The good intro to compilers is Engineering a Compiler. It focuse more on optimization then most intro books, and its all SSA.

If you want to go all in on SSA optimization, there is a book called Static Single Assignment Book and its written by a hole list of compiler writers. Its not finished but there is still a lot of information.

You can find it here: http://ssabook.gforge.inria.fr/latest/book.pdf

Or you can go with the classic, Advanced Compiler Design & Implementation. See here, http://www.amazon.com/Advanced-Compiler-Design-Implementatio...

All of them will teach you a lot about LLVM.