On 5 August 2011 18:29, Kenneth Graunke <kenn...@whitecape.org> wrote: > On 08/03/2011 05:07 PM, Paul Berry wrote: >> When link_functions.cpp adds a new function to the final linked >> program, it needs to add it after any global variable declarations >> that the function refers to, otherwise the IR will be invalid (because >> variable declarations must occur before variable accesses). The >> easiest way to do that is to have the linker emit functions to the >> tail of the final linked program. >> >> The linker used to emit functions to the head of the final linked >> program, in an effort to keep callees sorted before their callers. >> However, this was not reliable: it didn't work for functions declared >> or defined in the same compilation unit as main, for diamond-shaped >> patterns in the call graph, or for some obscure cases involving >> overloaded functions. And no code currently relies on this sort >> order. >> >> No Piglit regressions with i965 Ironlake. > > Seems reasonable. > > Reviewed-by: Kenneth Graunke <kenn...@whitecape.org> > > That said, I still dislike all this nonsense. I've really wanted to > separate these, so a shader contains three separate lists: > > 1. A list of global variable declarations (ir_variable *) > 2. A list of function declarations (ir_function *) > 3. Global initializer instructions (ir_instruction *) > > Then you wouldn't have any of this crap about emitting functions before > variable declarations, functions in functions, etc, etc. Plus you > wouldn't need to dynamically check whether things in your top-level list > are variables/functions/etc. > > Quite some time ago I took a stab at this, but wasn't thinking about > global initializers, so I made no provisions for them and ended up > tossing the code. It'd be nice to resurrect the idea. If you'd like to > try, feel free... :)
That's a really good idea. I'm not sure I have the time to pour into this right now, but I'll keep it in mind if I have to visit this code again. _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
