Beispiel #1
0
/**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 */
Beispiel #3
0
/**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 */
Beispiel #4
0
/**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 */
Beispiel #5
0
/**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 */
Beispiel #6
0
/**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 */
Beispiel #7
0
/**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 */