When work on Go started in late 2007, LLVM wasn't what it is today. I think that if we were doing Go again, starting today, it would make sense to use LLVM, but if you look at the kinds of things that were being done in LLVM in 2007 (llvm.org has the release notes linked), it wasn't a viable option (yet).
I for one would like to see a Go front end for LLVM. In fact, the front end used by gccgo is a separate project from gcc and BSD - not GPL - licensed (http://code.google.com/p/gofrontend) specifically to make that easier and so that gccgo and an eventual go-for-LLVM can share code.
I for one would like to see a Go front end for LLVM. In fact, the front end used by gccgo is a separate project from gcc and BSD - not GPL - licensed (http://code.google.com/p/gofrontend) specifically to make that easier and so that gccgo and an eventual go-for-LLVM can share code.