Using benchmarks from SPEC (gcc, bzip2...)

I’m planning on implementing a register allocator on LLVM and I’ve noticed that the LLVM test suite supports SPEC’s CINT2006 benchmarks with some makefiles. Since SPEC seems to be way too expensive, but some (all?) of its programs are available for free, I was thinking of making my own SPEC-based test suite.
How hard would it be for me to integrate whole-program benchmarks in LLVM?

Thanks in advance.

LLVM already has a whole-program benchmarks; see
http://llvm.org/docs/TestingGuide.html#testsuiterun .

-Eli