Julian Seward 6f8a54b6a5 Adds support for legalizing CLZ, CTZ and POPCOUNT on baseline x86_64 targets.
Changes:

* Adds a new generic instruction, SELECTIF, that does value selection (a la
  conditional move) similarly to existing SELECT, except that it is
  controlled by condition code input and flags-register inputs.

* Adds a new Intel x86_64 variant, 'baseline', that supports SSE2 and
  nothing else.

* Adds new Intel x86_64 instructions BSR and BSF.

* Implements generic CLZ, CTZ and POPCOUNT on x86_64 'baseline' targets
  using the new BSR, BSF and SELECTIF instructions.

* Implements SELECTIF on x86_64 targets using conditional-moves.

* new test filetests/isa/intel/baseline_clz_ctz_popcount.cton
  (for legalization)

* new test filetests/isa/intel/baseline_clz_ctz_popcount_encoding.cton
  (for encoding)

* Allow lib/cretonne/meta/gen_legalizer.py to generate non-snake-caseified
  Rust without rustc complaining.

Fixes #238.
2018-02-06 09:43:00 -08:00

=======================
Cretonne Code Generator
=======================

Cretonne is a low-level retargetable code generator. It translates a `target-independent
intermediate language <http://cretonne.readthedocs.io/en/latest/langref.html>`_ into executable
machine code.

*This is a work in progress that is not yet functional.*

.. image:: https://readthedocs.org/projects/cretonne/badge/?version=latest
    :target: https://cretonne.readthedocs.io/en/latest/?badge=latest
    :alt: Documentation Status

.. image:: https://travis-ci.org/stoklund/cretonne.svg?branch=master
    :target: https://travis-ci.org/stoklund/cretonne
    :alt: Build Status

For more information, see `the documentation
<https://cretonne.readthedocs.io/en/latest/?badge=latest>`_.

Planned uses
------------

Cretonne is designed to be a code generator for WebAssembly, but it is general enough to be useful
elsewhere too. The initial planned uses that affected its design are:

1. `WebAssembly compiler for the SpiderMonkey engine in Firefox
   <spidermonkey.rst#phase-1-webassembly>`_.
2. `Backend for the IonMonkey JavaScript JIT compiler in Firefox
   <spidermonkey.rst#phase-2-ionmonkey>`_.
3. `Debug build backend for the Rust compiler <rustc.rst>`_.

Building Cretonne
-----------------

Cretonne is using the Cargo package manager format. First, ensure you have
installed a current stable rust (stable, beta, and nightly should all work, but
only stable and beta are tested consistently). Then, change the working
directory to your clone of cretonne and run::

    cargo build

This will create a *target/debug* directory where you can find the generated
binary.

To build the optimized binary for release::

    cargo build --release

You can then run tests with::

    ./test-all.sh

You may need to install the *wat2wasm* tool from the `wabt
<https://github.com/WebAssembly/wabt>`_ project in order to run all of the
WebAssembly tests. Tests requiring wat2wasm are ignored if the tool is not
installed.

Building the documentation
--------------------------

To build the Cretonne documentation, you need the `Sphinx documentation
generator <http://www.sphinx-doc.org/>`_::

    $ pip install sphinx sphinx-autobuild sphinx_rtd_theme
    $ cd cretonne/docs
    $ make html
    $ open _build/html/index.html

We don't support Sphinx versions before 1.4 since the format of index tuples
has changed.
Description
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Readme 125 MiB
Languages
Rust 77.8%
WebAssembly 20.6%
C 1.3%