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Diffstat (limited to 'src/bdd/cudd/cuddDecomp.c')
| -rw-r--r-- | src/bdd/cudd/cuddDecomp.c | 2150 |
1 files changed, 2150 insertions, 0 deletions
diff --git a/src/bdd/cudd/cuddDecomp.c b/src/bdd/cudd/cuddDecomp.c new file mode 100644 index 00000000..4fde7392 --- /dev/null +++ b/src/bdd/cudd/cuddDecomp.c @@ -0,0 +1,2150 @@ +/**CFile*********************************************************************** + + FileName [cuddDecomp.c] + + PackageName [cudd] + + Synopsis [Functions for BDD decomposition.] + + Description [External procedures included in this file: + <ul> + <li> Cudd_bddApproxConjDecomp() + <li> Cudd_bddApproxDisjDecomp() + <li> Cudd_bddIterConjDecomp() + <li> Cudd_bddIterDisjDecomp() + <li> Cudd_bddGenConjDecomp() + <li> Cudd_bddGenDisjDecomp() + <li> Cudd_bddVarConjDecomp() + <li> Cudd_bddVarDisjDecomp() + </ul> + Static procedures included in this module: + <ul> + <li> cuddConjunctsAux() + <li> CreateBotDist() + <li> BuildConjuncts() + <li> ConjunctsFree() + </ul>] + + Author [Kavita Ravi, Fabio Somenzi] + + Copyright [This file was created at the University of Colorado at + Boulder. The University of Colorado at Boulder makes no warranty + about the suitability of this software for any purpose. It is + presented on an AS IS basis.] + +******************************************************************************/ + +#include "util_hack.h" +#include "cuddInt.h" + +/*---------------------------------------------------------------------------*/ +/* Constant declarations */ +/*---------------------------------------------------------------------------*/ +#define DEPTH 5 +#define THRESHOLD 10 +#define NONE 0 +#define PAIR_ST 1 +#define PAIR_CR 2 +#define G_ST 3 +#define G_CR 4 +#define H_ST 5 +#define H_CR 6 +#define BOTH_G 7 +#define BOTH_H 8 + +/*---------------------------------------------------------------------------*/ +/* Stucture declarations */ +/*---------------------------------------------------------------------------*/ + +/*---------------------------------------------------------------------------*/ +/* Type declarations */ +/*---------------------------------------------------------------------------*/ +typedef struct Conjuncts { + DdNode *g; + DdNode *h; +} Conjuncts; + +typedef struct NodeStat { + int distance; + int localRef; +} NodeStat; + + +/*---------------------------------------------------------------------------*/ +/* Variable declarations */ +/*---------------------------------------------------------------------------*/ + +#ifndef lint +static char rcsid[] DD_UNUSED = "$Id: cuddDecomp.c,v 1.1.1.1 2003/02/24 22:23:51 wjiang Exp $"; +#endif + +static DdNode *one, *zero; +long lastTimeG; + +/*---------------------------------------------------------------------------*/ +/* Macro declarations */ +/*---------------------------------------------------------------------------*/ + + +#define FactorsNotStored(factors) ((int)((long)(factors) & 01)) + +#define FactorsComplement(factors) ((Conjuncts *)((long)(factors) | 01)) + +#define FactorsUncomplement(factors) ((Conjuncts *)((long)(factors) ^ 01)) + +/**AutomaticStart*************************************************************/ + +/*---------------------------------------------------------------------------*/ +/* Static function prototypes */ +/*---------------------------------------------------------------------------*/ + +static NodeStat * CreateBotDist ARGS((DdNode * node, st_table * distanceTable)); +static double CountMinterms ARGS((DdNode * node, double max, st_table * mintermTable, FILE *fp)); +static void ConjunctsFree ARGS((DdManager * dd, Conjuncts * factors)); +static int PairInTables ARGS((DdNode * g, DdNode * h, st_table * ghTable)); +static Conjuncts * CheckTablesCacheAndReturn ARGS((DdNode * node, DdNode * g, DdNode * h, st_table * ghTable, st_table * cacheTable)); +static Conjuncts * PickOnePair ARGS((DdNode * node, DdNode * g1, DdNode * h1, DdNode * g2, DdNode * h2, st_table * ghTable, st_table * cacheTable)); +static Conjuncts * CheckInTables ARGS((DdNode * node, DdNode * g1, DdNode * h1, DdNode * g2, DdNode * h2, st_table * ghTable, st_table * cacheTable, int * outOfMem)); +static Conjuncts * ZeroCase ARGS((DdManager * dd, DdNode * node, Conjuncts * factorsNv, st_table * ghTable, st_table * cacheTable, int switched)); +static Conjuncts * BuildConjuncts ARGS((DdManager * dd, DdNode * node, st_table * distanceTable, st_table * cacheTable, int approxDistance, int maxLocalRef, st_table * ghTable, st_table * mintermTable)); +static int cuddConjunctsAux ARGS((DdManager * dd, DdNode * f, DdNode ** c1, DdNode ** c2)); + +/**AutomaticEnd***************************************************************/ + + +/*---------------------------------------------------------------------------*/ +/* Definition of exported functions */ +/*---------------------------------------------------------------------------*/ + + +/**Function******************************************************************** + + Synopsis [Performs two-way conjunctive decomposition of a BDD.] + + Description [Performs two-way conjunctive decomposition of a + BDD. This procedure owes its name to the use of supersetting to + obtain an initial factor of the given function. Returns the number + of conjuncts produced, that is, 2 if successful; 1 if no meaningful + decomposition was found; 0 otherwise. The conjuncts produced by this + procedure tend to be imbalanced.] + + SideEffects [The factors are returned in an array as side effects. + The array is allocated by this function. It is the caller's responsibility + to free it. On successful completion, the conjuncts are already + referenced. If the function returns 0, the array for the conjuncts is + not allocated. If the function returns 1, the only factor equals the + function to be decomposed.] + + SeeAlso [Cudd_bddApproxDisjDecomp Cudd_bddIterConjDecomp + Cudd_bddGenConjDecomp Cudd_bddVarConjDecomp Cudd_RemapOverApprox + Cudd_bddSqueeze Cudd_bddLICompaction] + +******************************************************************************/ +int +Cudd_bddApproxConjDecomp( + DdManager * dd /* manager */, + DdNode * f /* function to be decomposed */, + DdNode *** conjuncts /* address of the first factor */) +{ + DdNode *superset1, *superset2, *glocal, *hlocal; + int nvars = Cudd_SupportSize(dd,f); + + /* Find a tentative first factor by overapproximation and minimization. */ + superset1 = Cudd_RemapOverApprox(dd,f,nvars,0,1.0); + if (superset1 == NULL) return(0); + cuddRef(superset1); + superset2 = Cudd_bddSqueeze(dd,f,superset1); + if (superset2 == NULL) { + Cudd_RecursiveDeref(dd,superset1); + return(0); + } + cuddRef(superset2); + Cudd_RecursiveDeref(dd,superset1); + + /* Compute the second factor by minimization. */ + hlocal = Cudd_bddLICompaction(dd,f,superset2); + if (hlocal == NULL) { + Cudd_RecursiveDeref(dd,superset2); + return(0); + } + cuddRef(hlocal); + + /* Refine the first factor by minimization. If h turns out to be f, this + ** step guarantees that g will be 1. */ + glocal = Cudd_bddLICompaction(dd,superset2,hlocal); + if (glocal == NULL) { + Cudd_RecursiveDeref(dd,superset2); + Cudd_RecursiveDeref(dd,hlocal); + return(0); + } + cuddRef(glocal); + Cudd_RecursiveDeref(dd,superset2); + + if (glocal != DD_ONE(dd)) { + if (hlocal != DD_ONE(dd)) { + *conjuncts = ALLOC(DdNode *,2); + if (*conjuncts == NULL) { + Cudd_RecursiveDeref(dd,glocal); + Cudd_RecursiveDeref(dd,hlocal); + dd->errorCode = CUDD_MEMORY_OUT; + return(0); + } + (*conjuncts)[0] = glocal; + (*conjuncts)[1] = hlocal; + return(2); + } else { + Cudd_RecursiveDeref(dd,hlocal); + *conjuncts = ALLOC(DdNode *,1); + if (*conjuncts == NULL) { + Cudd_RecursiveDeref(dd,glocal); + dd->errorCode = CUDD_MEMORY_OUT; + return(0); + } + (*conjuncts)[0] = glocal; + return(1); + } + } else { + Cudd_RecursiveDeref(dd,glocal); + *conjuncts = ALLOC(DdNode *,1); + if (*conjuncts == NULL) { + Cudd_RecursiveDeref(dd,hlocal); + dd->errorCode = CUDD_MEMORY_OUT; + return(0); + } + (*conjuncts)[0] = hlocal; + return(1); + } + +} /* end of Cudd_bddApproxConjDecomp */ + + +/**Function******************************************************************** + + Synopsis [Performs two-way disjunctive decomposition of a BDD.] + + Description [Performs two-way disjunctive decomposition of a BDD. + Returns the number of disjuncts produced, that is, 2 if successful; + 1 if no meaningful decomposition was found; 0 otherwise. The + disjuncts produced by this procedure tend to be imbalanced.] + + SideEffects [The two disjuncts are returned in an array as side effects. + The array is allocated by this function. It is the caller's responsibility + to free it. On successful completion, the disjuncts are already + referenced. If the function returns 0, the array for the disjuncts is + not allocated. If the function returns 1, the only factor equals the + function to be decomposed.] + + SeeAlso [Cudd_bddApproxConjDecomp Cudd_bddIterDisjDecomp + Cudd_bddGenDisjDecomp Cudd_bddVarDisjDecomp] + +******************************************************************************/ +int +Cudd_bddApproxDisjDecomp( + DdManager * dd /* manager */, + DdNode * f /* function to be decomposed */, + DdNode *** disjuncts /* address of the array of the disjuncts */) +{ + int result, i; + + result = Cudd_bddApproxConjDecomp(dd,Cudd_Not(f),disjuncts); + for (i = 0; i < result; i++) { + (*disjuncts)[i] = Cudd_Not((*disjuncts)[i]); + } + return(result); + +} /* end of Cudd_bddApproxDisjDecomp */ + + +/**Function******************************************************************** + + Synopsis [Performs two-way conjunctive decomposition of a BDD.] + + Description [Performs two-way conjunctive decomposition of a + BDD. This procedure owes its name to the iterated use of + supersetting to obtain a factor of the given function. Returns the + number of conjuncts produced, that is, 2 if successful; 1 if no + meaningful decomposition was found; 0 otherwise. The conjuncts + produced by this procedure tend to be imbalanced.] + + SideEffects [The factors are returned in an array as side effects. + The array is allocated by this function. It is the caller's responsibility + to free it. On successful completion, the conjuncts are already + referenced. If the function returns 0, the array for the conjuncts is + not allocated. If the function returns 1, the only factor equals the + function to be decomposed.] + + SeeAlso [Cudd_bddIterDisjDecomp Cudd_bddApproxConjDecomp + Cudd_bddGenConjDecomp Cudd_bddVarConjDecomp Cudd_RemapOverApprox + Cudd_bddSqueeze Cudd_bddLICompaction] + +******************************************************************************/ +int +Cudd_bddIterConjDecomp( + DdManager * dd /* manager */, + DdNode * f /* function to be decomposed */, + DdNode *** conjuncts /* address of the array of conjuncts */) +{ + DdNode *superset1, *superset2, *old[2], *res[2]; + int sizeOld, sizeNew; + int nvars = Cudd_SupportSize(dd,f); + + old[0] = DD_ONE(dd); + cuddRef(old[0]); + old[1] = f; + cuddRef(old[1]); + sizeOld = Cudd_SharingSize(old,2); + + do { + /* Find a tentative first factor by overapproximation and + ** minimization. */ + superset1 = Cudd_RemapOverApprox(dd,old[1],nvars,0,1.0); + if (superset1 == NULL) { + Cudd_RecursiveDeref(dd,old[0]); + Cudd_RecursiveDeref(dd,old[1]); + return(0); + } + cuddRef(superset1); + superset2 = Cudd_bddSqueeze(dd,old[1],superset1); + if (superset2 == NULL) { + Cudd_RecursiveDeref(dd,old[0]); + Cudd_RecursiveDeref(dd,old[1]); + Cudd_RecursiveDeref(dd,superset1); + return(0); + } + cuddRef(superset2); + Cudd_RecursiveDeref(dd,superset1); + res[0] = Cudd_bddAnd(dd,old[0],superset2); + if (res[0] == NULL) { + Cudd_RecursiveDeref(dd,superset2); + Cudd_RecursiveDeref(dd,old[0]); + Cudd_RecursiveDeref(dd,old[1]); + return(0); + } + cuddRef(res[0]); + Cudd_RecursiveDeref(dd,superset2); + if (res[0] == old[0]) { + Cudd_RecursiveDeref(dd,res[0]); + break; /* avoid infinite loop */ + } + + /* Compute the second factor by minimization. */ + res[1] = Cudd_bddLICompaction(dd,old[1],res[0]); + if (res[1] == NULL) { + Cudd_RecursiveDeref(dd,old[0]); + Cudd_RecursiveDeref(dd,old[1]); + return(0); + } + cuddRef(res[1]); + + sizeNew = Cudd_SharingSize(res,2); + if (sizeNew <= sizeOld) { + Cudd_RecursiveDeref(dd,old[0]); + old[0] = res[0]; + Cudd_RecursiveDeref(dd,old[1]); + old[1] = res[1]; + sizeOld = sizeNew; + } else { + Cudd_RecursiveDeref(dd,res[0]); + Cudd_RecursiveDeref(dd,res[1]); + break; + } + + } while (1); + + /* Refine the first factor by minimization. If h turns out to + ** be f, this step guarantees that g will be 1. */ + superset1 = Cudd_bddLICompaction(dd,old[0],old[1]); + if (superset1 == NULL) { + Cudd_RecursiveDeref(dd,old[0]); + Cudd_RecursiveDeref(dd,old[1]); + return(0); + } + cuddRef(superset1); + Cudd_RecursiveDeref(dd,old[0]); + old[0] = superset1; + + if (old[0] != DD_ONE(dd)) { + if (old[1] != DD_ONE(dd)) { + *conjuncts = ALLOC(DdNode *,2); + if (*conjuncts == NULL) { + Cudd_RecursiveDeref(dd,old[0]); + Cudd_RecursiveDeref(dd,old[1]); + dd->errorCode = CUDD_MEMORY_OUT; + return(0); + } + (*conjuncts)[0] = old[0]; + (*conjuncts)[1] = old[1]; + return(2); + } else { + Cudd_RecursiveDeref(dd,old[1]); + *conjuncts = ALLOC(DdNode *,1); + if (*conjuncts == NULL) { + Cudd_RecursiveDeref(dd,old[0]); + dd->errorCode = CUDD_MEMORY_OUT; + return(0); + } + (*conjuncts)[0] = old[0]; + return(1); + } + } else { + Cudd_RecursiveDeref(dd,old[0]); + *conjuncts = ALLOC(DdNode *,1); + if (*conjuncts == NULL) { + Cudd_RecursiveDeref(dd,old[1]); + dd->errorCode = CUDD_MEMORY_OUT; + return(0); + } + (*conjuncts)[0] = old[1]; + return(1); + } + +} /* end of Cudd_bddIterConjDecomp */ + + +/**Function******************************************************************** + + Synopsis [Performs two-way disjunctive decomposition of a BDD.] + + Description [Performs two-way disjunctive decomposition of a BDD. + Returns the number of disjuncts produced, that is, 2 if successful; + 1 if no meaningful decomposition was found; 0 otherwise. The + disjuncts produced by this procedure tend to be imbalanced.] + + SideEffects [The two disjuncts are returned in an array as side effects. + The array is allocated by this function. It is the caller's responsibility + to free it. On successful completion, the disjuncts are already + referenced. If the function returns 0, the array for the disjuncts is + not allocated. If the function returns 1, the only factor equals the + function to be decomposed.] + + SeeAlso [Cudd_bddIterConjDecomp Cudd_bddApproxDisjDecomp + Cudd_bddGenDisjDecomp Cudd_bddVarDisjDecomp] + +******************************************************************************/ +int +Cudd_bddIterDisjDecomp( + DdManager * dd /* manager */, + DdNode * f /* function to be decomposed */, + DdNode *** disjuncts /* address of the array of the disjuncts */) +{ + int result, i; + + result = Cudd_bddIterConjDecomp(dd,Cudd_Not(f),disjuncts); + for (i = 0; i < result; i++) { + (*disjuncts)[i] = Cudd_Not((*disjuncts)[i]); + } + return(result); + +} /* end of Cudd_bddIterDisjDecomp */ + + +/**Function******************************************************************** + + Synopsis [Performs two-way conjunctive decomposition of a BDD.] + + Description [Performs two-way conjunctive decomposition of a + BDD. This procedure owes its name to the fact tht it generalizes the + decomposition based on the cofactors with respect to one + variable. Returns the number of conjuncts produced, that is, 2 if + successful; 1 if no meaningful decomposition was found; 0 + otherwise. The conjuncts produced by this procedure tend to be + balanced.] + + SideEffects [The two factors are returned in an array as side effects. + The array is allocated by this function. It is the caller's responsibility + to free it. On successful completion, the conjuncts are already + referenced. If the function returns 0, the array for the conjuncts is + not allocated. If the function returns 1, the only factor equals the + function to be decomposed.] + + SeeAlso [Cudd_bddGenDisjDecomp Cudd_bddApproxConjDecomp + Cudd_bddIterConjDecomp Cudd_bddVarConjDecomp] + +******************************************************************************/ +int +Cudd_bddGenConjDecomp( + DdManager * dd /* manager */, + DdNode * f /* function to be decomposed */, + DdNode *** conjuncts /* address of the array of conjuncts */) +{ + int result; + DdNode *glocal, *hlocal; + + one = DD_ONE(dd); + zero = Cudd_Not(one); + + do { + dd->reordered = 0; + result = cuddConjunctsAux(dd, f, &glocal, &hlocal); + } while (dd->reordered == 1); + + if (result == 0) { + return(0); + } + + if (glocal != one) { + if (hlocal != one) { + *conjuncts = ALLOC(DdNode *,2); + if (*conjuncts == NULL) { + Cudd_RecursiveDeref(dd,glocal); + Cudd_RecursiveDeref(dd,hlocal); + dd->errorCode = CUDD_MEMORY_OUT; + return(0); + } + (*conjuncts)[0] = glocal; + (*conjuncts)[1] = hlocal; + return(2); + } else { + Cudd_RecursiveDeref(dd,hlocal); + *conjuncts = ALLOC(DdNode *,1); + if (*conjuncts == NULL) { + Cudd_RecursiveDeref(dd,glocal); + dd->errorCode = CUDD_MEMORY_OUT; + return(0); + } + (*conjuncts)[0] = glocal; + return(1); + } + } else { + Cudd_RecursiveDeref(dd,glocal); + *conjuncts = ALLOC(DdNode *,1); + if (*conjuncts == NULL) { + Cudd_RecursiveDeref(dd,hlocal); + dd->errorCode = CUDD_MEMORY_OUT; + return(0); + } + (*conjuncts)[0] = hlocal; + return(1); + } + +} /* end of Cudd_bddGenConjDecomp */ + + +/**Function******************************************************************** + + Synopsis [Performs two-way disjunctive decomposition of a BDD.] + + Description [Performs two-way disjunctive decomposition of a BDD. + Returns the number of disjuncts produced, that is, 2 if successful; + 1 if no meaningful decomposition was found; 0 otherwise. The + disjuncts produced by this procedure tend to be balanced.] + + SideEffects [The two disjuncts are returned in an array as side effects. + The array is allocated by this function. It is the caller's responsibility + to free it. On successful completion, the disjuncts are already + referenced. If the function returns 0, the array for the disjuncts is + not allocated. If the function returns 1, the only factor equals the + function to be decomposed.] + + SeeAlso [Cudd_bddGenConjDecomp Cudd_bddApproxDisjDecomp + Cudd_bddIterDisjDecomp Cudd_bddVarDisjDecomp] + +******************************************************************************/ +int +Cudd_bddGenDisjDecomp( + DdManager * dd /* manager */, + DdNode * f /* function to be decomposed */, + DdNode *** disjuncts /* address of the array of the disjuncts */) +{ + int result, i; + + result = Cudd_bddGenConjDecomp(dd,Cudd_Not(f),disjuncts); + for (i = 0; i < result; i++) { + (*disjuncts)[i] = Cudd_Not((*disjuncts)[i]); + } + return(result); + +} /* end of Cudd_bddGenDisjDecomp */ + + +/**Function******************************************************************** + + Synopsis [Performs two-way conjunctive decomposition of a BDD.] + + Description [Conjunctively decomposes one BDD according to a + variable. If <code>f</code> is the function of the BDD and + <code>x</code> is the variable, the decomposition is + <code>(f+x)(f+x')</code>. The variable is chosen so as to balance + the sizes of the two conjuncts and to keep them small. Returns the + number of conjuncts produced, that is, 2 if successful; 1 if no + meaningful decomposition was found; 0 otherwise.] + + SideEffects [The two factors are returned in an array as side effects. + The array is allocated by this function. It is the caller's responsibility + to free it. On successful completion, the conjuncts are already + referenced. If the function returns 0, the array for the conjuncts is + not allocated. If the function returns 1, the only factor equals the + function to be decomposed.] + + SeeAlso [Cudd_bddVarDisjDecomp Cudd_bddGenConjDecomp + Cudd_bddApproxConjDecomp Cudd_bddIterConjDecomp] + +*****************************************************************************/ +int +Cudd_bddVarConjDecomp( + DdManager * dd /* manager */, + DdNode * f /* function to be decomposed */, + DdNode *** conjuncts /* address of the array of conjuncts */) +{ + int best; + int min; + DdNode *support, *scan, *var, *glocal, *hlocal; + + /* Find best cofactoring variable. */ + support = Cudd_Support(dd,f); + if (support == NULL) return(0); + if (Cudd_IsConstant(support)) { + *conjuncts = ALLOC(DdNode *,1); + if (*conjuncts == NULL) { + dd->errorCode = CUDD_MEMORY_OUT; + return(0); + } + (*conjuncts)[0] = f; + cuddRef((*conjuncts)[0]); + return(1); + } + cuddRef(support); + min = 1000000000; + best = -1; + scan = support; + while (!Cudd_IsConstant(scan)) { + int i = scan->index; + int est1 = Cudd_EstimateCofactor(dd,f,i,1); + int est0 = Cudd_EstimateCofactor(dd,f,i,0); + /* Minimize the size of the larger of the two cofactors. */ + int est = (est1 > est0) ? est1 : est0; + if (est < min) { + min = est; + best = i; + } + scan = cuddT(scan); + } +#ifdef DD_DEBUG + assert(best >= 0 && best < dd->size); +#endif + Cudd_RecursiveDeref(dd,support); + + var = Cudd_bddIthVar(dd,best); + glocal = Cudd_bddOr(dd,f,var); + if (glocal == NULL) { + return(0); + } + cuddRef(glocal); + hlocal = Cudd_bddOr(dd,f,Cudd_Not(var)); + if (hlocal == NULL) { + Cudd_RecursiveDeref(dd,glocal); + return(0); + } + cuddRef(hlocal); + + if (glocal != DD_ONE(dd)) { + if (hlocal != DD_ONE(dd)) { + *conjuncts = ALLOC(DdNode *,2); + if (*conjuncts == NULL) { + Cudd_RecursiveDeref(dd,glocal); + Cudd_RecursiveDeref(dd,hlocal); + dd->errorCode = CUDD_MEMORY_OUT; + return(0); + } + (*conjuncts)[0] = glocal; + (*conjuncts)[1] = hlocal; + return(2); + } else { + Cudd_RecursiveDeref(dd,hlocal); + *conjuncts = ALLOC(DdNode *,1); + if (*conjuncts == NULL) { + Cudd_RecursiveDeref(dd,glocal); + dd->errorCode = CUDD_MEMORY_OUT; + return(0); + } + (*conjuncts)[0] = glocal; + return(1); + } + } else { + Cudd_RecursiveDeref(dd,glocal); + *conjuncts = ALLOC(DdNode *,1); + if (*conjuncts == NULL) { + Cudd_RecursiveDeref(dd,hlocal); + dd->errorCode = CUDD_MEMORY_OUT; + return(0); + } + (*conjuncts)[0] = hlocal; + return(1); + } + +} /* end of Cudd_bddVarConjDecomp */ + + +/**Function******************************************************************** + + Synopsis [Performs two-way disjunctive decomposition of a BDD.] + + Description [Performs two-way disjunctive decomposition of a BDD + according to a variable. If <code>f</code> is the function of the + BDD and <code>x</code> is the variable, the decomposition is + <code>f*x + f*x'</code>. The variable is chosen so as to balance + the sizes of the two disjuncts and to keep them small. Returns the + number of disjuncts produced, that is, 2 if successful; 1 if no + meaningful decomposition was found; 0 otherwise.] + + SideEffects [The two disjuncts are returned in an array as side effects. + The array is allocated by this function. It is the caller's responsibility + to free it. On successful completion, the disjuncts are already + referenced. If the function returns 0, the array for the disjuncts is + not allocated. If the function returns 1, the only factor equals the + function to be decomposed.] + + SeeAlso [Cudd_bddVarConjDecomp Cudd_bddApproxDisjDecomp + Cudd_bddIterDisjDecomp Cudd_bddGenDisjDecomp] + +******************************************************************************/ +int +Cudd_bddVarDisjDecomp( + DdManager * dd /* manager */, + DdNode * f /* function to be decomposed */, + DdNode *** disjuncts /* address of the array of the disjuncts */) +{ + int result, i; + + result = Cudd_bddVarConjDecomp(dd,Cudd_Not(f),disjuncts); + for (i = 0; i < result; i++) { + (*disjuncts)[i] = Cudd_Not((*disjuncts)[i]); + } + return(result); + +} /* end of Cudd_bddVarDisjDecomp */ + + +/*---------------------------------------------------------------------------*/ +/* Definition of internal functions */ +/*---------------------------------------------------------------------------*/ + +/*---------------------------------------------------------------------------*/ +/* Definition of static functions */ +/*---------------------------------------------------------------------------*/ + + +/**Function******************************************************************** + + Synopsis [Get longest distance of node from constant.] + + Description [Get longest distance of node from constant. Returns the + distance of the root from the constant if successful; CUDD_OUT_OF_MEM + otherwise.] + + SideEffects [None] + + SeeAlso [] + +******************************************************************************/ +static NodeStat * +CreateBotDist( + DdNode * node, + st_table * distanceTable) +{ + DdNode *N, *Nv, *Nnv; + int distance, distanceNv, distanceNnv; + NodeStat *nodeStat, *nodeStatNv, *nodeStatNnv; + +#if 0 + if (Cudd_IsConstant(node)) { + return(0); + } +#endif + + /* Return the entry in the table if found. */ + N = Cudd_Regular(node); + if (st_lookup(distanceTable, (char *)N, (char **)&nodeStat)) { + nodeStat->localRef++; + return(nodeStat); + } + + Nv = cuddT(N); + Nnv = cuddE(N); + Nv = Cudd_NotCond(Nv, Cudd_IsComplement(node)); + Nnv = Cudd_NotCond(Nnv, Cudd_IsComplement(node)); + + /* Recur on the children. */ + nodeStatNv = CreateBotDist(Nv, distanceTable); + if (nodeStatNv == NULL) return(NULL); + distanceNv = nodeStatNv->distance; + + nodeStatNnv = CreateBotDist(Nnv, distanceTable); + if (nodeStatNnv == NULL) return(NULL); + distanceNnv = nodeStatNnv->distance; + /* Store max distance from constant; note sometimes this distance + ** may be to 0. + */ + distance = (distanceNv > distanceNnv) ? (distanceNv+1) : (distanceNnv + 1); + + nodeStat = ALLOC(NodeStat, 1); + if (nodeStat == NULL) { + return(0); + } + nodeStat->distance = distance; + nodeStat->localRef = 1; + + if (st_insert(distanceTable, (char *)N, (char *)nodeStat) == + ST_OUT_OF_MEM) { + return(0); + + } + return(nodeStat); + +} /* end of CreateBotDist */ + + +/**Function******************************************************************** + + Synopsis [Count the number of minterms of each node ina a BDD and + store it in a hash table.] + + Description [] + + SideEffects [None] + + SeeAlso [] + +******************************************************************************/ +static double +CountMinterms( + DdNode * node, + double max, + st_table * mintermTable, + FILE *fp) +{ + DdNode *N, *Nv, *Nnv; + double min, minNv, minNnv; + double *dummy; + + N = Cudd_Regular(node); + + if (cuddIsConstant(N)) { + if (node == zero) { + return(0); + } else { + return(max); + } + } + + /* Return the entry in the table if found. */ + if (st_lookup(mintermTable, (char *)node, (char **)&dummy)) { + min = *dummy; + return(min); + } + + Nv = cuddT(N); + Nnv = cuddE(N); + Nv = Cudd_NotCond(Nv, Cudd_IsComplement(node)); + Nnv = Cudd_NotCond(Nnv, Cudd_IsComplement(node)); + + /* Recur on the children. */ + minNv = CountMinterms(Nv, max, mintermTable, fp); + if (minNv == -1.0) return(-1.0); + minNnv = CountMinterms(Nnv, max, mintermTable, fp); + if (minNnv == -1.0) return(-1.0); + min = minNv / 2.0 + minNnv / 2.0; + /* store + */ + + dummy = ALLOC(double, 1); + if (dummy == NULL) return(-1.0); + *dummy = min; + if (st_insert(mintermTable, (char *)node, (char *)dummy) == ST_OUT_OF_MEM) { + (void) fprintf(fp, "st table insert failed\n"); + } + return(min); + +} /* end of CountMinterms */ + + +/**Function******************************************************************** + + Synopsis [Free factors structure] + + Description [] + + SideEffects [None] + + SeeAlso [] + +******************************************************************************/ +static void +ConjunctsFree( + DdManager * dd, + Conjuncts * factors) +{ + Cudd_RecursiveDeref(dd, factors->g); + Cudd_RecursiveDeref(dd, factors->h); + FREE(factors); + return; + +} /* end of ConjunctsFree */ + + +/**Function******************************************************************** + + Synopsis [Check whether the given pair is in the tables.] + + Description [.Check whether the given pair is in the tables. gTable + and hTable are combined. + absence in both is indicated by 0, + presence in gTable is indicated by 1, + presence in hTable by 2 and + presence in both by 3. + The values returned by this function are PAIR_ST, + PAIR_CR, G_ST, G_CR, H_ST, H_CR, BOTH_G, BOTH_H, NONE. + PAIR_ST implies g in gTable and h in hTable + PAIR_CR implies g in hTable and h in gTable + G_ST implies g in gTable and h not in any table + G_CR implies g in hTable and h not in any table + H_ST implies h in hTable and g not in any table + H_CR implies h in gTable and g not in any table + BOTH_G implies both in gTable + BOTH_H implies both in hTable + NONE implies none in table; ] + + SideEffects [] + + SeeAlso [CheckTablesCacheAndReturn CheckInTables] + +******************************************************************************/ +static int +PairInTables( + DdNode * g, + DdNode * h, + st_table * ghTable) +{ + int valueG, valueH, gPresent, hPresent; + + valueG = valueH = gPresent = hPresent = 0; + + gPresent = st_lookup_int(ghTable, (char *)Cudd_Regular(g), &valueG); + hPresent = st_lookup_int(ghTable, (char *)Cudd_Regular(h), &valueH); + + if (!gPresent && !hPresent) return(NONE); + + if (!hPresent) { + if (valueG & 1) return(G_ST); + if (valueG & 2) return(G_CR); + } + if (!gPresent) { + if (valueH & 1) return(H_CR); + if (valueH & 2) return(H_ST); + } + /* both in tables */ + if ((valueG & 1) && (valueH & 2)) return(PAIR_ST); + if ((valueG & 2) && (valueH & 1)) return(PAIR_CR); + + if (valueG & 1) { + return(BOTH_G); + } else { + return(BOTH_H); + } + +} /* end of PairInTables */ + + +/**Function******************************************************************** + + Synopsis [Check the tables for the existence of pair and return one + combination, cache the result.] + + Description [Check the tables for the existence of pair and return + one combination, cache the result. The assumption is that one of the + conjuncts is already in the tables.] + + SideEffects [g and h referenced for the cache] + + SeeAlso [ZeroCase] + +******************************************************************************/ +static Conjuncts * +CheckTablesCacheAndReturn( + DdNode * node, + DdNode * g, + DdNode * h, + st_table * ghTable, + st_table * cacheTable) +{ + int pairValue; + int value; + Conjuncts *factors; + + value = 0; + /* check tables */ + pairValue = PairInTables(g, h, ghTable); + assert(pairValue != NONE); + /* if both dont exist in table, we know one exists(either g or h). + * Therefore store the other and proceed + */ + factors = ALLOC(Conjuncts, 1); + if (factors == NULL) return(NULL); + if ((pairValue == BOTH_H) || (pairValue == H_ST)) { + if (g != one) { + value = 0; + if (st_lookup_int(ghTable, (char *)Cudd_Regular(g), &value)) { + value |= 1; + } else { + value = 1; + } + if (st_insert(ghTable, (char *)Cudd_Regular(g), + (char *)(long)value) == ST_OUT_OF_MEM) { + return(NULL); + } + } + factors->g = g; + factors->h = h; + } else if ((pairValue == BOTH_G) || (pairValue == G_ST)) { + if (h != one) { + value = 0; + if (st_lookup_int(ghTable, (char *)Cudd_Regular(h), &value)) { + value |= 2; + } else { + value = 2; + } + if (st_insert(ghTable, (char *)Cudd_Regular(h), + (char *)(long)value) == ST_OUT_OF_MEM) { + return(NULL); + } + } + factors->g = g; + factors->h = h; + } else if (pairValue == H_CR) { + if (g != one) { + value = 2; + if (st_insert(ghTable, (char *)Cudd_Regular(g), + (char *)(long)value) == ST_OUT_OF_MEM) { + return(NULL); + } + } + factors->g = h; + factors->h = g; + } else if (pairValue == G_CR) { + if (h != one) { + value = 1; + if (st_insert(ghTable, (char *)Cudd_Regular(h), + (char *)(long)value) == ST_OUT_OF_MEM) { + return(NULL); + } + } + factors->g = h; + factors->h = g; + } else if (pairValue == PAIR_CR) { + /* pair exists in table */ + factors->g = h; + factors->h = g; + } else if (pairValue == PAIR_ST) { + factors->g = g; + factors->h = h; + } + + /* cache the result for this node */ + if (st_insert(cacheTable, (char *)node, (char *)factors) == ST_OUT_OF_MEM) { + FREE(factors); + return(NULL); + } + + return(factors); + +} /* end of CheckTablesCacheAndReturn */ + +/**Function******************************************************************** + + Synopsis [Check the tables for the existence of pair and return one + combination, store in cache.] + + Description [Check the tables for the existence of pair and return + one combination, store in cache. The pair that has more pointers to + it is picked. An approximation of the number of local pointers is + made by taking the reference count of the pairs sent. ] + + SideEffects [] + + SeeAlso [ZeroCase BuildConjuncts] + +******************************************************************************/ +static Conjuncts * +PickOnePair( + DdNode * node, + DdNode * g1, + DdNode * h1, + DdNode * g2, + DdNode * h2, + st_table * ghTable, + st_table * cacheTable) +{ + int value; + Conjuncts *factors; + int oneRef, twoRef; + + factors = ALLOC(Conjuncts, 1); + if (factors == NULL) return(NULL); + + /* count the number of pointers to pair 2 */ + if (h2 == one) { + twoRef = (Cudd_Regular(g2))->ref; + } else if (g2 == one) { + twoRef = (Cudd_Regular(h2))->ref; + } else { + twoRef = ((Cudd_Regular(g2))->ref + (Cudd_Regular(h2))->ref)/2; + } + + /* count the number of pointers to pair 1 */ + if (h1 == one) { + oneRef = (Cudd_Regular(g1))->ref; + } else if (g1 == one) { + oneRef = (Cudd_Regular(h1))->ref; + } else { + oneRef = ((Cudd_Regular(g1))->ref + (Cudd_Regular(h1))->ref)/2; + } + + /* pick the pair with higher reference count */ + if (oneRef >= twoRef) { + factors->g = g1; + factors->h = h1; + } else { + factors->g = g2; + factors->h = h2; + } + + /* + * Store computed factors in respective tables to encourage + * recombination. + */ + if (factors->g != one) { + /* insert g in htable */ + value = 0; + if (st_lookup_int(ghTable, (char *)Cudd_Regular(factors->g), &value)) { + if (value == 2) { + value |= 1; + if (st_insert(ghTable, (char *)Cudd_Regular(factors->g), + (char *)(long)value) == ST_OUT_OF_MEM) { + FREE(factors); + return(NULL); + } + } + } else { + value = 1; + if (st_insert(ghTable, (char *)Cudd_Regular(factors->g), + (char *)(long)value) == ST_OUT_OF_MEM) { + FREE(factors); + return(NULL); + } + } + } + + if (factors->h != one) { + /* insert h in htable */ + value = 0; + if (st_lookup_int(ghTable, (char *)Cudd_Regular(factors->h), &value)) { + if (value == 1) { + value |= 2; + if (st_insert(ghTable, (char *)Cudd_Regular(factors->h), + (char *)(long)value) == ST_OUT_OF_MEM) { + FREE(factors); + return(NULL); + } + } + } else { + value = 2; + if (st_insert(ghTable, (char *)Cudd_Regular(factors->h), + (char *)(long)value) == ST_OUT_OF_MEM) { + FREE(factors); + return(NULL); + } + } + } + + /* Store factors in cache table for later use. */ + if (st_insert(cacheTable, (char *)node, (char *)factors) == + ST_OUT_OF_MEM) { + FREE(factors); + return(NULL); + } + + return(factors); + +} /* end of PickOnePair */ + + +/**Function******************************************************************** + + Synopsis [Check if the two pairs exist in the table, If any of the + conjuncts do exist, store in the cache and return the corresponding pair.] + + Description [Check if the two pairs exist in the table. If any of + the conjuncts do exist, store in the cache and return the + corresponding pair.] + + SideEffects [] + + SeeAlso [ZeroCase BuildConjuncts] + +******************************************************************************/ +static Conjuncts * +CheckInTables( + DdNode * node, + DdNode * g1, + DdNode * h1, + DdNode * g2, + DdNode * h2, + st_table * ghTable, + st_table * cacheTable, + int * outOfMem) +{ + int pairValue1, pairValue2; + Conjuncts *factors; + int value; + + *outOfMem = 0; + + /* check existence of pair in table */ + pairValue1 = PairInTables(g1, h1, ghTable); + pairValue2 = PairInTables(g2, h2, ghTable); + + /* if none of the 4 exist in the gh tables, return NULL */ + if ((pairValue1 == NONE) && (pairValue2 == NONE)) { + return NULL; + } + + factors = ALLOC(Conjuncts, 1); + if (factors == NULL) { + *outOfMem = 1; + return NULL; + } + + /* pairs that already exist in the table get preference. */ + if (pairValue1 == PAIR_ST) { + factors->g = g1; + factors->h = h1; + } else if (pairValue2 == PAIR_ST) { + factors->g = g2; + factors->h = h2; + } else if (pairValue1 == PAIR_CR) { + factors->g = h1; + factors->h = g1; + } else if (pairValue2 == PAIR_CR) { + factors->g = h2; + factors->h = g2; + } else if (pairValue1 == G_ST) { + /* g exists in the table, h is not found in either table */ + factors->g = g1; + factors->h = h1; + if (h1 != one) { + value = 2; + if (st_insert(ghTable, (char *)Cudd_Regular(h1), + (char *)(long)value) == ST_OUT_OF_MEM) { + *outOfMem = 1; + FREE(factors); + return(NULL); + } + } + } else if (pairValue1 == BOTH_G) { + /* g and h are found in the g table */ + factors->g = g1; + factors->h = h1; + if (h1 != one) { + value = 3; + if (st_insert(ghTable, (char *)Cudd_Regular(h1), + (char *)(long)value) == ST_OUT_OF_MEM) { + *outOfMem = 1; + FREE(factors); + return(NULL); + } + } + } else if (pairValue1 == H_ST) { + /* h exists in the table, g is not found in either table */ + factors->g = g1; + factors->h = h1; + if (g1 != one) { + value = 1; + if (st_insert(ghTable, (char *)Cudd_Regular(g1), + (char *)(long)value) == ST_OUT_OF_MEM) { + *outOfMem = 1; + FREE(factors); + return(NULL); + } + } + } else if (pairValue1 == BOTH_H) { + /* g and h are found in the h table */ + factors->g = g1; + factors->h = h1; + if (g1 != one) { + value = 3; + if (st_insert(ghTable, (char *)Cudd_Regular(g1), + (char *)(long)value) == ST_OUT_OF_MEM) { + *outOfMem = 1; + FREE(factors); + return(NULL); + } + } + } else if (pairValue2 == G_ST) { + /* g exists in the table, h is not found in either table */ + factors->g = g2; + factors->h = h2; + if (h2 != one) { + value = 2; + if (st_insert(ghTable, (char *)Cudd_Regular(h2), + (char *)(long)value) == ST_OUT_OF_MEM) { + *outOfMem = 1; + FREE(factors); + return(NULL); + } + } + } else if (pairValue2 == BOTH_G) { + /* g and h are found in the g table */ + factors->g = g2; + factors->h = h2; + if (h2 != one) { + value = 3; + if (st_insert(ghTable, (char *)Cudd_Regular(h2), + (char *)(long)value) == ST_OUT_OF_MEM) { + *outOfMem = 1; + FREE(factors); + return(NULL); + } + } + } else if (pairValue2 == H_ST) { + /* h exists in the table, g is not found in either table */ + factors->g = g2; + factors->h = h2; + if (g2 != one) { + value = 1; + if (st_insert(ghTable, (char *)Cudd_Regular(g2), + (char *)(long)value) == ST_OUT_OF_MEM) { + *outOfMem = 1; + FREE(factors); + return(NULL); + } + } + } else if (pairValue2 == BOTH_H) { + /* g and h are found in the h table */ + factors->g = g2; + factors->h = h2; + if (g2 != one) { + value = 3; + if (st_insert(ghTable, (char *)Cudd_Regular(g2), + (char *)(long)value) == ST_OUT_OF_MEM) { + *outOfMem = 1; + FREE(factors); + return(NULL); + } + } + } else if (pairValue1 == G_CR) { + /* g found in h table and h in none */ + factors->g = h1; + factors->h = g1; + if (h1 != one) { + value = 1; + if (st_insert(ghTable, (char *)Cudd_Regular(h1), + (char *)(long)value) == ST_OUT_OF_MEM) { + *outOfMem = 1; + FREE(factors); + return(NULL); + } + } + } else if (pairValue1 == H_CR) { + /* h found in g table and g in none */ + factors->g = h1; + factors->h = g1; + if (g1 != one) { + value = 2; + if (st_insert(ghTable, (char *)Cudd_Regular(g1), + (char *)(long)value) == ST_OUT_OF_MEM) { + *outOfMem = 1; + FREE(factors); + return(NULL); + } + } + } else if (pairValue2 == G_CR) { + /* g found in h table and h in none */ + factors->g = h2; + factors->h = g2; + if (h2 != one) { + value = 1; + if (st_insert(ghTable, (char *)Cudd_Regular(h2), + (char *)(long)value) == ST_OUT_OF_MEM) { + *outOfMem = 1; + FREE(factors); + return(NULL); + } + } + } else if (pairValue2 == H_CR) { + /* h found in g table and g in none */ + factors->g = h2; + factors->h = g2; + if (g2 != one) { + value = 2; + if (st_insert(ghTable, (char *)Cudd_Regular(g2), + (char *)(long)value) == ST_OUT_OF_MEM) { + *outOfMem = 1; + FREE(factors); + return(NULL); + } + } + } + + /* Store factors in cache table for later use. */ + if (st_insert(cacheTable, (char *)node, (char *)factors) == + ST_OUT_OF_MEM) { + *outOfMem = 1; + FREE(factors); + return(NULL); + } + return factors; +} /* end of CheckInTables */ + + + +/**Function******************************************************************** + + Synopsis [If one child is zero, do explicitly what Restrict does or better] + + Description [If one child is zero, do explicitly what Restrict does or better. + First separate a variable and its child in the base case. In case of a cube + times a function, separate the cube and function. As a last resort, look in + tables.] + + SideEffects [Frees the BDDs in factorsNv. factorsNv itself is not freed + because it is freed above.] + + SeeAlso [BuildConjuncts] + +******************************************************************************/ +static Conjuncts * +ZeroCase( + DdManager * dd, + DdNode * node, + Conjuncts * factorsNv, + st_table * ghTable, + st_table * cacheTable, + int switched) +{ + int topid; + DdNode *g, *h, *g1, *g2, *h1, *h2, *x, *N, *G, *H, *Gv, *Gnv; + DdNode *Hv, *Hnv; + int value; + int outOfMem; + Conjuncts *factors; + + /* get var at this node */ + N = Cudd_Regular(node); + topid = N->index; + x = dd->vars[topid]; + x = (switched) ? Cudd_Not(x): x; + cuddRef(x); + + /* Seprate variable and child */ + if (factorsNv->g == one) { + Cudd_RecursiveDeref(dd, factorsNv->g); + factors = ALLOC(Conjuncts, 1); + if (factors == NULL) { + dd->errorCode = CUDD_MEMORY_OUT; + Cudd_RecursiveDeref(dd, factorsNv->h); + Cudd_RecursiveDeref(dd, x); + return(NULL); + } + factors->g = x; + factors->h = factorsNv->h; + /* cache the result*/ + if (st_insert(cacheTable, (char *)node, (char *)factors) == ST_OUT_OF_MEM) { + dd->errorCode = CUDD_MEMORY_OUT; + Cudd_RecursiveDeref(dd, factorsNv->h); + Cudd_RecursiveDeref(dd, x); + FREE(factors); + return NULL; + } + + /* store x in g table, the other node is already in the table */ + if (st_lookup_int(ghTable, (char *)Cudd_Regular(x), &value)) { + value |= 1; + } else { + value = 1; + } + if (st_insert(ghTable, (char *)Cudd_Regular(x), (char *)(long)value) == ST_OUT_OF_MEM) { + dd->errorCode = CUDD_MEMORY_OUT; + return NULL; + } + return(factors); + } + + /* Seprate variable and child */ + if (factorsNv->h == one) { + Cudd_RecursiveDeref(dd, factorsNv->h); + factors = ALLOC(Conjuncts, 1); + if (factors == NULL) { + dd->errorCode = CUDD_MEMORY_OUT; + Cudd_RecursiveDeref(dd, factorsNv->g); + Cudd_RecursiveDeref(dd, x); + return(NULL); + } + factors->g = factorsNv->g; + factors->h = x; + /* cache the result. */ + if (st_insert(cacheTable, (char *)node, (char *)factors) == ST_OUT_OF_MEM) { + dd->errorCode = CUDD_MEMORY_OUT; + Cudd_RecursiveDeref(dd, factorsNv->g); + Cudd_RecursiveDeref(dd, x); + FREE(factors); + return(NULL); + } + /* store x in h table, the other node is already in the table */ + if (st_lookup_int(ghTable, (char *)Cudd_Regular(x), &value)) { + value |= 2; + } else { + value = 2; + } + if (st_insert(ghTable, (char *)Cudd_Regular(x), (char *)(long)value) == ST_OUT_OF_MEM) { + dd->errorCode = CUDD_MEMORY_OUT; + return NULL; + } + return(factors); + } + + G = Cudd_Regular(factorsNv->g); + Gv = cuddT(G); + Gnv = cuddE(G); + Gv = Cudd_NotCond(Gv, Cudd_IsComplement(node)); + Gnv = Cudd_NotCond(Gnv, Cudd_IsComplement(node)); + /* if the child below is a variable */ + if ((Gv == zero) || (Gnv == zero)) { + h = factorsNv->h; + g = cuddBddAndRecur(dd, x, factorsNv->g); + if (g != NULL) cuddRef(g); + Cudd_RecursiveDeref(dd, factorsNv->g); + Cudd_RecursiveDeref(dd, x); + if (g == NULL) { + Cudd_RecursiveDeref(dd, factorsNv->h); + return NULL; + } + /* CheckTablesCacheAndReturn responsible for allocating + * factors structure., g,h referenced for cache store the + */ + factors = CheckTablesCacheAndReturn(node, + g, + h, + ghTable, + cacheTable); + if (factors == NULL) { + dd->errorCode = CUDD_MEMORY_OUT; + Cudd_RecursiveDeref(dd, g); + Cudd_RecursiveDeref(dd, h); + } + return(factors); + } + + H = Cudd_Regular(factorsNv->h); + Hv = cuddT(H); + Hnv = cuddE(H); + Hv = Cudd_NotCond(Hv, Cudd_IsComplement(node)); + Hnv = Cudd_NotCond(Hnv, Cudd_IsComplement(node)); + /* if the child below is a variable */ + if ((Hv == zero) || (Hnv == zero)) { + g = factorsNv->g; + h = cuddBddAndRecur(dd, x, factorsNv->h); + if (h!= NULL) cuddRef(h); + Cudd_RecursiveDeref(dd, factorsNv->h); + Cudd_RecursiveDeref(dd, x); + if (h == NULL) { + Cudd_RecursiveDeref(dd, factorsNv->g); + return NULL; + } + /* CheckTablesCacheAndReturn responsible for allocating + * factors structure.g,h referenced for table store + */ + factors = CheckTablesCacheAndReturn(node, + g, + h, + ghTable, + cacheTable); + if (factors == NULL) { + dd->errorCode = CUDD_MEMORY_OUT; + Cudd_RecursiveDeref(dd, g); + Cudd_RecursiveDeref(dd, h); + } + return(factors); + } + + /* build g1 = x*g; h1 = h */ + /* build g2 = g; h2 = x*h */ + Cudd_RecursiveDeref(dd, x); + h1 = factorsNv->h; + g1 = cuddBddAndRecur(dd, x, factorsNv->g); + if (g1 != NULL) cuddRef(g1); + if (g1 == NULL) { + Cudd_RecursiveDeref(dd, factorsNv->g); + Cudd_RecursiveDeref(dd, factorsNv->h); + return NULL; + } + + g2 = factorsNv->g; + h2 = cuddBddAndRecur(dd, x, factorsNv->h); + if (h2 != NULL) cuddRef(h2); + if (h2 == NULL) { + Cudd_RecursiveDeref(dd, factorsNv->h); + Cudd_RecursiveDeref(dd, factorsNv->g); + return NULL; + } + + /* check whether any pair is in tables */ + factors = CheckInTables(node, g1, h1, g2, h2, ghTable, cacheTable, &outOfMem); + if (outOfMem) { + dd->errorCode = CUDD_MEMORY_OUT; + Cudd_RecursiveDeref(dd, g1); + Cudd_RecursiveDeref(dd, h1); + Cudd_RecursiveDeref(dd, g2); + Cudd_RecursiveDeref(dd, h2); + return NULL; + } + if (factors != NULL) { + if ((factors->g == g1) || (factors->g == h1)) { + Cudd_RecursiveDeref(dd, g2); + Cudd_RecursiveDeref(dd, h2); + } else { + Cudd_RecursiveDeref(dd, g1); + Cudd_RecursiveDeref(dd, h1); + } + return factors; + } + + /* check for each pair in tables and choose one */ + factors = PickOnePair(node,g1, h1, g2, h2, ghTable, cacheTable); + if (factors == NULL) { + dd->errorCode = CUDD_MEMORY_OUT; + Cudd_RecursiveDeref(dd, g1); + Cudd_RecursiveDeref(dd, h1); + Cudd_RecursiveDeref(dd, g2); + Cudd_RecursiveDeref(dd, h2); + } else { + /* now free what was created and not used */ + if ((factors->g == g1) || (factors->g == h1)) { + Cudd_RecursiveDeref(dd, g2); + Cudd_RecursiveDeref(dd, h2); + } else { + Cudd_RecursiveDeref(dd, g1); + Cudd_RecursiveDeref(dd, h1); + } + } + + return(factors); +} /* end of ZeroCase */ + + +/**Function******************************************************************** + + Synopsis [Builds the conjuncts recursively, bottom up.] + + Description [Builds the conjuncts recursively, bottom up. Constants + are returned as (f, f). The cache is checked for previously computed + result. The decomposition points are determined by the local + reference count of this node and the longest distance from the + constant. At the decomposition point, the factors returned are (f, + 1). Recur on the two children. The order is determined by the + heavier branch. Combine the factors of the two children and pick the + one that already occurs in the gh table. Occurence in g is indicated + by value 1, occurence in h by 2, occurence in both 3.] + + SideEffects [] + + SeeAlso [cuddConjunctsAux] + +******************************************************************************/ +static Conjuncts * +BuildConjuncts( + DdManager * dd, + DdNode * node, + st_table * distanceTable, + st_table * cacheTable, + int approxDistance, + int maxLocalRef, + st_table * ghTable, + st_table * mintermTable) +{ + int topid, distance; + Conjuncts *factorsNv, *factorsNnv, *factors; + Conjuncts *dummy; + DdNode *N, *Nv, *Nnv, *temp, *g1, *g2, *h1, *h2, *topv; + double minNv = 0.0, minNnv = 0.0; + double *doubleDummy; + int switched =0; + int outOfMem; + int freeNv = 0, freeNnv = 0, freeTemp; + NodeStat *nodeStat; + int value; + + /* if f is constant, return (f,f) */ + if (Cudd_IsConstant(node)) { + factors = ALLOC(Conjuncts, 1); + if (factors == NULL) { + dd->errorCode = CUDD_MEMORY_OUT; + return(NULL); + } + factors->g = node; + factors->h = node; + return(FactorsComplement(factors)); + } + + /* If result (a pair of conjuncts) in cache, return the factors. */ + if (st_lookup(cacheTable, (char *)node, (char **)&dummy)) { + factors = dummy; + return(factors); + } + + /* check distance and local reference count of this node */ + N = Cudd_Regular(node); + if (!st_lookup(distanceTable, (char *)N, (char **)&nodeStat)) { + (void) fprintf(dd->err, "Not in table, Something wrong\n"); + dd->errorCode = CUDD_INTERNAL_ERROR; + return(NULL); + } + distance = nodeStat->distance; + + /* at or below decomposition point, return (f, 1) */ + if (((nodeStat->localRef > maxLocalRef*2/3) && + (distance < approxDistance*2/3)) || + (distance <= approxDistance/4)) { + factors = ALLOC(Conjuncts, 1); + if (factors == NULL) { + dd->errorCode = CUDD_MEMORY_OUT; + return(NULL); + } + /* alternate assigning (f,1) */ + value = 0; + if (st_lookup_int(ghTable, (char *)Cudd_Regular(node), &value)) { + if (value == 3) { + if (!lastTimeG) { + factors->g = node; + factors->h = one; + lastTimeG = 1; + } else { + factors->g = one; + factors->h = node; + lastTimeG = 0; + } + } else if (value == 1) { + factors->g = node; + factors->h = one; + } else { + factors->g = one; + factors->h = node; + } + } else if (!lastTimeG) { + factors->g = node; + factors->h = one; + lastTimeG = 1; + value = 1; + if (st_insert(ghTable, (char *)Cudd_Regular(node), (char *)(long)value) == ST_OUT_OF_MEM) { + dd->errorCode = CUDD_MEMORY_OUT; + FREE(factors); + return NULL; + } + } else { + factors->g = one; + factors->h = node; + lastTimeG = 0; + value = 2; + if (st_insert(ghTable, (char *)Cudd_Regular(node), (char *)(long)value) == ST_OUT_OF_MEM) { + dd->errorCode = CUDD_MEMORY_OUT; + FREE(factors); + return NULL; + } + } + return(FactorsComplement(factors)); + } + + /* get the children and recur */ + Nv = cuddT(N); + Nnv = cuddE(N); + Nv = Cudd_NotCond(Nv, Cudd_IsComplement(node)); + Nnv = Cudd_NotCond(Nnv, Cudd_IsComplement(node)); + + /* Choose which subproblem to solve first based on the number of + * minterms. We go first where there are more minterms. + */ + if (!Cudd_IsConstant(Nv)) { + if (!st_lookup(mintermTable, (char *)Nv, (char **)&doubleDummy)) { + (void) fprintf(dd->err, "Not in table: Something wrong\n"); + dd->errorCode = CUDD_INTERNAL_ERROR; + return(NULL); + } + minNv = *doubleDummy; + } + + if (!Cudd_IsConstant(Nnv)) { + if (!st_lookup(mintermTable, (char *)Nnv, (char **)&doubleDummy)) { + (void) fprintf(dd->err, "Not in table: Something wrong\n"); + dd->errorCode = CUDD_INTERNAL_ERROR; + return(NULL); + } + minNnv = *doubleDummy; + } + + if (minNv < minNnv) { + temp = Nv; + Nv = Nnv; + Nnv = temp; + switched = 1; + } + + /* build gt, ht recursively */ + if (Nv != zero) { + factorsNv = BuildConjuncts(dd, Nv, distanceTable, + cacheTable, approxDistance, maxLocalRef, + ghTable, mintermTable); + if (factorsNv == NULL) return(NULL); + freeNv = FactorsNotStored(factorsNv); + factorsNv = (freeNv) ? FactorsUncomplement(factorsNv) : factorsNv; + cuddRef(factorsNv->g); + cuddRef(factorsNv->h); + + /* Deal with the zero case */ + if (Nnv == zero) { + /* is responsible for freeing factorsNv */ + factors = ZeroCase(dd, node, factorsNv, ghTable, + cacheTable, switched); + if (freeNv) FREE(factorsNv); + return(factors); + } + } + + /* build ge, he recursively */ + if (Nnv != zero) { + factorsNnv = BuildConjuncts(dd, Nnv, distanceTable, + cacheTable, approxDistance, maxLocalRef, + ghTable, mintermTable); + if (factorsNnv == NULL) { + Cudd_RecursiveDeref(dd, factorsNv->g); + Cudd_RecursiveDeref(dd, factorsNv->h); + if (freeNv) FREE(factorsNv); + return(NULL); + } + freeNnv = FactorsNotStored(factorsNnv); + factorsNnv = (freeNnv) ? FactorsUncomplement(factorsNnv) : factorsNnv; + cuddRef(factorsNnv->g); + cuddRef(factorsNnv->h); + + /* Deal with the zero case */ + if (Nv == zero) { + /* is responsible for freeing factorsNv */ + factors = ZeroCase(dd, node, factorsNnv, ghTable, + cacheTable, switched); + if (freeNnv) FREE(factorsNnv); + return(factors); + } + } + + /* construct the 2 pairs */ + /* g1 = x*gt + x'*ge; h1 = x*ht + x'*he; */ + /* g2 = x*gt + x'*he; h2 = x*ht + x'*ge */ + if (switched) { + factors = factorsNnv; + factorsNnv = factorsNv; + factorsNv = factors; + freeTemp = freeNv; + freeNv = freeNnv; + freeNnv = freeTemp; + } + + /* Build the factors for this node. */ + topid = N->index; + topv = dd->vars[topid]; + + g1 = cuddBddIteRecur(dd, topv, factorsNv->g, factorsNnv->g); + if (g1 == NULL) { + Cudd_RecursiveDeref(dd, factorsNv->g); + Cudd_RecursiveDeref(dd, factorsNv->h); + Cudd_RecursiveDeref(dd, factorsNnv->g); + Cudd_RecursiveDeref(dd, factorsNnv->h); + if (freeNv) FREE(factorsNv); + if (freeNnv) FREE(factorsNnv); + return(NULL); + } + + cuddRef(g1); + + h1 = cuddBddIteRecur(dd, topv, factorsNv->h, factorsNnv->h); + if (h1 == NULL) { + Cudd_RecursiveDeref(dd, factorsNv->g); + Cudd_RecursiveDeref(dd, factorsNv->h); + Cudd_RecursiveDeref(dd, factorsNnv->g); + Cudd_RecursiveDeref(dd, factorsNnv->h); + Cudd_RecursiveDeref(dd, g1); + if (freeNv) FREE(factorsNv); + if (freeNnv) FREE(factorsNnv); + return(NULL); + } + + cuddRef(h1); + + g2 = cuddBddIteRecur(dd, topv, factorsNv->g, factorsNnv->h); + if (g2 == NULL) { + Cudd_RecursiveDeref(dd, factorsNv->h); + Cudd_RecursiveDeref(dd, factorsNv->g); + Cudd_RecursiveDeref(dd, factorsNnv->g); + Cudd_RecursiveDeref(dd, factorsNnv->h); + Cudd_RecursiveDeref(dd, g1); + Cudd_RecursiveDeref(dd, h1); + if (freeNv) FREE(factorsNv); + if (freeNnv) FREE(factorsNnv); + return(NULL); + } + cuddRef(g2); + Cudd_RecursiveDeref(dd, factorsNv->g); + Cudd_RecursiveDeref(dd, factorsNnv->h); + + h2 = cuddBddIteRecur(dd, topv, factorsNv->h, factorsNnv->g); + if (h2 == NULL) { + Cudd_RecursiveDeref(dd, factorsNv->g); + Cudd_RecursiveDeref(dd, factorsNv->h); + Cudd_RecursiveDeref(dd, factorsNnv->g); + Cudd_RecursiveDeref(dd, factorsNnv->h); + Cudd_RecursiveDeref(dd, g1); + Cudd_RecursiveDeref(dd, h1); + Cudd_RecursiveDeref(dd, g2); + if (freeNv) FREE(factorsNv); + if (freeNnv) FREE(factorsNnv); + return(NULL); + } + cuddRef(h2); + Cudd_RecursiveDeref(dd, factorsNv->h); + Cudd_RecursiveDeref(dd, factorsNnv->g); + if (freeNv) FREE(factorsNv); + if (freeNnv) FREE(factorsNnv); + + /* check for each pair in tables and choose one */ + factors = CheckInTables(node, g1, h1, g2, h2, ghTable, cacheTable, &outOfMem); + if (outOfMem) { + dd->errorCode = CUDD_MEMORY_OUT; + Cudd_RecursiveDeref(dd, g1); + Cudd_RecursiveDeref(dd, h1); + Cudd_RecursiveDeref(dd, g2); + Cudd_RecursiveDeref(dd, h2); + return(NULL); + } + if (factors != NULL) { + if ((factors->g == g1) || (factors->g == h1)) { + Cudd_RecursiveDeref(dd, g2); + Cudd_RecursiveDeref(dd, h2); + } else { + Cudd_RecursiveDeref(dd, g1); + Cudd_RecursiveDeref(dd, h1); + } + return(factors); + } + + /* if not in tables, pick one pair */ + factors = PickOnePair(node,g1, h1, g2, h2, ghTable, cacheTable); + if (factors == NULL) { + dd->errorCode = CUDD_MEMORY_OUT; + Cudd_RecursiveDeref(dd, g1); + Cudd_RecursiveDeref(dd, h1); + Cudd_RecursiveDeref(dd, g2); + Cudd_RecursiveDeref(dd, h2); + } else { + /* now free what was created and not used */ + if ((factors->g == g1) || (factors->g == h1)) { + Cudd_RecursiveDeref(dd, g2); + Cudd_RecursiveDeref(dd, h2); + } else { + Cudd_RecursiveDeref(dd, g1); + Cudd_RecursiveDeref(dd, h1); + } + } + + return(factors); + +} /* end of BuildConjuncts */ + + +/**Function******************************************************************** + + Synopsis [Procedure to compute two conjunctive factors of f and place in *c1 and *c2.] + + Description [Procedure to compute two conjunctive factors of f and + place in *c1 and *c2. Sets up the required data - table of distances + from the constant and local reference count. Also minterm table. ] + + SideEffects [] + + SeeAlso [] + +******************************************************************************/ +static int +cuddConjunctsAux( + DdManager * dd, + DdNode * f, + DdNode ** c1, + DdNode ** c2) +{ + st_table *distanceTable = NULL; + st_table *cacheTable = NULL; + st_table *mintermTable = NULL; + st_table *ghTable = NULL; + st_generator *stGen; + char *key, *value; + Conjuncts *factors; + int distance, approxDistance; + double max, minterms; + int freeFactors; + NodeStat *nodeStat; + int maxLocalRef; + + /* initialize */ + *c1 = NULL; + *c2 = NULL; + + /* initialize distances table */ + distanceTable = st_init_table(st_ptrcmp,st_ptrhash); + if (distanceTable == NULL) goto outOfMem; + + /* make the entry for the constant */ + nodeStat = ALLOC(NodeStat, 1); + if (nodeStat == NULL) goto outOfMem; + nodeStat->distance = 0; + nodeStat->localRef = 1; + if (st_insert(distanceTable, (char *)one, (char *)nodeStat) == ST_OUT_OF_MEM) { + goto outOfMem; + } + + /* Count node distances from constant. */ + nodeStat = CreateBotDist(f, distanceTable); + if (nodeStat == NULL) goto outOfMem; + + /* set the distance for the decomposition points */ + approxDistance = (DEPTH < nodeStat->distance) ? nodeStat->distance : DEPTH; + distance = nodeStat->distance; + + if (distance < approxDistance) { + /* Too small to bother. */ + *c1 = f; + *c2 = DD_ONE(dd); + cuddRef(*c1); cuddRef(*c2); + stGen = st_init_gen(distanceTable); + if (stGen == NULL) goto outOfMem; + while(st_gen(stGen, (char **)&key, (char **)&value)) { + FREE(value); + } + st_free_gen(stGen); stGen = NULL; + st_free_table(distanceTable); + return(1); + } + + /* record the maximum local reference count */ + maxLocalRef = 0; + stGen = st_init_gen(distanceTable); + if (stGen == NULL) goto outOfMem; + while(st_gen(stGen, (char **)&key, (char **)&value)) { + nodeStat = (NodeStat *)value; + maxLocalRef = (nodeStat->localRef > maxLocalRef) ? + nodeStat->localRef : maxLocalRef; + } + st_free_gen(stGen); stGen = NULL; + + + /* Count minterms for each node. */ + max = pow(2.0, (double)Cudd_SupportSize(dd,f)); /* potential overflow */ + mintermTable = st_init_table(st_ptrcmp,st_ptrhash); + if (mintermTable == NULL) goto outOfMem; + minterms = CountMinterms(f, max, mintermTable, dd->err); + if (minterms == -1.0) goto outOfMem; + + lastTimeG = Cudd_Random() & 1; + cacheTable = st_init_table(st_ptrcmp, st_ptrhash); + if (cacheTable == NULL) goto outOfMem; + ghTable = st_init_table(st_ptrcmp, st_ptrhash); + if (ghTable == NULL) goto outOfMem; + + /* Build conjuncts. */ + factors = BuildConjuncts(dd, f, distanceTable, cacheTable, + approxDistance, maxLocalRef, ghTable, mintermTable); + if (factors == NULL) goto outOfMem; + + /* free up tables */ + stGen = st_init_gen(distanceTable); + if (stGen == NULL) goto outOfMem; + while(st_gen(stGen, (char **)&key, (char **)&value)) { + FREE(value); + } + st_free_gen(stGen); stGen = NULL; + st_free_table(distanceTable); distanceTable = NULL; + st_free_table(ghTable); ghTable = NULL; + + stGen = st_init_gen(mintermTable); + if (stGen == NULL) goto outOfMem; + while(st_gen(stGen, (char **)&key, (char **)&value)) { + FREE(value); + } + st_free_gen(stGen); stGen = NULL; + st_free_table(mintermTable); mintermTable = NULL; + + freeFactors = FactorsNotStored(factors); + factors = (freeFactors) ? FactorsUncomplement(factors) : factors; + if (factors != NULL) { + *c1 = factors->g; + *c2 = factors->h; + cuddRef(*c1); + cuddRef(*c2); + if (freeFactors) FREE(factors); + +#if 0 + if ((*c1 == f) && (!Cudd_IsConstant(f))) { + assert(*c2 == one); + } + if ((*c2 == f) && (!Cudd_IsConstant(f))) { + assert(*c1 == one); + } + + if ((*c1 != one) && (!Cudd_IsConstant(f))) { + assert(!Cudd_bddLeq(dd, *c2, *c1)); + } + if ((*c2 != one) && (!Cudd_IsConstant(f))) { + assert(!Cudd_bddLeq(dd, *c1, *c2)); + } +#endif + } + + stGen = st_init_gen(cacheTable); + if (stGen == NULL) goto outOfMem; + while(st_gen(stGen, (char **)&key, (char **)&value)) { + ConjunctsFree(dd, (Conjuncts *)value); + } + st_free_gen(stGen); stGen = NULL; + + st_free_table(cacheTable); cacheTable = NULL; + + return(1); + +outOfMem: + if (distanceTable != NULL) { + stGen = st_init_gen(distanceTable); + if (stGen == NULL) goto outOfMem; + while(st_gen(stGen, (char **)&key, (char **)&value)) { + FREE(value); + } + st_free_gen(stGen); stGen = NULL; + st_free_table(distanceTable); distanceTable = NULL; + } + if (mintermTable != NULL) { + stGen = st_init_gen(mintermTable); + if (stGen == NULL) goto outOfMem; + while(st_gen(stGen, (char **)&key, (char **)&value)) { + FREE(value); + } + st_free_gen(stGen); stGen = NULL; + st_free_table(mintermTable); mintermTable = NULL; + } + if (ghTable != NULL) st_free_table(ghTable); + if (cacheTable != NULL) { + stGen = st_init_gen(cacheTable); + if (stGen == NULL) goto outOfMem; + while(st_gen(stGen, (char **)&key, (char **)&value)) { + ConjunctsFree(dd, (Conjuncts *)value); + } + st_free_gen(stGen); stGen = NULL; + st_free_table(cacheTable); cacheTable = NULL; + } + dd->errorCode = CUDD_MEMORY_OUT; + return(0); + +} /* end of cuddConjunctsAux */ |