.

This code comes complements of Chris Babcock (a.k.a. "VOR")



i_bignum  dq        04238000000000000h

FADD   [i_bignum]
...
FSTP  [qword ptr i_temp]
...
MOV  eax,[dword ptr i_temp]   ; eax = 16.16