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Merge pull request #16 from YosysHQ/reroute
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Add cleanup reroute passes to router1, improve reuse of wires
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@cliffordwolf
cliffordwolf committed Aug 2, 2018
2 parents fb06fd4 + 2b0bf3f commit 0208897
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Showing 5 changed files with 178 additions and 48 deletions.
203 changes: 159 additions & 44 deletions common/router1.cc
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Original file line number Diff line number Diff line change
Expand Up @@ -105,6 +105,7 @@ void ripup_net(Context *ctx, IdString net_name)
struct Router
{
Context *ctx;
const Router1Cfg &cfg;
RipupScoreboard scores;
IdString net_name;

Expand All @@ -128,7 +129,7 @@ struct Router
QueuedWire qw;
qw.wire = it.first;
qw.pip = PipId();
qw.delay = it.second;
qw.delay = it.second - (it.second / 16);
qw.togo = ctx->estimateDelay(qw.wire, dst_wire);
qw.randtag = ctx->rng();

Expand Down Expand Up @@ -200,8 +201,7 @@ struct Router
continue;
#if 0 // FIXME
if (ctx->debug)
log("Found better route to %s. Old vs new delay "
"estimate: %.3f %.3f\n",
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));
Expand All @@ -227,9 +227,9 @@ struct Router
visitCnt += thisVisitCnt;
}

Router(Context *ctx, RipupScoreboard &scores, WireId src_wire, WireId dst_wire, bool ripup = false,
delay_t ripup_penalty = 0)
: ctx(ctx), scores(scores), ripup(ripup), ripup_penalty(ripup_penalty)
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();
Expand All @@ -252,9 +252,9 @@ struct Router
}
}

Router(Context *ctx, RipupScoreboard &scores, IdString net_name, int user_idx = -1, bool reroute = false,
bool ripup = false, delay_t ripup_penalty = 0)
: ctx(ctx), scores(scores), net_name(net_name), ripup(ripup), ripup_penalty(ripup_penalty)
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();

Expand All @@ -274,16 +274,19 @@ struct Router
log(" Source wire: %s\n", ctx->getWireName(src_wire).c_str(ctx));

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

if (user_idx < 0) {
// route all users
for (int user_idx = 0; user_idx < int(net_info->users.size()); user_idx++)
users_array.push_back(user_idx);
ctx->shuffle(users_array);
// 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(user_idx);
users_array.push_back(std::pair<delay_t, int>(delay_t(), user_idx));
}

if (reroute) {
Expand Down Expand Up @@ -315,7 +318,6 @@ struct Router
delay_t delay = register_existing_path(ctx->getPipSrcWire(pip));
delay += ctx->getPipDelay(pip).maxDelay();
delay += ctx->getWireDelay(wire).maxDelay();
delay -= 2 * ctx->getDelayEpsilon();
src_wires[wire] = delay;

return delay;
Expand Down Expand Up @@ -347,7 +349,9 @@ struct Router
}
}

for (int user_idx : users_array) {
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));
Expand Down Expand Up @@ -452,7 +456,8 @@ struct RouteJob
};
};

void addFullNetRouteJob(Context *ctx, IdString net_name, std::unordered_map<IdString, std::vector<bool>> &cache,
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();
Expand Down Expand Up @@ -517,7 +522,8 @@ void addFullNetRouteJob(Context *ctx, IdString net_name, std::unordered_map<IdSt
net_cache[user_idx] = true;
}

void addNetRouteJobs(Context *ctx, IdString net_name, std::unordered_map<IdString, std::vector<bool>> &cache,
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();
Expand Down Expand Up @@ -565,11 +571,114 @@ void addNetRouteJobs(Context *ctx, IdString net_name, std::unordered_map<IdStrin
}
}

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)
bool router1(Context *ctx, const Router1Cfg &cfg)
{
try {
int totalVisitCnt = 0, totalRevisitCnt = 0, totalOvertimeRevisitCnt = 0;
Expand All @@ -580,11 +689,12 @@ bool router1(Context *ctx)
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, net_it.first, jobCache, jobQueue);
addNetRouteJobs(ctx, cfg, net_it.first, jobCache, jobQueue);

if (jobQueue.empty()) {
log_info("found no unrouted source-sink pairs. no routing necessary.\n");
Expand All @@ -597,7 +707,7 @@ bool router1(Context *ctx)
int iterCnt = 0;

while (!jobQueue.empty()) {
if (iterCnt == 200) {
if (iterCnt == cfg.maxIterCnt) {
log_warning("giving up after %d iterations.\n", iterCnt);
log_info("Checksum: 0x%08x\n", ctx->checksum());
#ifndef NDEBUG
Expand Down Expand Up @@ -630,6 +740,9 @@ bool router1(Context *ctx)
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()),
Expand All @@ -638,7 +751,7 @@ bool router1(Context *ctx)
log_info(" routing user %d of net %s\n", user_idx, net_name.c_str(ctx));
}

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

jobCnt++;
visitCnt += router.visitCnt;
Expand Down Expand Up @@ -669,15 +782,12 @@ bool router1(Context *ctx)
}

if (ctx->verbose)
log_info(" visited %d PIPs (%.2f%% revisits, %.2f%% overtime "
"revisits).\n",
visitCnt, (100.0 * revisitCnt) / visitCnt, (100.0 * overtimeRevisitCnt) / visitCnt);
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()));
log_info("failed to route %d nets. re-routing in ripup mode.\n", int(ripupQueue.size()));

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

Expand All @@ -691,11 +801,14 @@ bool router1(Context *ctx)
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, scores, net_name, -1, false, true, ripup_penalty);
Router router(ctx, cfg, scores, net_name, -1, false, true, ripup_penalty);

netCnt++;
visitCnt += router.visitCnt;
Expand All @@ -705,8 +818,11 @@ bool router1(Context *ctx)
if (!router.routedOkay)
log_error("Net %s is impossible to route.\n", net_name.c_str(ctx));

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

if (printNets) {
if (router.rippedNets.size() < 10) {
Expand All @@ -730,14 +846,11 @@ bool router1(Context *ctx)
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);
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()));
log_info(" ripped up %d previously routed nets. continue routing.\n", int(jobQueue.size()));
}

if (!ctx->verbose)
Expand All @@ -751,15 +864,17 @@ bool router1(Context *ctx)
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);
log_info("visited %d PIPs (%.2f%% revisits, %.2f%% overtime revisits).\n", totalVisitCnt,
(100.0 * totalRevisitCnt) / totalVisitCnt, (100.0 * totalOvertimeRevisitCnt) / totalVisitCnt);

{
float tns = 0;
Expand Down Expand Up @@ -798,7 +913,7 @@ bool router1(Context *ctx)
jobCache.clear();

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

#ifndef NDEBUG
if (!jobQueue.empty()) {
Expand Down Expand Up @@ -833,7 +948,7 @@ bool router1(Context *ctx)
bool Context::getActualRouteDelay(WireId src_wire, WireId dst_wire, delay_t &delay)
{
RipupScoreboard scores;
Router router(this, scores, src_wire, dst_wire);
Router router(this, Router1Cfg(), scores, src_wire, dst_wire);
if (router.routedOkay)
delay = router.visited.at(dst_wire).delay;
return router.routedOkay;
Expand Down
9 changes: 8 additions & 1 deletion common/router1.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -24,7 +24,14 @@

NEXTPNR_NAMESPACE_BEGIN

extern bool router1(Context *ctx);
struct Router1Cfg
{
int maxIterCnt = 200;
bool cleanupReroute = true;
bool fullCleanupReroute = true;
};

extern bool router1(Context *ctx, const Router1Cfg &cfg);

NEXTPNR_NAMESPACE_END

Expand Down
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