f0fc9c9477
During parsing, it is possible to see instruction operands that reference values or EBBs that have not been created yet. These references have to be resolved by a second pass following parsing once all EBBs and values have been created. To prepare for this second pass, start creating Ebb and Value references that use the numbering from the source file rather than the in-memory real references. Maintain Value -> Value and Ebb -> Ebb mappings. This makes it possible to store source-numbered Ebb and Value references in instructions. All other entities are created in the preamble, so they should have been created before they are referenced.
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Cretonne Code Generator
=======================
Cretonne is a low-level retargetable code generator. It translates a
target-independent intermediate language into executable machine code.
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:alt: Documentation Status
.. image:: https://travis-ci.org/stoklund/cretonne.svg?branch=master
:target: https://travis-ci.org/stoklund/cretonne
:alt: Build Status
Cretonne is designed to be a code generator for WebAssembly with these design
goals:
No undefined behavior
Cretonne does not have a nasal demons clause, and it won't generate code
with unexpected behavior if invariants are broken.
Portable semantics
As far as possible, Cretonne's input language has well-defined semantics
that are the same on all target architectures. The semantics are usually
the same as WebAssembly's.
Fast sandbox verification
Cretonne's input language has a safe subset for sandboxed code. No advanced
analysis is required to verify memory safety as long as only the safe
instructions are used. The safe instruction set is expressive enough to
implement WebAssembly.
Scalable performance
Cretonne can be configured to generate code as quickly as possible, or it
can generate very good code at the cost of slower compile times.
Predictable performance
When optimizing, Cretonne focuses on adapting the target-independent IL to
the quirks of the target architecture. There are no advanced optimizations
that sometimes work, somtimes fail.
Building the documentation
--------------------------
To build the Cretonne documentation, you need the `Sphinx documentation
generator <http://www.sphinx-doc.org/>`_::
$ pip install sphinx
$ cd cretonne/docs
$ make html
$ open _build/html/index.html