Re: compiling very large functions.

[Paolo Bonzini]

While I agree with you, I think that there are so many things we are 
already trying to address, that this one can wait.  I think we've been 
doing a very good job on large functions too, and I believe that authors 
of very large functions are just getting not only what they deserve, but 
actually what the expect: large compile times (superlinear).

Not too mention, that these huge functions are usually central to the 
program.  If GCC decided that it is not worth optimizing the 
machine-generated bytecode interpreter of GNU Smalltalk, for example, I 
might as well rewrite it in assembly (or as a JIT compiler).  Same for 
interpret.cc in libjava, though it is a tad smaller than GNU Smalltalk's 
interpreter.

Unlike the authors of other VM's, I have no problem writing code so that 
the *latest* version of GCC will do its best, instead of complaining 
that GCC compiles my code worse on every release.  So, I am ok with GCC 
doing stupid things because of bugs that I/we can fix, but not with GCC 
just giving up optimization on code that has always been compiled 
perfectly (in one/two minutes for about 30,000 lines of 
machine-generated code, despite being chock-full of computed gotos), 
that *can* be optimized very well, and that is central to the 
performance of a program.

Paolo