lib6502-jit is a (mostly) compatible implementation of Ian Piumarta's lib6502
which uses LLVM to perform JIT compilation of 6502 machine code to host code.
This will doubtless be useful to the large community of people stuck doing
number-crunching tasks with legacy 6502 code. :-)

README.lib6502 is a copy of the original lib6502 README. You should probably go
and read that before reading any further.

lib6502-compatibility.txt documents the differences between lib6502 and
lib6502-jit.

CREDITS contains acknowledgements of the various people and groups on whose
work lib6502-jit is built.

COPYING contains license details for lib6502-jit.

TODO contains some notes on possible enhancements to lib6502-jit.

How to build:

You'll need the following installed:
- a C/C++ compiler (I've tested with gcc 4.7.2, gcc 4.8.2 and clang 3.5)
- LLVM development libraries (I've tested with various 3.5 pre-release snapshots)
- boost (including boost::thread) (I've tested with 1.49, 1.54 and 1.55)

I have somewhat reluctantly set up an autotools build system; compiling and
linking against LLVM and boost::thread on different platforms was otherwise
just that bit too fiddly. So in theory all you need to do is:

    ./configure
    make

I suggest you actually do:
    CFLAGS='-g -O3' CXXFLAGS='-g -O3' ./configure
to increase the optimisation level. (I would have made that the default, but
apparently that would go against user expectations for an autotools build
system.)

"make install" should work as well if you feel inclined to do so, but it's not
necessary.

I've tested on three platforms, and for what it's worth here are more detailed
instructions for those:

Ubuntu (14.04 x86):
    apt-get install libboost-dev libboost-thread-dev llvm-3.5-dev libedit-dev
    export CFLAGS='-g -O3' 
    export CXXFLAGS='-g -O3' 
    ./configure --with-llvm-config=llvm-config-3.5
    make

Debian (7.5 x86-64):
    apt-get install libboost-dev libboost-thread-dev 
    [I used the llvm-3.5-dev package from the wheezy repository here: http://llvm.org/apt/]
    export CFLAGS='-g -O3' 
    export CXXFLAGS='-g -O3' 
    ./configure
    make

FreeBSD (10.0-RELEASE x86-64):
    pkg install boost-all-1.55.0
    pkg install llvm-devel-3.5.r203994
    export CFLAGS='-g -O3' 
    export CXXFLAGS='-g -O3' 
    ./configure --with-llvm-config=/usr/local/llvm-devel/bin/llvm-config
    make

There are some tests which will run if you type "make check". Some will be
skipped unless you have the "xa" assembler
(http://www.floodgap.com/retrotech/xa/) on your PATH.

The above assumes you downloaded a lib6502-jit*tar.bz2 package, which will
contain a "configure" script. This is not (following what I understand to be
best practice) checked into source control, so if you downloaded the source
using something like git or svn, you need to either:
- download the tarball - it will be much easier, especially if you're just
  taking a quick look at lib6502-jit and don't plan to make changes to the code
  (yet)
- install autoconf, automake and libtool, then cross your fingers and run
  "autoreconf -i", which will generate a "configure" script for you if you're
  lucky.

If you have any queries, comments or bug reports, please drop me (Steven
Flintham) an e-mail at lib6502-jit@lemma.co.uk.