/**Function********************************************************************
Synopsis [Restores the variable order in array by a series of sifts up.]
Description [Restores the variable order in array by a series of sifts up.
Returns 1 in case of success; 0 otherwise.]
SideEffects [None]
SeeAlso []
******************************************************************************/
static int
restoreOrder(
DdManager * table,
int * array,
int lower,
int upper)
{
int i, x, y, size;
int nvars = upper - lower + 1;
for (i = 0; i < nvars; i++) {
x = table->perm[array[i]];
#ifdef DD_DEBUG
assert(x >= lower && x <= upper);
#endif
y = cuddNextLow(table,x);
while (y >= i + lower) {
size = cuddSwapInPlace(table,y,x);
if (size == 0) return(0);
x = y;
y = cuddNextLow(table,x);
}
}
return(1);
} /* end of restoreOrder */
/**
@brief Undoes the swap of two groups.
@details x is assumed to be the bottom variable of the first
group. y is assumed to be the top variable of the second group.
@return the number of keys in the table if successful; 0 otherwise.
@sideeffect None
*/
static int
ddSymmGroupMoveBackward(
DdManager * table,
int x,
int y)
{
int size = (int) (table->keys - table->isolated);
int i,j;
int xtop,xbot,xsize,ytop,ybot,ysize,newxtop;
#ifdef DD_DEBUG
assert(x < y); /* We assume that x < y */
#endif
/* Find top, bottom, and size for the two groups. */
xbot = x;
xtop = table->subtables[x].next;
xsize = xbot - xtop + 1;
ybot = y;
while ((unsigned) ybot < table->subtables[ybot].next)
ybot = table->subtables[ybot].next;
ytop = y;
ysize = ybot - ytop + 1;
#ifdef DD_DEBUG
assert(xsize > 0);
assert(ysize > 0);
#endif
/* Sift the variables of the second group up through the first group. */
for (i = 1; i <= ysize; i++) {
for (j = 1; j <= xsize; j++) {
size = cuddSwapInPlace(table,x,y);
if (size == 0) return(0);
y = x;
x = cuddNextLow(table,y);
}
y = ytop + i;
x = y - 1;
}
/* Fix symmetries. */
y = xtop;
for (i = 0; i < ysize-1 ; i++) {
table->subtables[y].next = y + 1;
y = y + 1;
}
table->subtables[y].next = xtop; /* y is bottom of its group, join */
/* its symmetry to top of its group */
x = y + 1;
newxtop = x;
for (i = 0; i < xsize-1 ; i++) {
table->subtables[x].next = x + 1;
x = x + 1;
}
table->subtables[x].next = newxtop; /* x is bottom of its group, join */
/* its symmetry to top of its group */
return(size);
} /* end of ddSymmGroupMoveBackward */
/**Function********************************************************************
Synopsis [This function is for jumping up.]
Description [This is a simplified version of ddSiftingUp. It does not
use lower bounding. Returns the set of moves in case of success; NULL
if memory is full.]
SideEffects [None]
SeeAlso []
******************************************************************************/
static Move *
ddJumpingUp(
DdManager * table,
int x,
int x_low,
int initial_size)
{
Move *moves;
Move *move;
int y;
int size;
int limit_size = initial_size;
moves = NULL;
y = cuddNextLow(table,x);
while (y >= x_low) {
size = cuddSwapInPlace(table,y,x);
if (size == 0) goto ddJumpingUpOutOfMem;
move = (Move *)cuddDynamicAllocNode(table);
if (move == NULL) goto ddJumpingUpOutOfMem;
move->x = y;
move->y = x;
move->size = size;
move->next = moves;
moves = move;
if ((double) size > table->maxGrowth * (double) limit_size) {
break;
} else if (size < limit_size) {
limit_size = size;
}
x = y;
y = cuddNextLow(table,x);
}
return(moves);
ddJumpingUpOutOfMem:
while (moves != NULL) {
move = moves->next;
cuddDeallocNode(table, (DdNode *) moves);
moves = move;
}
return(NULL);
} /* end of ddJumpingUp */
/**Function********************************************************************
Synopsis [Moves a variable to a specified position.]
Description [If x==x_low, it executes jumping_down. If x==x_high, it
executes jumping_up. This funcion is similar to ddSiftingAux. Returns
1 in case of success; 0 otherwise.]
SideEffects [None]
SeeAlso []
******************************************************************************/
static int
ddJumpingAux(
DdManager * table,
int x,
int x_low,
int x_high,
double temp)
{
Move *move;
Move *moves; /* list of moves */
int initial_size;
int result;
initial_size = table->keys - table->isolated;
#ifdef DD_DEBUG
assert(table->subtables[x].keys > 0);
#endif
moves = NULL;
if (cuddNextLow(table,x) < x_low) {
if (cuddNextHigh(table,x) > x_high) return(1);
moves = ddJumpingDown(table,x,x_high,initial_size);
/* after that point x --> x_high unless early termination */
if (moves == NULL) goto ddJumpingAuxOutOfMem;
/* move backward and stop at best position or accept uphill move */
result = siftBackwardProb(table,moves,initial_size,temp);
if (!result) goto ddJumpingAuxOutOfMem;
} else if (cuddNextHigh(table,x) > x_high) {
moves = ddJumpingUp(table,x,x_low,initial_size);
/* after that point x --> x_low unless early termination */
if (moves == NULL) goto ddJumpingAuxOutOfMem;
/* move backward and stop at best position or accept uphill move */
result = siftBackwardProb(table,moves,initial_size,temp);
if (!result) goto ddJumpingAuxOutOfMem;
} else {
(void) fprintf(table->err,"Unexpected condition in ddJumping\n");
goto ddJumpingAuxOutOfMem;
}
while (moves != NULL) {
move = moves->next;
cuddDeallocNode(table, (DdNode *) moves);
moves = move;
}
return(1);
ddJumpingAuxOutOfMem:
while (moves != NULL) {
move = moves->next;
cuddDeallocNode(table, (DdNode *) moves);
moves = move;
}
return(0);
} /* end of ddJumpingAux */
/**Function********************************************************************
Synopsis [Moves one variable up.]
Description [Takes a variable from position x and sifts it up to
position x_low; x_low should be less than x. Returns 1 if successful;
0 otherwise]
SideEffects [None]
SeeAlso []
******************************************************************************/
static int
sift_up(
DdManager * table,
int x,
int x_low)
{
int y;
int size;
y = cuddNextLow(table,x);
while (y >= x_low) {
size = cuddSwapInPlace(table,y,x);
if (size == 0) {
return(0);
}
x = y;
y = cuddNextLow(table,x);
}
return(1);
} /* end of sift_up */
/**Function********************************************************************
Synopsis [This function is for exchanging two variables, x and y.]
Description [This is the same funcion as ddSwapping except for
comparison expression. Use probability function, exp(-size_change/temp).]
SideEffects [None]
SeeAlso []
******************************************************************************/
static int
ddExchange(
DdManager * table,
int x,
int y,
double temp)
{
Move *move,*moves;
int tmp;
int x_ref,y_ref;
int x_next,y_next;
int size, result;
int initial_size, limit_size;
x_ref = x;
y_ref = y;
x_next = cuddNextHigh(table,x);
y_next = cuddNextLow(table,y);
moves = NULL;
initial_size = limit_size = table->keys - table->isolated;
for (;;) {
if (x_next == y_next) {
size = cuddSwapInPlace(table,x,x_next);
if (size == 0) goto ddExchangeOutOfMem;
move = (Move *)cuddDynamicAllocNode(table);
if (move == NULL) goto ddExchangeOutOfMem;
move->x = x;
move->y = x_next;
move->size = size;
move->next = moves;
moves = move;
size = cuddSwapInPlace(table,y_next,y);
if (size == 0) goto ddExchangeOutOfMem;
move = (Move *)cuddDynamicAllocNode(table);
if (move == NULL) goto ddExchangeOutOfMem;
move->x = y_next;
move->y = y;
move->size = size;
move->next = moves;
moves = move;
size = cuddSwapInPlace(table,x,x_next);
if (size == 0) goto ddExchangeOutOfMem;
move = (Move *)cuddDynamicAllocNode(table);
if (move == NULL) goto ddExchangeOutOfMem;
move->x = x;
move->y = x_next;
move->size = size;
move->next = moves;
moves = move;
tmp = x;
x = y;
y = tmp;
} else if (x == y_next) {
size = cuddSwapInPlace(table,x,x_next);
if (size == 0) goto ddExchangeOutOfMem;
move = (Move *)cuddDynamicAllocNode(table);
if (move == NULL) goto ddExchangeOutOfMem;
move->x = x;
move->y = x_next;
move->size = size;
move->next = moves;
moves = move;
tmp = x;
x = y;
y = tmp;
} else {
size = cuddSwapInPlace(table,x,x_next);
if (size == 0) goto ddExchangeOutOfMem;
move = (Move *)cuddDynamicAllocNode(table);
if (move == NULL) goto ddExchangeOutOfMem;
move->x = x;
move->y = x_next;
move->size = size;
move->next = moves;
moves = move;
size = cuddSwapInPlace(table,y_next,y);
if (size == 0) goto ddExchangeOutOfMem;
move = (Move *)cuddDynamicAllocNode(table);
if (move == NULL) goto ddExchangeOutOfMem;
move->x = y_next;
move->y = y;
move->size = size;
move->next = moves;
moves = move;
x = x_next;
y = y_next;
}
x_next = cuddNextHigh(table,x);
y_next = cuddNextLow(table,y);
if (x_next > y_ref) break;
if ((double) size > DD_MAX_REORDER_GROWTH * (double) limit_size) {
break;
} else if (size < limit_size) {
limit_size = size;
}
}
if (y_next>=x_ref) {
size = cuddSwapInPlace(table,y_next,y);
if (size == 0) goto ddExchangeOutOfMem;
move = (Move *)cuddDynamicAllocNode(table);
if (move == NULL) goto ddExchangeOutOfMem;
move->x = y_next;
move->y = y;
move->size = size;
move->next = moves;
moves = move;
}
/* move backward and stop at best position or accept uphill move */
result = siftBackwardProb(table,moves,initial_size,temp);
if (!result) goto ddExchangeOutOfMem;
while (moves != NULL) {
move = moves->next;
cuddDeallocNode(table, (DdNode *) moves);
moves = move;
}
return(1);
ddExchangeOutOfMem:
while (moves != NULL) {
move = moves->next;
cuddDeallocNode(table,(DdNode *) moves);
moves = move;
}
return(0);
} /* end of ddExchange */
/**Function********************************************************************
Synopsis [Moves x up until either it reaches the bound (xLow) or
the size of the DD heap increases too much.]
Description [Moves x up until either it reaches the bound (xLow) or
the size of the DD heap increases too much. Assumes that x is the top
of a symmetry group. Checks x for symmetry to the adjacent
variables. If symmetry is found, the symmetry group of x is merged
with the symmetry group of the other variable. Returns the set of
moves in case of success; MV_OOM if memory is full.]
SideEffects [None]
******************************************************************************/
static Move *
ddSymmSiftingUp(
DdManager * table,
int y,
int xLow)
{
Move *moves;
Move *move;
int x;
int size;
int i;
int gxtop,gybot;
int limitSize;
int xindex, yindex;
int zindex;
int z;
int isolated;
int L; /* lower bound on DD size */
#ifdef DD_DEBUG
int checkL;
#endif
moves = NULL;
yindex = table->invperm[y];
/* Initialize the lower bound.
** The part of the DD below the bottom of y' group 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;
gybot = y;
while ((unsigned) gybot < table->subtables[gybot].next)
gybot = table->subtables[gybot].next;
for (z = xLow + 1; z <= gybot; z++) {
zindex = table->invperm[z];
if (zindex == yindex || cuddTestInteract(table,zindex,yindex)) {
isolated = table->vars[zindex]->ref == 1;
L -= table->subtables[z].keys - isolated;
}
}
x = cuddNextLow(table,y);
while (x >= xLow && L <= limitSize) {
#ifdef DD_DEBUG
gybot = y;
while ((unsigned) gybot < table->subtables[gybot].next)
gybot = table->subtables[gybot].next;
checkL = table->keys - table->isolated;
for (z = xLow + 1; z <= gybot; z++) {
zindex = table->invperm[z];
if (zindex == yindex || cuddTestInteract(table,zindex,yindex)) {
isolated = table->vars[zindex]->ref == 1;
checkL -= table->subtables[z].keys - isolated;
}
}
assert(L == checkL);
#endif
gxtop = table->subtables[x].next;
if (cuddSymmCheck(table,x,y)) {
/* Symmetry found, attach symm groups */
table->subtables[x].next = y;
i = table->subtables[y].next;
while (table->subtables[i].next != (unsigned) y)
i = table->subtables[i].next;
table->subtables[i].next = gxtop;
} else if (table->subtables[x].next == (unsigned) x &&
table->subtables[y].next == (unsigned) y) {
/* x and y have self symmetry */
xindex = table->invperm[x];
size = cuddSwapInPlace(table,x,y);
#ifdef DD_DEBUG
assert(table->subtables[x].next == (unsigned) x);
assert(table->subtables[y].next == (unsigned) y);
#endif
if (size == 0) goto ddSymmSiftingUpOutOfMem;
/* 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 ddSymmSiftingUpOutOfMem;
move->x = x;
move->y = y;
move->size = size;
move->next = moves;
moves = move;
if ((double) size > (double) limitSize * table->maxGrowth)
return(moves);
if (size < limitSize) limitSize = size;
} else { /* Group move */
size = ddSymmGroupMove(table,x,y,&moves);
if (size == 0) goto ddSymmSiftingUpOutOfMem;
/* Update the lower bound. */
z = moves->y;
do {
zindex = table->invperm[z];
if (cuddTestInteract(table,zindex,yindex)) {
isolated = table->vars[zindex]->ref == 1;
L += table->subtables[z].keys - isolated;
}
z = table->subtables[z].next;
} while (z != (int) moves->y);
if ((double) size > (double) limitSize * table->maxGrowth)
return(moves);
if (size < limitSize) limitSize = size;
}
y = gxtop;
x = cuddNextLow(table,y);
}
return(moves);
ddSymmSiftingUpOutOfMem:
while (moves != NULL) {
move = moves->next;
cuddDeallocMove(table, moves);
moves = move;
}
return(MV_OOM);
} /* end of ddSymmSiftingUp */