This post originated from an RSS feed registered with .NET Buzz by Eric Gunnerson. Original Post: Decreased performance when compiling with no options... Feed Title: Eric Gunnerson's C# Compendium Feed URL: /msdnerror.htm?aspxerrorpath=/ericgu/Rss.aspx Feed Description: Eric comments on C#, programming and dotnet in general, and the aerodynamic characteristics of the red-nosed flying squirrel of the Lesser Antilles Latest .NET Buzz Posts Latest .NET Buzz Posts by Eric Gunnerson Latest Posts From Eric Gunnerson's C# Compendium

One of the things that we've done in Whidbey is add some extra IL instructions to improve the debugging experience. This allows you to (for example) set a break on a closing brace.

Because /o- is the default setting, this means that performance if you just compile with “csc” will be slightly degraded in Whidbey. If you've been building without setting /o+ and you care about perf, you will want to change your code to throw /o+ explicitly.

If you're using VS release and debug configurations, this will be set automatically for you.