/**CFile***********************************************************************
FileName [cuddReorder.c]
PackageName [cudd]
Synopsis [Functions for dynamic variable reordering.]
Description [External procedures included in this file:
<ul>
<li> Cudd_ReduceHeap()
<li> Cudd_ShuffleHeap()
</ul>
Internal procedures included in this module:
<ul>
<li> cuddDynamicAllocNode()
<li> cuddSifting()
<li> cuddSwapping()
<li> cuddNextHigh()
<li> cuddNextLow()
<li> cuddSwapInPlace()
<li> cuddBddAlignToZdd()
</ul>
Static procedures included in this module:
<ul>
<li> ddUniqueCompare()
<li> ddSwapAny()
<li> ddSiftingAux()
<li> ddSiftingUp()
<li> ddSiftingDown()
<li> ddSiftingBackward()
<li> ddReorderPreprocess()
<li> ddReorderPostprocess()
<li> ddShuffle()
<li> ddSiftUp()
<li> bddFixTree()
</ul>]
Author [Shipra Panda, Bernard Plessier, 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 */
/*---------------------------------------------------------------------------*/
#define DD_MAX_SUBTABLE_SPARSITY 8
#define DD_SHRINK_FACTOR 2
/*---------------------------------------------------------------------------*/
/* Stucture declarations */
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
/* Type declarations */
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
/* Variable declarations */
/*---------------------------------------------------------------------------*/
#ifndef lint
static char rcsid[] DD_UNUSED = "$Id: cuddReorder.c,v 1.69 2009/02/21 18:24:10 fabio Exp $";
#endif
static int *entry;
int ddTotalNumberSwapping;
#ifdef DD_STATS
int ddTotalNISwaps;
#endif
/*---------------------------------------------------------------------------*/
/* Macro declarations */
/*---------------------------------------------------------------------------*/
/**AutomaticStart*************************************************************/
/*---------------------------------------------------------------------------*/
/* Static function prototypes */
/*---------------------------------------------------------------------------*/
static int ddUniqueCompare (int *ptrX, int *ptrY);
static Move * ddSwapAny (DdManager *table, int x, int y);
static int ddSiftingAux (DdManager *table, int x, int xLow, int xHigh);
static Move * ddSiftingUp (DdManager *table, int y, int xLow);
static Move * ddSiftingDown (DdManager *table, int x, int xHigh);
static int ddSiftingBackward (DdManager *table, int size, Move *moves);
static int ddReorderPreprocess (DdManager *table);
static int ddReorderPostprocess (DdManager *table);
static int ddShuffle (DdManager *table, int *permutation);
static int ddSiftUp (DdManager *table, int x, int xLow);
static void bddFixTree (DdManager *table, MtrNode *treenode);
static int ddUpdateMtrTree (DdManager *table, MtrNode *treenode, int *perm, int *invperm);
static int ddCheckPermuation (DdManager *table, MtrNode *treenode, int *perm, int *invperm);
/**AutomaticEnd***************************************************************/
/*---------------------------------------------------------------------------*/
/* Definition of exported functions */
/*---------------------------------------------------------------------------*/
/**Function********************************************************************
Synopsis [Main dynamic reordering routine.]
Description [Main dynamic reordering routine.
Calls one of the possible reordering procedures:
<ul>
<li>Swapping
<li>Sifting
<li>Symmetric Sifting
<li>Group Sifting
<li>Window Permutation
<li>Simulated Annealing
<li>Genetic Algorithm
<li>Dynamic Programming (exact)
</ul>
For sifting, symmetric sifting, group sifting, and window
permutation it is possible to request reordering to convergence.<p>
The core of all methods is the reordering procedure
cuddSwapInPlace() which swaps two adjacent variables and is based
on Rudell's paper.
Returns 1 in case of success; 0 otherwise. In the case of symmetric
sifting (with and without convergence) returns 1 plus the number of
symmetric variables, in case of success.]
SideEffects [Changes the variable order for all diagrams and clears
the cache.]
******************************************************************************/
int
Cudd_ReduceHeap(
DdManager * table /* DD manager */,
Cudd_ReorderingType heuristic /* method used for reordering */,
int minsize /* bound below which no reordering occurs */)
{
DdHook *hook;
int result;
unsigned int nextDyn;
#ifdef DD_STATS
unsigned int initialSize;
unsigned int finalSize;
#endif
long localTime;
/* Don't reorder if there are too many dead nodes. */
if (table->keys - table->dead < (unsigned) minsize)
return(1);
if (heuristic == CUDD_REORDER_SAME) {
heuristic = table->autoMethod;
}
if (heuristic == CUDD_REORDER_NONE) {
return(1);
}
/* This call to Cudd_ReduceHeap does initiate reordering. Therefore
** we count it.
*/
table->reorderings++;
localTime = util_cpu_time();
/* Run the hook functions. */
hook = table->preReorderingHook;
while (hook != NULL) {
int res = (hook->f)(table, "BDD", (void *)heuristic);
if (res == 0) return(0);
hook = hook->next;
}
if (!ddReorderPreprocess(table)) return(0);
ddTotalNumberSwapping = 0;
if (table->keys > table->peakLiveNodes) {
table->peakLiveNodes = table->keys;
}
#ifdef DD_STATS
initialSize = table->keys - table->isolated;
ddTotalNISwaps = 0;
switch(heuristic) {
case CUDD_REORDER_RANDOM:
case CUDD_REORDER_RANDOM_PIVOT:
(void) fprintf(table->out,"#:I_RANDOM ");
break;
case CUDD_REORDER_SIFT:
case CUDD_REORDER_SIFT_CONVERGE:
case CUDD_REORDER_SYMM_SIFT:
case CUDD_REORDER_SYMM_SIFT_CONV:
case CUDD_REORDER_GROUP_SIFT:
case CUDD_REORDER_GROUP_SIFT_CONV:
(void) fprintf(table->out,"#:I_SIFTING ");
break;
case CUDD_REORDER_WINDOW2:
case CUDD_REORDER_WINDOW3:
case CUDD_REORDER_WINDOW4:
case CUDD_REORDER_WINDOW2_CONV:
case CUDD_REORDER_WINDOW3_CONV:
case CUDD_REORDER_WINDOW4_CONV:
(void) fprintf(table->out,"#:I_WINDOW ");
break;
case CUDD_REORDER_ANNEALING:
(void) fprintf(table->out,"#:I_ANNEAL ");
break;
case CUDD_REORDER_GENETIC:
(void) fprintf(table->out,"#:I_GENETIC ");
break;
case CUDD_REORDER_LINEAR:
case CUDD_REORDER_LINEAR_CONVERGE:
(void) fprintf(table->out,"#:I_LINSIFT ");
break;
case CUDD_REORDER_EXACT:
(void) fprintf(table->out,"#:I_EXACT ");
break;
default:
return(0);
}
(void) fprintf(table->out,"%8d: initial size",initialSize);
#endif
/* See if we should use alternate threshold for maximum growth. */
if (table->reordCycle && table->reorderings % table->reordCycle == 0) {
double saveGrowth = table->maxGrowth;
table->maxGrowth = table->maxGrowthAlt;
result = cuddTreeSifting(table,heuristic);
table->maxGrowth = saveGrowth;
} else {
result = cuddTreeSifting(table,heuristic);
}
#ifdef DD_STATS
(void) fprintf(table->out,"\n");
finalSize = table->keys - table->isolated;
(void) fprintf(table->out,"#:F_REORDER %8d: final size\n",finalSize);
(void) fprintf(table->out,"#:T_REORDER %8g: total time (sec)\n",
((double)(util_cpu_time() - localTime)/1000.0));
(void) fprintf(table->out,"#:N_REORDER %8d: total swaps\n",
ddTotalNumberSwapping);
(void) fprintf(table->out,"#:M_REORDER %8d: NI swaps\n",ddTotalNISwaps);
#endif
if (result == 0)
return(0);
if (!ddReorderPostprocess(table))
return(0);
if (table->realign) {
if (!cuddZddAlignToBdd(table))
return(0);
}
nextDyn = (table->keys - table->constants.keys + 1) *
DD_DYN_RATIO + table->constants.keys;
if (table->reorderings < 20 || nextDyn > table->nextDyn)
table->nextDyn = nextDyn;
else
table->nextDyn += 20;
table->reordered = 1;
/* Run hook functions. */
hook = table->postReorderingHook;
while (hook != NULL) {
int res = (hook->f)(table, "BDD", (void *)localTime);
if (res == 0) return(0);
hook = hook->next;
}
/* Update cumulative reordering time. */
table->reordTime += util_cpu_time() - localTime;
return(result);
} /* end of Cudd_ReduceHeap */
/**Function********************************************************************
Synopsis [Reorders variables according to given permutation.]
Description [Reorders variables according to given permutation.
The i-th entry of the permutation array contains the index of the variable
that should be brought to the i-th level. The size of the array should be
equal or greater to the number of variables currently in use.
Returns 1 in case of success; 0 otherwise.]
SideEffects [Changes the variable order for all diagrams and clears
the cache.]
SeeAlso [Cudd_ReduceHeap]
******************************************************************************/
int
Cudd_ShuffleHeap(
DdManager * table /* DD manager */,
int * permutation /* required variable permutation */)
{
int result;
int i;
int identity = 1;
int *perm;
/* Don't waste time in case of identity permutation. */
for (i = 0; i < table->size; i++) {
if (permutation[i] != table->invperm[i]) {
identity = 0;
break;
}
}
if (identity == 1) {
return(1);
}
if (!ddReorderPreprocess(table)) return(0);
if (table->keys > table->peakLiveNodes) {
table->peakLiveNodes = table->keys;
}
perm = ABC_ALLOC(int, table->size);
for (i = 0; i < table->size; i++)
perm[permutation[i]] = i;
if (!ddCheckPermuation(table,table->tree,perm,permutation)) {
ABC_FREE(perm);
return(0);
}
if (!ddUpdateMtrTree(table,table->tree,perm,permutation)) {
ABC_FREE(perm);
return(0);
}
ABC_FREE(perm);
result = ddShuffle(table,permutation);
if (!ddReorderPostprocess(table)) return(0);
return(result);
} /* end of Cudd_ShuffleHeap */
/*---------------------------------------------------------------------------*/
/* Definition of internal functions */
/*---------------------------------------------------------------------------*/
/**Function********************************************************************
Synopsis [Dynamically allocates a Node.]
Description [Dynamically allocates a Node. This procedure is similar
to cuddAllocNode in Cudd_Table.c, but it does not attempt garbage
collection, because during reordering there are no dead nodes.
Returns a pointer to a new node if successful; NULL is memory is
full.]
SideEffects [None]
SeeAlso [cuddAllocNode]
******************************************************************************/
DdNode *
cuddDynamicAllocNode(
DdManager * table)
{
int i;
DdNodePtr *mem;
DdNode *list, *node;
extern DD_OOMFP MMoutOfMemory;
DD_OOMFP saveHandler;
if (table->nextFree == NULL) { /* free list is empty */
/* Try to allocate a new block. */
saveHandler = MMoutOfMemory;
MMoutOfMemory = Cudd_OutOfMem;
// mem = (DdNodePtr *) ABC_ALLOC(DdNode, DD_MEM_CHUNK + 1);
mem = (DdNodePtr *) ABC_ALLOC(DdNode, DD_MEM_CHUNK + 2);
MMoutOfMemory = saveHandler;
if (mem == NULL && table->stash != NULL) {
ABC_FREE(table->stash);
table->stash = NULL;
/* Inhibit resizing of tables. */
table->maxCacheHard = table->cacheSlots - 1;
table->cacheSlack = - (int) (table->cacheSlots + 1);
for (i = 0; i < table->size; i++) {
table->subtables[i].maxKeys <<= 2;
}
// mem = (DdNodePtr *) ABC_ALLOC(DdNode,DD_MEM_CHUNK + 1);
mem = (DdNodePtr *) ABC_ALLOC(DdNode,DD_MEM_CHUNK + 2);
}
if (mem == NULL) {
/* Out of luck. Call the default handler to do
** whatever it specifies for a failed malloc. If this
** handler returns, then set error code, print
** warning, and return. */
(*MMoutOfMemory)(sizeof(DdNode)*(DD_MEM_CHUNK + 1));
table->errorCode = CUDD_MEMORY_OUT;
#ifdef DD_VERBOSE
(void) fprintf(table->err,
"cuddDynamicAllocNode: out of memory");
(void) fprintf(table->err,"Memory in use = %lu\n",
table->memused);
#endif
return(NULL);
} else { /* successful allocation; slice memory */
unsigned long offset;
table->memused += (DD_MEM_CHUNK + 1) * sizeof(DdNode);
mem[0] = (DdNode *) table->memoryList;
table->memoryList = mem;
/* Here we rely on the fact that the size of a DdNode is a
** power of 2 and a multiple of the size of a pointer.
** If we align one node, all the others will be aligned
** as well. */
// offset = (unsigned long) mem & (sizeof(DdNode) - 1);
// mem += (sizeof(DdNode) - offset) / sizeof(DdNodePtr);
offset = (unsigned long) mem & (32 - 1);
mem += (32 - offset) / sizeof(DdNodePtr);
#ifdef DD_DEBUG
// assert(((unsigned long) mem & (sizeof(DdNode) - 1)) == 0);
assert(((unsigned long) mem & (32 - 1)) == 0);
#endif
list = (DdNode *) mem;
i = 1;
do {
list[i - 1].ref = 0;
list[i - 1].next = &list[i];
} while (++i < DD_MEM_CHUNK);
list[DD_MEM_CHUNK-1].ref = 0;
list[DD_MEM_CHUNK - 1].next = NULL;
table->nextFree = &list[0];
}
} /* if free list empty */
node = table->nextFree;
table->nextFree = node->next;
return (node);
} /* end of cuddDynamicAllocNode */
/**Function********************************************************************
Synopsis [Implementation of Rudell's sifting algorithm.]
Description [Implementation of Rudell's sifting algorithm.
Assumes that no dead nodes are present.
<ol>
<li> Order all the variables according to the number of entries
in each unique table.
<li> Sift the variable up and down, remembering each time the
total size of the DD heap.
<li> Select the best permutation.
<li> Repeat 3 and 4 for all variables.
</ol>
Returns 1 if successful; 0 otherwise.]
SideEffects [None]
******************************************************************************/
int
cuddSifting(
DdManager * table,
int lower,
int upper)
{
int i;
int *var;
int size;
int x;
int result;
#ifdef DD_STATS
int previousSize;
#endif
size = table->size;
/* Find order in which to sift variables. */
var = NULL;
entry = ABC_ALLOC(int,size);
if (entry == NULL) {
table->errorCode = CUDD_MEMORY_OUT;
goto cuddSiftingOutOfMem;
}
var = ABC_ALLOC(int,size);
if (var == NULL) {
table->errorCode = CUDD_MEMORY_OUT;
goto cuddSiftingOutOfMem;
}
for (i = 0; i < size; i++) {
x = table->perm[i];
entry[i] = table->subtables[x].keys;
var[i] = i;
}
qsort((void *)var,size,sizeof(int),(DD_QSFP)ddUniqueCompare);
/* Now sift. */
for (i = 0; i < ddMin(table->siftMaxVar,size); i++) {
if (ddTotalNumberSwapping >= table->siftMaxSwap)
break;
x = table->perm[var[i]];
if (x < lower || x > upper || table->subtables[x].bindVar == 1)
continue;
#ifdef DD_STATS
previousSize = table->keys - table->isolated;
#endif
result = ddSiftingAux(table, x, lower, upper);
if (!result) goto cuddSiftingOutOfMem;
#ifdef DD_STATS
if (table->keys < (unsigned) previousSize + table->isolated) {
(void) fprintf(table->out,"-");
} else if (table->keys > (unsigned) previousSize + table->isolated) {
(void) fprintf(table->out,"+"); /* should never happen */
(void) fprintf(table->err,"\nSize increased from %d to %d while sifting variable %d\n", previousSize, table->keys - table->isolated, var[i]);
} else {
(void) fprintf(table->out,"=");
}
fflush(table->out);
#endif
}
ABC_FREE(var);
ABC_FREE(entry);
return(1);
cuddSiftingOutOfMem:
if (entry != NULL) ABC_FREE(entry);
if (var != NULL) ABC_FREE(var);
return(0);
} /* end of cuddSifting */
/**Function********************************************************************
Synopsis [Reorders variables by a sequence of (non-adjacent) swaps.]
Description [Implementation of Plessier's algorithm that reorders
variables by a sequence of (non-adjacent) swaps.
<ol>
<li> Select two variables (RANDOM or HEURISTIC).
<li> Permute these variables.
<li> If the nodes have decreased accept the permutation.
<li> Otherwise reconstruct the original heap.
<li> Loop.
</ol>
Returns 1 in case of success; 0 otherwise.]
SideEffects [None]
******************************************************************************/
int
cuddSwapping(
DdManager * table,
int lower,
int upper,
Cudd_ReorderingType heuristic)
{
int i, j;
int max, keys;
int nvars;
int x, y;
int iterate;
int previousSize;
Move *moves, *move;
int pivot = -1;
int modulo;
int result;
#ifdef DD_DEBUG
/* Sanity check */
assert(lower >= 0 && upper < table->size && lower <= upper);
#endif
nvars = upper - lower + 1;
iterate = nvars;
for (i = 0; i < iterate; i++) {
if (ddTotalNumberSwapping >= table->siftMaxSwap)
break;
if (heuristic == CUDD_REORDER_RANDOM_PIVOT) {
max = -1;
for (j = lower; j <= upper; j++) {
if ((keys = table->subtables[j].keys) > max) {
max = keys;
pivot = j;
}
}
modulo = upper - pivot;
if (modulo == 0) {
y = pivot;
} else{
y = pivot + 1 + ((int) Cudd_Random() % modulo);
}
modulo = pivot - lower - 1;
if (modulo < 1) {
x = lower;
} else{
do {
x = (int) Cudd_Random() % modulo;
} while (x == y);
}
} else {
x = ((int) Cudd_Random() % nvars) + lower;
do {
y = ((int) Cudd_Random() % nvars) + lower;
} while (x == y);
}
previousSize = table->keys - table->isolated;
moves = ddSwapAny(table,x,y);
if (moves == NULL) goto cuddSwappingOutOfMem;
result = ddSiftingBackward(table,previousSize,moves);
if (!result) goto cuddSwappingOutOfMem;
while (moves != NULL) {
move = moves->next;
cuddDeallocMove(table, moves);
moves = move;
}
#ifdef DD_STATS
if (table->keys < (unsigned) previousSize + table->isolated) {
(void) fprintf(table->out,"-");
} else if (table->keys > (unsigned) previousSize + table->isolated) {
(void) fprintf(table->out,"+"); /* should never happen */
} else {
(void) fprintf(table->out,"=");
}
fflush(table->out);
#endif
#if 0
(void) fprintf(table->out,"#:t_SWAPPING %8d: tmp size\n",
table->keys - table->isolated);
#endif
}
return(1);
cuddSwappingOutOfMem:
while (moves != NULL) {
move = moves->next;
cuddDeallocMove(table, moves);
moves = move;
}
return(0);
} /* end of cuddSwapping */
/**Function********************************************************************
Synopsis [Finds the next subtable with a larger index.]
Description [Finds the next subtable with a larger index. Returns the
index.]
SideEffects [None]
SeeAlso [cuddNextLow]
******************************************************************************/
int
cuddNextHigh(
DdManager * table,
int x)
{
return(x+1);
} /* end of cuddNextHigh */
/**Function********************************************************************
Synopsis [Finds the next subtable with a smaller index.]
Description [Finds the next subtable with a smaller index. Returns the
index.]
SideEffects [None]
SeeAlso [cuddNextHigh]
******************************************************************************/
int
cuddNextLow(
DdManager * table,
int x)
{
return(x-1);
} /* end of cuddNextLow */
/**Function********************************************************************
Synopsis [Swaps two adjacent variables.]
Description [Swaps two adjacent variables. It assumes that no dead
nodes are present on entry to this procedure. The procedure then
guarantees that no dead nodes will be present when it terminates.
cuddSwapInPlace assumes that x < y. Returns the number of keys in
the table if successful; 0 otherwise.]
SideEffects [None]
******************************************************************************/
int
cuddSwapInPlace(
DdManager * table,
int x,
int y)
{
DdNodePtr *xlist, *ylist;
int xindex, yindex;
int xslots, yslots;
int xshift, yshift;
int oldxkeys, oldykeys;
int newxkeys, newykeys;
int comple, newcomplement;
int i;
Cudd_VariableType varType;
Cudd_LazyGroupType groupType;
int posn;
int isolated;
DdNode *f,*f0,*f1,*f01,*f00,*f11,*f10,*newf1,*newf0;
DdNode *g,*next;
DdNodePtr *previousP;
DdNode *tmp;
DdNode *sentinel = &(table->sentinel);
extern DD_OOMFP MMoutOfMemory;
DD_OOMFP saveHandler;
#ifdef DD_DEBUG
int count,idcheck;
#endif
#ifdef DD_DEBUG
assert(x < y);
assert(cuddNextHigh(table,x) == y);
assert(table->subtables[x].keys != 0);
assert(table->subtables[y].keys != 0);
assert(table->subtables[x].dead == 0);
assert(table->subtables[y].dead == 0);
#endif
ddTotalNumberSwapping++;
/* Get parameters of x subtable. */
xindex = table->invperm[x];
xlist = table->subtables[x].nodelist;
oldxkeys = table->subtables[x].keys;
xslots = table->subtables[x].slots;
xshift = table->subtables[x].shift;
/* Get parameters of y subtable. */
yindex = table->invperm[y];
ylist = table->subtables[y].nodelist;
oldykeys = table->subtables[y].keys;
yslots = table->subtables[y].slots;
yshift = table->subtables[y].shift;
if (!cuddTestInteract(table,xindex,yindex)) {
#ifdef DD_STATS
ddTotalNISwaps++;
#endif
newxkeys = oldxkeys;
newykeys = oldykeys;
} else {
newxkeys = 0;
newykeys = oldykeys;
/* Check whether the two projection functions involved in this
** swap are isolated. At the end, we'll be able to tell how many
** isolated projection functions are there by checking only these
** two functions again. This is done to eliminate the isolated
** projection functions from the node count.
*/
isolated = - ((table->vars[xindex]->ref == 1) +
(table->vars[yindex]->ref == 1));
/* The nodes in the x layer that do not depend on
** y will stay there; the others are put in a chain.
** The chain is handled as a LIFO; g points to the beginning.
*/
g = NULL;
if ((oldxkeys >= xslots || (unsigned) xslots == table->initSlots) &&
oldxkeys <= DD_MAX_SUBTABLE_DENSITY * xslots) {
for (i = 0; i < xslots; i++) {
previousP = &(xlist[i]);
f = *previousP;
while (f != sentinel) {
next = f->next;
f1 = cuddT(f); f0 = cuddE(f);
if (f1->index != (DdHalfWord) yindex &&
Cudd_Regular(f0)->index != (DdHalfWord) yindex) {
/* stays */
newxkeys++;
*previousP = f;
previousP = &(f->next);
} else {
f->index = yindex;
f->next = g;
g = f;
}
f = next;
} /* while there are elements in the collision chain */
*previousP = sentinel;
} /* for each slot of the x subtable */
} else { /* resize xlist */
DdNode *h = NULL;
DdNodePtr *newxlist;
unsigned int newxslots;
int newxshift;
/* Empty current xlist. Nodes that stay go to list h;
** nodes that move go to list g. */
for (i = 0; i < xslots; i++) {
f = xlist[i];
while (f != sentinel) {
next = f->next;
f1 = cuddT(f); f0 = cuddE(f);
if (f1->index != (DdHalfWord) yindex &&
Cudd_Regular(f0)->index != (DdHalfWord) yindex) {
/* stays */
f->next = h;
h = f;
newxkeys++;
} else {
f->index = yindex;
f->next = g;
g = f;
}
f = next;
} /* while there are elements in the collision chain */
} /* for each slot of the x subtable */
/* Decide size of new subtable. */
newxshift = xshift;
newxslots = xslots;
while ((unsigned) oldxkeys > DD_MAX_SUBTABLE_DENSITY * newxslots) {
newxshift--;
newxslots <<= 1;
}
while ((unsigned) oldxkeys < newxslots &&
newxslots > table->initSlots) {
newxshift++;
newxslots >>= 1;
}
/* Try to allocate new table. Be ready to back off. */
saveHandler = MMoutOfMemory;
MMoutOfMemory = Cudd_OutOfMem;
newxlist = ABC_ALLOC(DdNodePtr, newxslots);
MMoutOfMemory = saveHandler;
if (newxlist == NULL) {
(void) fprintf(table->err, "Unable to resize subtable %d for lack of memory\n", i);
newxlist = xlist;
newxslots = xslots;
newxshift = xshift;
} else {
table->slots += ((int) newxslots - xslots);
table->minDead = (unsigned)
(table->gcFrac * (double) table->slots);
table->cacheSlack = (int)
ddMin(table->maxCacheHard, DD_MAX_CACHE_TO_SLOTS_RATIO
* table->slots) - 2 * (int) table->cacheSlots;
table->memused +=
((int) newxslots - xslots) * sizeof(DdNodePtr);
ABC_FREE(xlist);
xslots = newxslots;
xshift = newxshift;
xlist = newxlist;
}
/* Initialize new subtable. */
for (i = 0; i < xslots; i++) {
xlist[i] = sentinel;
}
/* Move nodes that were parked in list h to their new home. */
f = h;
while (f != NULL) {
next = f->next;
f1 = cuddT(f);
f0 = cuddE(f);
/* Check xlist for pair (f11,f01). */
posn = ddHash(cuddF2L(f1), cuddF2L(f0), xshift);
/* For each element tmp in collision list xlist[posn]. */
previousP = &(xlist[posn]);
tmp = *previousP;
while (f1 < cuddT(tmp)) {
previousP = &(tmp->next);
tmp = *previousP;
}
while (f1 == cuddT(tmp) && f0 < cuddE(tmp)) {
previousP = &(tmp->next);
tmp = *previousP;
}
f->next = *previousP;
*previousP = f;
f = next;
}
}
#ifdef DD_COUNT
table->swapSteps += oldxkeys - newxkeys;
#endif
/* Take care of the x nodes that must be re-expressed.
** They form a linked list pointed by g. Their index has been
** already changed to yindex.
*/
f = g;
while (f != NULL) {
next = f->next;
/* Find f1, f0, f11, f10, f01, f00. */
f1 = cuddT(f);
#ifdef DD_DEBUG
assert(!(Cudd_IsComplement(f1)));
#endif
if ((int) f1->index == yindex) {
f11 = cuddT(f1); f10 = cuddE(f1);
} else {
f11 = f10 = f1;
}
#ifdef DD_DEBUG
assert(!(Cudd_IsComplement(f11)));
#endif
f0 = cuddE(f);
comple = Cudd_IsComplement(f0);
f0 = Cudd_Regular(f0);
if ((int) f0->index == yindex) {
f01 = cuddT(f0); f00 = cuddE(f0);
} else {
f01 = f00 = f0;
}
if (comple) {
f01 = Cudd_Not(f01);
f00 = Cudd_Not(f00);
}
/* Decrease ref count of f1. */
cuddSatDec(f1->ref);
/* Create the new T child. */
if (f11 == f01) {
newf1 = f11;
cuddSatInc(newf1->ref);
} else {
/* Check xlist for triple (xindex,f11,f01). */
posn = ddHash(cuddF2L(f11), cuddF2L(f01), xshift);
/* For each element newf1 in collision list xlist[posn]. */
previousP = &(xlist[posn]);
newf1 = *previousP;
while (f11 < cuddT(newf1)) {
previousP = &(newf1->next);
newf1 = *previousP;
}
while (f11 == cuddT(newf1) && f01 < cuddE(newf1)) {
previousP = &(newf1->next);
newf1 = *previousP;
}
if (cuddT(newf1) == f11 && cuddE(newf1) == f01) {
cuddSatInc(newf1->ref);
} else { /* no match */
newf1 = cuddDynamicAllocNode(table);
if (newf1 == NULL)
goto cuddSwapOutOfMem;
newf1->index = xindex; newf1->ref = 1;
cuddT(newf1) = f11;
cuddE(newf1) = f01;
/* Insert newf1 in the collision list xlist[posn];
** increase the ref counts of f11 and f01.
*/
newxkeys++;
newf1->next = *previousP;
*previousP = newf1;
cuddSatInc(f11->ref);
tmp = Cudd_Regular(f01);
cuddSatInc(tmp->ref);
}
}
cuddT(f) = newf1;
#ifdef DD_DEBUG
assert(!(Cudd_IsComplement(newf1)));
#endif
/* Do the same for f0, keeping complement dots into account. */
/* Decrease ref count of f0. */
tmp = Cudd_Regular(f0);
cuddSatDec(tmp->ref);
/* Create the new E child. */
if (f10 == f00) {
newf0 = f00;
tmp = Cudd_Regular(newf0);
cuddSatInc(tmp->ref);
} else {
/* make sure f10 is regular */
newcomplement = Cudd_IsComplement(f10);
if (newcomplement) {
f10 = Cudd_Not(f10);
f00 = Cudd_Not(f00);
}
/* Check xlist for triple (xindex,f10,f00). */
posn = ddHash(cuddF2L(f10), cuddF2L(f00), xshift);
/* For each element newf0 in collision list xlist[posn]. */
previousP = &(xlist[posn]);
newf0 = *previousP;
while (f10 < cuddT(newf0)) {
previousP = &(newf0->next);
newf0 = *previousP;
}
while (f10 == cuddT(newf0) && f00 < cuddE(newf0)) {
previousP = &(newf0->next);
newf0 = *previousP;
}
if (cuddT(newf0) == f10 && cuddE(newf0) == f00) {
cuddSatInc(newf0->ref);
} else { /* no match */
newf0 = cuddDynamicAllocNode(table);
if (newf0 == NULL)
goto cuddSwapOutOfMem;
newf0->index = xindex; newf0->ref = 1;
cuddT(newf0) = f10;
cuddE(newf0) = f00;
/* Insert newf0 in the collision list xlist[posn];
** increase the ref counts of f10 and f00.
*/
newxkeys++;
newf0->next = *previousP;
*previousP = newf0;
cuddSatInc(f10->ref);
tmp = Cudd_Regular(f00);
cuddSatInc(tmp->ref);
}
if (newcomplement) {
newf0 = Cudd_Not(newf0);
}
}
cuddE(f) = newf0;
/* Insert the modified f in ylist.
** The modified f does not already exists in ylist.
** (Because of the uniqueness of the cofactors.)
*/
posn = ddHash(cuddF2L(newf1), cuddF2L(newf0), yshift);
newykeys++;
previousP = &(ylist[posn]);
tmp = *previousP;
while (newf1 < cuddT(tmp)) {
previousP = &(tmp->next);
tmp = *previousP;
}
while (newf1 == cuddT(tmp) && newf0 < cuddE(tmp)) {
previousP = &(tmp->next);
tmp = *previousP;
}
f->next = *previousP;
*previousP = f;
f = next;
} /* while f != NULL */
/* GC the y layer. */
/* For each node f in ylist. */
for (i = 0; i < yslots; i++) {
previousP = &(ylist[i]);
f = *previousP;
while (f != sentinel) {
next = f->next;
if (f->ref == 0) {
tmp = cuddT(f);
cuddSatDec(tmp->ref);
tmp = Cudd_Regular(cuddE(f));
cuddSatDec(tmp->ref);
cuddDeallocNode(table,f);
newykeys--;
} else {
*previousP = f;
previousP = &(f->next);
}
f = next;
} /* while f */
*previousP = sentinel;
} /* for i */
#ifdef DD_DEBUG
#if 0
(void) fprintf(table->out,"Swapping %d and %d\n",x,y);
#endif
count = 0;
idcheck = 0;
for (i = 0; i < yslots; i++) {
f = ylist[i];
while (f != sentinel) {
count++;
if (f->index != (DdHalfWord) yindex)
idcheck++;
f = f->next;
}
}
if (count != newykeys) {
(void) fprintf(table->out,
"Error in finding newykeys\toldykeys = %d\tnewykeys = %d\tactual = %d\n",
oldykeys,newykeys,count);
}
if (idcheck != 0)
(void) fprintf(table->out,
"Error in id's of ylist\twrong id's = %d\n",
idcheck);
count = 0;
idcheck = 0;
for (i = 0; i < xslots; i++) {
f = xlist[i];
while (f != sentinel) {
count++;
if (f->index != (DdHalfWord) xindex)
idcheck++;
f = f->next;
}
}
if (count != newxkeys) {
(void) fprintf(table->out,
"Error in finding newxkeys\toldxkeys = %d \tnewxkeys = %d \tactual = %d\n",
oldxkeys,newxkeys,count);
}
if (idcheck != 0)
(void) fprintf(table->out,
"Error in id's of xlist\twrong id's = %d\n",
idcheck);
#endif
isolated += (table->vars[xindex]->ref == 1) +
(table->vars[yindex]->ref == 1);
table->isolated += isolated;
}
/* Set the appropriate fields in table. */
table->subtables[x].nodelist = ylist;
table->subtables[x].slots = yslots;
table->subtables[x].shift = yshift;
table->subtables[x].keys = newykeys;
table->subtables[x].maxKeys = yslots * DD_MAX_SUBTABLE_DENSITY;
i = table->subtables[x].bindVar;
table->subtables[x].bindVar = table->subtables[y].bindVar;
table->subtables[y].bindVar = i;
/* Adjust filds for lazy sifting. */
varType = table->subtables[x].varType;
table->subtables[x].varType = table->subtables[y].varType;
table->subtables[y].varType = varType;
i = table->subtables[x].pairIndex;
table->subtables[x].pairIndex = table->subtables[y].pairIndex;
table->subtables[y].pairIndex = i;
i = table->subtables[x].varHandled;
table->subtables[x].varHandled = table->subtables[y].varHandled;
table->subtables[y].varHandled = i;
groupType = table->subtables[x].varToBeGrouped;
table->subtables[x].varToBeGrouped = table->subtables[y].varToBeGrouped;
table->subtables[y].varToBeGrouped = groupType;
table->subtables[y].nodelist = xlist;
table->subtables[y].slots = xslots;
table->subtables[y].shift = xshift;
table->subtables[y].keys = newxkeys;
table->subtables[y].maxKeys = xslots * DD_MAX_SUBTABLE_DENSITY;
table->perm[xindex] = y; table->perm[yindex] = x;
table->invperm[x] = yindex; table->invperm[y] = xindex;
table->keys += newxkeys + newykeys - oldxkeys - oldykeys;
return(table->keys - table->isolated);
cuddSwapOutOfMem:
(void) fprintf(table->err,"Error: cuddSwapInPlace out of memory\n");
return (0);
} /* end of cuddSwapInPlace */
/**Function********************************************************************
Synopsis [Reorders BDD variables according to the order of the ZDD
variables.]
Description [Reorders BDD variables according to the order of the
ZDD variables. This function can be called at the end of ZDD
reordering to insure that the order of the BDD variables is
consistent with the order of the ZDD variables. The number of ZDD
variables must be a multiple of the number of BDD variables. Let
<code>M</code> be the ratio of the two numbers. cuddBddAlignToZdd
then considers the ZDD variables from <code>M*i</code> to
<code>(M+1)*i-1</code> as corresponding to BDD variable
<code>i</code>. This function should be normally called from
Cudd_zddReduceHeap, which clears the cache. Returns 1 in case of
success; 0 otherwise.]
SideEffects [Changes the BDD variable order for all diagrams and performs
garbage collection of the BDD unique table.]
SeeAlso [Cudd_ShuffleHeap Cudd_zddReduceHeap]
******************************************************************************/
int
cuddBddAlignToZdd(
DdManager * table /* DD manager */)
{
int *invperm; /* permutation array */
int M; /* ratio of ZDD variables to BDD variables */
int i; /* loop index */
int result; /* return value */
/* We assume that a ratio of 0 is OK. */
if (table->size == 0)
return(1);
M = table->sizeZ / table->size;
/* Check whether the number of ZDD variables is a multiple of the
** number of BDD variables.
*/
if (M * table->size != table->sizeZ)
return(0);
/* Create and initialize the inverse permutation array. */
invperm = ABC_ALLOC(int,table->size);
if (invperm == NULL) {
table->errorCode = CUDD_MEMORY_OUT;
return(0);
}
for (i = 0; i < table->sizeZ; i += M) {
int indexZ = table->invpermZ[i];
int index = indexZ / M;
invperm[i / M] = index;
}
/* Eliminate dead nodes. Do not scan the cache again, because we
** assume that Cudd_zddReduceHeap has already cleared it.
*/
cuddGarbageCollect(table,0);
/* Initialize number of isolated projection functions. */
table->isolated = 0;
for (i = 0; i < table->size; i++) {
if (table->vars[i]->ref == 1) table->isolated++;
}
/* Initialize the interaction matrix. */
result = cuddInitInteract(table);
if (result == 0) return(0);
result = ddShuffle(table, invperm);
ABC_FREE(invperm);
/* Free interaction matrix. */
ABC_FREE(table->interact);
/* Fix the BDD variable group tree. */
bddFixTree(table,table->tree);
return(result);
} /* end of cuddBddAlignToZdd */
/*---------------------------------------------------------------------------*/
/* Definition of static functions */
/*---------------------------------------------------------------------------*/
/**Function********************************************************************
Synopsis [Comparison function used by qsort.]
Description [Comparison function used by qsort to order the
variables according to the number of keys in the subtables.
Returns the difference in number of keys between the two
variables being compared.]
SideEffects [None]
******************************************************************************/
static int
ddUniqueCompare(
int * ptrX,
int * ptrY)
{
#if 0
if (entry[*ptrY] == entry[*ptrX]) {
return((*ptrX) - (*ptrY));
}
#endif
return(entry[*ptrY] - entry[*ptrX]);
} /* end of ddUniqueCompare */
/**Function********************************************************************
Synopsis [Swaps any two variables.]
Description [Swaps any two variables. Returns the set of moves.]
SideEffects [None]
******************************************************************************/
static Move *
ddSwapAny(
DdManager * table,
int x,
int y)
{
Move *move, *moves;
int xRef,yRef;
int xNext,yNext;
int size;
int limitSize;
int tmp;
if (x >y) {
tmp = x; x = y; y = tmp;
}
xRef = x; yRef = y;
xNext = cuddNextHigh(table,x);
yNext = cuddNextLow(table,y);
moves = NULL;
limitSize = table->keys - table->isolated;
for (;;) {
if ( xNext == yNext) {
size = cuddSwapInPlace(table,x,xNext);
if (size == 0) goto ddSwapAnyOutOfMem;
move = (Move *) cuddDynamicAllocNode(table);
if (move == NULL) goto ddSwapAnyOutOfMem;
move->x = x;
move->y = xNext;
move->size = size;
move->next = moves;
moves = move;
size = cuddSwapInPlace(table,yNext,y);
if (size == 0) goto ddSwapAnyOutOfMem;
move = (Move *) cuddDynamicAllocNode(table);
if (move == NULL) goto ddSwapAnyOutOfMem;
move->x = yNext;
move->y = y;
move->size = size;
move->next = moves;
moves = move;
size = cuddSwapInPlace(table,x,xNext);
if (size == 0) goto ddSwapAnyOutOfMem;
move = (Move *) cuddDynamicAllocNode(table);
if (move == NULL) goto ddSwapAnyOutOfMem;
move->x = x;
move->y = xNext;
move->size = size;
move->next = moves;
moves = move;
tmp = x; x = y; y = tmp;
} else if (x == yNext) {
size = cuddSwapInPlace(table,x,xNext);
if (size == 0) goto ddSwapAnyOutOfMem;
move = (Move *) cuddDynamicAllocNode(table);
if (move == NULL) goto ddSwapAnyOutOfMem;
move->x = x;
move->y = xNext;
move->size = size;
move->next = moves;
moves = move;
tmp = x; x = y; y = tmp;
} else {
size = cuddSwapInPlace(table,x,xNext);
if (size == 0) goto ddSwapAnyOutOfMem;
move = (Move *) cuddDynamicAllocNode(table);
if (move == NULL) goto ddSwapAnyOutOfMem;
move->x = x;
move->y = xNext;
move->size = size;
move->next = moves;
moves = move;
size = cuddSwapInPlace(table,yNext,y);
if (size == 0) goto ddSwapAnyOutOfMem;
move = (Move *) cuddDynamicAllocNode(table);
if (move == NULL) goto ddSwapAnyOutOfMem;
move->x = yNext;
move->y = y;
move->size = size;
move->next = moves;
moves = move;
x = xNext;
y = yNext;
}
xNext = cuddNextHigh(table,x);
yNext = cuddNextLow(table,y);
if (xNext > yRef) break;
if ((double) size > table->maxGrowth * (double) limitSize) break;
if (size < limitSize) limitSize = size;
}
if (yNext>=xRef) {
size = cuddSwapInPlace(table,yNext,y);
if (size == 0) goto ddSwapAnyOutOfMem;
move = (Move *) cuddDynamicAllocNode(table);
if (move == NULL) goto ddSwapAnyOutOfMem;
move->x = yNext;
move->y = y;
move->size = size;
move->next = moves;
moves = move;
}
return(moves);
ddSwapAnyOutOfMem:
while (moves != NULL) {
move = moves->next;
cuddDeallocMove(table, moves);
moves = move;
}
return(NULL);
} /* end of ddSwapAny */
/**Function********************************************************************
Synopsis [Given xLow <= x <= xHigh moves x up and down between the
boundaries.]
Description [Given xLow <= x <= xHigh moves x up and down between the
boundaries. Finds the best position and does the required changes.
Returns 1 if successful; 0 otherwise.]
SideEffects [None]
******************************************************************************/
static int
ddSiftingAux(
DdManager * table,
int x,
int xLow,
int xHigh)
{
Move *move;
Move *moveUp; /* list of up moves */
Move *moveDown; /* list of down moves */
int initialSize;
int result;
initialSize = table->keys - table->isolated;
moveDown = NULL;
moveUp = NULL;
if (x == xLow) {
moveDown = ddSiftingDown(table,x,xHigh);
/* At this point x --> xHigh unless bounding occurred. */
if (moveDown == (Move *) CUDD_OUT_OF_MEM) goto ddSiftingAuxOutOfMem;
/* Move backward and stop at best position. */
result = ddSiftingBackward(table,initialSize,moveDown);
if (!result) goto ddSiftingAuxOutOfMem;
} else if (x == xHigh) {
moveUp = ddSiftingUp(table,x,xLow);
/* At this point x --> xLow unless bounding occurred. */
if (moveUp == (Move *) CUDD_OUT_OF_MEM) goto ddSiftingAuxOutOfMem;
/* Move backward and stop at best position. */
result = ddSiftingBackward(table,initialSize,moveUp);
if (!result) goto ddSiftingAuxOutOfMem;
} else if ((x - xLow) > (xHigh - x)) { /* must go down first: shorter */
moveDown = ddSiftingDown(table,x,xHigh);
/* At this point x --> xHigh unless bounding occurred. */
if (moveDown == (Move *) CUDD_OUT_OF_MEM) goto ddSiftingAuxOutOfMem;
if (moveDown != NULL) {
x = moveDown->y;
}
moveUp = ddSiftingUp(table,x,xLow);
if (moveUp == (Move *) CUDD_OUT_OF_MEM) goto ddSiftingAuxOutOfMem;
/* Move backward and stop at best position */
result = ddSiftingBackward(table,initialSize,moveUp);
if (!result) goto ddSiftingAuxOutOfMem;
} else { /* must go up first: shorter */
moveUp = ddSiftingUp(table,x,xLow);
/* At this point x --> xLow unless bounding occurred. */
if (moveUp == (Move *) CUDD_OUT_OF_MEM) goto ddSiftingAuxOutOfMem;
if (moveUp != NULL) {
x = moveUp->x;
}
moveDown = ddSiftingDown(table,x,xHigh);
if (moveDown == (Move *) CUDD_OUT_OF_MEM) goto ddSiftingAuxOutOfMem;
/* Move backward and stop at best position. */
result = ddSiftingBackward(table,initialSize,moveDown);
if (!result) goto ddSiftingAuxOutOfMem;
}
while (moveDown != NULL) {
move = moveDown->next;
cuddDeallocMove(table, moveDown);
moveDown = move;
}
while (moveUp != NULL) {
move = moveUp->next;
cuddDeallocMove(table, moveUp);
moveUp = move;
}
return(1);
ddSiftingAuxOutOfMem:
if (moveDown != (Move *) CUDD_OUT_OF_MEM) {
while (moveDown != NULL) {
move = moveDown->next;
cuddDeallocMove(table, moveDown);
moveDown = move;
}
}
if (moveUp != (Move *) CUDD_OUT_OF_MEM) {
while (moveUp != NULL) {
move = moveUp->next;
cuddDeallocMove(table, moveUp);
moveUp = move;
}
}
return(0);
} /* end of ddSiftingAux */
/**Function********************************************************************
Synopsis [Sifts a variable up.]
Description [Sifts a variable up. Moves y up until either it reaches
the bound (xLow) or the size of the DD heap increases too much.
Returns the set of moves in case of success; NULL if memory is full.]
SideEffects [None]
******************************************************************************/
static Move *
ddSiftingUp(
DdManager * table,
int y,
int xLow)
{
Move *moves;
Move *move;
int x;
int size;
int limitSize;
int xindex, yindex;
int isolated;
int L; /* lower bound on DD size */
#ifdef DD_DEBUG
int checkL;
int z;
int zindex;
#endif
moves = NULL;
yindex = table->invperm[y];
/* Initialize the lower bound.
** The part of the DD below y will not change.
** The part of the DD above y that does not interact with y will not
** change. The rest may vanish in the best case, except for
** the nodes at level xLow, which will not vanish, regardless.
*/
limitSize = L = table->keys - table->isolated;
for (x = xLow + 1; x < y; x++) {
xindex = table->invperm[x];
if (cuddTestInteract(table,xindex,yindex)) {
isolated = table->vars[xindex]->ref == 1;
L -= table->subtables[x].keys - isolated;
}
}
isolated = table->vars[yindex]->ref == 1;
L -= table->subtables[y].keys - isolated;
x = cuddNextLow(table,y);
while (x >= xLow && L <= limitSize) {
xindex = table->invperm[x];
#ifdef DD_DEBUG
checkL = table->keys - table->isolated;
for (z = xLow + 1; z < y; z++) {
zindex = table->invperm[z];
if (cuddTestInteract(table,zindex,yindex)) {
isolated = table->vars[zindex]->ref == 1;
checkL -= table->subtables[z].keys - isolated;
}
}
isolated = table->vars[yindex]->ref == 1;
checkL -= table->subtables[y].keys - isolated;
assert(L == checkL);
#endif
size = cuddSwapInPlace(table,x,y);
if (size == 0) goto ddSiftingUpOutOfMem;
/* Update the lower bound. */
if (cuddTestInteract(table,xindex,yindex)) {
isolated = table->vars[xindex]->ref == 1;
L += table->subtables[y].keys - isolated;
}
move = (Move *) cuddDynamicAllocNode(table);
if (move == NULL) goto ddSiftingUpOutOfMem;
move->x = x;
move->y = y;
move->size = size;
move->next = moves;
moves = move;
if ((double) size > (double) limitSize * table->maxGrowth) break;
if (size < limitSize) limitSize = size;
y = x;
x = cuddNextLow(table,y);
}
return(moves);
ddSiftingUpOutOfMem:
while (moves != NULL) {
move = moves->next;
cuddDeallocMove(table, moves);
moves = move;
}
return((Move *) CUDD_OUT_OF_MEM);
} /* end of ddSiftingUp */
/**Function********************************************************************
Synopsis [Sifts a variable down.]
Description [Sifts a variable down. Moves x down until either it
reaches the bound (xHigh) or the size of the DD heap increases too
much. Returns the set of moves in case of success; NULL if memory is
full.]
SideEffects [None]
******************************************************************************/
static Move *
ddSiftingDown(
DdManager * table,
int x,
int xHigh)
{
Move *moves;
Move *move;
int y;
int size;
int R; /* upper bound on node decrease */
int limitSize;
int xindex, yindex;
int isolated;
#ifdef DD_DEBUG
int checkR;
int z;
int zindex;
#endif
moves = NULL;
/* Initialize R */
xindex = table->invperm[x];
limitSize = size = table->keys - table->isolated;
R = 0;
for (y = xHigh; y > x; y--) {
yindex = table->invperm[y];
if (cuddTestInteract(table,xindex,yindex)) {
isolated = table->vars[yindex]->ref == 1;
R += table->subtables[y].keys - isolated;
}
}
y = cuddNextHigh(table,x);
while (y <= xHigh && size - R < limitSize) {
#ifdef DD_DEBUG
checkR = 0;
for (z = xHigh; z > x; z--) {
zindex = table->invperm[z];
if (cuddTestInteract(table,xindex,zindex)) {
isolated = table->vars[zindex]->ref == 1;
checkR += table->subtables[z].keys - isolated;
}
}
assert(R == checkR);
#endif
/* Update upper bound on node decrease. */
yindex = table->invperm[y];
if (cuddTestInteract(table,xindex,yindex)) {
isolated = table->vars[yindex]->ref == 1;
R -= table->subtables[y].keys - isolated;
}
size = cuddSwapInPlace(table,x,y);
if (size == 0) goto ddSiftingDownOutOfMem;
move = (Move *) cuddDynamicAllocNode(table);
if (move == NULL) goto ddSiftingDownOutOfMem;
move->x = x;
move->y = y;
move->size = size;
move->next = moves;
moves = move;
if ((double) size > (double) limitSize * table->maxGrowth) break;
if (size < limitSize) limitSize = size;
x = y;
y = cuddNextHigh(table,x);
}
return(moves);
ddSiftingDownOutOfMem:
while (moves != NULL) {
move = moves->next;
cuddDeallocMove(table, moves);
moves = move;
}
return((Move *) CUDD_OUT_OF_MEM);
} /* end of ddSiftingDown */
/**Function********************************************************************
Synopsis [Given a set of moves, returns the DD heap to the position
giving the minimum size.]
Description [Given a set of moves, returns the DD heap to the
position giving the minimum size. In case of ties, returns to the
closest position giving the minimum size. Returns 1 in case of
success; 0 otherwise.]
SideEffects [None]
******************************************************************************/
static int
ddSiftingBackward(
DdManager * table,
int size,
Move * moves)
{
Move *move;
int res;
for (move = moves; move != NULL; move = move->next) {
if (move->size < size) {
size = move->size;
}
}
for (move = moves; move != NULL; move = move->next) {
if (move->size == size) return(1);
res = cuddSwapInPlace(table,(int)move->x,(int)move->y);
if (!res) return(0);
}
return(1);
} /* end of ddSiftingBackward */
/**Function********************************************************************
Synopsis [Prepares the DD heap for dynamic reordering.]
Description [Prepares the DD heap for dynamic reordering. Does
garbage collection, to guarantee that there are no dead nodes;
clears the cache, which is invalidated by dynamic reordering; initializes
the number of isolated projection functions; and initializes the
interaction matrix. Returns 1 in case of success; 0 otherwise.]
SideEffects [None]
******************************************************************************/
static int
ddReorderPreprocess(
DdManager * table)
{
int i;
int res;
/* Clear the cache. */
cuddCacheFlush(table);
cuddLocalCacheClearAll(table);
/* Eliminate dead nodes. Do not scan the cache again. */
cuddGarbageCollect(table,0);
/* Initialize number of isolated projection functions. */
table->isolated = 0;
for (i = 0; i < table->size; i++) {
if (table->vars[i]->ref == 1) table->isolated++;
}
/* Initialize the interaction matrix. */
res = cuddInitInteract(table);
if (res == 0) return(0);
return(1);
} /* end of ddReorderPreprocess */
/**Function********************************************************************
Synopsis [Cleans up at the end of reordering.]
Description []
SideEffects [None]
******************************************************************************/
static int
ddReorderPostprocess(
DdManager * table)
{
#ifdef DD_VERBOSE
(void) fflush(table->out);
#endif
/* Free interaction matrix. */
ABC_FREE(table->interact);
return(1);
} /* end of ddReorderPostprocess */
/**Function********************************************************************
Synopsis [Reorders variables according to a given permutation.]
Description [Reorders variables according to a given permutation.
The i-th permutation array contains the index of the variable that
should be brought to the i-th level. ddShuffle assumes that no
dead nodes are present and that the interaction matrix is properly
initialized. The reordering is achieved by a series of upward sifts.
Returns 1 if successful; 0 otherwise.]
SideEffects [None]
SeeAlso []
******************************************************************************/
static int
ddShuffle(
DdManager * table,
int * permutation)
{
int index;
int level;
int position;
int numvars;
int result;
#ifdef DD_STATS
long localTime;
int initialSize;
int finalSize;
int previousSize;
#endif
ddTotalNumberSwapping = 0;
#ifdef DD_STATS
localTime = util_cpu_time();
initialSize = table->keys - table->isolated;
(void) fprintf(table->out,"#:I_SHUFFLE %8d: initial size\n",
initialSize);
ddTotalNISwaps = 0;
#endif
numvars = table->size;
for (level = 0; level < numvars; level++) {
index = permutation[level];
position = table->perm[index];
#ifdef DD_STATS
previousSize = table->keys - table->isolated;
#endif
result = ddSiftUp(table,position,level);
if (!result) return(0);
#ifdef DD_STATS
if (table->keys < (unsigned) previousSize + table->isolated) {
(void) fprintf(table->out,"-");
} else if (table->keys > (unsigned) previousSize + table->isolated) {
(void) fprintf(table->out,"+"); /* should never happen */
} else {
(void) fprintf(table->out,"=");
}
fflush(table->out);
#endif
}
#ifdef DD_STATS
(void) fprintf(table->out,"\n");
finalSize = table->keys - table->isolated;
(void) fprintf(table->out,"#:F_SHUFFLE %8d: final size\n",finalSize);
(void) fprintf(table->out,"#:T_SHUFFLE %8g: total time (sec)\n",
((double)(util_cpu_time() - localTime)/1000.0));
(void) fprintf(table->out,"#:N_SHUFFLE %8d: total swaps\n",
ddTotalNumberSwapping);
(void) fprintf(table->out,"#:M_SHUFFLE %8d: NI swaps\n",ddTotalNISwaps);
#endif
return(1);
} /* end of ddShuffle */
/**Function********************************************************************
Synopsis [Moves one variable up.]
Description [Takes a variable from position x and sifts it up to
position xLow; xLow should be less than or equal to x.
Returns 1 if successful; 0 otherwise]
SideEffects [None]
SeeAlso []
******************************************************************************/
static int
ddSiftUp(
DdManager * table,
int x,
int xLow)
{
int y;
int size;
y = cuddNextLow(table,x);
while (y >= xLow) {
size = cuddSwapInPlace(table,y,x);
if (size == 0) {
return(0);
}
x = y;
y = cuddNextLow(table,x);
}
return(1);
} /* end of ddSiftUp */
/**Function********************************************************************
Synopsis [Fixes the BDD variable group tree after a shuffle.]
Description [Fixes the BDD variable group tree after a
shuffle. Assumes that the order of the variables in a terminal node
has not been changed.]
SideEffects [Changes the BDD variable group tree.]
SeeAlso []
******************************************************************************/
static void
bddFixTree(
DdManager * table,
MtrNode * treenode)
{
if (treenode == NULL) return;
treenode->low = ((int) treenode->index < table->size) ?
table->perm[treenode->index] : treenode->index;
if (treenode->child != NULL) {
bddFixTree(table, treenode->child);
}
if (treenode->younger != NULL)
bddFixTree(table, treenode->younger);
if (treenode->parent != NULL && treenode->low < treenode->parent->low) {
treenode->parent->low = treenode->low;
treenode->parent->index = treenode->index;
}
return;
} /* end of bddFixTree */
/**Function********************************************************************
Synopsis [Updates the BDD variable group tree before a shuffle.]
Description [Updates the BDD variable group tree before a shuffle.
Returns 1 if successful; 0 otherwise.]
SideEffects [Changes the BDD variable group tree.]
SeeAlso []
******************************************************************************/
static int
ddUpdateMtrTree(
DdManager * table,
MtrNode * treenode,
int * perm,
int * invperm)
{
int i, size;
int index, level, minLevel, maxLevel, minIndex;
if (treenode == NULL) return(1);
minLevel = CUDD_MAXINDEX;
maxLevel = 0;
minIndex = -1;
/* i : level */
for (i = treenode->low; i < treenode->low + treenode->size; i++) {
index = table->invperm[i];
level = perm[index];
if (level < minLevel) {
minLevel = level;
minIndex = index;
}
if (level > maxLevel)
maxLevel = level;
}
size = maxLevel - minLevel + 1;
if (minIndex == -1) return(0);
if (size == treenode->size) {
treenode->low = minLevel;
treenode->index = minIndex;
} else {
return(0);
}
if (treenode->child != NULL) {
if (!ddUpdateMtrTree(table, treenode->child, perm, invperm))
return(0);
}
if (treenode->younger != NULL) {
if (!ddUpdateMtrTree(table, treenode->younger, perm, invperm))
return(0);
}
return(1);
}
/**Function********************************************************************
Synopsis [Checks the BDD variable group tree before a shuffle.]
Description [Checks the BDD variable group tree before a shuffle.
Returns 1 if successful; 0 otherwise.]
SideEffects [Changes the BDD variable group tree.]
SeeAlso []
******************************************************************************/
static int
ddCheckPermuation(
DdManager * table,
MtrNode * treenode,
int * perm,
int * invperm)
{
int i, size;
int index, level, minLevel, maxLevel;
if (treenode == NULL) return(1);
minLevel = table->size;
maxLevel = 0;
/* i : level */
for (i = treenode->low; i < treenode->low + treenode->size; i++) {
index = table->invperm[i];
level = perm[index];
if (level < minLevel)
minLevel = level;
if (level > maxLevel)
maxLevel = level;
}
size = maxLevel - minLevel + 1;
if (size != treenode->size)
return(0);
if (treenode->child != NULL) {
if (!ddCheckPermuation(table, treenode->child, perm, invperm))
return(0);
}
if (treenode->younger != NULL) {
if (!ddCheckPermuation(table, treenode->younger, perm, invperm))
return(0);
}
return(1);
}
ABC_NAMESPACE_IMPL_END