[LLVMdev] Turning Off Backend Passes

[David Greene]

So LLVMTargetMachine.cpp adds lots of transformation passes in the
various addPasses* routines.  We'd prefer not to run all of these
things (LSR, for example).  We've sort of dealt with it for now but
we'd really like to be able to turn some of these things off in a
convenient way.

We could just comment stuff out but we'd like to remain as close to
upstream as possible.  Can anyone think of a good way to provide the
needed flexibility here?  Maybe a flags that says "just do the bare 
minimum to generate code?"  Would anyone object to that?

                            -Dave