clang -o hello.l -I../../include/wolf -Os -S -emit-llvm hello.c
opt -S hello.s > hello-opt.s
xxdiff hello.s hello-opt.s
llc -O0 hello.l -march=x86-64 -p hello-amd64.s
llc -O0 hello.l -march=mipsel -o hello-mipsel.s