shlysis.cpp

Go to the documentation of this file.

/************************************************************************
 ************************************************************************
    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.
 ************************************************************************
 ************************************************************************/
 
 
 
/*****************************************************************************
******************************************************************************
                                Tree Sharing Analysis
                        Y. Orlarey, (c) Grame 2002
------------------------------------------------------------------------------
The sharing analysis of tree t is the annotation of all its subtrees t' 
with their number of occurences in t. As this annotation of t' depends of
a context (the tree t for which t' is a subtree) a specific property key
unique to each sharing analysis must be generated.

 API:
 ---- 
    
    shprkey(t) -> k     = unique sharing property key of t
    shcount(k,t') -> n  = returns the number of occurences of t' in t (where k = shprkey(t))
    shlysis(t)  -> k    = annotated the subtrees of t with prop (key sharing-count)
                          (0 if t' is not a subtree of t)

 History :
 ---------
    2002-04-08 : First version
    2006-03-25 : Modifications for new symbolic rec trees
    
******************************************************************************
*****************************************************************************/

#include    <string.h>
#include    <stdlib.h>
#include    <stdio.h>

#include    "shlysis.hh"
#include "compatibility.hh"

Tree shprkey(Tree t) 
{
    char    name[256];
    snprintf(name, 256, "SHARED IN %p : ", (CTree*)t);
    return tree(unique(name));
}   


int shcount(Tree key, Tree t)
{
    Tree c;
    if (getProperty(t, key, c)) {
        return c->node().getInt();
    } else {
        return 0;
    }
}   



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

static void annotate(Tree k, Tree t, barrier foo);

static bool nobarrier (const Tree& t) { return false; }

Tree shlysis(Tree t, barrier foo)
{
    Tree k = shprkey(t);
    annotate(k, t, foo);
    return k;
}


Tree shlysis(Tree t)
{
    Tree k = shprkey(t);
    annotate(k, t, nobarrier);
    return k;
}


static void annotate(Tree k, Tree t, barrier foo)
{
    cerr << "Annotate " << *t << endl;
    int c = shcount(k,t);
    if (c==0) {
        // First visit
        Tree var, body;
        if (isRec(t, var, body)) {
            // special case for recursive trees
            setProperty(t, k, tree(1));
            annotate(k, body, foo);
            return;
        } else {
            int n = t->arity();
            if (n>0 && ! foo(t)) {
                for (int i=0; i<n; i++) annotate(k, t->branch(i), foo);
            }
        }
    } else {
        //printf(" annotate %p with %d\n", (CTree*)t, c+1);
    }
    setProperty(t, k, tree(c+1));
}