## Section: New Results

### n-Synchronous Languages

Participants : Louis Mandel [contact] , Marc Pouzet, Albert Cohen, Adrien Guatto.

The n-synchronous model introduced a way to compose streams which have
*almost the same clock* and can be synchronized through the use
of a finite buffer.

We have designed the language Lucy-n to program in this model of computation [40] . This language is similar to the first order synchronous data-flow language Lustre in which a buffer operator is added. A dedicated type system allows to check that programs can be executed in bounded memory and to compute sufficient buffer sizes. Technically it is done through the introduction of a subtyping constraint at each bufferization point.

In collaboration with F. Plateau (Prove&Run), we developed a new resolution constraint algorithm for the clocking of Lucy-n programs [8] . Even if the new algorithm is less efficient that the one using abstraction, it has the advantage to be more precise and thus to accept more programs. It is useful for example for the static scheduling of Latency Insensitive Designs [41] .

We worked on an extension of the synchronous model with integer clocks. This extension allows to produce and consume several values at each activation. It has large implication on the semantics, clock typing, causality and code generation of the language.

We have continue the work on the code generation. In particular, we have been designing a new intermediate representation that allows to deal with integer clocks.