Welcome to LLVM.
This documentation describes the internal software that makes up LLVM, not the external use of LLVM. There are no instructions here on how to use LLVM, only the APIs that make up the software. For usage instructions, please see the programmer's guide or reference manual.
This documentation is generated directly from the source code with doxygen. Since LLVM is constantly under active development, what you're about to read is out of date! However, it may still be useful since certain portions of LLVM are very stable.