FloPoCo

Circuits computing just right

The best and most versatile free floating point unit out there is FloPoCo. (...) It outperforms even expensive professional solutions.

http://embdev.net/topic/215370

Version 3.0 is being released in 2015! See the release notes

A lot has been going on (transition to Sollya4, rewriting operators for bit-heaps, fixed-point support, ...). flopoco-3.0 is still beta, with a lot of operators broken by these framework changes. If you use it, please test each operator with the associated testbench generator (testbenches can be trusted and checked!).

FPGA Arithmetic the way it should be

FloPoCo is a generator of arithmetic cores (Floating-Point Cores, but not only) for FPGAs (but not only).

The first motto of FloPoCo is that arithmetic on FPGAs should not mimick processor arithmetic. By designing radically new operators, one may obtain more accurate results with less hardware in less time. This thesis was first detailed in this document.

The second motto of FloPoCo is to enable computing just right. All FloPoCo operators are

  1. fully parameterized in precision, so that your application may use just the precision it needs, and
  2. accurate to the last bit, so that your wires don't carry meaningless noise.
Internally, FloPoCo operators are carefully designed to ensure that no bit is computed that is not useful to the final result.

FloPoCo is not a library of operators, but a generator of operators written in C++. It inputs operator specifications, and outputs synthesizable VHDL.

Distribution

FloPoCo is open-source. Contributions are welcome!

The intent of the authors is to distribute FloPoCo as free software (in the FSF AGPL sense), while imposing that the source code generated by FloPoCo is also free software (also AGPL-like). The (A)GPL doesn't seem to allow that, so it seems we have to invent something.

Current state of the license is therefore "all right reserved", which just means that the distribution terms are still being decided by the copyright owners (a consortium of the employers of the authors).

If this is a problem for your application, we are ready to negociate a commercial license: contact us.

Documentation

Installation instructions for Linux and Windows.

User manual

Developer manual

Publications related to FloPoCo

For some slides, see a FloPoCo tutorial at HiPEAC 2013.

Publications describing FloPoCo or FloPoCo operators

Publications using FloPoCo

How to cite FloPoCo

If you want to refer to a specific operator, please cite the publication that describes it, if it exists.

Otherwise, or if you want to refer to the framework, or the project as a whole, please cite publication below:

Florent de Dinechin and Bogdan Pasca. Designing custom arithmetic data paths with FloPoCo. IEEE Design & Test of Computers, 28(4):18--27, July 2011. [ bib | .pdf ]


Authors and credits

FloPoCo is managed by Florent de Dinechin (contact: Florent.de-Dinechin at insa-lyon.fr).

Active developers: Nicolas Brunie, Fabrizio Ferrandi, Matei Istoan, Antoine Martinet, David Thomas.

Former developers: Sebastian Banescu, Sylvain Collange, Kinga Illyes, Cristian Klein, Mioara Joldes, Bogdan Pasca, Bogdan Popa, Xavier Pujol, Guillaume Sergent, Radu Tudoran, Alvaro Vasquez.

Much of FloPoCo's operator code is based on FPLibrary and HOTBM code by Jérémie Detrey.

The following people have contributed to FloPoCo in some sort or some other: Greg Davey, Mariusz Grad, Daniele Mastrandrea, Pedro Echeverría Aramendi.

FloPoCo uses Sollya, developed by Christoph Lauter, Sylvain Chevillard and Mioara Joldes. It also relies on GMP and MPFR.

FloPoCo is essentially developed using Free Software. Special thanks to the GHDL project for providing us a perfectly useable VHDL simulator that we can use when we are away from our ModelSim license servers.

The following support is gratefully acknowledged