/*
 * Revision Control Information
 *
 * $Source: /vol/opua/opua2/sis/sis-1.2/common/src/sis/speed/RCS/speed_or.c,v $
 * $Author: sis $
 * $Revision: 1.3 $
 * $Date: 1992/05/06 19:02:12 $
 *
 */
/*
 * Routine to decompose a sum-of-products representation 
 * into a tree of and(nand) gates.
 */

#include <stdio.h>
#include "sis.h"
#include "speed_int.h"

int
speed_and_or_decomp(network, node, speed_param)
network_t *network;
node_t *node;
speed_global_t *speed_param;
{
    int i;
    array_t *collapse_array;
    node_t *cube, *temp, *new_node, *nlit;

    if ( node_num_cube(node) > 1) {
	new_node = node_constant(1);
	for ( i = 0; i < node_num_cube(node); i++){
	    cube = speed_dec_node_cube(node, i);
	    network_add_node(network, cube);

	    nlit = node_literal(cube, 0);
	    temp = node_and(new_node, nlit);
	    node_free(new_node);
	    node_free(nlit);
	    new_node = temp;
	}
	node_replace(node, new_node);

	foreach_fanin(node, i, cube){
	    /*
	     * speed decompose the cubes 
	     */
	    if ( !speed_and_decomp( network, cube, speed_param, 0)){
		error_append("Failed to decompose cube");
		fail(error_string());
	    }
	}

	if ( !speed_param->add_inv) {
	    collapse_array = array_alloc(node_t *, 0);
	    foreach_fanin(node, i, cube){
		if ( node_num_fanin(cube) <= 1) {
		    array_insert_last(node_t *, collapse_array, cube);
		}
	    }
	    for ( i = 0; i < array_n(collapse_array); i++){
		cube = array_fetch(node_t *, collapse_array, i);
		(void) node_collapse( node, cube);
		if ( node_num_fanout( cube) == 0) 
			network_delete_node( network, cube);
	    }
	    array_free(collapse_array);
	}
	/*
	 * Decompose the cube that combines all the cubes.
	 * The arrival time at the cube o/p will be set.
	 */

	if ( !speed_and_decomp( network, node, speed_param, 1) ){
	    error_append("Failed to decompose node combining cubes ");
	    fail(error_string());
	}
    } else if ( !speed_and_decomp( network, node, speed_param, 0)){
	error_append("Failed to decompose single cube");
	fail(error_string());
    }

    return 1;
}