Right, Srihari. If you go back and read the thread from the top (it's very long, now, you can be forgiven :) you'll see this has been our driving assumption -- that the JIT compiler would have to do some static analysis on the call-tree, to ensure that the struct's members are accessed in a read-only fashion.
As long as all the code is verifiable (ie: don't use the C# 'unsafe' keyword) this kind of thing is possible. I think the conclusion is that this opt would be a very obscure corner-case scenario, if not for the DirectX APIs cited, and not ordinarily worth spending valuable JIT cycles on. Now, the DX team obviously cares about performance -- it'll be very interesting to see where this goes. Either a change in API, or a big enhancement to the JIT... maybe an additional metadata flag (const? ;) on method params, to give the JIT a hint that the arg is not modified... -S On Fri, 21 May 2004 22:52:38 -0400, Srihari Angaluri <[EMAIL PROTECTED] SOFTTECH.COM> wrote: >Doesn't it alter the whole semantics of value types if the implementation >is allowed to do "hidden" optimizations like these? For example, if the >compiler passes the struct by reference after a threshold size (let's say >more than 1MB), any modifications I make to the structure inside the method >will alter the actual parameter passed to the method, right? That clearly >is inconsitent with the semantics of value types.. > >Srihari > >=================================== >This list is hosted by DevelopMentorŪ http://www.develop.com >Some .NET courses you may be interested in: > >NEW! Guerrilla ASP.NET, 17 May 2004, in Los Angeles >http://www.develop.com/courses/gaspdotnetls > >View archives and manage your subscription(s) at http://discuss.develop.com =================================== This list is hosted by DevelopMentorŪ http://www.develop.com Some .NET courses you may be interested in: NEW! Guerrilla ASP.NET, 17 May 2004, in Los Angeles http://www.develop.com/courses/gaspdotnetls View archives and manage your subscription(s) at http://discuss.develop.com
