/**CFile*********************************************************************** FileName [cuddAndAbs.c] PackageName [cudd] Synopsis [Combined AND and existential abstraction for BDDs] Description [External procedures included in this module: Internal procedures included in this module: ] Author [Fabio Somenzi] Copyright [Copyright (c) 1995-2004, Regents of the University of Colorado All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. Neither the name of the University of Colorado nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.] ******************************************************************************/ #include "misc/util/util_hack.h" #include "cuddInt.h" ABC_NAMESPACE_IMPL_START /*---------------------------------------------------------------------------*/ /* Constant declarations */ /*---------------------------------------------------------------------------*/ /*---------------------------------------------------------------------------*/ /* Stucture declarations */ /*---------------------------------------------------------------------------*/ /*---------------------------------------------------------------------------*/ /* Type declarations */ /*---------------------------------------------------------------------------*/ /*---------------------------------------------------------------------------*/ /* Variable declarations */ /*---------------------------------------------------------------------------*/ #ifndef lint static char rcsid[] DD_UNUSED = "$Id: cuddAndAbs.c,v 1.19 2004/08/13 18:04:46 fabio Exp $"; #endif /*---------------------------------------------------------------------------*/ /* Macro declarations */ /*---------------------------------------------------------------------------*/ /**AutomaticStart*************************************************************/ /*---------------------------------------------------------------------------*/ /* Static function prototypes */ /*---------------------------------------------------------------------------*/ /**AutomaticEnd***************************************************************/ /*---------------------------------------------------------------------------*/ /* Definition of exported functions */ /*---------------------------------------------------------------------------*/ /**Function******************************************************************** Synopsis [Takes the AND of two BDDs and simultaneously abstracts the variables in cube.] Description [Takes the AND of two BDDs and simultaneously abstracts the variables in cube. The variables are existentially abstracted. Returns a pointer to the result is successful; NULL otherwise. Cudd_bddAndAbstract implements the semiring matrix multiplication algorithm for the boolean semiring.] SideEffects [None] SeeAlso [Cudd_addMatrixMultiply Cudd_addTriangle Cudd_bddAnd] ******************************************************************************/ DdNode * Cudd_bddAndAbstract( DdManager * manager, DdNode * f, DdNode * g, DdNode * cube) { DdNode *res; do { manager->reordered = 0; res = cuddBddAndAbstractRecur(manager, f, g, cube); } while (manager->reordered == 1); return(res); } /* end of Cudd_bddAndAbstract */ /**Function******************************************************************** Synopsis [Takes the AND of two BDDs and simultaneously abstracts the variables in cube. Returns NULL if too many nodes are required.] Description [Takes the AND of two BDDs and simultaneously abstracts the variables in cube. The variables are existentially abstracted. Returns a pointer to the result is successful; NULL otherwise. In particular, if the number of new nodes created exceeds limit, this function returns NULL.] SideEffects [None] SeeAlso [Cudd_bddAndAbstract] ******************************************************************************/ DdNode * Cudd_bddAndAbstractLimit( DdManager * manager, DdNode * f, DdNode * g, DdNode * cube, unsigned int limit) { DdNode *res; unsigned int saveLimit = manager->maxLive; manager->maxLive = (manager->keys - manager->dead) + (manager->keysZ - manager->deadZ) + limit; do { manager->reordered = 0; res = cuddBddAndAbstractRecur(manager, f, g, cube); } while (manager->reordered == 1); manager->maxLive = saveLimit; return(res); } /* end of Cudd_bddAndAbstractLimit */ /*---------------------------------------------------------------------------*/ /* Definition of internal functions */ /*---------------------------------------------------------------------------*/ /**Function******************************************************************** Synopsis [Takes the AND of two BDDs and simultaneously abstracts the variables in cube.] Description [Takes the AND of two BDDs and simultaneously abstracts the variables in cube. The variables are existentially abstracted. Returns a pointer to the result is successful; NULL otherwise.] SideEffects [None] SeeAlso [Cudd_bddAndAbstract] ******************************************************************************/ DdNode * cuddBddAndAbstractRecur( DdManager * manager, DdNode * f, DdNode * g, DdNode * cube) { DdNode *F, *ft, *fe, *G, *gt, *ge; DdNode *one, *zero, *r, *t, *e; unsigned int topf, topg, topcube, top, index; statLine(manager); one = DD_ONE(manager); zero = Cudd_Not(one); /* Terminal cases. */ if (f == zero || g == zero || f == Cudd_Not(g)) return(zero); if (f == one && g == one) return(one); if (cube == one) { return(cuddBddAndRecur(manager, f, g)); } if (f == one || f == g) { return(cuddBddExistAbstractRecur(manager, g, cube)); } if (g == one) { return(cuddBddExistAbstractRecur(manager, f, cube)); } /* At this point f, g, and cube are not constant. */ if (f > g) { /* Try to increase cache efficiency. */ DdNode *tmp = f; f = g; g = tmp; } /* Here we can skip the use of cuddI, because the operands are known ** to be non-constant. */ F = Cudd_Regular(f); G = Cudd_Regular(g); topf = manager->perm[F->index]; topg = manager->perm[G->index]; top = ddMin(topf, topg); topcube = manager->perm[cube->index]; while (topcube < top) { cube = cuddT(cube); if (cube == one) { return(cuddBddAndRecur(manager, f, g)); } topcube = manager->perm[cube->index]; } /* Now, topcube >= top. */ /* Check cache. */ if (F->ref != 1 || G->ref != 1) { r = cuddCacheLookup(manager, DD_BDD_AND_ABSTRACT_TAG, f, g, cube); if (r != NULL) { return(r); } } if ( manager->TimeStop && clock() > manager->TimeStop ) return NULL; if (topf == top) { index = F->index; ft = cuddT(F); fe = cuddE(F); if (Cudd_IsComplement(f)) { ft = Cudd_Not(ft); fe = Cudd_Not(fe); } } else { index = G->index; ft = fe = f; } if (topg == top) { gt = cuddT(G); ge = cuddE(G); if (Cudd_IsComplement(g)) { gt = Cudd_Not(gt); ge = Cudd_Not(ge); } } else { gt = ge = g; } if (topcube == top) { /* quantify */ DdNode *Cube = cuddT(cube); t = cuddBddAndAbstractRecur(manager, ft, gt, Cube); if (t == NULL) return(NULL); /* Special case: 1 OR anything = 1. Hence, no need to compute ** the else branch if t is 1. Likewise t + t * anything == t. ** Notice that t == fe implies that fe does not depend on the ** variables in Cube. Likewise for t == ge. */ if (t == one || t == fe || t == ge) { if (F->ref != 1 || G->ref != 1) cuddCacheInsert(manager, DD_BDD_AND_ABSTRACT_TAG, f, g, cube, t); return(t); } cuddRef(t); /* Special case: t + !t * anything == t + anything. */ if (t == Cudd_Not(fe)) { e = cuddBddExistAbstractRecur(manager, ge, Cube); } else if (t == Cudd_Not(ge)) { e = cuddBddExistAbstractRecur(manager, fe, Cube); } else { e = cuddBddAndAbstractRecur(manager, fe, ge, Cube); } if (e == NULL) { Cudd_IterDerefBdd(manager, t); return(NULL); } if (t == e) { r = t; cuddDeref(t); } else { cuddRef(e); r = cuddBddAndRecur(manager, Cudd_Not(t), Cudd_Not(e)); if (r == NULL) { Cudd_IterDerefBdd(manager, t); Cudd_IterDerefBdd(manager, e); return(NULL); } r = Cudd_Not(r); cuddRef(r); Cudd_DelayedDerefBdd(manager, t); Cudd_DelayedDerefBdd(manager, e); cuddDeref(r); } } else { t = cuddBddAndAbstractRecur(manager, ft, gt, cube); if (t == NULL) return(NULL); cuddRef(t); e = cuddBddAndAbstractRecur(manager, fe, ge, cube); if (e == NULL) { Cudd_IterDerefBdd(manager, t); return(NULL); } if (t == e) { r = t; cuddDeref(t); } else { cuddRef(e); if (Cudd_IsComplement(t)) { r = cuddUniqueInter(manager, (int) index, Cudd_Not(t), Cudd_Not(e)); if (r == NULL) { Cudd_IterDerefBdd(manager, t); Cudd_IterDerefBdd(manager, e); return(NULL); } r = Cudd_Not(r); } else { r = cuddUniqueInter(manager,(int)index,t,e); if (r == NULL) { Cudd_IterDerefBdd(manager, t); Cudd_IterDerefBdd(manager, e); return(NULL); } } cuddDeref(e); cuddDeref(t); } } if (F->ref != 1 || G->ref != 1) cuddCacheInsert(manager, DD_BDD_AND_ABSTRACT_TAG, f, g, cube, r); return (r); } /* end of cuddBddAndAbstractRecur */ /*---------------------------------------------------------------------------*/ /* Definition of static functions */ /*---------------------------------------------------------------------------*/ ABC_NAMESPACE_IMPL_END n251'>251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379