On Mon, 12 Mar 2007, Mike Stump wrote: > :-) I don't have any objections, as long as people can keep the compilation > speed up, though, sounds like a bit of work. I'd look towards a project > architect to help steer us towards goodness and keep us out of trouble. I can > see some advantage to having a cleaner boundary between the front-ends and the > mid-end.
You won't get a very clean separation, given that back ends manipulate C and C++ structures for target-specific built-in functions (including overloaded ones), attributes, pragmas, etc., that layout information is needed in the front ends, and that debug info involves target-specific and languages-specific information. You can improve things, but the (language, target, debug format) combinations will always be there with the associated need for one part of the compiler to know about structures from others. If you want separation, I suggest starting by making one thing at a time that shouldn't be a tree cease to be a tree everywhere. Partial work on TREE_LIST elimination is on the LTO branch. The CALL_EXPR parts have been merged, work on merging the TYPE_ARG_TYPES parts is in progress, there are many smaller patches there not yet merged and many other TREE_LIST cases not yet eliminated. Where those cases are front-end-specific structures, they can become front-end-local types. Another case that shouldn't be trees is identifiers. Key here is that each incremental stage should reduce memory usage and be useful on its own. -- Joseph S. Myers [EMAIL PROTECTED]
