clang and llvm: patch, -target, -ppc-asm-full-reg-names

18. How to specify different triple for clang?
-target powerpc64-unknown-unknown

19. How to apply a patch?
patch < ~/patches/test.diff

21. How to dump all registers with name?
clang++ teset.cpp  -S -O2 -o - -mllvm -ppc-asm-full-reg-names