To: seminaire@pauillac.inria.fr
From: Didier.Remy@inria.fr
Subject: SEM - INRIA : Mosvova - 27/06/03 - Paris - FR

      Vous pouvez maintenant vous abonner à nos annonces de séminaires
             http://pauillac.inria.fr/seminaires/subscribe.html


                             S E M I N A I R E
                                         . ___ 
                           /   _   _      /   _   /
                          /   / \ / \  / /   __| /
                         |___ |_/ |_/ / |__ |_/ |_
       ___      .                  /    
      /    ___   __  /_  _   /   _/        /| /|  _   __ __ _       _ 
     /    /   / /_  /   __| /             / |/ | / \ /_ /  / \ | / __|
    |___ /   / __/ |_  |_/ |_            /     | |_/__/ |_ |_/ |/ |_/
                                                
                          I N R I A - Rocquencourt
                                Amphi Turing

                          Vendredi 27 juin, 10h30

                              ---------------
                              Olivier Tardieu
                              ---------------


                 =========================================
                 Instantaneous Termination in Pure Esterel
                 =========================================


   Esterel  is  a  design  language  for  the  representation  of  embedded
   systems.  Based  on the  synchronous  reactive  paradigm, its  execution
   relies  on  a  clear  distinction  of  instants  of  computation.  As  a
   consequence, deciding  whether a piece of  a program may or  may not run
   instantaneously  is   central  to  any  compilation   scheme,  both  for
   correctness and efficiency. In general, this information can be obtained
   by an exhaustive  exploration of all possible execution  paths, which is
   expensive.  Most compilers  approximate it  through  algorithmic methods
   amenable  to static  analysis.  In  this work,  we  first formalize  the
   analysis involved in detecting  statements that may run instantaneously.
   Then, we  identify statements that may terminate  and be instantaneously
   reentered. This  allows us to model precisely  these compilers front-end
   activities with a clear mathematical specification and led us to uncover
   inefficiencies in the Esterel v5  academic compiler from Ecole des Mines
   and INRIA.