/**Function********************************************************************
Synopsis [Computes shortest paths in a state graph.]
Description [Computes shortest paths in the state transition graph of
a network. Three methods are availabe:
<ul>
<li> Bellman-Ford algorithm for single-source shortest paths; the
algorithm computes the distance (number of transitions) from the initial
states to all states.
<li> Floyd-Warshall algorithm for all-pair shortest paths.
<li> Repeated squaring algorithm for all-pair shortest paths.
</ul>
The function returns 1 in case of success; 0 otherwise.
]
SideEffects [ADD variables are created in the manager.]
SeeAlso []
******************************************************************************/
int
Ntr_ShortestPaths(
DdManager * dd,
BnetNetwork * net,
NtrOptions * option)
{
NtrPartTR *TR;
DdNode *edges, *source, *res, *r, *q, *bddSource;
DdNode **xadd, **yadd, **zadd;
int i;
int pr = option->verb;
int algorithm = option->shortPath;
int selectiveTrace = option->selectiveTrace;
int nvars = net->nlatches;
/* Set background to infinity for shortest paths. */
Cudd_SetBackground(dd,Cudd_ReadPlusInfinity(dd));
/* Build the monolithic TR. */
TR = Ntr_buildTR(dd,net,option,NTR_IMAGE_MONO);
/* Build the ADD variable vectors for x and y. */
xadd = ALLOC(DdNode *, nvars);
yadd = ALLOC(DdNode *, nvars);
for(i = 0; i < nvars; i++) {
q = Cudd_addIthVar(dd,TR->x[i]->index);
Cudd_Ref(q);
xadd[i] = q;
q = Cudd_addIthVar(dd,TR->y[i]->index);
Cudd_Ref(q);
yadd[i] = q;
}
/* Convert the transition relation BDD into an ADD... */
q = Cudd_BddToAdd(dd,TR->part[0]);
Cudd_Ref(q);
/* ...replacing zeroes with infinities... */
r = Cudd_addIte(dd,q,Cudd_ReadOne(dd),Cudd_ReadPlusInfinity(dd));
Cudd_Ref(r);
Cudd_RecursiveDeref(dd,q);
/* ...and zeroing the diagonal. */
q = Cudd_addXeqy(dd,nvars,xadd,yadd);
Cudd_Ref(q);
edges = Cudd_addIte(dd,q,Cudd_ReadZero(dd),r);
Cudd_Ref(edges);
Cudd_RecursiveDeref(dd,r);
Cudd_RecursiveDeref(dd,q);
switch(algorithm) {
case NTR_SHORT_BELLMAN:
bddSource = Ntr_initState(dd,net,option);
source = Cudd_BddToAdd(dd,bddSource);
Cudd_Ref(source);
res = ntrBellman(dd,edges,source,xadd,yadd,nvars,pr);
if (res == NULL) return(0);
Cudd_Ref(res);
Cudd_RecursiveDeref(dd,source);
Cudd_RecursiveDeref(dd,bddSource);
if (pr >= 0) {
(void) fprintf(stdout,"Distance Matrix");
Cudd_PrintDebug(dd,res,nvars,pr);
}
break;
case NTR_SHORT_FLOYD:
res = ntrWarshall(dd,edges,xadd,yadd,nvars,pr);
if (res == NULL) return(0);
Cudd_Ref(res);
if (pr >= 0) {
(void) fprintf(stdout,"Distance Matrix");
Cudd_PrintDebug(dd,res,2*nvars,pr);
}
break;
case NTR_SHORT_SQUARE:
/* Create a third set of ADD variables. */
zadd = ALLOC(DdNode *, nvars);
for(i = 0; i < nvars; i++) {
int level;
level = Cudd_ReadIndex(dd,TR->x[i]->index);
q = Cudd_addNewVarAtLevel(dd,level);
Cudd_Ref(q);
zadd[i] = q;
}
/* Compute the shortest paths. */
res = ntrSquare(dd,edges,zadd,yadd,xadd,nvars,pr,selectiveTrace);
if (res == NULL) return(0);
Cudd_Ref(res);
/* Dispose of the extra variables. */
for(i = 0; i < nvars; i++) {
Cudd_RecursiveDeref(dd,zadd[i]);
}
FREE(zadd);
if (pr >= 0) {
(void) fprintf(stdout,"Distance Matrix");
Cudd_PrintDebug(dd,res,2*nvars,pr);
}
break;
default:
(void) printf("Unrecognized method. Try again.\n");
return(0);
}
/* Here we should compute the paths. */
/* Clean up. */
Ntr_freeTR(dd,TR);
Cudd_RecursiveDeref(dd,edges);
Cudd_RecursiveDeref(dd,res);
for(i = 0; i < nvars; i++) {
Cudd_RecursiveDeref(dd,xadd[i]);
Cudd_RecursiveDeref(dd,yadd[i]);
}
FREE(xadd);
FREE(yadd);
if (option->autoDyn & 1) {
(void) printf("Order after short path computation\n");
if (!Bnet_PrintOrder(net,dd)) return(0);
}
return(1);
} /* end of Ntr_ShortestPaths */
/**Function********************************************************************
Synopsis [Main program for ntr.]
Description [Main program for ntr. Performs initialization. Reads command
line options and network(s). Builds BDDs with reordering, and optionally
does reachability analysis. Prints stats.]
SideEffects [None]
SeeAlso []
******************************************************************************/
int
main(
int argc,
char ** argv)
{
NtrOptions *option; /* options */
FILE *fp1; /* first network file pointer */
BnetNetwork *net1 = NULL; /* first network */
FILE *fp2; /* second network file pointer */
BnetNetwork *net2 = NULL; /* second network */
DdManager *dd; /* pointer to DD manager */
int exitval; /* return value of Cudd_CheckZeroRef */
int ok; /* overall return value from main() */
int result; /* stores the return value of functions */
BnetNode *node; /* auxiliary pointer to network node */
int i; /* loop index */
int j; /* loop index */
double *signatures; /* array of signatures */
int pr; /* verbosity level */
int reencoded; /* linear transformations attempted */
/* Initialize. */
option = mainInit();
ntrReadOptions(argc,argv,option);
pr = option->verb;
reencoded = option->reordering == CUDD_REORDER_LINEAR ||
option->reordering == CUDD_REORDER_LINEAR_CONVERGE ||
option->autoMethod == CUDD_REORDER_LINEAR ||
option->autoMethod == CUDD_REORDER_LINEAR_CONVERGE;
/* Currently traversal requires global BDDs. Override whatever
** was specified for locGlob.
*/
if (option->traverse == TRUE || option->envelope == TRUE ||
option->scc == TRUE) {
option->locGlob = BNET_GLOBAL_DD;
}
/* Read the first network... */
fp1 = open_file(option->file1, "r");
net1 = Bnet_ReadNetwork(fp1,pr);
(void) fclose(fp1);
if (net1 == NULL) {
(void) fprintf(stderr,"Syntax error in %s.\n",option->file1);
exit(2);
}
/* ... and optionally echo it to the standard output. */
if (pr > 2) {
Bnet_PrintNetwork(net1);
}
/* Read the second network... */
if (option->verify == TRUE || option->second == TRUE ||
option->clip > 0.0 || option->dontcares) {
fp2 = open_file(option->file2, "r");
net2 = Bnet_ReadNetwork(fp2,pr);
(void) fclose(fp2);
if (net2 == NULL) {
(void) fprintf(stderr,"Syntax error in %s.\n",option->file2);
exit(2);
}
/* ... and optionally echo it to the standard output. */
if (pr > 2) {
Bnet_PrintNetwork(net2);
}
}
/* Initialize manager. We start with 0 variables, because
** Ntr_buildDDs will create new variables rather than using
** whatever already exists.
*/
dd = startCudd(option,net1->ninputs);
if (dd == NULL) { exit(2); }
/* Build the BDDs for the nodes of the first network. */
result = Ntr_buildDDs(net1,dd,option,NULL);
if (result == 0) { exit(2); }
/* Build the BDDs for the nodes of the second network if requested. */
if (option->verify == TRUE || option->second == TRUE ||
option->clip > 0.0 || option->dontcares == TRUE) {
char *nodesave = option->node;
option->node = NULL;
result = Ntr_buildDDs(net2,dd,option,net1);
option->node = nodesave;
if (result == 0) { exit(2); }
}
if (option->noBuild == TRUE) {
Bnet_FreeNetwork(net1);
if (option->verify == TRUE || option->second == TRUE ||
option->clip > 0.0) {
Bnet_FreeNetwork(net2);
}
freeOption(option);
exit(0);
}
if (option->locGlob != BNET_LOCAL_DD) {
/* Print the order before the final reordering. */
(void) printf("Order before final reordering\n");
result = Bnet_PrintOrder(net1,dd);
if (result == 0) exit(2);
}
/* Perform final reordering */
if (option->zddtest == FALSE) {
result = reorder(net1,dd,option);
if (result == 0) exit(2);
/* Print final order. */
if ((option->reordering != CUDD_REORDER_NONE || option->gaOnOff) &&
option->locGlob != BNET_LOCAL_DD) {
(void) printf("New order\n");
result = Bnet_PrintOrder(net1,dd);
if (result == 0) exit(2);
}
/* Print the re-encoded inputs. */
if (pr >= 1 && reencoded == 1) {
for (i = 0; i < net1->npis; i++) {
if (!st_lookup(net1->hash,net1->inputs[i],&node)) {
exit(2);
}
(void) fprintf(stdout,"%s:",node->name);
Cudd_PrintDebug(dd,node->dd,Cudd_ReadSize(dd),pr);
}
for (i = 0; i < net1->nlatches; i++) {
if (!st_lookup(net1->hash,net1->latches[i][1],&node)) {
exit(2);
}
(void) fprintf(stdout,"%s:",node->name);
Cudd_PrintDebug(dd,node->dd,Cudd_ReadSize(dd),pr);
}
if (pr >= 3) {
result = Cudd_PrintLinear(dd);
if (result == 0) exit(2);
}
}
}
/* Verify (combinational) equivalence. */
if (option->verify == TRUE) {
result = Ntr_VerifyEquivalence(dd,net1,net2,option);
if (result == 0) {
(void) printf("Verification abnormally terminated\n");
exit(2);
} else if (result == -1) {
(void) printf("Combinational verification failed\n");
} else {
(void) printf("Verification succeeded\n");
}
}
/* Traverse if requested and if the circuit is sequential. */
result = Ntr_Trav(dd,net1,option);
if (result == 0) exit(2);
/* Traverse with trasitive closure. */
result = Ntr_ClosureTrav(dd,net1,option);
if (result == 0) exit(2);
/* Compute outer envelope if requested and if the circuit is sequential. */
if (option->envelope == TRUE && net1->nlatches > 0) {
NtrPartTR *T;
T = Ntr_buildTR(dd,net1,option,option->image);
result = Ntr_Envelope(dd,T,NULL,option);
Ntr_freeTR(dd,T);
}
/* Compute SCCs if requested and if the circuit is sequential. */
result = Ntr_SCC(dd,net1,option);
if (result == 0) exit(2);
/* Test Constrain Decomposition. */
if (option->partition == TRUE && net1->nlatches > 0) {
NtrPartTR *T;
DdNode *product;
DdNode **decomp;
int sharingSize;
T = Ntr_buildTR(dd,net1,option,NTR_IMAGE_MONO);
decomp = Cudd_bddConstrainDecomp(dd,T->part[0]);
if (decomp == NULL) exit(2);
sharingSize = Cudd_SharingSize(decomp, Cudd_ReadSize(dd));
(void) fprintf(stdout, "Decomposition Size: %d components %d nodes\n",
Cudd_ReadSize(dd), sharingSize);
product = Cudd_ReadOne(dd);
Cudd_Ref(product);
for (i = 0; i < Cudd_ReadSize(dd); i++) {
DdNode *intermediate = Cudd_bddAnd(dd, product, decomp[i]);
if (intermediate == NULL) {
exit(2);
}
Cudd_Ref(intermediate);
Cudd_IterDerefBdd(dd, product);
product = intermediate;
}
if (product != T->part[0])
exit(2);
Cudd_IterDerefBdd(dd, product);
for (i = 0; i < Cudd_ReadSize(dd); i++) {
Cudd_IterDerefBdd(dd, decomp[i]);
}
FREE(decomp);
Ntr_freeTR(dd,T);
}
/* Test char-to-vect conversion. */
result = Ntr_TestCharToVect(dd,net1,option);
if (result == 0) exit(2);
/* Test extraction of two-literal clauses. */
result = Ntr_TestTwoLiteralClauses(dd,net1,option);
if (result == 0) exit(2);
/* Test BDD minimization functions. */
result = Ntr_TestMinimization(dd,net1,net2,option);
if (result == 0) exit(2);
/* Test density-related functions. */
result = Ntr_TestDensity(dd,net1,option);
if (result == 0) exit(2);
/* Test decomposition functions. */
result = Ntr_TestDecomp(dd,net1,option);
if (result == 0) exit(2);
/* Test cofactor estimation functions. */
result = Ntr_TestCofactorEstimate(dd,net1,option);
if (result == 0) exit(2);
/* Test BDD clipping functions. */
result = Ntr_TestClipping(dd,net1,net2,option);
if (result == 0) exit(2);
/* Test BDD equivalence and containment under DC functions. */
result = Ntr_TestEquivAndContain(dd,net1,net2,option);
if (result == 0) exit(2);
/* Test BDD Cudd_bddClosestCube. */
result = Ntr_TestClosestCube(dd,net1,option);
if (result == 0) exit(2);
/* Test ZDDs if requested. */
if (option->stateOnly == FALSE && option->zddtest == TRUE) {
result = Ntr_testZDD(dd,net1,option);
if (result == 0)
(void) fprintf(stdout,"ZDD test failed.\n");
result = Ntr_testISOP(dd,net1,option);
if (result == 0)
(void) fprintf(stdout,"ISOP test failed.\n");
}
/* Compute maximum flow if requested and if the circuit is sequential. */
if (option->maxflow == TRUE && net1->nlatches > 0) {
result = Ntr_maxflow(dd,net1,option);
if (result == 0)
(void) fprintf(stdout,"Maxflow computation failed.\n");
}
/* Compute shortest paths if requested and if the circuit is sequential. */
if (option->shortPath != NTR_SHORT_NONE && net1->nlatches > 0) {
result = Ntr_ShortestPaths(dd,net1,option);
if (result == 0)
(void) fprintf(stdout,"Shortest paths computation failed.\n");
}
/* Compute output signatures if so requested. */
if (option->signatures) {
(void) printf("Positive cofactor measures\n");
for (i = 0; i < net1->noutputs; i++) {
if (!st_lookup(net1->hash,net1->outputs[i],&node)) {
exit(2);
}
signatures = Cudd_CofMinterm(dd, node->dd);
if (signatures) {
(void) printf("%s:\n", node->name);
for (j = 0; j < Cudd_ReadSize(dd); j++) {
if((j%5 == 0)&&i) (void) printf("\n");
(void) printf("%5d: %-#8.4g ", j, signatures[j]);
}
(void) printf("\n");
FREE(signatures);
} else {
(void) printf("Signature computation failed.\n");
}
}
}
/* Dump BDDs if so requested. */
if (option->bdddump && option->second == FALSE &&
option->density == FALSE && option->decomp == FALSE &&
option->cofest == FALSE && option->clip < 0.0 &&
option->scc == FALSE) {
(void) printf("Dumping BDDs to %s\n", option->dumpfile);
if (option->node != NULL) {
if (!st_lookup(net1->hash,option->node,&node)) {
exit(2);
}
result = Bnet_bddArrayDump(dd,net1,option->dumpfile,&(node->dd),
&(node->name),1,option->dumpFmt);
} else {
result = Bnet_bddDump(dd, net1, option->dumpfile,
option->dumpFmt, reencoded);
}
if (result != 1) {
(void) printf("BDD dump failed.\n");
}
}
/* Print stats and clean up. */
if (pr >= 0) {
result = Cudd_PrintInfo(dd,stdout);
if (result != 1) {
(void) printf("Cudd_PrintInfo failed.\n");
}
}
#if defined(DD_DEBUG) && !defined(DD_NO_DEATH_ROW)
(void) fprintf(dd->err,"%d empty slots in death row\n",
cuddTimesInDeathRow(dd,NULL));
#endif
(void) printf("Final size: %ld\n", Cudd_ReadNodeCount(dd));
/* Dispose of node BDDs. */
node = net1->nodes;
while (node != NULL) {
if (node->dd != NULL &&
node->type != BNET_INPUT_NODE &&
node->type != BNET_PRESENT_STATE_NODE) {
Cudd_IterDerefBdd(dd,node->dd);
}
node = node->next;
}
/* Dispose of network. */
Bnet_FreeNetwork(net1);
/* Do the same cleanup for the second network if it was created. */
if (option->verify == TRUE || option->second == TRUE ||
option->clip > 0.0 || option->dontcares == TRUE) {
node = net2->nodes;
while (node != NULL) {
if (node->dd != NULL &&
node->type != BNET_INPUT_NODE &&
node->type != BNET_PRESENT_STATE_NODE) {
Cudd_IterDerefBdd(dd,node->dd);
}
node = node->next;
}
Bnet_FreeNetwork(net2);
}
/* Check reference counts: At this point we should have dereferenced
** everything we had, except in the case of re-encoding.
*/
exitval = Cudd_CheckZeroRef(dd);
ok = exitval != 0; /* ok == 0 means O.K. */
if (exitval != 0) {
(void) fflush(stdout);
(void) fprintf(stderr,
"%d non-zero DD reference counts after dereferencing\n", exitval);
}
#ifdef DD_DEBUG
Cudd_CheckKeys(dd);
#endif
Cudd_Quit(dd);
if (pr >= 0) (void) printf("total time = %s\n",
util_print_time(util_cpu_time() - option->initialTime));
freeOption(option);
if (pr >= 0) util_print_cpu_stats(stdout);
#ifdef MNEMOSYNE
mnem_writestats();
#endif
exit(ok);
/* NOTREACHED */
} /* end of main */
