I've had good luck using the llvm-gcc & llvm-g++ on small projects,
but I just discovered that it's apparently missing some of the GCC
intrinsic functions -- specifically, when I try and compile VXL
(http://vxl.sourceforge.net) it dies when it encounters
This is on OS X with the llvm-gcc-4.2 & llvm_g++-42 that are part of
the XCode 3.2.3
I don't know if this was the LLVM-GCC developer's oversight or Apple's
but it keeps me from using llvm-gcc as my default compiler.