cudd/cuddZddSymm.c File Reference

Functions for symmetry-based ZDD variable reordering. More...

#include "util.h"
#include "cuddInt.h"
Include dependency graph for cuddZddSymm.c:

Defines

#define ZDD_MV_OOM   (Move *)1

Functions

void Cudd_zddSymmProfile (DdManager *table, int lower, int upper)
 Prints statistics on symmetric ZDD variables.
int cuddZddSymmCheck (DdManager *table, int x, int y)
 Checks for symmetry of x and y.
int cuddZddSymmSifting (DdManager *table, int lower, int upper)
 Symmetric sifting algorithm for ZDDs.
int cuddZddSymmSiftingConv (DdManager *table, int lower, int upper)
 Symmetric sifting to convergence algorithm for ZDDs.
static int cuddZddSymmSiftingAux (DdManager *table, int x, int x_low, int x_high)
 Given x_low <= x <= x_high moves x up and down between the boundaries.
static int cuddZddSymmSiftingConvAux (DdManager *table, int x, int x_low, int x_high)
 Given x_low <= x <= x_high moves x up and down between the boundaries.
static MovecuddZddSymmSifting_up (DdManager *table, int x, int x_low, int initial_size)
 Moves x up until either it reaches the bound (x_low) or the size of the ZDD heap increases too much.
static MovecuddZddSymmSifting_down (DdManager *table, int x, int x_high, int initial_size)
 Moves x down until either it reaches the bound (x_high) or the size of the ZDD heap increases too much.
static int cuddZddSymmSiftingBackward (DdManager *table, Move *moves, int size)
 Given a set of moves, returns the ZDD heap to the position giving the minimum size.
static int zdd_group_move (DdManager *table, int x, int y, Move **moves)
 Swaps two groups.
static int zdd_group_move_backward (DdManager *table, int x, int y)
 Undoes the swap of two groups.
static void cuddZddSymmSummary (DdManager *table, int lower, int upper, int *symvars, int *symgroups)
 Counts numbers of symmetric variables and symmetry groups.

Detailed Description

Functions for symmetry-based ZDD variable reordering.

See also:
cuddSymmetry.c
Author:
Hyong-Kyoon Shin, In-Ho Moon

Copyright (c) 1995-2015, 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.


Function Documentation

void Cudd_zddSymmProfile ( DdManager table,
int  lower,
int  upper 
)

Prints statistics on symmetric ZDD variables.

Side effects
None
int cuddZddSymmCheck ( DdManager table,
int  x,
int  y 
)

Checks for symmetry of x and y.

Ignores projection functions, unless they are isolated.

Returns:
1 in case of symmetry; 0 otherwise.
Side effects
None
int cuddZddSymmSifting ( DdManager table,
int  lower,
int  upper 
)

Symmetric sifting algorithm for ZDDs.

Assumes that no dead nodes are present.

  1. Order all the variables according to the number of entries in each unique subtable.
  2. Sift the variable up and down, remembering each time the total size of the ZDD heap and grouping variables that are symmetric.
  3. Select the best permutation.
  4. Repeat 3 and 4 for all variables.
Returns:
1 plus the number of symmetric variables if successful; 0 otherwise.
Side effects
None
See also:
cuddZddSymmSiftingConv
static Move* cuddZddSymmSifting_down ( DdManager table,
int  x,
int  x_high,
int  initial_size 
) [static]

Moves x down until either it reaches the bound (x_high) or the size of the ZDD heap increases too much.

Assumes that x is the bottom 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; ZDD_MV_OOM if memory is full.
Side effects
None
static Move* cuddZddSymmSifting_up ( DdManager table,
int  x,
int  x_low,
int  initial_size 
) [static]

Moves x up until either it reaches the bound (x_low) or the size of the ZDD 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; ZDD_MV_OOM if memory is full.
Side effects
None
static int cuddZddSymmSiftingAux ( DdManager table,
int  x,
int  x_low,
int  x_high 
) [static]

Given x_low <= x <= x_high moves x up and down between the boundaries.

Finds the best position and does the required changes. Assumes that x is not part of a symmetry group.

Returns:
1 if successful; 0 otherwise.
Side effects
None
static int cuddZddSymmSiftingBackward ( DdManager table,
Move moves,
int  size 
) [static]

Given a set of moves, returns the ZDD 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.
Side effects
None
int cuddZddSymmSiftingConv ( DdManager table,
int  lower,
int  upper 
)

Symmetric sifting to convergence algorithm for ZDDs.

Assumes that no dead nodes are present.

  1. Order all the variables according to the number of entries in each unique subtable.
  2. Sift the variable up and down, remembering each time the total size of the ZDD heap and grouping variables that are symmetric.
  3. Select the best permutation.
  4. Repeat 3 and 4 for all variables.
  5. Repeat 1-4 until no further improvement.
Returns:
1 plus the number of symmetric variables if successful; 0 otherwise.
Side effects
None
See also:
cuddZddSymmSifting
static int cuddZddSymmSiftingConvAux ( DdManager table,
int  x,
int  x_low,
int  x_high 
) [static]

Given x_low <= x <= x_high moves x up and down between the boundaries.

Finds the best position and does the required changes. Assumes that x is either an isolated variable, or it is the bottom of a symmetry group. All symmetries may not have been found, because of exceeded growth limit.

Returns:
1 if successful; 0 otherwise.
Side effects
None
static void cuddZddSymmSummary ( DdManager table,
int  lower,
int  upper,
int *  symvars,
int *  symgroups 
) [static]

Counts numbers of symmetric variables and symmetry groups.

Side effects
None
static int zdd_group_move ( DdManager table,
int  x,
int  y,
Move **  moves 
) [static]

Swaps two groups.

x is assumed to be the bottom variable of the first group. y is assumed to be the top variable of the second group. Updates the list of moves.

Returns:
the number of keys in the table if successful; 0 otherwise.
Side effects
None
static int zdd_group_move_backward ( DdManager table,
int  x,
int  y 
) [static]

Undoes the swap of two groups.

x is assumed to be the bottom variable of the first group. y is assumed to be the top variable of the second group.

Returns:
1 if successful; 0 otherwise.
Side effects
None
 All Data Structures Files Functions Variables Typedefs Enumerations Defines

Generated on 31 Dec 2015 for cudd by  doxygen 1.6.1