inline function

在想要optimize AAC encoder 的速度的時候
想要inline fabs()
卻無法成功

1. inline is for C++, __inline is for C & C++
2.要change compiler option /Ob0 to /Ob1 or /Ob2 ( In C++ --> Optimization --> Inline function expansion )
http://msdn.microsoft.com/en-us/library/47238hez.aspx
3. /Ob1 和 /ZI (Edit and Continue) 選項衝突，改用 /Zi
4. __forceinline 強迫inline 但compiler 不一定會照做，參考
http://msdn.microsoft.com/en-us/library/z8y1yy88.aspx