SRC/check_route.c

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#include <assert.h>
#include <stdio.h>
#include "util.h"
#include "vpr_types.h"
#include "globals.h"
#include "mst.h"
#include "route_export.h"
#include "check_route.h"
#include "rr_graph.h"
#include "check_rr_graph.h"


/******************** Subroutines local to this module **********************/
static void check_node_and_range(int inode,
                                 enum e_route_type route_type);
static void check_source(int inode,
                         int inet);
static void check_sink(int inode,
                       int inet,
                       boolean * pin_done);
static void check_switch(struct s_trace *tptr,
                         int num_switch);
static boolean check_adjacent(int from_node,
                              int to_node);
static int pin_and_chan_adjacent(int pin_node,
                                 int chan_node);
static int chanx_chany_adjacent(int chanx_node,
                                int chany_node);
static void reset_flags(int inet,
                        boolean * connected_to_route);
static void recompute_occupancy_from_scratch(t_ivec ** fb_opins_used_locally);
static void check_locally_used_fb_opins(t_ivec ** fb_opins_used_locally,
                                        enum e_route_type route_type);

/************************ Subroutine definitions ****************************/


void
check_route(enum e_route_type route_type,
            int num_switch,
            t_ivec ** fb_opins_used_locally)
{

/* This routine checks that a routing:  (1) Describes a properly         *
 * connected path for each net, (2) this path connects all the           *
 * pins spanned by that net, and (3) that no routing resources are       *
 * oversubscribed (the occupancy of everything is recomputed from        *
 * scratch).                                                             */

    int inet, ipin, max_pins, inode, prev_node;
    boolean valid, connects;
    boolean *connected_to_route;        /* [0 .. num_rr_nodes-1] */
    struct s_trace *tptr;
    boolean *pin_done;

    printf("\nChecking to ensure routing is legal ...\n");

/* Recompute the occupancy from scratch and check for overuse of routing *
 * resources.  This was already checked in order to determine that this  *
 * is a successful routing, but I want to double check it here.          */

    recompute_occupancy_from_scratch(fb_opins_used_locally);
    valid = feasible_routing();
    if(valid == FALSE)
        {
            printf
                ("Error in check_route -- routing resources are overused.\n");
            exit(1);
        }

    check_locally_used_fb_opins(fb_opins_used_locally, route_type);

    connected_to_route = (boolean *) my_calloc(num_rr_nodes, sizeof(boolean));

    max_pins = 0;
    for(inet = 0; inet < num_nets; inet++)
        max_pins = max(max_pins, (net[inet].num_sinks + 1));

    pin_done = (boolean *) my_malloc(max_pins * sizeof(boolean));

/* Now check that all nets are indeed connected. */

    for(inet = 0; inet < num_nets; inet++)
        {

            if(net[inet].is_global)     /* Skip global nets. */
                continue;

            for(ipin = 0; ipin < (net[inet].num_sinks + 1); ipin++)
                pin_done[ipin] = FALSE;

/* Check the SOURCE of the net. */

            tptr = trace_head[inet];
            if(tptr == NULL)
                {
                    printf("Error in check_route:  net %d has no routing.\n",
                           inet);
                    exit(1);
                }

            inode = tptr->index;
            check_node_and_range(inode, route_type);
            check_switch(tptr, num_switch);
            connected_to_route[inode] = TRUE;   /* Mark as in path. */

            check_source(inode, inet);
            pin_done[0] = TRUE;

            prev_node = inode;
            tptr = tptr->next;

/* Check the rest of the net */

            while(tptr != NULL)
                {
                    inode = tptr->index;
                    check_node_and_range(inode, route_type);
                    check_switch(tptr, num_switch);

                    if(rr_node[prev_node].type == SINK)
                        {
                            if(connected_to_route[inode] == FALSE)
                                {
                                    printf
                                        ("Error in check_route.  Node %d does not link "
                                         "into the existing routing for net %d.\n",
                                         inode, inet);
                                    exit(1);
                                }
                        }

                    else
                        {
                            connects = check_adjacent(prev_node, inode);
                            if(!connects)
                                {
                                    printf
                                        ("Error in check_route while checking net %d.\n",
                                         inet);
                                    printf
                                        ("Non-adjacent segments in traceback.\n");
                                    exit(1);
                                }

                            if(connected_to_route[inode]
                               && rr_node[inode].type != SINK)
                                {

                                    /* Note:  Can get multiple connections to the same logically-equivalent     *
                                     * SINK in some logic blocks.                                               */

                                    printf
                                        ("Error in check_route:  net %d routing is not a tree.\n",
                                         inet);
                                    exit(1);
                                }

                            connected_to_route[inode] = TRUE;   /* Mark as in path. */

                            if(rr_node[inode].type == SINK)
                                check_sink(inode, inet, pin_done);

                        }       /* End of prev_node type != SINK */
                    prev_node = inode;
                    tptr = tptr->next;
                }               /* End while */

            if(rr_node[prev_node].type != SINK)
                {
                    printf("Error in check_route.  Net %d does not end\n",
                           inet);
                    printf("with a SINK.\n");
                    exit(1);
                }

            for(ipin = 0; ipin < (net[inet].num_sinks + 1); ipin++)
                {
                    if(pin_done[ipin] == FALSE)
                        {
                            printf
                                ("Error in check_route.  Net %d does not \n",
                                 inet);
                            printf("connect to pin %d.\n", ipin);
                            exit(1);
                        }
                }

            reset_flags(inet, connected_to_route);

        }                       /* End for each net */

    free(pin_done);
    free(connected_to_route);
    printf("Completed routing consistency check successfully.\n\n");
}

static void
check_sink(int inode,
           int inet,
           boolean * pin_done)
{

/* Checks that this SINK node is one of the terminals of inet, and marks   *
 * the appropriate pin as being reached.                                   */

    int i, j, ipin, ifound, ptc_num, bnum, iclass, node_block_pin, iblk;
    t_type_ptr type;

    assert(rr_node[inode].type == SINK);
    i = rr_node[inode].xlow;
    j = rr_node[inode].ylow;
    type = grid[i][j].type;
    ptc_num = rr_node[inode].ptc_num;   /* For sinks, ptc_num is the class */
    ifound = 0;

    for(iblk = 0; iblk < type->capacity; iblk++)
        {
            bnum = grid[i][j].blocks[iblk];     /* Hardcoded to one block */
            for(ipin = 1; ipin < (net[inet].num_sinks + 1); ipin++)
                {               /* All net SINKs */
                    if(net[inet].node_block[ipin] == bnum)
                        {
                            node_block_pin = net[inet].node_block_pin[ipin];
                            iclass = type->pin_class[node_block_pin];
                            if(iclass == ptc_num)
                                {
/* Could connect to same pin class on the same fb more than once.  Only   *
 * update pin_done for a pin that hasn't been reached yet.                 */

                                    if(pin_done[ipin] == FALSE)
                                        {
                                            ifound++;
                                            pin_done[ipin] = TRUE;
                                        }
                                }
                        }
                }
        }

    if(ifound > 1 && type == IO_TYPE)
        {
            printf("Error in check_sink:  found %d terminals of net %d of pad"
                   "\n %d at location (%d, %d).\n", ifound, inet, ptc_num, i,
                   j);
            exit(1);
        }

    if(ifound < 1)
        {
            printf
                ("Error in check_sink:  node %d does not connect to any terminal "
                 "\n of net %d.\n", inode, inet);
            exit(1);
        }
}


static void
check_source(int inode,
             int inet)
{

/* Checks that the node passed in is a valid source for this net.        */

    t_rr_type rr_type;
    t_type_ptr type;
    int i, j, ptc_num, bnum, node_block_pin, iclass;

    rr_type = rr_node[inode].type;
    if(rr_type != SOURCE)
        {
            printf
                ("Error in check_source:  net %d begins with a node of type %d.\n",
                 inet, rr_type);
            exit(1);
        }

    i = rr_node[inode].xlow;
    j = rr_node[inode].ylow;
    ptc_num = rr_node[inode].ptc_num;   /* for sinks and sources, ptc_num is class */
    bnum = net[inet].node_block[0];     /* First node_block for net is the source */
    type = grid[i][j].type;

    if(block[bnum].x != i || block[bnum].y != j)
        {
            printf
                ("Error in check_source:  net SOURCE is in wrong location (%d,%d)."
                 "\n", i, j);
            exit(1);
        }

    node_block_pin = net[inet].node_block_pin[0];
    iclass = type->pin_class[node_block_pin];

    if(ptc_num != iclass)
        {
            printf
                ("Error in check_source:  net SOURCE is of wrong class (%d).\n",
                 ptc_num);
            exit(1);
        }
}


static void
check_switch(struct s_trace *tptr,
             int num_switch)
{

/* Checks that the switch leading from this traceback element to the next *
 * one is a legal switch type.                                            */

    int inode;
    short switch_type;

    inode = tptr->index;
    switch_type = tptr->iswitch;

    if(rr_node[inode].type != SINK)
        {
            if(switch_type < 0 || switch_type >= num_switch)
                {
                    printf
                        ("Error in check_switch: rr_node %d left via switch type %d.\n",
                         inode, switch_type);
                    printf("Switch type is out of range.\n");
                    exit(1);
                }
        }

    else
        {                       /* Is a SINK */

/* Without feedthroughs, there should be no switch.  If feedthroughs are    *
 * allowed, change to treat a SINK like any other node (as above).          */

            if(switch_type != OPEN)
                {
                    printf
                        ("Error in check_switch:  rr_node %d is a SINK, but attempts \n"
                         "to use a switch of type %d.\n", inode, switch_type);
                    exit(1);
                }
        }
}


static void
reset_flags(int inet,
            boolean * connected_to_route)
{

/* This routine resets the flags of all the channel segments contained *
 * in the traceback of net inet to 0.  This allows us to check the     * 
 * next net for connectivity (and the default state of the flags       * 
 * should always be zero after they have been used).                   */

    struct s_trace *tptr;
    int inode;

    tptr = trace_head[inet];

    while(tptr != NULL)
        {
            inode = tptr->index;
            connected_to_route[inode] = FALSE;  /* Not in routed path now. */
            tptr = tptr->next;
        }
}


static boolean
check_adjacent(int from_node,
               int to_node)
{

/* This routine checks if the rr_node to_node is reachable from from_node.   *
 * It returns TRUE if is reachable and FALSE if it is not.  Check_node has   *
 * already been used to verify that both nodes are valid rr_nodes, so only   *
 * adjacency is checked here.                                                */

    int from_xlow, from_ylow, to_xlow, to_ylow, from_ptc, to_ptc, iclass;
    int num_adj, to_xhigh, to_yhigh, from_xhigh, from_yhigh, iconn;
    boolean reached;
    t_rr_type from_type, to_type;
    t_type_ptr from_grid_type, to_grid_type;

    reached = FALSE;

    for(iconn = 0; iconn < rr_node[from_node].num_edges; iconn++)
        {
            if(rr_node[from_node].edges[iconn] == to_node)
                {
                    reached = TRUE;
                    break;
                }
        }

    if(!reached)
        return (FALSE);

/* Now we know the rr graph says these two nodes are adjacent.  Double  *
 * check that this makes sense, to verify the rr graph.                 */

    num_adj = 0;

    from_type = rr_node[from_node].type;
    from_xlow = rr_node[from_node].xlow;
    from_ylow = rr_node[from_node].ylow;
    from_xhigh = rr_node[from_node].xhigh;
    from_yhigh = rr_node[from_node].yhigh;
    from_ptc = rr_node[from_node].ptc_num;
    to_type = rr_node[to_node].type;
    to_xlow = rr_node[to_node].xlow;
    to_ylow = rr_node[to_node].ylow;
    to_xhigh = rr_node[to_node].xhigh;
    to_yhigh = rr_node[to_node].yhigh;
    to_ptc = rr_node[to_node].ptc_num;

    switch (from_type)
        {

        case SOURCE:
            assert(to_type == OPIN);
            if(from_xlow == to_xlow && from_ylow == to_ylow
               && from_xhigh == to_xhigh && from_yhigh == to_yhigh)
                {

                    from_grid_type = grid[from_xlow][from_ylow].type;
                    to_grid_type = grid[to_xlow][to_ylow].type;
                    assert(from_grid_type == to_grid_type);

                    iclass = to_grid_type->pin_class[to_ptc];
                    if(iclass == from_ptc)
                        num_adj++;
                }
            break;

        case SINK:
            /* SINKS are adjacent to not connected */
            break;

        case OPIN:
            assert(to_type == CHANX || to_type == CHANY);
            num_adj += pin_and_chan_adjacent(from_node, to_node);

            break;

        case IPIN:
            assert(to_type == SINK);
            if(from_xlow == to_xlow && from_ylow == to_ylow
               && from_xhigh == to_xhigh && from_yhigh == to_yhigh)
                {

                    from_grid_type = grid[from_xlow][from_ylow].type;
                    to_grid_type = grid[to_xlow][to_ylow].type;
                    assert(from_grid_type == to_grid_type);

                    iclass = from_grid_type->pin_class[from_ptc];
                    if(iclass == to_ptc)
                        num_adj++;
                }
            break;

        case CHANX:
            if(to_type == IPIN)
                {
                    num_adj += pin_and_chan_adjacent(to_node, from_node);
                }
            else if(to_type == CHANX)
                {
                    from_xhigh = rr_node[from_node].xhigh;
                    to_xhigh = rr_node[to_node].xhigh;
                    if(from_ylow == to_ylow)
                        {
                            /* UDSD Modification by WMF Begin */
                            /*For Fs > 3, can connect to overlapping wire segment */
                            if(to_xhigh == from_xlow - 1
                               || from_xhigh == to_xlow - 1)
                                {
                                    num_adj++;
                                }
                            /* Overlapping */
                            else
                                {
                                    int i;

                                    for(i = from_xlow; i <= from_xhigh; i++)
                                        {
                                            if(i >= to_xlow && i <= to_xhigh)
                                                {
                                                    num_adj++;
                                                    break;
                                                }
                                        }
                                }
                            /* UDSD Modification by WMF End */
                        }
                }
            else if(to_type == CHANY)
                {
                    num_adj += chanx_chany_adjacent(from_node, to_node);
                }
            else
                {
                    assert(0);
                }
            break;

        case CHANY:
            if(to_type == IPIN)
                {
                    num_adj += pin_and_chan_adjacent(to_node, from_node);
                }
            else if(to_type == CHANY)
                {
                    from_yhigh = rr_node[from_node].yhigh;
                    to_yhigh = rr_node[to_node].yhigh;
                    if(from_xlow == to_xlow)
                        {
                            /* UDSD Modification by WMF Begin */
                            if(to_yhigh == from_ylow - 1
                               || from_yhigh == to_ylow - 1)
                                {
                                    num_adj++;
                                }
                            /* Overlapping */
                            else
                                {
                                    int j;

                                    for(j = from_ylow; j <= from_yhigh; j++)
                                        {
                                            if(j >= to_ylow && j <= to_yhigh)
                                                {
                                                    num_adj++;
                                                    break;
                                                }
                                        }
                                }
                            /* UDSD Modification by WMF End */
                        }
                }
            else if(to_type == CHANX)
                {
                    num_adj += chanx_chany_adjacent(to_node, from_node);
                }
            else
                {
                    assert(0);
                }
            break;

        default:
            break;

        }

    if(num_adj == 1)
        return (TRUE);
    else if(num_adj == 0)
        return (FALSE);

    printf("Error in check_adjacent: num_adj = %d. Expected 0 or 1.\n",
           num_adj);
    exit(1);
}


static int
chanx_chany_adjacent(int chanx_node,
                     int chany_node)
{

/* Returns 1 if the specified CHANX and CHANY nodes are adjacent, 0         *
 * otherwise.                                                               */

    int chanx_y, chanx_xlow, chanx_xhigh;
    int chany_x, chany_ylow, chany_yhigh;

    chanx_y = rr_node[chanx_node].ylow;
    chanx_xlow = rr_node[chanx_node].xlow;
    chanx_xhigh = rr_node[chanx_node].xhigh;

    chany_x = rr_node[chany_node].xlow;
    chany_ylow = rr_node[chany_node].ylow;
    chany_yhigh = rr_node[chany_node].yhigh;

    if(chany_ylow > chanx_y + 1 || chany_yhigh < chanx_y)
        return (0);

    if(chanx_xlow > chany_x + 1 || chanx_xhigh < chany_x)
        return (0);

    return (1);
}


static int
pin_and_chan_adjacent(int pin_node,
                      int chan_node)
{

/* Checks if pin_node is adjacent to chan_node.  It returns 1 if the two   *
 * nodes are adjacent and 0 if they are not (any other value means there's *
 * a bug in this routine).                                                 */

    int num_adj, pin_xlow, pin_ylow, pin_xhigh, pin_yhigh, chan_xlow,
        chan_ylow, chan_xhigh, chan_yhigh;
    int pin_ptc, i;
    t_rr_type chan_type;
    t_type_ptr pin_grid_type;

    num_adj = 0;
    pin_xlow = rr_node[pin_node].xlow;
    pin_ylow = rr_node[pin_node].ylow;
    pin_xhigh = rr_node[pin_node].xhigh;
    pin_yhigh = rr_node[pin_node].yhigh;
    pin_grid_type = grid[pin_xlow][pin_ylow].type;
    pin_ptc = rr_node[pin_node].ptc_num;
    chan_type = rr_node[chan_node].type;
    chan_xlow = rr_node[chan_node].xlow;
    chan_ylow = rr_node[chan_node].ylow;
    chan_xhigh = rr_node[chan_node].xhigh;
    chan_yhigh = rr_node[chan_node].yhigh;

    if(chan_type == CHANX)
        {
            if(chan_ylow == pin_yhigh)
                {               /* CHANX above FB */
                    if(pin_grid_type->
                       pinloc[pin_grid_type->height - 1][TOP][pin_ptc] == 1
                       && pin_xlow <= chan_xhigh && pin_xhigh >= chan_xlow)
                        num_adj++;
                }
            else if(chan_ylow == pin_ylow - 1)
                {               /* CHANX below FB */
                    if(pin_grid_type->pinloc[0][BOTTOM][pin_ptc] == 1
                       && pin_xlow <= chan_xhigh && pin_xhigh >= chan_xlow)
                        num_adj++;
                }
        }
    else if(chan_type == CHANY)
        {
            for(i = 0; i < pin_grid_type->height; i++)
                {
                    if(chan_xlow == pin_xhigh)
                        {       /* CHANY to right of FB */
                            if(pin_grid_type->pinloc[i][RIGHT][pin_ptc] == 1
                               && pin_ylow <= chan_yhigh
                               && pin_yhigh >= chan_ylow)
                                num_adj++;
                        }
                    else if(chan_xlow == pin_xlow - 1)
                        {       /* CHANY to left of FB */
                            if(pin_grid_type->pinloc[i][LEFT][pin_ptc] == 1
                               && pin_ylow <= chan_yhigh
                               && pin_yhigh >= chan_ylow)
                                num_adj++;
                        }
                }
        }
    return (num_adj);
}


static void
recompute_occupancy_from_scratch(t_ivec ** fb_opins_used_locally)
{

/* This routine updates the occ field in the rr_node structure according to *
 * the resource usage of the current routing.  It does a brute force        *
 * recompute from scratch that is useful for sanity checking.               */

    int inode, inet, iblk, iclass, ipin, num_local_opins;
    struct s_trace *tptr;

/* First set the occupancy of everything to zero. */

    for(inode = 0; inode < num_rr_nodes; inode++)
        rr_node[inode].occ = 0;

/* Now go through each net and count the tracks and pins used everywhere */

    for(inet = 0; inet < num_nets; inet++)
        {

            if(net[inet].is_global)     /* Skip global nets. */
                continue;

            tptr = trace_head[inet];
            if(tptr == NULL)
                continue;

            for(;;)
                {
                    inode = tptr->index;
                    rr_node[inode].occ++;

                    if(rr_node[inode].type == SINK)
                        {
                            tptr = tptr->next;  /* Skip next segment. */
                            if(tptr == NULL)
                                break;
                        }

                    tptr = tptr->next;
                }
        }

/* Now update the occupancy of each of the "locally used" OPINs on each FB *
 * (FB outputs used up by being directly wired to subblocks used only      *
 * locally).                                                                */

    for(iblk = 0; iblk < num_blocks; iblk++)
        {
            for(iclass = 0; iclass < block[iblk].type->num_class; iclass++)
                {
                    num_local_opins =
                        fb_opins_used_locally[iblk][iclass].nelem;
                    /* Will always be 0 for pads or SINK classes. */
                    for(ipin = 0; ipin < num_local_opins; ipin++)
                        {
                            inode =
                                fb_opins_used_locally[iblk][iclass].
                                list[ipin];
                            rr_node[inode].occ++;
                        }
                }
        }
}


static void
check_locally_used_fb_opins(t_ivec ** fb_opins_used_locally,
                            enum e_route_type route_type)
{

/* Checks that enough OPINs on CLBs have been set aside (used up) to make a *
 * legal routing if subblocks connect to OPINs directly.                    */

    int iclass, iblk, num_local_opins, inode, ipin;
    t_rr_type rr_type;

    for(iblk = 0; iblk < num_blocks; iblk++)
        {
            for(iclass = 0; iclass < block[iblk].type->num_class; iclass++)
                {
                    num_local_opins =
                        fb_opins_used_locally[iblk][iclass].nelem;
                    /* Always 0 for pads and for SINK classes */

                    for(ipin = 0; ipin < num_local_opins; ipin++)
                        {
                            inode =
                                fb_opins_used_locally[iblk][iclass].
                                list[ipin];
                            check_node_and_range(inode, route_type);    /* Node makes sense? */

                            /* Now check that node is an OPIN of the right type. */

                            rr_type = rr_node[inode].type;
                            if(rr_type != OPIN)
                                {
                                    printf
                                        ("Error in check_locally_used_opins:  Block #%d (%s)\n"
                                         "\tclass %d locally used OPIN is of the wrong rr_type --\n"
                                         "\tit is rr_node #%d of type %d.\n",
                                         iblk, block[iblk].name, iclass,
                                         inode, rr_type);
                                    exit(1);
                                }

                            ipin = rr_node[inode].ptc_num;
                            if(block[iblk].type->pin_class[ipin] != iclass)
                                {
                                    printf
                                        ("Error in check_locally_used_opins:  Block #%d (%s):\n"
                                         "\tExpected class %d locally used OPIN, got class %d."
                                         "\trr_node #: %d.\n", iblk,
                                         block[iblk].name, iclass,
                                         block[iblk].type->pin_class[ipin],
                                         inode);
                                    exit(1);
                                }
                        }
                }
        }
}


static void
check_node_and_range(int inode,
                     enum e_route_type route_type)
{

/* Checks that inode is within the legal range, then calls check_node to    *
 * check that everything else about the node is OK.                         */

    if(inode < 0 || inode >= num_rr_nodes)
        {
            printf
                ("Error in check_node_and_range:  rr_node #%d is out of legal "
                 "\trange (0 to %d).\n", inode, num_rr_nodes - 1);
            exit(1);
        }
    check_node(inode, route_type);
}

---