sharing.cpp

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/************************************************************************
 ************************************************************************
    FAUST compiler
    Copyright (C) 2003-2004 GRAME, Centre National de Creation Musicale
    ---------------------------------------------------------------------
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 ************************************************************************
 ************************************************************************/



/*****************************************************************************
******************************************************************************
                            FAUST SIGNAL COMPILER
                        Y. Orlarey, (c) Grame 2002
------------------------------------------------------------------------------
Compile a list of FAUST signals into a C++ class .

 History :
 ---------
    2002-02-08 : First version

******************************************************************************
*****************************************************************************/



#include <stdio.h>

#include "compile_vect.hh"
#include "compile_scal.hh"
#include "sigtype.hh"
#include "sigtyperules.hh"
#include "sigprint.hh"



/*****************************************************************************
******************************************************************************

                                SHARING ANALYSIS

******************************************************************************
*****************************************************************************/

//------------------------------------------------------------------------------
// Create a specific property key for the sharing count of subtrees of t
//------------------------------------------------------------------------------

int ScalarCompiler::getSharingCount(Tree sig)
{
    //cerr << "getSharingCount of : " << *sig << " = ";
    Tree c;
    if (getProperty(sig, fSharingKey, c)) {
        //cerr << c->node().getInt() << endl;
        return c->node().getInt();
    } else {
        //cerr << 0 << endl;
        return 0;
    }
}

void ScalarCompiler::setSharingCount(Tree sig, int count)
{
    //cerr << "setSharingCount of : " << *sig << " <- " << count << endl;
    setProperty(sig, fSharingKey, tree(count));
}



//------------------------------------------------------------------------------
// Create a specific property key for the sharing count of subtrees of t
//------------------------------------------------------------------------------


void ScalarCompiler::sharingAnalysis(Tree t)
{
    fSharingKey = shprkey(t);
    if (isList(t)) {
        while (isList(t)) {
            sharingAnnotation(kSamp, hd(t));
            t = tl(t);
        }
    } else {
        sharingAnnotation(kSamp, t);
    }
}



//------------------------------------------------------------------------------
// Create a specific property key for the sharing count of subtrees of t
//------------------------------------------------------------------------------
void ScalarCompiler::sharingAnnotation(int vctxt, Tree sig)
{
    Tree    c, x, y, z;

    //cerr << "START sharing annotation of " << *sig << endl;
    int count = getSharingCount(sig);

    if (count > 0) {
        // it is not our first visit
        setSharingCount(sig, count+1);

    } else {
        // it is our first visit,
        int v = getCertifiedSigType(sig)->variability();

        // check "time sharing" cases
        if (v < vctxt) {
            setSharingCount(sig, 2);    // time sharing occurence : slower expression in faster context
        } else {
            setSharingCount(sig, 1);    // regular occurence
        }

        if (isSigSelect3(sig,c,y,x,z)) {
            // make a special case for select3 implemented with real if
            // because the c expression will be used twice in the C++
            // translation
            sharingAnnotation(v, c);
            sharingAnnotation(v, c);
            sharingAnnotation(v, x);
            sharingAnnotation(v, y);
            sharingAnnotation(v, z);
        } else {
            // Annotate the sub signals
            vector<Tree> subsig;
            int n = getSubSignals(sig, subsig);
            if (n>0 && ! isSigGen(sig)) {
                for (int i=0; i<n; i++) sharingAnnotation(v, subsig[i]);
            }
        }
    }
    //cerr << "END sharing annotation of " << *sig << endl;
}