What is the fastest way to convert float to int on x86

Question

What is the fastest way you know to convert a floating-point number to an int on an x86 CPU. Preferrably in C or assembly (that can be in-lined in C) for any combination of

Answer 1

If you really care about the speed of this make sure your compiler is generating the FIST instruction. In MSVC you can do this with /QIfist, see this MSDN overview

You can also consider using SSE intrinsics to do the work for you, see this article from Intel: http://softwarecommunity.intel.com/articles/eng/2076.htm