There are still plenty of open problems in compilers. For instance, writing a program to effectively use all four of my CPU cores is pretty tedious. It would be awfully nice if my compiler could automatically parallelize operations, do effective register allocation across cores, distribute data for best use of L1 cache, etc.
Certainly researchers who are working on this sort of thing today are doing it in LLVM or some custom framework. I can't imagine GCC has any significant traction at least.
The only open problem here is the one i stated "serious loop transforms". Parallelization is not even "hard", it's just hard for languages like C++. Fortran compilers have been parallelization for 20+years
Certainly researchers who are working on this sort of thing today are doing it in LLVM or some custom framework. I can't imagine GCC has any significant traction at least.