I needed to compile LLVM from scratch since the llvmruby gem needs it compiled with position independent code and the repo version doesn't seem to be, the gem whines compiling, etc, etc. The docs for LLVM don't seem to be that great when it comes to compiling this stuff from scratch, so here's what I did, as one big script chunk. You can probably copy and paste this, but I make no promises that it will work, only that it Works on My Machine. And…

I always find myself needing this but never remember. -fverbose-asm Throw that at gcc when you are outputting asm (-S flag) and you'll get some useful comments to see what some of the code is actually working on.