rudyb2001 / llvm-min-caml Goto Github PK

This is a modern fork of the `llvm-min-camll` project.

My immediate goals are to explore and document this archived project.

Forking this project made me feel like an archeologist, stumbling upon a
long-dormant relic of the past. I have beginner level knowledge of OCAML
and have not yet taken a compilers class. I have never touched LLVM IR.


ALL OF THE INFORMATION BELOW IS FROM THE ORIGINAL `llvm-min-caml` PROJECT


OVERVIEW:

llvm-min-caml is a compiler for a subset of the OCaml programming
language that targets the LLVM intermediate representation. It builds
directly on the work of Eijiro Sumii, Moe Masuko, Kenichi Asai, who
built the min-caml compiler targeting SPARC, PowerPC, and x86 assembly.
Their project (along with documentation) can be found at

            http://min-caml.sourceforge.net/index-e.html

I added a new backend targeting LLVM. Since I have no intention of
mantaining the other backends, I have removed them (along with all other
supporting files) from my distribution.

The current status is full support of all the features of the original
min-caml compiler, as can be found in the above website. In particular,
we perform full tail-call optimization.

OTHER LLVM PORTS:

There are at least two other LLVM ports of min-caml that can be found
through Google, but both fail to correctly perform tail-call optimization
in all cases.

* https://github.com/mzp/min-caml

* https://github.com/kmacy/llmincaml

The second one (llmincaml) failed to produce any LLVM output in fact when
I compiled it. But inspection of the source shows that it does not perform
tail call optimization in the case of an 'If' in tail position.

PREREQUISITES:

* OCaml

I have 4.00.0 in my machine, but it should work with
previous versions as well. I will update this README once
I find out about this. The OCaml distribution can be
downloaded from

      http://caml.inria.fr

* LLVM with Ocaml bindings

I used LLVM version 3.1 but, again, it should work with
earlier versions as well. I will update this README once
I find out about this.

In any case, installing this should be as easy as running

      opam install llvm

BUILDING:

If both the prerequisites are installed and configured
correclty, then follow the steps to build the llvm-min-caml
compiler.

1- Get the source from GitHub

      git clone https://github.com/nojb/llvm-min-caml.git

2- A directory named 'llvm-min-caml' will have been created.
   Move into it.

      cd llvm-min-caml

3- Build the sources.

      ocamlbuild main.native

4- Test the compiler.

I will add a proper test suite in the future, but for now
you can do the following to compile the test test/gcd.ml.

      ./main.native -iter 0 test/gcd

(the flag -iter 0 disables all optimizations so that the output
is easier to read.) This will create a file test/gcd.bc containing
the LLVM bitcode. To actually see it, you can use the llvm-dis utility
from the LLVM distribution.

      llvm-dis < test/gcd.bc

COPYRIGHT:

All the files are copyright 2005, 2006, 2007, 2008, 2013, Eijiro
Sumii, Moe Masuko, Kenichi Asai, Nicolas Ojeda Bar, and distributed
under the conditions stated in the file LICENCE.

BUG REPORTS AND USER FEEDBACK:

Please report bugs and any user feedback directly to me at

                [email protected].

CHANGELOG FOR PRE-LLVM VERSIONS:

[Update on July 24, 2012]

- 32-bit x86 (with SSE2, that is, Pentium IV or later) is now
  supported (on Linux and Cygwin); execute ./to_x86 before make.

[Updates on September 17, 2008]

- PowerPC is now supported (in addition to SPARC), thanks to
  Ms. Masuko and Prof. Asai in Ochanomizu University.  You _must_
  execute either ./to_ppc or ./to_sparc _before_ make.

- The register allocator now uses a simpler algorithm.  It omits the
  backtracking (ToSpill and NoSpill) in previous versions.