compile with command line


I could’t get cuda and intel fortran work in Visual Studio 2005, so I decide to use command line to compile my program. In the fortran_cuda file that NVIDIA provided. They use nvcc -c -O3
-c is compile the .cu file to obj file, but I can’t find -O3 in the nvcc PDF file. What does the -O3 do? I have search for a while and still can’t find the answer.
Thank you


-O3 is for maximum optimization level, I suppose.