[14] | 1 | /**CFile*********************************************************************** |
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| 2 | |
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| 3 | FileName [ordNodes.c] |
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| 4 | |
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| 5 | PackageName [ord] |
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| 6 | |
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| 7 | Synopsis [Routines to order the nodes in the TFI of the roots of a network.] |
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| 8 | |
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| 9 | Description [Routines to order the nodes in the TFI of the roots of a |
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| 10 | network. To add a new method, create a new value for the Ord_NodeMethod |
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| 11 | enumerated type, and add a call to the new procedure from |
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| 12 | OrdNetworkOrderTFIOfRoots.] |
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| 13 | |
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| 14 | Author [Tom Shiple and Fabio Somenzi] |
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| 15 | |
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| 16 | Copyright [Copyright (c) 1994-1996 The Regents of the Univ. of California. |
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| 17 | All rights reserved. |
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| 18 | |
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| 19 | Permission is hereby granted, without written agreement and without license |
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| 20 | or royalty fees, to use, copy, modify, and distribute this software and its |
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| 21 | documentation for any purpose, provided that the above copyright notice and |
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| 22 | the following two paragraphs appear in all copies of this software. |
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| 23 | |
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| 24 | IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR |
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| 25 | DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT |
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| 26 | OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF THE UNIVERSITY OF |
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| 27 | CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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| 28 | |
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| 29 | THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES, |
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| 30 | INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND |
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| 31 | FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS ON AN |
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| 32 | "AS IS" BASIS, AND THE UNIVERSITY OF CALIFORNIA HAS NO OBLIGATION TO PROVIDE |
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| 33 | MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.] |
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| 34 | |
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| 35 | ******************************************************************************/ |
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| 36 | |
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| 37 | #include "ordInt.h" |
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| 38 | |
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| 39 | static char rcsid[] UNUSED = "$Id: ordNodes.c,v 1.12 2005/04/16 06:15:25 fabio Exp $"; |
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| 40 | |
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| 41 | /*---------------------------------------------------------------------------*/ |
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| 42 | /* Constant declarations */ |
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| 43 | /*---------------------------------------------------------------------------*/ |
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| 44 | |
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| 45 | |
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| 46 | /*---------------------------------------------------------------------------*/ |
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| 47 | /* Type declarations */ |
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| 48 | /*---------------------------------------------------------------------------*/ |
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| 49 | |
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| 50 | |
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| 51 | /*---------------------------------------------------------------------------*/ |
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| 52 | /* Structure declarations */ |
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| 53 | /*---------------------------------------------------------------------------*/ |
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| 54 | /**Struct********************************************************************** |
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| 55 | |
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| 56 | Synopsis [State needed for performing variable ordering.] |
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| 57 | |
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| 58 | SeeAlso [NetworkInitializeOrderingState OrderingStateFree] |
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| 59 | |
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| 60 | ******************************************************************************/ |
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| 61 | typedef struct OrderingStateStruct { |
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| 62 | st_table *nodeToOrderList; /* Ntk_Node_t * to lsList; top. order of tfi |
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| 63 | nodes */ |
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| 64 | st_table *from; /* Ntk_Node_t * to Ntk_Node_t */ |
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| 65 | lsGen last; /* insertion point */ |
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| 66 | Ntk_Node_t *root; /* current output */ |
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| 67 | } OrderingState_t; |
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| 68 | |
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| 69 | /*---------------------------------------------------------------------------*/ |
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| 70 | /* Variable declarations */ |
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| 71 | /*---------------------------------------------------------------------------*/ |
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| 72 | |
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| 73 | |
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| 74 | /*---------------------------------------------------------------------------*/ |
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| 75 | /* Macro declarations */ |
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| 76 | /*---------------------------------------------------------------------------*/ |
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| 77 | |
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| 78 | |
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| 79 | /**AutomaticStart*************************************************************/ |
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| 80 | |
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| 81 | /*---------------------------------------------------------------------------*/ |
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| 82 | /* Static function prototypes */ |
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| 83 | /*---------------------------------------------------------------------------*/ |
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| 84 | |
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| 85 | static lsList NetworkOrderTFIOfRootsByMerging(Ntk_Network_t *network, lsList roots, Ord_ListMergeMethod method, st_table *nodeToHandle, int verbose); |
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| 86 | static lsList NodeOrderRecursivelyByMerging(Ntk_Node_t * node, OrderingState_t * orderingState, Ord_ListMergeMethod method, int verbose); |
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| 87 | static lsList NetworkOrderTFIOfRootsByAppending(Ntk_Network_t *network, lsList roots, st_table *nodeToHandle, int verbose); |
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| 88 | static void NodeOrderRecursivelyByAppending(Ntk_Node_t * node, lsList orderList, st_table *nodeToHandle, int verbose); |
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| 89 | static lsList NetworkOrderTFIOfRootsByInterleaving(Ntk_Network_t *network, lsList roots, st_table *nodeToHandle, int verbose); |
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| 90 | static void NodeOrderRecursivelyByInterleaving(Ntk_Node_t * node, lsList orderList, st_table *nodeToHandle, OrderingState_t *orderingState, int verbose); |
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| 91 | static OrderingState_t * NetworkInitializeOrderingState(Ntk_Network_t * network); |
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| 92 | static void OrderingStateSetLast(Ntk_Node_t * node, st_table * nodeToHandle, OrderingState_t * orderingState); |
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| 93 | static void OrderingStateFree(OrderingState_t * orderingState); |
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| 94 | static lsList NodeReadOrderList(Ntk_Node_t * node, OrderingState_t * orderingState); |
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| 95 | static void NodeSetOrderList(Ntk_Node_t * node, lsList orderList, OrderingState_t * orderingState); |
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| 96 | static Ntk_Node_t * NodeReadFrom(Ntk_Node_t * node, OrderingState_t * orderingState); |
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| 97 | static void NodeSetFrom(Ntk_Node_t * node, OrderingState_t * orderingState); |
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| 98 | |
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| 99 | /**AutomaticEnd***************************************************************/ |
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| 100 | |
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| 101 | |
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| 102 | /*---------------------------------------------------------------------------*/ |
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| 103 | /* Definition of exported functions */ |
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| 104 | /*---------------------------------------------------------------------------*/ |
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| 105 | |
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| 106 | |
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| 107 | /*---------------------------------------------------------------------------*/ |
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| 108 | /* Definition of internal functions */ |
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| 109 | /*---------------------------------------------------------------------------*/ |
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| 110 | |
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| 111 | /**Function******************************************************************** |
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| 112 | |
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| 113 | Synopsis [Orders the nodes of a network in TFI of roots.] |
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| 114 | |
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| 115 | Description [Orders the nodes of a network that are in the transitive fanin |
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| 116 | of the list of roots, including the roots themselves. The roots are visited |
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| 117 | in the order given in the root list. Combinational inputs (primary inputs, |
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| 118 | pseudo inputs, and latches) and constants terminate the recursion. If you |
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| 119 | want a latch next state function to be a root, then the corresponding data |
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| 120 | input should be in the root list, not the latch itself. Note that next state |
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| 121 | variables are not included in the ordering; these should be added as a |
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| 122 | post-processing step.<p> |
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| 123 | |
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| 124 | The different node ordering methods are documented in the static_order |
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| 125 | command. If nodeMethod is Ord_NodesByDefault_c, then one of the ordering |
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| 126 | methods is called by default.<p> |
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| 127 | |
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| 128 | nodeToHandle should be an empty table created using st_init_table(st_ptrcmp, |
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| 129 | st_ptrhash). For every node in the returned list, there is an entry in |
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| 130 | nodeToHandle mapping the node to the node's handle in the returned list.] |
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| 131 | |
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| 132 | SideEffects [nodeToHandle table is modified] |
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| 133 | |
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| 134 | SeeAlso [Ord_NetworkOrderRoots] |
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| 135 | |
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| 136 | ******************************************************************************/ |
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| 137 | lsList |
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| 138 | OrdNetworkOrderTFIOfRoots( |
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| 139 | Ntk_Network_t *network, |
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| 140 | lsList roots /* of Ntk_Node_t */, |
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| 141 | Ord_NodeMethod nodeOrderMethod, |
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| 142 | st_table *nodeToHandle /* modified */, |
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| 143 | int verbose) |
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| 144 | { |
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| 145 | switch (nodeOrderMethod) { |
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| 146 | case Ord_NodesByDefault_c: |
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| 147 | case Ord_NodesByInterleaving_c: |
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| 148 | return NetworkOrderTFIOfRootsByInterleaving(network, roots, |
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| 149 | nodeToHandle, verbose); |
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| 150 | case Ord_NodesByMergingLeft_c: |
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| 151 | return NetworkOrderTFIOfRootsByMerging(network, roots, |
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| 152 | Ord_ListMergeLeft_c, |
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| 153 | nodeToHandle, verbose); |
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| 154 | case Ord_NodesByMergingRight_c: |
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| 155 | return NetworkOrderTFIOfRootsByMerging(network, roots, |
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| 156 | Ord_ListMergeRight_c, |
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| 157 | nodeToHandle, verbose); |
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| 158 | case Ord_NodesByAppending_c: |
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| 159 | return NetworkOrderTFIOfRootsByAppending(network, roots, |
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| 160 | nodeToHandle, verbose); |
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| 161 | default: |
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| 162 | fail("unrecognized node ordering method"); |
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| 163 | return (lsList) 0; |
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| 164 | } |
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| 165 | } |
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| 166 | |
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| 167 | |
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| 168 | /*---------------------------------------------------------------------------*/ |
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| 169 | /* Definition of static functions */ |
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| 170 | /*---------------------------------------------------------------------------*/ |
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| 171 | |
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| 172 | /**Function******************************************************************** |
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| 173 | |
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| 174 | Synopsis [Orders the nodes of a network by the merging method.] |
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| 175 | |
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| 176 | Description [Orders the nodes of a network by the merging method. The |
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| 177 | parameters are the same as in OrdNetworkOrderTFIOfRoots.<p> |
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| 178 | |
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| 179 | This function implements an algorithm alluded to in Section 3.2 of Fujii et |
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| 180 | al., "Interleaving Based Variable Ordering Methods for OBDDs", ICCAD 1993, |
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| 181 | p. 38. The ordering returned is a topological ordering. The algorithm |
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| 182 | works as follows. For every node, a topological ordering on the tfi nodes |
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| 183 | is created and stored at the node. This is done recursively. For leaves of |
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| 184 | the recursion, a trivial list of length 1 is created. For the general case, |
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| 185 | the order lists at the fanins are merged together, and then the node itself |
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| 186 | is appended to the end of the list. The merging is done from the highest |
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| 187 | priority fanin to the lowest priority, where a "merge right" or "merge |
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| 188 | right" is performed, depending on the value of method. Nodes with greater |
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| 189 | depth have higher priority.<p> |
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| 190 | |
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| 191 | TODO: This function is consuming more memory than is |
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| 192 | necessary. Specifically, a node list is computed and stored at each network |
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| 193 | node. Currently, this list is not freed until the very end of the node |
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| 194 | ordering computation. Instead, a reference count could be precomputed for |
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| 195 | each node, and when this falls to zero, the list can be immediately freed.] |
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| 196 | |
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| 197 | SideEffects [nodeToHandle table is modified] |
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| 198 | |
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| 199 | SeeAlso [OrdNetworkOrderTFIOfRoots NodeOrderRecursivelyByMerging |
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| 200 | OrdNetworkComputeNodeDepths] |
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| 201 | |
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| 202 | ******************************************************************************/ |
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| 203 | static lsList |
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| 204 | NetworkOrderTFIOfRootsByMerging( |
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| 205 | Ntk_Network_t *network, |
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| 206 | lsList roots /* list of Ntk_Node_t */, |
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| 207 | Ord_ListMergeMethod method, |
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| 208 | st_table *nodeToHandle /* modified */, |
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| 209 | int verbose) |
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| 210 | { |
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| 211 | lsGen gen; |
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| 212 | Ntk_Node_t *root; |
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| 213 | OrderingState_t *orderingState; |
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| 214 | lsList orderList = lsCreate(); /* return list */ |
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| 215 | |
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| 216 | |
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| 217 | /* |
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| 218 | * Compute and store the depth of each node in the network. (The depth of a |
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| 219 | * node is stored in the undef field of the node). |
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| 220 | */ |
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| 221 | OrdNetworkComputeNodeDepths(network, roots); |
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| 222 | |
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| 223 | /* |
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| 224 | * Initialize the necessary state needed for recursing through the network. |
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| 225 | */ |
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| 226 | orderingState = NetworkInitializeOrderingState(network); |
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| 227 | |
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| 228 | /* |
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| 229 | * For each root, recursively order all nodes in its transitive fanin, and |
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| 230 | * merge this ordering into the nodes already ordered. |
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| 231 | */ |
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| 232 | lsForEachItem(roots, gen, root) { |
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| 233 | lsList rootOrderList = NodeOrderRecursivelyByMerging(root, orderingState, |
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| 234 | method, verbose); |
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| 235 | Ord_ListMergeListUsingTable(orderList, rootOrderList, nodeToHandle, method); |
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| 236 | |
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| 237 | if (verbose > 2) { |
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| 238 | /* This can generate a lot of output. */ |
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| 239 | (void) fprintf(vis_stdout, "\nOrder list after merging node %s\n", |
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| 240 | Ntk_NodeReadName(root)); |
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| 241 | OrdNodeListWrite(vis_stdout, orderList); |
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| 242 | } |
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| 243 | } |
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| 244 | |
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| 245 | /* |
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| 246 | * Clean up and return the ordering list. |
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| 247 | */ |
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| 248 | OrderingStateFree(orderingState); |
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| 249 | return orderList; |
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| 250 | } |
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| 251 | |
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| 252 | |
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| 253 | /**Function******************************************************************** |
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| 254 | |
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| 255 | Synopsis [Orders the fanins of a node, and then orders the node itself.] |
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| 256 | |
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| 257 | Description [Orders the fanins of a node, and then orders the node |
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| 258 | itself. The fanins of a node are visited in order of decreasing depth, and |
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| 259 | their orderings are merged. The node appears in the order just after its |
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| 260 | fanins, yielding a topological order. If node has already been visited, |
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| 261 | then simply return the order previously found.] |
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| 262 | |
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| 263 | SideEffects [] |
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| 264 | |
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| 265 | SeeAlso [OrdNetworkComputeNodeDepths NetworkOrderTFIOfRootsByMerging] |
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| 266 | |
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| 267 | ******************************************************************************/ |
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| 268 | static lsList |
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| 269 | NodeOrderRecursivelyByMerging( |
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| 270 | Ntk_Node_t * node, |
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| 271 | OrderingState_t * orderingState, |
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| 272 | Ord_ListMergeMethod method, |
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| 273 | int verbose) |
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| 274 | { |
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| 275 | lsList orderList; |
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| 276 | |
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| 277 | |
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| 278 | /* |
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| 279 | * If node has already been visited (i.e. its orderList is non-NULL), then |
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| 280 | * just return the orderList already computed. |
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| 281 | */ |
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| 282 | orderList = NodeReadOrderList(node, orderingState); |
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| 283 | if (orderList != (lsList) NULL) { |
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| 284 | return orderList; |
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| 285 | } |
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| 286 | |
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| 287 | /* |
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| 288 | * Node has not yet been visited. Create the orderList for node. |
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| 289 | */ |
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| 290 | if (Ntk_NodeTestIsCombInput(node) || Ntk_NodeTestIsConstant(node)) { |
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| 291 | /* |
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| 292 | * Combinational inputs and constants terminate the recursion. If node is |
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| 293 | * one of these, then just create an empty list, to which we will add the |
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| 294 | * node. |
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| 295 | */ |
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| 296 | orderList = lsCreate(); |
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| 297 | } |
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| 298 | else if (Ntk_NodeReadNumFanins(node) == 1) { |
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| 299 | /* |
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| 300 | * If there is just one fanin, then just make a copy of the the fanin's |
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| 301 | * orderList. This case is distinguished from the general case for |
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| 302 | * efficiency. |
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| 303 | */ |
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| 304 | lsList faninOrderList = NodeOrderRecursivelyByMerging(Ntk_NodeReadFaninNode(node, 0), |
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| 305 | orderingState, |
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| 306 | method, verbose); |
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| 307 | orderList = lsCopy(faninOrderList, (lsGeneric (*) (lsGeneric)) NULL); |
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| 308 | } |
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| 309 | else { |
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| 310 | int i; |
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| 311 | array_t *sortedFanins; |
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| 312 | st_table *nodeToHandle; |
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| 313 | |
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| 314 | /* |
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| 315 | * Sort the fanins of node in decreasing order of depth. See |
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| 316 | * OrdNetworkComputeNodeDepths. |
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| 317 | */ |
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| 318 | sortedFanins = array_dup(Ntk_NodeReadFanins(node)); |
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| 319 | array_sort(sortedFanins, OrdNodesFromArrayCompareDepth); |
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| 320 | |
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| 321 | /* |
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| 322 | * Start with an empty list for the orderList of the node. Also, start |
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| 323 | * with an empty nodeToHandle table. This table is only used locally, and |
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| 324 | * will be deleted below. |
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| 325 | */ |
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| 326 | orderList = lsCreate(); |
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| 327 | nodeToHandle = st_init_table(st_ptrcmp, st_ptrhash); |
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| 328 | |
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| 329 | /* |
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| 330 | * Recursively visit the fanins in order of decreasing depth. The |
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| 331 | * nodeToHandle table keeps track of the nodes currently in orderList. |
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| 332 | */ |
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| 333 | for (i = 0; i < array_n(sortedFanins); i++) { |
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| 334 | Ntk_Node_t *fanin = array_fetch(Ntk_Node_t *, sortedFanins, i); |
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| 335 | lsList faninOrderList = NodeOrderRecursivelyByMerging(fanin, |
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| 336 | orderingState, |
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| 337 | method, verbose); |
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| 338 | /* |
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| 339 | * Merge faninOrderList into the list of nodes already ordered. |
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| 340 | */ |
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| 341 | Ord_ListMergeListUsingTable(orderList, faninOrderList, nodeToHandle, method); |
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| 342 | } |
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| 343 | array_free(sortedFanins); |
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| 344 | st_free_table(nodeToHandle); |
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| 345 | } |
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| 346 | |
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| 347 | /* |
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| 348 | * Regardless of the branch taken above, add node to the end of the |
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| 349 | * orderList, and set the node's orderList. |
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| 350 | */ |
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| 351 | (void) lsNewEnd(orderList, (lsGeneric) node, LS_NH); |
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| 352 | NodeSetOrderList(node, orderList, orderingState); |
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| 353 | |
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| 354 | if (verbose > 2) { |
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| 355 | /* This can generate a lot of output. */ |
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| 356 | (void) fprintf(vis_stdout, "\nOrder list for node %s\n", Ntk_NodeReadName(node)); |
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| 357 | OrdNodeListWrite(vis_stdout, orderList); |
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| 358 | } |
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| 359 | |
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| 360 | return orderList; |
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| 361 | } |
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| 362 | |
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| 363 | |
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| 364 | /**Function******************************************************************** |
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| 365 | |
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| 366 | Synopsis [Orders the nodes of a network by the appending method.] |
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| 367 | |
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| 368 | Description [Orders the nodes of a network by the appending method. The |
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| 369 | parameters are the same as in OrdNetworkOrderTFIOfRoots.<p> |
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| 370 | |
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| 371 | This function implements the algorithm of Malik, et al. "Logic Verification |
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| 372 | using Binary Decision Diagrams in a Logic Synthesis Environment," ICCAD, |
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| 373 | 1988. The ordering returned is a topological ordering. The algorithm works |
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| 374 | as follows. For every root, a topological ordering on the tfi nodes not |
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| 375 | yet ordered is generated by DFS. The ordered obtained starting from a root |
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| 376 | is appended to the order already found.] |
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| 377 | |
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| 378 | SideEffects [nodeToHandle table is modified] |
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| 379 | |
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| 380 | SeeAlso [OrdNetworkOrderTFIOfRoots NodeOrderRecursivelyByAppending] |
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| 381 | |
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| 382 | ******************************************************************************/ |
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| 383 | static lsList |
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| 384 | NetworkOrderTFIOfRootsByAppending( |
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| 385 | Ntk_Network_t *network, |
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| 386 | lsList roots /* list of Ntk_Node_t */, |
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| 387 | st_table *nodeToHandle /* modified */, |
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| 388 | int verbose) |
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| 389 | { |
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| 390 | lsGen gen; |
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| 391 | Ntk_Node_t *root; |
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| 392 | lsList orderList = lsCreate(); /* return list */ |
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| 393 | |
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| 394 | |
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| 395 | /* |
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| 396 | * Compute and store the depth of each node in the network. (The depth of a |
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| 397 | * node is stored in the undef field of the node). |
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| 398 | */ |
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| 399 | OrdNetworkComputeNodeDepths(network, roots); |
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| 400 | |
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| 401 | if (verbose > 1) { |
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| 402 | Ntk_Node_t *node; |
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| 403 | (void) fprintf(vis_stdout, "\nDepths of network nodes:\n"); |
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| 404 | Ntk_NetworkForEachNode(network, gen, node) { |
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| 405 | (void) fprintf(vis_stdout, "%s: depth = %ld\n", Ntk_NodeReadName(node), |
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| 406 | OrdNodeReadDepth(node)); |
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| 407 | } |
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| 408 | } |
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| 409 | |
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| 410 | /* |
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| 411 | * For each root, recursively order all nodes in its transitive fanin. |
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| 412 | */ |
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| 413 | lsForEachItem(roots, gen, root) { |
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| 414 | NodeOrderRecursivelyByAppending(root, orderList, nodeToHandle, verbose); |
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| 415 | } |
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| 416 | |
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| 417 | return orderList; |
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| 418 | } |
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| 419 | |
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| 420 | |
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| 421 | /**Function******************************************************************** |
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| 422 | |
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| 423 | Synopsis [Orders the fanins of a node, and then orders the node itself.] |
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| 424 | |
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| 425 | Description [Orders the fanins of a node, and then orders the node |
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| 426 | itself. The fanins of a node are visited in order of decreasing depth. The |
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| 427 | node appears in the order just after its fanins, yielding a topological |
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| 428 | order. If node has already been visited, then simply return the order |
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| 429 | previously found.] |
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| 430 | |
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| 431 | Comment [The nodeToHandle table serves as the visited table for the DFS.] |
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| 432 | |
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| 433 | SideEffects [nodeToHandle table is modified] |
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| 434 | |
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| 435 | SeeAlso [NetworkOrderTFIOfRootsByAppending OrdNetworkComputeNodeDepths] |
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| 436 | |
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| 437 | ******************************************************************************/ |
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| 438 | static void |
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| 439 | NodeOrderRecursivelyByAppending( |
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| 440 | Ntk_Node_t * node, |
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| 441 | lsList orderList, |
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| 442 | st_table *nodeToHandle, |
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| 443 | int verbose) |
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| 444 | { |
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| 445 | lsHandle handle; |
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| 446 | |
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| 447 | /* |
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| 448 | * If node has already been visited (i.e. its in the nodeToHandle table), then |
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| 449 | * just return. |
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| 450 | */ |
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| 451 | if (st_is_member(nodeToHandle, (char *) node)) { |
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| 452 | return; |
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| 453 | } |
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| 454 | |
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| 455 | /* |
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| 456 | * Node has not yet been visited. Recurse on the inputs, and then add node |
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| 457 | * to the end of the current ordering. |
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| 458 | */ |
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| 459 | if (!(Ntk_NodeTestIsCombInput(node) || Ntk_NodeTestIsConstant(node))) { |
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| 460 | /* |
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| 461 | * Combinational inputs and constants terminate the recursion. If node is |
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| 462 | * not one of these, then recurse on the inputs. |
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| 463 | */ |
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| 464 | int i; |
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| 465 | array_t *sortedFanins; |
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| 466 | |
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| 467 | /* |
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| 468 | * Sort the fanins of node in decreasing order of depth. See |
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| 469 | * OrdNetworkComputeNodeDepths. |
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| 470 | */ |
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| 471 | sortedFanins = array_dup(Ntk_NodeReadFanins(node)); |
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| 472 | array_sort(sortedFanins, OrdNodesFromArrayCompareDepth); |
---|
| 473 | |
---|
| 474 | /* |
---|
| 475 | * Recursively visit the fanins in order of decreasing depth. The |
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| 476 | * nodeToHandle table keeps track of the nodes currently in orderList. |
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| 477 | */ |
---|
| 478 | for (i = 0; i < array_n(sortedFanins); i++) { |
---|
| 479 | Ntk_Node_t *fanin = array_fetch(Ntk_Node_t *, sortedFanins, i); |
---|
| 480 | |
---|
| 481 | NodeOrderRecursivelyByAppending(fanin, orderList, nodeToHandle, verbose); |
---|
| 482 | } |
---|
| 483 | array_free(sortedFanins); |
---|
| 484 | } |
---|
| 485 | |
---|
| 486 | /* |
---|
| 487 | * Regardless of the branch taken above, add node to the end of the |
---|
| 488 | * orderList and to the nodeToHandle table. |
---|
| 489 | */ |
---|
| 490 | (void) lsNewEnd(orderList, (lsGeneric) node, &handle); |
---|
| 491 | st_insert(nodeToHandle, (char *) node, (char *) handle); |
---|
| 492 | } |
---|
| 493 | |
---|
| 494 | |
---|
| 495 | /**Function******************************************************************** |
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| 496 | |
---|
| 497 | Synopsis [Orders the nodes of a network by the interleaving method.] |
---|
| 498 | |
---|
| 499 | Description [Orders the nodes of a network by the interleaving method. The |
---|
| 500 | parameters are the same as in OrdNetworkOrderTFIOfRoots.<p> |
---|
| 501 | |
---|
| 502 | This function implements Algorithm 2 of Fujii, et al. "Inteleaving Based |
---|
| 503 | Variable Ordering Methods for Ordered Binary Decision Diagrams," ICCAD, |
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| 504 | 1993. The ordering returned is a topological ordering. The algorithm is a |
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| 505 | modified DFS that keeps track of an insertion point so that variables in the |
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| 506 | tfi of the second and successive outputs be properly interleaved with the |
---|
| 507 | variables already ordered.] |
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| 508 | |
---|
| 509 | SideEffects [nodeToHandle table is modified] |
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| 510 | |
---|
| 511 | SeeAlso [OrdNetworkOrderTFIOfRoots NodeOrderRecursivelyByInterleaving] |
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| 512 | |
---|
| 513 | ******************************************************************************/ |
---|
| 514 | static lsList |
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| 515 | NetworkOrderTFIOfRootsByInterleaving( |
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| 516 | Ntk_Network_t *network, |
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| 517 | lsList roots /* list of Ntk_Node_t */, |
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| 518 | st_table *nodeToHandle /* modified */, |
---|
| 519 | int verbose) |
---|
| 520 | { |
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| 521 | lsGen gen; |
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| 522 | Ntk_Node_t *root; |
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| 523 | lsList orderList = lsCreate(); /* return list */ |
---|
| 524 | OrderingState_t *orderingState; |
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| 525 | |
---|
| 526 | /* |
---|
| 527 | * Compute and store the depth of each node in the network. (The depth of a |
---|
| 528 | * node is stored in the undef field of the node.) |
---|
| 529 | */ |
---|
| 530 | OrdNetworkComputeNodeDepths(network, roots); |
---|
| 531 | |
---|
| 532 | /* |
---|
| 533 | * Initialize the state needed for recurring through the network. |
---|
| 534 | */ |
---|
| 535 | orderingState = NetworkInitializeOrderingState(network); |
---|
| 536 | |
---|
| 537 | if (verbose > 1) { |
---|
| 538 | Ntk_Node_t *node; |
---|
| 539 | (void) fprintf(vis_stdout, "\nDepths of network nodes:\n"); |
---|
| 540 | Ntk_NetworkForEachNode(network, gen, node) { |
---|
| 541 | (void) fprintf(vis_stdout, "%s: depth = %ld\n", Ntk_NodeReadName(node), |
---|
| 542 | OrdNodeReadDepth(node)); |
---|
| 543 | } |
---|
| 544 | } |
---|
| 545 | |
---|
| 546 | /* |
---|
| 547 | * For each root, recursively order all nodes in its transitive fanin. |
---|
| 548 | */ |
---|
| 549 | lsForEachItem(roots, gen, root) { |
---|
| 550 | orderingState->root = root; |
---|
| 551 | orderingState->last = lsStart(orderList); |
---|
| 552 | NodeOrderRecursivelyByInterleaving(root, orderList, nodeToHandle, |
---|
| 553 | orderingState, verbose); |
---|
| 554 | lsFinish(orderingState->last); |
---|
| 555 | |
---|
| 556 | if (verbose > 2) { |
---|
| 557 | /* This can generate a lot of output. */ |
---|
| 558 | (void) fprintf(vis_stdout, "\nOrder list after merging node %s\n", |
---|
| 559 | Ntk_NodeReadName(root)); |
---|
| 560 | OrdNodeListWrite(vis_stdout, orderList); |
---|
| 561 | } |
---|
| 562 | } |
---|
| 563 | |
---|
| 564 | /* |
---|
| 565 | * Clean up and return the ordering list. |
---|
| 566 | */ |
---|
| 567 | OrderingStateFree(orderingState); |
---|
| 568 | return orderList; |
---|
| 569 | } |
---|
| 570 | |
---|
| 571 | |
---|
| 572 | /**Function******************************************************************** |
---|
| 573 | |
---|
| 574 | Synopsis [Orders the fanins of a node, and then orders the node itself.] |
---|
| 575 | |
---|
| 576 | Description [Orders the fanins of a node, and then orders the node |
---|
| 577 | itself. The fanins of a node are visited in order of decreasing depth. The |
---|
| 578 | node appears in the order just after its fanins, yielding a topological |
---|
| 579 | order. If node has already been visited, then simply update the info on |
---|
| 580 | the output from which it was last reached, and change the insertion point.] |
---|
| 581 | |
---|
| 582 | Comment [The nodeToHandle table serves as the visited table for the DFS.] |
---|
| 583 | |
---|
| 584 | SideEffects [nodeToHandle table is modified] |
---|
| 585 | |
---|
| 586 | SeeAlso [NetworkOrderTFIOfRootsByAppending OrdNetworkComputeNodeDepths] |
---|
| 587 | |
---|
| 588 | ******************************************************************************/ |
---|
| 589 | static void |
---|
| 590 | NodeOrderRecursivelyByInterleaving( |
---|
| 591 | Ntk_Node_t * node, |
---|
| 592 | lsList orderList, |
---|
| 593 | st_table *nodeToHandle, |
---|
| 594 | OrderingState_t *orderingState, |
---|
| 595 | int verbose) |
---|
| 596 | { |
---|
| 597 | lsHandle handle; |
---|
| 598 | |
---|
| 599 | /* |
---|
| 600 | * If node has already been visited (i.e., it is in the nodeToHandle table), |
---|
| 601 | * then update the info on the output from which it was last reached, |
---|
| 602 | * and change the insertion point to this node. |
---|
| 603 | */ |
---|
| 604 | if (st_is_member(nodeToHandle, (char *) node)) { |
---|
| 605 | if (NodeReadFrom(node, orderingState) != orderingState->root) { |
---|
| 606 | OrderingStateSetLast(node, nodeToHandle, orderingState); |
---|
| 607 | NodeSetFrom(node, orderingState); |
---|
| 608 | } |
---|
| 609 | return; |
---|
| 610 | } |
---|
| 611 | |
---|
| 612 | /* |
---|
| 613 | * Node has not yet been visited. Recur on the inputs, and then add node |
---|
| 614 | * to the end of the current ordering. |
---|
| 615 | */ |
---|
| 616 | if (!(Ntk_NodeTestIsCombInput(node) || Ntk_NodeTestIsConstant(node))) { |
---|
| 617 | /* |
---|
| 618 | * Combinational inputs and constants terminate the recursion. If node is |
---|
| 619 | * not one of these, then recur on the inputs. |
---|
| 620 | */ |
---|
| 621 | int i; |
---|
| 622 | array_t *sortedFanins; |
---|
| 623 | |
---|
| 624 | /* |
---|
| 625 | * Sort the fanins of node in decreasing order of depth. See |
---|
| 626 | * OrdNetworkComputeNodeDepths. |
---|
| 627 | */ |
---|
| 628 | sortedFanins = array_dup(Ntk_NodeReadFanins(node)); |
---|
| 629 | array_sort(sortedFanins, OrdNodesFromArrayCompareDepth); |
---|
| 630 | |
---|
| 631 | /* |
---|
| 632 | * Recursively visit the fanins in order of decreasing depth. The |
---|
| 633 | * nodeToHandle table keeps track of the nodes currently in orderList. |
---|
| 634 | */ |
---|
| 635 | for (i = 0; i < array_n(sortedFanins); i++) { |
---|
| 636 | Ntk_Node_t *fanin = array_fetch(Ntk_Node_t *, sortedFanins, i); |
---|
| 637 | |
---|
| 638 | NodeOrderRecursivelyByInterleaving(fanin, orderList, nodeToHandle, |
---|
| 639 | orderingState,verbose); |
---|
| 640 | } |
---|
| 641 | array_free(sortedFanins); |
---|
| 642 | } |
---|
| 643 | |
---|
| 644 | /* |
---|
| 645 | * Regardless of the branch taken above, add node to orderList at the |
---|
| 646 | * insertion point and to the nodeToHandle table. Make node the new |
---|
| 647 | * insertion point. |
---|
| 648 | */ |
---|
| 649 | NodeSetFrom(node, orderingState); |
---|
| 650 | (void) lsInBefore(orderingState->last, (lsGeneric) node, &handle); |
---|
| 651 | st_insert(nodeToHandle, (char *) node, (char *) handle); |
---|
| 652 | OrderingStateSetLast(node, nodeToHandle, orderingState); |
---|
| 653 | } |
---|
| 654 | |
---|
| 655 | |
---|
| 656 | /**Function******************************************************************** |
---|
| 657 | |
---|
| 658 | Synopsis [Initializes structure needed to maintain state of ordering |
---|
| 659 | routine.] |
---|
| 660 | |
---|
| 661 | Description [Allocates and initializes data structure needed to maintain the |
---|
| 662 | state of the variable ordering routine.] |
---|
| 663 | |
---|
| 664 | SideEffects [] |
---|
| 665 | |
---|
| 666 | Comment [The node depths are not stored in a hash table of orderingState, |
---|
| 667 | because, for OrdNodesFromArrayCompareDepth, we need to be able to access the |
---|
| 668 | depth of a node given *just* the node.] |
---|
| 669 | |
---|
| 670 | SeeAlso [OrderingStateFree] |
---|
| 671 | |
---|
| 672 | ******************************************************************************/ |
---|
| 673 | static OrderingState_t * |
---|
| 674 | NetworkInitializeOrderingState( |
---|
| 675 | Ntk_Network_t * network) |
---|
| 676 | { |
---|
| 677 | OrderingState_t *orderingState = ALLOC(OrderingState_t, 1); |
---|
| 678 | |
---|
| 679 | /* nodeToOrderList is used by the merging method. */ |
---|
| 680 | orderingState->nodeToOrderList = st_init_table(st_ptrcmp, st_ptrhash); |
---|
| 681 | |
---|
| 682 | /* from, last, and root used by the interleaving method. */ |
---|
| 683 | orderingState->from = st_init_table(st_ptrcmp, st_ptrhash); |
---|
| 684 | orderingState->last = NULL; |
---|
| 685 | orderingState->root = NULL; |
---|
| 686 | |
---|
| 687 | return orderingState; |
---|
| 688 | } |
---|
| 689 | |
---|
| 690 | |
---|
| 691 | /**Function******************************************************************** |
---|
| 692 | |
---|
| 693 | Synopsis [Updates the insertion point in orderingState.] |
---|
| 694 | |
---|
| 695 | Description [Updates the insertion point in orderingState. Assumes that |
---|
| 696 | node is already in nodeToHandle.] |
---|
| 697 | |
---|
| 698 | SideEffects [] |
---|
| 699 | |
---|
| 700 | SeeAlso [NetworkInitializeOrderingState] |
---|
| 701 | |
---|
| 702 | ******************************************************************************/ |
---|
| 703 | static void |
---|
| 704 | OrderingStateSetLast( |
---|
| 705 | Ntk_Node_t * node, |
---|
| 706 | st_table * nodeToHandle, |
---|
| 707 | OrderingState_t * orderingState) |
---|
| 708 | { |
---|
| 709 | lsHandle handle; |
---|
| 710 | lsGen gen; |
---|
| 711 | lsGeneric data; |
---|
| 712 | |
---|
| 713 | /* Dispose of the current generator. */ |
---|
| 714 | lsFinish(orderingState->last); |
---|
| 715 | |
---|
| 716 | /* Get a handle for the current node. */ |
---|
| 717 | st_lookup(nodeToHandle, node, &handle); |
---|
| 718 | |
---|
| 719 | /* |
---|
| 720 | * Create a new generator positioned after node and register it |
---|
| 721 | * in orderingState. |
---|
| 722 | */ |
---|
| 723 | gen = lsGenHandle(handle,&data,LS_AFTER); |
---|
| 724 | orderingState->last = gen; |
---|
| 725 | } |
---|
| 726 | |
---|
| 727 | /**Function******************************************************************** |
---|
| 728 | |
---|
| 729 | Synopsis [Frees all memory associated with an ordering state.] |
---|
| 730 | |
---|
| 731 | SideEffects [] |
---|
| 732 | |
---|
| 733 | SeeAlso [NetworkInitializeOrderingState] |
---|
| 734 | |
---|
| 735 | ******************************************************************************/ |
---|
| 736 | static void |
---|
| 737 | OrderingStateFree( |
---|
| 738 | OrderingState_t * orderingState) |
---|
| 739 | { |
---|
| 740 | st_generator *stGen; |
---|
| 741 | lsList orderList; |
---|
| 742 | Ntk_Node_t *node; |
---|
| 743 | |
---|
| 744 | st_foreach_item(orderingState->nodeToOrderList, stGen, &node, &orderList) { |
---|
| 745 | (void) lsDestroy(orderList, (void (*) (lsGeneric)) NULL); |
---|
| 746 | } |
---|
| 747 | |
---|
| 748 | st_free_table(orderingState->nodeToOrderList); |
---|
| 749 | st_free_table(orderingState->from); |
---|
| 750 | |
---|
| 751 | FREE(orderingState); |
---|
| 752 | } |
---|
| 753 | |
---|
| 754 | |
---|
| 755 | /**Function******************************************************************** |
---|
| 756 | |
---|
| 757 | Synopsis [Gets the order list of a node.] |
---|
| 758 | |
---|
| 759 | Description [Gets the order list of a node. This is a topological ordering |
---|
| 760 | of all the nodes in the transitive fanin of the node. Returns NULL if node |
---|
| 761 | is not in the nodeToOrderList hash table of orderingState.] |
---|
| 762 | |
---|
| 763 | SideEffects [] |
---|
| 764 | |
---|
| 765 | SeeAlso [NodeSetOrderList] |
---|
| 766 | |
---|
| 767 | ******************************************************************************/ |
---|
| 768 | static lsList |
---|
| 769 | NodeReadOrderList( |
---|
| 770 | Ntk_Node_t * node, |
---|
| 771 | OrderingState_t * orderingState) |
---|
| 772 | { |
---|
| 773 | lsList orderList = (lsList) NULL; |
---|
| 774 | |
---|
| 775 | st_lookup(orderingState->nodeToOrderList, node, &orderList); |
---|
| 776 | |
---|
| 777 | return orderList; |
---|
| 778 | } |
---|
| 779 | |
---|
| 780 | |
---|
| 781 | /**Function******************************************************************** |
---|
| 782 | |
---|
| 783 | Synopsis [Sets the orderList of a node.] |
---|
| 784 | |
---|
| 785 | SideEffects [] |
---|
| 786 | |
---|
| 787 | SeeAlso [NodeReadOrderList] |
---|
| 788 | |
---|
| 789 | ******************************************************************************/ |
---|
| 790 | static void |
---|
| 791 | NodeSetOrderList( |
---|
| 792 | Ntk_Node_t * node, |
---|
| 793 | lsList orderList, |
---|
| 794 | OrderingState_t * orderingState) |
---|
| 795 | { |
---|
| 796 | st_insert(orderingState->nodeToOrderList, (char *) node, (char *) orderList); |
---|
| 797 | } |
---|
| 798 | |
---|
| 799 | |
---|
| 800 | /**Function******************************************************************** |
---|
| 801 | |
---|
| 802 | Synopsis [Gets the from root of a node.] |
---|
| 803 | |
---|
| 804 | Description [Gets the from node of a node. This is the root from |
---|
| 805 | which the node was last reached during DFS. Returns NULL if node is |
---|
| 806 | not in the from hash table of orderingState.] |
---|
| 807 | |
---|
| 808 | SideEffects [none] |
---|
| 809 | |
---|
| 810 | SeeAlso [NodeSetFrom] |
---|
| 811 | |
---|
| 812 | ******************************************************************************/ |
---|
| 813 | static Ntk_Node_t * |
---|
| 814 | NodeReadFrom( |
---|
| 815 | Ntk_Node_t * node, |
---|
| 816 | OrderingState_t * orderingState) |
---|
| 817 | { |
---|
| 818 | Ntk_Node_t * from = NULL; |
---|
| 819 | |
---|
| 820 | st_lookup(orderingState->from, node, &from); |
---|
| 821 | |
---|
| 822 | return from; |
---|
| 823 | } |
---|
| 824 | |
---|
| 825 | |
---|
| 826 | /**Function******************************************************************** |
---|
| 827 | |
---|
| 828 | Synopsis [Sets the from root of a node to the current root.] |
---|
| 829 | |
---|
| 830 | SideEffects [The from table of orderingState is modified.] |
---|
| 831 | |
---|
| 832 | SeeAlso [NodeReadFrom] |
---|
| 833 | |
---|
| 834 | ******************************************************************************/ |
---|
| 835 | static void |
---|
| 836 | NodeSetFrom( |
---|
| 837 | Ntk_Node_t * node, |
---|
| 838 | OrderingState_t * orderingState) |
---|
| 839 | { |
---|
| 840 | st_insert(orderingState->from, (char *) node, (char *) orderingState->root); |
---|
| 841 | } |
---|