What's in Here
--------------

This is a simple demo backend for MLRISC.  It only includes instruction
selection and register allocation.  It takes MLTREE statements as input
and emit assembly code in either Alpha or Sparc format.  A lot of things
are ignored here: for example, how the stack frame is laid out.  So don't
expect the assembly output to run without some changes.

You can probably use this as a starting point for developing your backend, 
as a lot of stuff here is just boilerplate functor instantiation.

Note: you do not need to have an Alpha or Sparc machine to use the system.

How to Build the System
-----------------------

I assume you already have either SML/NJ version 110.0.6, 110.25 or 110.29+
Unfortunately, the building process are slightly different across
the versions because of changes to CM.  So three different build files
are provided.

1.  Run sml in this directory
2.  Type:

      use "build-<version>.sml"

    Once you have done this all the code generator definitions are loaded 
    into memory.

3.  You can try: 

      use "eg-sparc.sml"
      use "eg-alpha.sml"

    to load the test inputs.
    Running eg1() and eg2() should produce the assembly. 

