Dmitry Olshansky:
Perhaps the biggest one would be convincing GCC/LLVM devs to accept patches :)
From what I've seen LLVM devs seem open enough to good patches. They have accepted several changes to allow LLVM to become the back-end of GHC (Haskell compiler), and generally my enhancement requests to improve LDC1 life were well accepted. They have even kept open a large request enhancement of mine to optimize D vector ops in the back-end.
Bye, bearophile
