Omega

This tool is a variation of Omega+ and CodeGen+ using suif as it's IR.

Author

This project is originally authored by Chun Chen and contains references to the following repositories.

1. http://ctop.cs.utah.edu/downloads/omega.tar.gz2.
2. https://github.com/CompOpt4Apps/Artifact-DataDepSimplify/tree/master/chill/omega3.
3. https://github.com/BoiseState-AdaptLab/the-omega-project.git

Contributors to this repository: Tobi , Anna, Cathie

Requirements

Bison version 3.7.+ Automake 1.3.+

Build Instructions

autoreconf -i
./configure
make

Omega+ and Codegen+ 2.2

Omega+ and CodeGen+ 2.2 open source release See LICENSE file for copyright information.

Omega+ is a mathematical library for manipulating integer linear constraints over integer variables in first order logic, and operations on integer sets and their mappings. CodeGen+ is a code generation library by scanning the points in a union of polytopes. A command-line interface to libraries is also included.

What is new?

version 2.2:

• Redesigned polyhedra scanning which generates higher quality code than before especially for complex set of polyhedra.
• New SimpleHull for hull approximation (deprecate Hull).
• Command line editing and history support in calculator.

version 2.1:

• Updated "effort" parameter's meaning in MMGenerateCode: value n (n >= 0, default to 1) means that control overheads are removed from all n-depth innermost loops.
• Enhanced stride handling in the code generation.
• Support code generation for a set of iteration spaces with different dimensionality.
• New ConvexRepresentation that reduces the number of conjuncts in a union (deprecate CheckForConvexPairs and CheckForConvexRepresentation).
• Handle floor/ceiling defined variables cleanly in output code.
• Use namespace omega for the library.
• New closure functions contributed by Klimek Tomasz (R^+ and R^@).

version 2.0:

• Improved internal code generation interface so that it generates both string and suif ouput now, and more easily extendable for new compiler intermediate representations.
• Improved gist function so that integer modular constraints are handled more gracefully.
• Merge duplicate if-conditions in generated code, which might still miss a few opportunities due to the way AST is constructed.
• Correct output/input variable substitution for non-unimodular mapping relations.
• Deprecate Omega's assert/Exit interface.
• Some fixing in calculator's parsing and interactive interface.

version 1.2 (Omega Project):

• Support for code generation with memory mappings, as described in Tina Shen's MASPLAS '98 paper. This is available in oc via the tcodegen function; see examples/calc/mm* for examples.
• Use of the compile-time flags -DSTILL_CHECK_MULT=1 -DNDEBUG turns off all assertions and chechk except some checks for integer overflow during variable elimination in the omega core. Unless you know a priori that overflow cannot occur, you should use this instead of just plain -DNDEBUG when optimizing.
• You can now use "assertUnsatisfiable relation" to cause oc to quit if "relation" could be satisfiable. This is mainly useful when running oc in a script.

version 1.1 (Omega Project):

• An exact convex hull computation.
• An improved system for handling inexact relations, including taking upper and lower bounds, checking for subsets, and checking tautologies.
• Better handling of existentially quantified variables: we can now negate and generate code for sets like: {[i]: 1 <= i <= n && exists (alpha: i <= 10*alpha <= i+k)}.
• An Example operator, that gives a sample solution to set or relation.

version 0.90 (Omega Project):

• Initial release.

DIRECTORIES

omega/ omega_lib/ source files for the Omega+ library code_gen/ source files for the CodeGen+ library omega_calc/ source files for the calculator examples/ script examples using calculator c_code/ code examples for using libraries bin/ links to executables: oc lib/ links to libraries: libomega.a, libcode_gen.a include/ links to header files

DOCUMENTATION AND QUESTIONS

There are only old documents from the Omega Project under doc/ subdirectory for now.

Software website: http://www.chunchen.info/omega

For questions, bug reports or suggestions, please contact: mailto:riverofdreams@gmail.com