aboutsummaryrefslogtreecommitdiffstats
path: root/common/router1.cc
blob: 77e84696192d4fba194e183c622ef37f74a33834 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
/*
 *  nextpnr -- Next Generation Place and Route
 *
 *  Copyright (C) 2018  Clifford Wolf <clifford@symbioticeda.com>
 *
 *  Permission to use, copy, modify, and/or distribute this software for any
 *  purpose with or without fee is hereby granted, provided that the above
 *  copyright notice and this permission notice appear in all copies.
 *
 *  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 *  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 *  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 *  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 *  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 *  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 *  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 */

#include <cmath>
#include <queue>

#include "log.h"
#include "router1.h"
#include "timing.h"

namespace {

USING_NEXTPNR_NAMESPACE

struct hash_id_wire
{
    std::size_t operator()(const std::pair<IdString, WireId> &arg) const noexcept
    {
        std::size_t seed = std::hash<IdString>()(arg.first);
        seed ^= std::hash<WireId>()(arg.second) + 0x9e3779b9 + (seed << 6) + (seed >> 2);
        return seed;
    }
};

struct hash_id_pip
{
    std::size_t operator()(const std::pair<IdString, PipId> &arg) const noexcept
    {
        std::size_t seed = std::hash<IdString>()(arg.first);
        seed ^= std::hash<PipId>()(arg.second) + 0x9e3779b9 + (seed << 6) + (seed >> 2);
        return seed;
    }
};

struct QueuedWire
{
    WireId wire;
    PipId pip;

    delay_t delay = 0, togo = 0;
    int randtag = 0;

    struct Greater
    {
        bool operator()(const QueuedWire &lhs, const QueuedWire &rhs) const noexcept
        {
            delay_t l = lhs.delay + lhs.togo, r = rhs.delay + rhs.togo;
            return l == r ? lhs.randtag > rhs.randtag : l > r;
        }
    };
};

struct RipupScoreboard
{
    std::unordered_map<WireId, int> wireScores;
    std::unordered_map<PipId, int> pipScores;
    std::unordered_map<std::pair<IdString, WireId>, int, hash_id_wire> netWireScores;
    std::unordered_map<std::pair<IdString, PipId>, int, hash_id_pip> netPipScores;
};

void ripup_net(Context *ctx, IdString net_name)
{
    if (ctx->debug)
        log("Ripping up all routing for net %s.\n", net_name.c_str(ctx));

    auto net_info = ctx->nets.at(net_name).get();
    std::vector<PipId> pips;
    std::vector<WireId> wires;

    pips.reserve(net_info->wires.size());
    wires.reserve(net_info->wires.size());

    for (auto &it : net_info->wires) {
        if (it.second.pip != PipId())
            pips.push_back(it.second.pip);
        else
            wires.push_back(it.first);
    }

    for (auto pip : pips)
        ctx->unbindPip(pip);

    for (auto wire : wires)
        ctx->unbindWire(wire);

    NPNR_ASSERT(net_info->wires.empty());
}

struct Router
{
    Context *ctx;
    const Router1Cfg &cfg;
    RipupScoreboard scores;
    IdString net_name;

    bool ripup;
    delay_t ripup_penalty;

    std::unordered_set<IdString> rippedNets;
    std::unordered_map<WireId, QueuedWire> visited;
    int visitCnt = 0, revisitCnt = 0, overtimeRevisitCnt = 0;
    bool routedOkay = false;
    delay_t maxDelay = 0.0;
    WireId failedDest;

    void route(const std::unordered_map<WireId, delay_t> &src_wires, WireId dst_wire)
    {
        std::priority_queue<QueuedWire, std::vector<QueuedWire>, QueuedWire::Greater> queue;

        visited.clear();

        for (auto &it : src_wires) {
            QueuedWire qw;
            qw.wire = it.first;
            qw.pip = PipId();
            qw.delay = it.second - (it.second / 16);
            if (cfg.useEstimate)
                qw.togo = ctx->estimateDelay(qw.wire, dst_wire);
            qw.randtag = ctx->rng();

            queue.push(qw);
            visited[qw.wire] = qw;
        }

        int thisVisitCnt = 0;
        int thisVisitCntLimit = 0;

        while (!queue.empty() && (thisVisitCntLimit == 0 || thisVisitCnt < thisVisitCntLimit)) {
            QueuedWire qw = queue.top();
            queue.pop();

            if (thisVisitCntLimit == 0 && visited.count(dst_wire))
                thisVisitCntLimit = (thisVisitCnt * 3) / 2;

            for (auto pip : ctx->getPipsDownhill(qw.wire)) {
                delay_t next_delay = qw.delay + ctx->getPipDelay(pip).maxDelay();
                WireId next_wire = ctx->getPipDstWire(pip);
                bool foundRipupNet = false;
                thisVisitCnt++;

                next_delay += ctx->getWireDelay(next_wire).maxDelay();

                if (!ctx->checkWireAvail(next_wire)) {
                    if (!ripup)
                        continue;
                    IdString ripupWireNet = ctx->getConflictingWireNet(next_wire);
                    if (ripupWireNet == net_name || ripupWireNet == IdString())
                        continue;

                    auto it1 = scores.wireScores.find(next_wire);
                    if (it1 != scores.wireScores.end())
                        next_delay += (it1->second * ripup_penalty) / 8;

                    auto it2 = scores.netWireScores.find(std::make_pair(ripupWireNet, next_wire));
                    if (it2 != scores.netWireScores.end())
                        next_delay += it2->second * ripup_penalty;

                    foundRipupNet = true;
                }

                if (!ctx->checkPipAvail(pip)) {
                    if (!ripup)
                        continue;
                    IdString ripupPipNet = ctx->getConflictingPipNet(pip);
                    if (ripupPipNet == net_name || ripupPipNet == IdString())
                        continue;

                    auto it1 = scores.pipScores.find(pip);
                    if (it1 != scores.pipScores.end())
                        next_delay += (it1->second * ripup_penalty) / 8;

                    auto it2 = scores.netPipScores.find(std::make_pair(ripupPipNet, pip));
                    if (it2 != scores.netPipScores.end())
                        next_delay += it2->second * ripup_penalty;

                    foundRipupNet = true;
                }

                if (foundRipupNet)
                    next_delay += ripup_penalty;

                NPNR_ASSERT(next_delay >= 0);

                if (visited.count(next_wire)) {
                    if (visited.at(next_wire).delay <= next_delay + ctx->getDelayEpsilon())
                        continue;
#if 0 // FIXME
                    if (ctx->debug)
                        log("Found better route to %s. Old vs new delay estimate: %.3f %.3f\n",
                            ctx->getWireName(next_wire).c_str(),
                            ctx->getDelayNS(visited.at(next_wire).delay),
                            ctx->getDelayNS(next_delay));
#endif
                    if (thisVisitCntLimit == 0)
                        revisitCnt++;
                    else
                        overtimeRevisitCnt++;
                }

                QueuedWire next_qw;
                next_qw.wire = next_wire;
                next_qw.pip = pip;
                next_qw.delay = next_delay;
                if (cfg.useEstimate)
                    next_qw.togo = ctx->estimateDelay(next_wire, dst_wire);
                next_qw.randtag = ctx->rng();

                visited[next_qw.wire] = next_qw;
                queue.push(next_qw);
            }
        }

        visitCnt += thisVisitCnt;
    }

    Router(Context *ctx, const Router1Cfg &cfg, RipupScoreboard &scores, WireId src_wire, WireId dst_wire,
           bool ripup = false, delay_t ripup_penalty = 0)
            : ctx(ctx), cfg(cfg), scores(scores), ripup(ripup), ripup_penalty(ripup_penalty)
    {
        std::unordered_map<WireId, delay_t> src_wires;
        src_wires[src_wire] = ctx->getWireDelay(src_wire).maxDelay();
        route(src_wires, dst_wire);
        routedOkay = visited.count(dst_wire);

        if (ctx->debug) {
            log("Route (from destination to source):\n");

            WireId cursor = dst_wire;

            while (1) {
                log("  %8.3f %s\n", ctx->getDelayNS(visited[cursor].delay), ctx->getWireName(cursor).c_str(ctx));

                if (cursor == src_wire)
                    break;

                cursor = ctx->getPipSrcWire(visited[cursor].pip);
            }
        }
    }

    Router(Context *ctx, const Router1Cfg &cfg, RipupScoreboard &scores, IdString net_name, int user_idx = -1,
           bool reroute = false, bool ripup = false, delay_t ripup_penalty = 0)
            : ctx(ctx), cfg(cfg), scores(scores), net_name(net_name), ripup(ripup), ripup_penalty(ripup_penalty)
    {
        auto net_info = ctx->nets.at(net_name).get();

        if (ctx->debug)
            log("Routing net %s.\n", net_name.c_str(ctx));

        if (ctx->debug)
            log("  Source: %s.%s.\n", net_info->driver.cell->name.c_str(ctx), net_info->driver.port.c_str(ctx));

        auto src_wire = ctx->getNetinfoSourceWire(net_info);

        if (src_wire == WireId())
            log_error("No wire found for port %s on source cell %s.\n", net_info->driver.port.c_str(ctx),
                      net_info->driver.cell->name.c_str(ctx));

        if (ctx->debug)
            log("    Source wire: %s\n", ctx->getWireName(src_wire).c_str(ctx));

        std::unordered_map<WireId, delay_t> src_wires;
        std::vector<std::pair<delay_t, int>> users_array;

        if (user_idx < 0) {
            // route all users, from worst to best slack
            for (int user_idx = 0; user_idx < int(net_info->users.size()); user_idx++) {
                auto dst_wire = ctx->getNetinfoSinkWire(net_info, net_info->users[user_idx]);
                delay_t slack = net_info->users[user_idx].budget - ctx->estimateDelay(src_wire, dst_wire);
                users_array.push_back(std::pair<delay_t, int>(slack, user_idx));
            }
            std::sort(users_array.begin(), users_array.end());
        } else {
            // route only the selected user
            users_array.push_back(std::pair<delay_t, int>(delay_t(), user_idx));
        }

        if (reroute) {
            // complete ripup
            ripup_net(ctx, net_name);
            ctx->bindWire(src_wire, net_name, STRENGTH_WEAK);
            src_wires[src_wire] = ctx->getWireDelay(src_wire).maxDelay();
        } else {
            // re-use existing routes as much as possible
            if (net_info->wires.count(src_wire) == 0)
                ctx->bindWire(src_wire, net_name, STRENGTH_WEAK);
            src_wires[src_wire] = ctx->getWireDelay(src_wire).maxDelay();

            for (int user_idx = 0; user_idx < int(net_info->users.size()); user_idx++) {
                auto dst_wire = ctx->getNetinfoSinkWire(net_info, net_info->users[user_idx]);

                if (dst_wire == WireId())
                    log_error("No wire found for port %s on destination cell %s.\n",
                              net_info->users[user_idx].port.c_str(ctx),
                              net_info->users[user_idx].cell->name.c_str(ctx));

                std::function<delay_t(WireId)> register_existing_path =
                        [ctx, net_info, &src_wires, &register_existing_path](WireId wire) -> delay_t {
                    auto it = src_wires.find(wire);
                    if (it != src_wires.end())
                        return it->second;

                    PipId pip = net_info->wires.at(wire).pip;
                    delay_t delay = register_existing_path(ctx->getPipSrcWire(pip));
                    delay += ctx->getPipDelay(pip).maxDelay();
                    delay += ctx->getWireDelay(wire).maxDelay();
                    src_wires[wire] = delay;

                    return delay;
                };

                WireId cursor = dst_wire;
                while (src_wires.count(cursor) == 0) {
                    auto it = net_info->wires.find(cursor);
                    if (it == net_info->wires.end())
                        goto check_next_user_for_existing_path;
                    NPNR_ASSERT(it->second.pip != PipId());
                    cursor = ctx->getPipSrcWire(it->second.pip);
                }

                register_existing_path(dst_wire);
            check_next_user_for_existing_path:;
            }

            std::vector<WireId> ripup_wires;
            for (auto &it : net_info->wires)
                if (src_wires.count(it.first) == 0)
                    ripup_wires.push_back(it.first);

            for (auto &it : ripup_wires) {
                if (ctx->debug)
                    log("  Unbind dangling wire for net %s: %s\n", net_name.c_str(ctx),
                        ctx->getWireName(it).c_str(ctx));
                ctx->unbindWire(it);
            }
        }

        for (auto user_idx_it : users_array) {
            int user_idx = user_idx_it.second;

            if (ctx->debug)
                log("  Route to: %s.%s.\n", net_info->users[user_idx].cell->name.c_str(ctx),
                    net_info->users[user_idx].port.c_str(ctx));

            auto dst_wire = ctx->getNetinfoSinkWire(net_info, net_info->users[user_idx]);

            if (dst_wire == WireId())
                log_error("No wire found for port %s on destination cell %s.\n",
                          net_info->users[user_idx].port.c_str(ctx), net_info->users[user_idx].cell->name.c_str(ctx));

            if (ctx->debug) {
                log("    Destination wire: %s\n", ctx->getWireName(dst_wire).c_str(ctx));
                log("    Path delay estimate: %.2f\n", float(ctx->estimateDelay(src_wire, dst_wire)));
            }

            route(src_wires, dst_wire);

            if (visited.count(dst_wire) == 0) {
                if (ctx->debug)
                    log("Failed to route %s -> %s.\n", ctx->getWireName(src_wire).c_str(ctx),
                        ctx->getWireName(dst_wire).c_str(ctx));
                else if (ripup)
                    log_info("Failed to route %s -> %s.\n", ctx->getWireName(src_wire).c_str(ctx),
                             ctx->getWireName(dst_wire).c_str(ctx));
                ripup_net(ctx, net_name);
                failedDest = dst_wire;
                return;
            }

            if (ctx->debug)
                log("    Final path delay: %.3f\n", ctx->getDelayNS(visited[dst_wire].delay));
            maxDelay = fmaxf(maxDelay, visited[dst_wire].delay);

            if (ctx->debug)
                log("    Route (from destination to source):\n");

            WireId cursor = dst_wire;

            while (1) {
                if (ctx->debug)
                    log("    %8.3f %s\n", ctx->getDelayNS(visited[cursor].delay), ctx->getWireName(cursor).c_str(ctx));

                if (src_wires.count(cursor))
                    break;

                IdString conflicting_wire_net = ctx->getConflictingWireNet(cursor);

                if (conflicting_wire_net != IdString()) {
                    NPNR_ASSERT(ripup);
                    NPNR_ASSERT(conflicting_wire_net != net_name);

                    ctx->unbindWire(cursor);
                    if (!ctx->checkWireAvail(cursor))
                        ripup_net(ctx, conflicting_wire_net);

                    rippedNets.insert(conflicting_wire_net);
                    scores.wireScores[cursor]++;
                    scores.netWireScores[std::make_pair(net_name, cursor)]++;
                    scores.netWireScores[std::make_pair(conflicting_wire_net, cursor)]++;
                }

                PipId pip = visited[cursor].pip;
                IdString conflicting_pip_net = ctx->getConflictingPipNet(pip);

                if (conflicting_pip_net != IdString()) {
                    NPNR_ASSERT(ripup);
                    NPNR_ASSERT(conflicting_pip_net != net_name);

                    if (ctx->getBoundPipNet(pip) == conflicting_pip_net)
                        ctx->unbindPip(pip);

                    if (!ctx->checkPipAvail(pip))
                        ripup_net(ctx, conflicting_pip_net);

                    rippedNets.insert(conflicting_pip_net);
                    scores.pipScores[visited[cursor].pip]++;
                    scores.netPipScores[std::make_pair(net_name, visited[cursor].pip)]++;
                    scores.netPipScores[std::make_pair(conflicting_pip_net, visited[cursor].pip)]++;
                }

                ctx->bindPip(visited[cursor].pip, net_name, STRENGTH_WEAK);
                src_wires[cursor] = visited[cursor].delay;
                cursor = ctx->getPipSrcWire(visited[cursor].pip);
            }
        }

        routedOkay = true;
    }
};

struct RouteJob
{
    IdString net;
    int user_idx = -1;
    delay_t slack = 0;
    int randtag = 0;

    struct Greater
    {
        bool operator()(const RouteJob &lhs, const RouteJob &rhs) const noexcept
        {
            return lhs.slack == rhs.slack ? lhs.randtag > rhs.randtag : lhs.slack > rhs.slack;
        }
    };
};

void addFullNetRouteJob(Context *ctx, const Router1Cfg &cfg, IdString net_name,
                        std::unordered_map<IdString, std::vector<bool>> &cache,
                        std::priority_queue<RouteJob, std::vector<RouteJob>, RouteJob::Greater> &queue)
{
    NetInfo *net_info = ctx->nets.at(net_name).get();

    if (net_info->driver.cell == nullptr)
        return;

    auto src_wire = ctx->getNetinfoSourceWire(net_info);

    if (src_wire == WireId())
        log_error("No wire found for port %s on source cell %s.\n", net_info->driver.port.c_str(ctx),
                  net_info->driver.cell->name.c_str(ctx));

    auto &net_cache = cache[net_name];

    if (net_cache.empty())
        net_cache.resize(net_info->users.size());

    RouteJob job;
    job.net = net_name;
    job.user_idx = -1;
    job.slack = 0;
    job.randtag = ctx->rng();

    bool got_slack = false;

    for (int user_idx = 0; user_idx < int(net_info->users.size()); user_idx++) {
        if (net_cache[user_idx])
            continue;

        auto dst_wire = ctx->getNetinfoSinkWire(net_info, net_info->users[user_idx]);

        if (dst_wire == WireId())
            log_error("No wire found for port %s on destination cell %s.\n", net_info->users[user_idx].port.c_str(ctx),
                      net_info->users[user_idx].cell->name.c_str(ctx));

        if (user_idx == 0)
            job.slack = net_info->users[user_idx].budget - ctx->estimateDelay(src_wire, dst_wire);
        else
            job.slack = std::min(job.slack, net_info->users[user_idx].budget - ctx->estimateDelay(src_wire, dst_wire));

        WireId cursor = dst_wire;
        while (src_wire != cursor) {
            auto it = net_info->wires.find(cursor);
            if (it == net_info->wires.end()) {
                if (!got_slack)
                    job.slack = net_info->users[user_idx].budget - ctx->estimateDelay(src_wire, dst_wire);
                else
                    job.slack = std::min(job.slack,
                                         net_info->users[user_idx].budget - ctx->estimateDelay(src_wire, dst_wire));
                got_slack = true;
                break;
            }
            NPNR_ASSERT(it->second.pip != PipId());
            cursor = ctx->getPipSrcWire(it->second.pip);
        }
    }

    queue.push(job);

    for (int user_idx = 0; user_idx < int(net_info->users.size()); user_idx++)
        net_cache[user_idx] = true;
}

void addNetRouteJobs(Context *ctx, const Router1Cfg &cfg, IdString net_name,
                     std::unordered_map<IdString, std::vector<bool>> &cache,
                     std::priority_queue<RouteJob, std::vector<RouteJob>, RouteJob::Greater> &queue)
{
    NetInfo *net_info = ctx->nets.at(net_name).get();

    if (net_info->driver.cell == nullptr)
        return;

    auto src_wire = ctx->getNetinfoSourceWire(net_info);

    if (src_wire == WireId())
        log_error("No wire found for port %s on source cell %s.\n", net_info->driver.port.c_str(ctx),
                  net_info->driver.cell->name.c_str(ctx));

    auto &net_cache = cache[net_name];

    if (net_cache.empty())
        net_cache.resize(net_info->users.size());

    for (int user_idx = 0; user_idx < int(net_info->users.size()); user_idx++) {
        if (net_cache[user_idx])
            continue;

        auto dst_wire = ctx->getNetinfoSinkWire(net_info, net_info->users[user_idx]);

        if (dst_wire == WireId())
            log_error("No wire found for port %s on destination cell %s.\n", net_info->users[user_idx].port.c_str(ctx),
                      net_info->users[user_idx].cell->name.c_str(ctx));

        WireId cursor = dst_wire;
        while (src_wire != cursor) {
            auto it = net_info->wires.find(cursor);
            if (it == net_info->wires.end()) {
                RouteJob job;
                job.net = net_name;
                job.user_idx = user_idx;
                job.slack = net_info->users[user_idx].budget - ctx->estimateDelay(src_wire, dst_wire);
                job.randtag = ctx->rng();
                queue.push(job);
                net_cache[user_idx] = true;
                break;
            }
            NPNR_ASSERT(it->second.pip != PipId());
            cursor = ctx->getPipSrcWire(it->second.pip);
        }
    }
}

void cleanupReroute(Context *ctx, const Router1Cfg &cfg, RipupScoreboard &scores,
                    std::unordered_set<IdString> &cleanupQueue,
                    std::priority_queue<RouteJob, std::vector<RouteJob>, RouteJob::Greater> &jobQueue,
                    int &totalVisitCnt, int &totalRevisitCnt, int &totalOvertimeRevisitCnt)
{
    std::priority_queue<RouteJob, std::vector<RouteJob>, RouteJob::Greater> cleanupJobs;
    std::vector<NetInfo *> allNetinfos;

    for (auto net_name : cleanupQueue) {
        NetInfo *net_info = ctx->nets.at(net_name).get();
        auto src_wire = ctx->getNetinfoSourceWire(net_info);

        if (ctx->verbose)
            allNetinfos.push_back(net_info);

        std::unordered_map<WireId, int> useCounters;
        std::vector<int> candidateArcs;

        for (int user_idx = 0; user_idx < int(net_info->users.size()); user_idx++) {
            auto dst_wire = ctx->getNetinfoSinkWire(net_info, net_info->users[user_idx]);

            if (dst_wire == src_wire)
                continue;

            auto cursor = dst_wire;
            useCounters[cursor]++;

            while (cursor != src_wire) {
                auto it = net_info->wires.find(cursor);
                if (it == net_info->wires.end())
                    break;
                cursor = ctx->getPipSrcWire(it->second.pip);
                useCounters[cursor]++;
            }

            if (cursor != src_wire)
                continue;

            candidateArcs.push_back(user_idx);
        }

        for (int user_idx : candidateArcs) {
            auto dst_wire = ctx->getNetinfoSinkWire(net_info, net_info->users[user_idx]);

            if (useCounters.at(dst_wire) != 1)
                continue;

            RouteJob job;
            job.net = net_name;
            job.user_idx = user_idx;
            job.slack = net_info->users[user_idx].budget - ctx->estimateDelay(src_wire, dst_wire);
            job.randtag = ctx->rng();
            cleanupJobs.push(job);
        }
    }

    log_info("running cleanup re-route of %d nets (%d arcs).\n", int(cleanupQueue.size()), int(cleanupJobs.size()));

    cleanupQueue.clear();

    int visitCnt = 0, revisitCnt = 0, overtimeRevisitCnt = 0;
    int totalWireCountDelta = 0;

    if (ctx->verbose) {
        for (auto it : allNetinfos)
            totalWireCountDelta -= it->wires.size();
    }

    while (!cleanupJobs.empty()) {
        RouteJob job = cleanupJobs.top();
        cleanupJobs.pop();

        auto net_name = job.net;
        auto user_idx = job.user_idx;

        NetInfo *net_info = ctx->nets.at(net_name).get();
        auto dst_wire = ctx->getNetinfoSinkWire(net_info, net_info->users[user_idx]);

        ctx->unbindWire(dst_wire);

        Router router(ctx, cfg, scores, net_name, user_idx, false, false);

        if (!router.routedOkay)
            log_error("Failed to re-route arc %d of net %s.\n", user_idx, net_name.c_str(ctx));

        visitCnt += router.visitCnt;
        revisitCnt += router.revisitCnt;
        overtimeRevisitCnt += router.overtimeRevisitCnt;
    }

    if (ctx->verbose) {
        for (auto it : allNetinfos)
            totalWireCountDelta += it->wires.size();

        log_info("  visited %d PIPs (%.2f%% revisits, %.2f%% overtime), %+d wires.\n", visitCnt,
                 (100.0 * revisitCnt) / visitCnt, (100.0 * overtimeRevisitCnt) / visitCnt, totalWireCountDelta);
    }

    totalVisitCnt += visitCnt;
    totalRevisitCnt += revisitCnt;
    totalOvertimeRevisitCnt += overtimeRevisitCnt;
}

} // namespace

NEXTPNR_NAMESPACE_BEGIN

bool router1(Context *ctx, const Router1Cfg &cfg)
{
    try {
        int totalVisitCnt = 0, totalRevisitCnt = 0, totalOvertimeRevisitCnt = 0;
        delay_t ripup_penalty = ctx->getRipupDelayPenalty();
        RipupScoreboard scores;

        log_break();
        log_info("Routing..\n");
        ctx->lock();

        std::unordered_set<IdString> cleanupQueue;
        std::unordered_map<IdString, std::vector<bool>> jobCache;
        std::priority_queue<RouteJob, std::vector<RouteJob>, RouteJob::Greater> jobQueue;

        for (auto &net_it : ctx->nets)
            addNetRouteJobs(ctx, cfg, net_it.first, jobCache, jobQueue);

        if (jobQueue.empty()) {
            log_info("found no unrouted source-sink pairs. no routing necessary.\n");
            ctx->unlock();
            return true;
        }

        log_info("found %d unrouted source-sink pairs. starting routing procedure.\n", int(jobQueue.size()));

        int iterCnt = 0;

        while (!jobQueue.empty()) {
            if (iterCnt == cfg.maxIterCnt) {
                log_warning("giving up after %d iterations.\n", iterCnt);
                log_info("Checksum: 0x%08x\n", ctx->checksum());
#ifndef NDEBUG
                ctx->check();
#endif
                ctx->unlock();
                return false;
            }

            iterCnt++;
            if (ctx->verbose)
                log_info("-- %d --\n", iterCnt);

            int visitCnt = 0, revisitCnt = 0, overtimeRevisitCnt = 0, jobCnt = 0, failedCnt = 0;

            std::unordered_set<IdString> normalRouteNets, ripupQueue;

            if (ctx->verbose || iterCnt == 1)
                log_info("routing queue contains %d jobs.\n", int(jobQueue.size()));
            else if (ctx->slack_redist_iter > 0 && iterCnt % ctx->slack_redist_iter == 0)
                assign_budget(ctx, true /* quiet */);

            bool printNets = ctx->verbose && (jobQueue.size() < 10);

            while (!jobQueue.empty()) {
                if (ctx->debug)
                    log("Next job slack: %f\n", double(jobQueue.top().slack));

                auto net_name = jobQueue.top().net;
                auto user_idx = jobQueue.top().user_idx;
                jobQueue.pop();

                if (cfg.fullCleanupReroute)
                    cleanupQueue.insert(net_name);

                if (printNets) {
                    if (user_idx < 0)
                        log_info("  routing all %d users of net %s\n", int(ctx->nets.at(net_name)->users.size()),
                                 net_name.c_str(ctx));
                    else
                        log_info("  routing user %d of net %s\n", user_idx, net_name.c_str(ctx));
                }

                Router router(ctx, cfg, scores, net_name, user_idx, false, false);

                jobCnt++;
                visitCnt += router.visitCnt;
                revisitCnt += router.revisitCnt;
                overtimeRevisitCnt += router.overtimeRevisitCnt;

                if (!router.routedOkay) {
                    if (printNets)
                        log_info("    failed to route to %s.\n", ctx->getWireName(router.failedDest).c_str(ctx));
                    ripupQueue.insert(net_name);
                    failedCnt++;
                } else {
                    normalRouteNets.insert(net_name);
                }

                if ((ctx->verbose || iterCnt == 1) && !printNets && (jobCnt % 100 == 0)) {
                    log_info("  processed %d jobs. (%d routed, %d failed)\n", jobCnt, jobCnt - failedCnt, failedCnt);
                    ctx->yield();
                }
            }

            NPNR_ASSERT(jobQueue.empty());
            jobCache.clear();

            if ((ctx->verbose || iterCnt == 1) && (jobCnt % 100 != 0)) {
                log_info("  processed %d jobs. (%d routed, %d failed)\n", jobCnt, jobCnt - failedCnt, failedCnt);
                ctx->yield();
            }

            if (ctx->verbose)
                log_info("  visited %d PIPs (%.2f%% revisits, %.2f%% overtime revisits).\n", visitCnt,
                         (100.0 * revisitCnt) / visitCnt, (100.0 * overtimeRevisitCnt) / visitCnt);

            if (!ripupQueue.empty()) {
                if (ctx->verbose || iterCnt == 1)
                    log_info("failed to route %d nets. re-routing in ripup mode.\n", int(ripupQueue.size()));

                printNets = ctx->verbose && (ripupQueue.size() < 10);

                visitCnt = 0;
                revisitCnt = 0;
                overtimeRevisitCnt = 0;
                int netCnt = 0;
                int ripCnt = 0;

                std::vector<IdString> ripupArray(ripupQueue.begin(), ripupQueue.end());
                ctx->sorted_shuffle(ripupArray);

                for (auto net_name : ripupArray) {
                    if (cfg.cleanupReroute)
                        cleanupQueue.insert(net_name);

                    if (printNets)
                        log_info("  routing net %s. (%d users)\n", net_name.c_str(ctx),
                                 int(ctx->nets.at(net_name)->users.size()));

                    Router router(ctx, cfg, scores, net_name, -1, false, true, ripup_penalty);

                    netCnt++;
                    visitCnt += router.visitCnt;
                    revisitCnt += router.revisitCnt;
                    overtimeRevisitCnt += router.overtimeRevisitCnt;

                    if (!router.routedOkay)
                        log_error("Net %s is impossible to route.\n", net_name.c_str(ctx));

                    for (auto it : router.rippedNets) {
                        addFullNetRouteJob(ctx, cfg, it, jobCache, jobQueue);
                        if (cfg.cleanupReroute)
                            cleanupQueue.insert(it);
                    }

                    if (printNets) {
                        if (router.rippedNets.size() < 10) {
                            log_info("    ripped up %d other nets:\n", int(router.rippedNets.size()));
                            for (auto n : router.rippedNets)
                                log_info("      %s (%d users)\n", n.c_str(ctx), int(ctx->nets.at(n)->users.size()));
                        } else {
                            log_info("    ripped up %d other nets.\n", int(router.rippedNets.size()));
                        }
                    }

                    ripCnt += router.rippedNets.size();

                    if ((ctx->verbose || iterCnt == 1) && !printNets && (netCnt % 100 == 0)) {
                        log_info("  routed %d nets, ripped %d nets.\n", netCnt, ripCnt);
                        ctx->yield();
                    }
                }

                if ((ctx->verbose || iterCnt == 1) && (netCnt % 100 != 0))
                    log_info("  routed %d nets, ripped %d nets.\n", netCnt, ripCnt);

                if (ctx->verbose)
                    log_info("  visited %d PIPs (%.2f%% revisits, %.2f%% overtime revisits).\n", visitCnt,
                             (100.0 * revisitCnt) / visitCnt, (100.0 * overtimeRevisitCnt) / visitCnt);

                if (ctx->verbose && !jobQueue.empty())
                    log_info("  ripped up %d previously routed nets. continue routing.\n", int(jobQueue.size()));
            }

            if (!ctx->verbose)
                log_info("iteration %d: routed %d nets without ripup, routed %d nets with ripup.\n", iterCnt,
                         int(normalRouteNets.size()), int(ripupQueue.size()));

            totalVisitCnt += visitCnt;
            totalRevisitCnt += revisitCnt;
            totalOvertimeRevisitCnt += overtimeRevisitCnt;

            if (iterCnt == 8 || iterCnt == 16 || iterCnt == 32 || iterCnt == 64 || iterCnt == 128)
                ripup_penalty += ctx->getRipupDelayPenalty();

            if (jobQueue.empty() || (iterCnt % 5) == 0 || (cfg.fullCleanupReroute && iterCnt == 1))
                cleanupReroute(ctx, cfg, scores, cleanupQueue, jobQueue, totalVisitCnt, totalRevisitCnt,
                               totalOvertimeRevisitCnt);

            ctx->yield();
        }

        log_info("routing complete after %d iterations.\n", iterCnt);

        log_info("visited %d PIPs (%.2f%% revisits, %.2f%% overtime revisits).\n", totalVisitCnt,
                 (100.0 * totalRevisitCnt) / totalVisitCnt, (100.0 * totalOvertimeRevisitCnt) / totalVisitCnt);

        {
            float tns = 0;
            int tns_net_count = 0;
            int tns_arc_count = 0;
            for (auto &net_it : ctx->nets) {
                bool got_negative_slack = false;
                NetInfo *net_info = ctx->nets.at(net_it.first).get();
                for (int user_idx = 0; user_idx < int(net_info->users.size()); user_idx++) {
                    delay_t arc_delay = ctx->getNetinfoRouteDelay(net_info, net_info->users[user_idx]);
                    delay_t arc_budget = net_info->users[user_idx].budget;
                    delay_t arc_slack = arc_budget - arc_delay;
                    if (arc_slack < 0) {
                        if (!got_negative_slack) {
                            if (ctx->verbose)
                                log_info("net %s has negative slack arcs:\n", net_info->name.c_str(ctx));
                            tns_net_count++;
                        }
                        if (ctx->verbose)
                            log_info("  arc %s -> %s has %f ns slack (delay %f, budget %f)\n",
                                     ctx->getWireName(ctx->getNetinfoSourceWire(net_info)).c_str(ctx),
                                     ctx->getWireName(ctx->getNetinfoSinkWire(net_info, net_info->users[user_idx]))
                                             .c_str(ctx),
                                     ctx->getDelayNS(arc_slack), ctx->getDelayNS(arc_delay),
                                     ctx->getDelayNS(arc_budget));
                        tns += ctx->getDelayNS(arc_slack);
                        tns_arc_count++;
                    }
                }
            }
            log_info("final tns with respect to arc budgets: %f ns (%d nets, %d arcs)\n", tns, tns_net_count,
                     tns_arc_count);
        }

        NPNR_ASSERT(jobQueue.empty());
        jobCache.clear();

        for (auto &net_it : ctx->nets)
            addNetRouteJobs(ctx, cfg, net_it.first, jobCache, jobQueue);

#ifndef NDEBUG
        if (!jobQueue.empty()) {
            log_info("Design strangely still contains unrouted source-sink pairs:\n");
            while (!jobQueue.empty()) {
                log_info("  user %d on net %s.\n", jobQueue.top().user_idx, jobQueue.top().net.c_str(ctx));
                jobQueue.pop();
            }
            log_info("Checksum: 0x%08x\n", ctx->checksum());
            ctx->check();
            ctx->unlock();
            return false;
        }
#endif

        log_info("Checksum: 0x%08x\n", ctx->checksum());
#ifndef NDEBUG
        ctx->check();
#endif
        timing_analysis(ctx, true /* slack_histogram */, true /* print_path */);
        ctx->unlock();
        return true;
    } catch (log_execution_error_exception) {
#ifndef NDEBUG
        ctx->check();
#endif
        ctx->unlock();
        return false;
    }
}

bool Context::getActualRouteDelay(WireId src_wire, WireId dst_wire, delay_t *delay,
                                  std::unordered_map<WireId, PipId> *route, bool useEstimate)
{
    RipupScoreboard scores;
    Router1Cfg cfg;
    cfg.useEstimate = useEstimate;

    Router router(this, cfg, scores, src_wire, dst_wire);

    if (!router.routedOkay)
        return false;

    if (delay != nullptr)
        *delay = router.visited.at(dst_wire).delay;

    if (route != nullptr) {
        WireId cursor = dst_wire;
        while (1) {
            PipId pip = router.visited.at(cursor).pip;
            (*route)[cursor] = pip;
            if (pip == PipId())
                break;
            cursor = getPipSrcWire(pip);
        }
    }

    return true;
}

NEXTPNR_NAMESPACE_END