The /optimize option enables or disables optimizations performed by the compiler to make your output file smaller, faster, and more efficient.
/optimize[+ | -]
/optimize also tells the common language runtime to optimize code at runtime.
By default, optimizations are disabled. Specify /optimize+ to enable optimizations.
When building a module to be used by an assembly, use the same /optimize settings as those of the assembly.
/o is the short form of /optimize.
It is possible to combine the /optimize and /debug options.
To set this compiler option in the Visual Studio development environment
Open the project's Properties page.
Click the Build property page.
Modify the Optimize Code property.
For information on how to set this compiler option programmatically, see Optimize.
t2.cs and enable compiler optimizations:
csc t2.cs /optimize