Dissecting LLVM Obfuscator
Karim El-Faramawi described in detail the dissecting obfuscator LLVM in his blog, as well as any possible shortcomings in the implementation of obfuscative passages.
Obfuscator-LLVM is a project launched in June 2010 by the Information Security Team of the University of Applied Sciences and Arts in Western Switzerland, Yverdon-les-Bains. Obfuscation and tamper-proofing. The aim of this project is to provide an open source for the LLVM. The open source LLVM Obfuscator manifests as 3 relatively disjoint LLVM passes, each implementing some sort of obfuscation that obscures the CFG or arithmetic computation of the original program in some way.
More information can be found in this blog.