simplify.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.
 ************************************************************************
 ************************************************************************/



#include <stdio.h>
#include <assert.h>
#include "list.hh"
#include "signals.hh"
#include "sigtype.hh"
#include "recursivness.hh"
#include "sigtyperules.hh"
#include "sigorderrules.hh"
#include "sigprint.hh"
#include "ppsig.hh"
#include "simplify.hh"
#include "num.hh"
#include "xtended.hh"
#include <map>
#include "compatibility.hh"

#include "normalize.hh"

#undef TRACE

// declarations
Tree SIMPLIFIED = tree(symbol("sigSimplifiedProp"));
//static Tree binequiv (Tree sig, int opnum, Tree a, Tree b);
static Tree simplification (Tree sig);
static Tree sigMap (Tree key, tfun f, Tree t);

static Tree traced_simplification(Tree sig)
{
    assert(sig);
#ifdef TRACE
    cerr << ++TABBER << "Start simplification of : " << ppsig(sig) << endl;
    /*
    fprintf(stderr, "\nStart simplification of : ");
    printSignal(sig, stderr);
    fprintf(stderr, "\n");
    */
#endif
    Tree r = simplification(sig);
    assert(r!=0);
#ifdef TRACE
    cerr << --TABBER << "Simplification of : " << ppsig(sig) << " Returns : " << ppsig(r) << endl;
    /*
    fprintf(stderr, "Simplification of : ");
    printSignal(sig, stderr);
    fprintf(stderr, " -> ");
    printSignal(r, stderr);
    fprintf(stderr, "\n");
    */
#endif
    return r;
}

Tree simplify (Tree sig)
{
    return sigMap(SIMPLIFIED, traced_simplification, sig);
}


// Implementation

static Tree simplification (Tree sig)
{
    assert(sig);
    int     opnum;
    Tree    t1, t2, t3, t4;

    xtended* xt = (xtended*) getUserData(sig);
    // primitive elements
    if (xt)
    {
        //return 3;
        vector<Tree> args;
        for (int i=0; i<sig->arity(); i++) { args.push_back( sig->branch(i) ); }

        // to avoid negative power to further normalization
        if (xt != gPowPrim) {
            return xt->computeSigOutput(args);
        } else {
            return normalizeAddTerm(xt->computeSigOutput(args));
        }

    } else if (isSigBinOp(sig, &opnum, t1, t2)) {

        BinOp* op = gBinOpTable[opnum];

        Node n1 = t1->node();
        Node n2 = t2->node();

        if (isNum(n1) && isNum(n2))         return tree(op->compute(n1,n2));

        else if (op->isLeftNeutral(n1))     return t2;

        else if (op->isRightNeutral(n2))    return t1;

        else                                return normalizeAddTerm(sig);

    } else if (isSigDelay1(sig, t1)) {

        return normalizeDelay1Term (t1);

    } else if (isSigFixDelay(sig, t1, t2)) {

        return normalizeFixedDelayTerm (t1, t2);

    } else if (isSigIntCast(sig, t1)) {

        Tree    tx;
        int     i;
        double  x;
        Node    n1 = t1->node();

        if (isInt(n1, &i))          return t1;
        if (isDouble(n1, &x))       return tree(int(x));
        if (isSigIntCast(t1, tx))   return t1;

        return sig;

    } else if (isSigFloatCast(sig, t1)) {

        Tree    tx;
        int     i;
        double  x;
        Node    n1 = t1->node();

        if (isInt(n1, &i))              return tree(double(i));
        if (isDouble(n1, &x))           return t1;
        if (isSigFloatCast(t1, tx))     return t1;

        return sig;

     } else if (isSigSelect2(sig, t1, t2, t3)){

        Node n1 = t1->node();

        if (isZero(n1)) return t2;
        if (isNum(n1))  return t3;

        if (t2==t3) return t2;

        return sig;

    } else if (isSigSelect3(sig, t1, t2, t3, t4)){

        Node n1 = t1->node();

        if (isZero(n1)) return t2;
        if (isOne(n1))  return t3;
        if (isNum(n1))  return t4;

        if (t3==t4) return simplification(sigSelect2(t1,t2,t3));

        return sig;

    } else {

        return sig;
    }
}

static Tree sigMap (Tree key, tfun f, Tree t)
{
    //printf("start sigMap\n");
    Tree p,id,body;

    if (getProperty(t, key, p)) {

        return (isNil(p)) ? t : p;  // truc pour eviter les boucles

    } else if (isRec(t, id, body)) {

        setProperty(t, key, nil);   // avoid infinite loop
        return rec(id, sigMap(key, f, body));

    } else {
        tvec br;
        int n = t->arity();
        for (int i = 0; i < n; i++) {
            br.push_back(sigMap(key,f,t->branch(i)));
        }

        Tree r1 = tree(t->node(), br);

        Tree r2 = f(r1);
        if (r2 == t) {
            setProperty(t, key, nil);
        } else {
            setProperty(t, key, r2);
        }
        return r2;
    }
}





static Tree sigMapRename (Tree key, Tree env, tfun f, Tree t)
{
    //printf("start sigMap\n");
    Tree p,id,body;

    if (getProperty(t, key, p)) {

        return (isNil(p)) ? t : p;  // truc pour eviter les boucles

    } else if (isRec(t, id, body)) {

        assert(isRef(t,id)); // controle temporaire

        Tree id2;
        if (searchEnv(id, id2, env)) {
            // déjà en cours de visite de cette recursion
            return ref(id2);
        } else {
            // premiere visite de cette recursion
            id2 = tree(Node(unique("renamed")));
            Tree body2 = sigMapRename(key, pushEnv(id, id2, env), f, body);
            return rec(id2,body2);
        }

    } else {

        tvec br;
        int n = t->arity();
        for (int i = 0; i < n; i++) {
            br.push_back( sigMapRename(key,env,f,t->branch(i)) );
        }

        Tree r1 = tree(t->node(), br);


        Tree r2 = f(r1);
        if (r2 == t) {
            setProperty(t, key, nil);
        } else {
            setProperty(t, key, r2);
        }
        return r2;
    }
}

#if 0
static void eraseProperties (Tree key, Tree t)
{
    //printf("start sigMap\n");
    Tree p,id,body;

    if (getProperty(t, key, p)) {
        // already erased, nothing to do

    } else if (isRec(t, id, body)) {
        t->clearProperties();
        Tree r=rec(id, body);
        assert(r==t);
        setProperty(t, key, nil);   // avoid infinite loop
        eraseProperties(key, body);

    } else {

        for (int i=0; i<t->arity(); i++) {
            eraseProperties(key,t->branch(i));
        }
    }
}

void eraseAllProperties(Tree t)
{
    cerr << "begin eraseAllProperties" << endl;
    eraseProperties(tree(Node(unique("erase_"))), t);
    cerr << "end eraseAllProperties" << endl;
}
#endif

Tree DOCTABLES = tree(symbol("DocTablesProp"));

static Tree docTableConverter (Tree sig);

static Tree NULLENV = tree(symbol("NullRenameEnv"));

Tree docTableConvertion (Tree sig)
{
    Tree r  = sigMapRename(DOCTABLES, NULLENV, docTableConverter, sig);
    return r;
}


// Implementation

static Tree docTableConverter (Tree sig)
{
    Tree tbl, tbl2, id, id2, size, igen, isig, ridx, widx, wsig;

    if (isSigRDTbl(sig, tbl, ridx)) {
        // we are in a table to convert
        if (isSigTable(tbl, id, size, igen)) {
            // it's a read only table
            assert(isSigGen(igen, isig));
            return sigDocAccessTbl(sigDocConstantTbl(size,isig),ridx);
        } else {
            // it's a read write table
            assert(isSigWRTbl(tbl,id,tbl2,widx,wsig));
            assert(isSigTable(tbl2, id2, size, igen));
            assert(isSigGen(igen, isig));

            return sigDocAccessTbl(sigDocWriteTbl(size,isig,widx,wsig),ridx);
        }

    } else {
        // nothing to convert
        return sig;
    }
}