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Refactoring of router1

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- Use source-sink pairs as jobs, not whole nets
- Route nets with smallest slack first
- Preserve routes for already routed source-sink pairs
- Add small incentive for re-using wires

Signed-off-by: Clifford Wolf <clifford@clifford.at>
This commit is contained in:
Clifford Wolf 2018-07-21 17:02:53 +02:00
parent a8eadb5ba2
commit 41194d934b
2 changed files with 332 additions and 99 deletions
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430
common/router1.cc
View File

@ -75,6 +75,9 @@ struct RipupScoreboard
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;
@ -248,7 +251,7 @@ struct Router
}
}
Router(Context *ctx, RipupScoreboard &scores, IdString net_name, bool ripup = false, delay_t ripup_penalty = 0)
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)
{
auto net_info = ctx->nets.at(net_name).get();
@ -286,13 +289,91 @@ struct Router
log(" Source wire: %s\n", ctx->getWireName(src_wire).c_str(ctx));
std::unordered_map<WireId, delay_t> src_wires;
src_wires[src_wire] = ctx->getWireDelay(src_wire).maxDelay();
std::vector<PortRef> users_array;
ripup_net(ctx, net_name);
ctx->bindWire(src_wire, net_name, STRENGTH_WEAK);
if (user_idx < 0) {
// route all users
users_array = net_info->users;
ctx->shuffle(users_array);
} else {
// route only the selected user
users_array.push_back(net_info->users[user_idx]);
}
std::vector<PortRef> users_array = net_info->users;
ctx->shuffle(users_array);
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
src_wires[src_wire] = ctx->getWireDelay(src_wire).maxDelay();
for (auto &user_it : net_info->users) {
auto dst_bel = user_it.cell->bel;
if (dst_bel == BelId())
log_error("Destination cell %s (%s) is not mapped to a bel.\n", user_it.cell->name.c_str(ctx),
user_it.cell->type.c_str(ctx));
if (ctx->debug)
log(" Destination bel: %s\n", ctx->getBelName(dst_bel).c_str(ctx));
IdString user_port = user_it.port;
auto user_port_it = user_it.cell->pins.find(user_port);
if (user_port_it != user_it.cell->pins.end())
user_port = user_port_it->second;
auto dst_wire = ctx->getWireBelPin(dst_bel, ctx->portPinFromId(user_port));
if (dst_wire == WireId())
log_error("No wire found for port %s (pin %s) on destination "
"cell %s (bel %s).\n",
user_it.port.c_str(ctx), user_port.c_str(ctx), user_it.cell->name.c_str(ctx),
ctx->getBelName(dst_bel).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();
delay -= 2*ctx->getDelayEpsilon();
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_it : users_array) {
if (ctx->debug)
@ -400,6 +481,205 @@ struct Router
}
};
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, 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_bel = net_info->driver.cell->bel;
if (src_bel == BelId())
log_error("Source cell %s (%s) is not mapped to a bel.\n", net_info->driver.cell->name.c_str(ctx),
net_info->driver.cell->type.c_str(ctx));
IdString driver_port = net_info->driver.port;
auto driver_port_it = net_info->driver.cell->pins.find(driver_port);
if (driver_port_it != net_info->driver.cell->pins.end())
driver_port = driver_port_it->second;
auto src_wire = ctx->getWireBelPin(src_bel, ctx->portPinFromId(driver_port));
if (src_wire == WireId())
log_error("No wire found for port %s (pin %s) on source cell %s "
"(bel %s).\n",
net_info->driver.port.c_str(ctx), driver_port.c_str(ctx), net_info->driver.cell->name.c_str(ctx),
ctx->getBelName(src_bel).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 &user_info = net_info->users[user_idx];
auto dst_bel = user_info.cell->bel;
if (dst_bel == BelId())
log_error("Destination cell %s (%s) is not mapped to a bel.\n",
user_info.cell->name.c_str(ctx), user_info.cell->type.c_str(ctx));
IdString user_port = user_info.port;
auto user_port_it = user_info.cell->pins.find(user_port);
if (user_port_it != user_info.cell->pins.end())
user_port = user_port_it->second;
auto dst_wire = ctx->getWireBelPin(dst_bel, ctx->portPinFromId(user_port));
if (dst_wire == WireId())
log_error("No wire found for port %s (pin %s) on destination "
"cell %s (bel %s).\n",
user_info.port.c_str(ctx), user_port.c_str(ctx), user_info.cell->name.c_str(ctx),
ctx->getBelName(dst_bel).c_str(ctx));
if (user_idx == 0)
job.slack = user_info.budget - ctx->estimateDelay(src_wire, dst_wire);
else
job.slack = std::min(job.slack, user_info.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 = user_info.budget - ctx->estimateDelay(src_wire, dst_wire);
else
job.slack = std::min(job.slack, user_info.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, 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_bel = net_info->driver.cell->bel;
if (src_bel == BelId())
log_error("Source cell %s (%s) is not mapped to a bel.\n", net_info->driver.cell->name.c_str(ctx),
net_info->driver.cell->type.c_str(ctx));
IdString driver_port = net_info->driver.port;
auto driver_port_it = net_info->driver.cell->pins.find(driver_port);
if (driver_port_it != net_info->driver.cell->pins.end())
driver_port = driver_port_it->second;
auto src_wire = ctx->getWireBelPin(src_bel, ctx->portPinFromId(driver_port));
if (src_wire == WireId())
log_error("No wire found for port %s (pin %s) on source cell %s "
"(bel %s).\n",
net_info->driver.port.c_str(ctx), driver_port.c_str(ctx), net_info->driver.cell->name.c_str(ctx),
ctx->getBelName(src_bel).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 &user_info = net_info->users[user_idx];
auto dst_bel = user_info.cell->bel;
if (dst_bel == BelId())
log_error("Destination cell %s (%s) is not mapped to a bel.\n",
user_info.cell->name.c_str(ctx), user_info.cell->type.c_str(ctx));
IdString user_port = user_info.port;
auto user_port_it = user_info.cell->pins.find(user_port);
if (user_port_it != user_info.cell->pins.end())
user_port = user_port_it->second;
auto dst_wire = ctx->getWireBelPin(dst_bel, ctx->portPinFromId(user_port));
if (dst_wire == WireId())
log_error("No wire found for port %s (pin %s) on destination "
"cell %s (bel %s).\n",
user_info.port.c_str(ctx), user_port.c_str(ctx), user_info.cell->name.c_str(ctx),
ctx->getBelName(dst_bel).c_str(ctx));
WireId cursor = dst_wire;
while (src_wire != cursor) {
auto it = net_info->wires.find(cursor);
if (it == net_info->wires.end()) {
if (ctx->debug)
log("Adding job [%s %d]: %s %s (%s) -> %s %s (%s)\n",
net_name.c_str(ctx), user_idx,
ctx->getBelName(src_bel).c_str(ctx), driver_port.c_str(ctx),
ctx->getWireName(src_wire).c_str(ctx),
ctx->getBelName(dst_bel).c_str(ctx), user_port.c_str(ctx),
ctx->getWireName(dst_wire).c_str(ctx));
RouteJob job;
job.net = net_name;
job.user_idx = user_idx;
job.slack = user_info.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);
}
}
}
} // namespace
NEXTPNR_NAMESPACE_BEGIN
@ -414,79 +694,22 @@ bool router1(Context *ctx)
log_break();
log_info("Routing..\n");
std::unordered_set<IdString> netsQueue;
std::unordered_map<IdString, std::vector<bool>> jobCache;
std::priority_queue<RouteJob, std::vector<RouteJob>, RouteJob::Greater> jobQueue;
for (auto &net_it : ctx->nets) {
auto net_name = net_it.first;
auto net_info = net_it.second.get();
for (auto &net_it : ctx->nets)
addNetRouteJobs(ctx, net_it.first, jobCache, jobQueue);
if (net_info->driver.cell == nullptr)
continue;
if (!net_info->wires.empty())
continue;
netsQueue.insert(net_name);
}
if (netsQueue.empty()) {
log_info("found no unrouted nets. no routing necessary.\n");
if (jobQueue.empty()) {
log_info("found no unrouted source-sink pairs. no routing necessary.\n");
return true;
}
log_info("found %d unrouted nets. starting routing procedure.\n", int(netsQueue.size()));
delay_t estimatedTotalDelay = 0.0;
int estimatedTotalDelayCnt = 0;
for (auto net_name : netsQueue) {
auto net_info = ctx->nets.at(net_name).get();
auto src_bel = net_info->driver.cell->bel;
if (src_bel == BelId())
continue;
IdString driver_port = net_info->driver.port;
auto driver_port_it = net_info->driver.cell->pins.find(driver_port);
if (driver_port_it != net_info->driver.cell->pins.end())
driver_port = driver_port_it->second;
auto src_wire = ctx->getWireBelPin(src_bel, ctx->portPinFromId(driver_port));
if (src_wire == WireId())
continue;
for (auto &user_it : net_info->users) {
auto dst_bel = user_it.cell->bel;
if (dst_bel == BelId())
continue;
IdString user_port = user_it.port;
auto user_port_it = user_it.cell->pins.find(user_port);
if (user_port_it != user_it.cell->pins.end())
user_port = user_port_it->second;
auto dst_wire = ctx->getWireBelPin(dst_bel, ctx->portPinFromId(user_port));
if (dst_wire == WireId())
continue;
estimatedTotalDelay += ctx->estimateDelay(src_wire, dst_wire);
estimatedTotalDelayCnt++;
}
}
log_info("estimated total wire delay: %.2f (avg %.2f)\n", float(estimatedTotalDelay),
float(estimatedTotalDelay) / estimatedTotalDelayCnt);
log_info("found %d unrouted source-sink pairs. starting routing procedure.\n", int(jobQueue.size()));
int iterCnt = 0;
while (!netsQueue.empty()) {
while (!jobQueue.empty()) {
if (iterCnt == 200) {
log_warning("giving up after %d iterations.\n", iterCnt);
log_info("Checksum: 0x%08x\n", ctx->checksum());
@ -500,27 +723,34 @@ bool router1(Context *ctx)
if (ctx->verbose)
log_info("-- %d --\n", iterCnt);
int visitCnt = 0, revisitCnt = 0, overtimeRevisitCnt = 0, netCnt = 0;
int visitCnt = 0, revisitCnt = 0, overtimeRevisitCnt = 0, jobCnt = 0, failedCnt = 0;
std::unordered_set<IdString> ripupQueue;
std::unordered_set<IdString> normalRouteNets, ripupQueue;
if (ctx->verbose || iterCnt == 1)
log_info("routing queue contains %d nets.\n", int(netsQueue.size()));
log_info("routing queue contains %d jobs.\n", int(jobQueue.size()));
bool printNets = ctx->verbose && (netsQueue.size() < 10);
bool printNets = ctx->verbose && (jobQueue.size() < 10);
std::vector<IdString> netsArray(netsQueue.begin(), netsQueue.end());
ctx->sorted_shuffle(netsArray);
netsQueue.clear();
while (!jobQueue.empty()) {
if(ctx->debug)
log("Next job slack: %f\n", double(jobQueue.top().slack));
for (auto net_name : netsArray) {
if (printNets)
log_info(" routing net %s. (%d users)\n", net_name.c_str(ctx),
int(ctx->nets.at(net_name)->users.size()));
auto net_name = jobQueue.top().net;
auto user_idx = jobQueue.top().user_idx;
jobQueue.pop();
Router router(ctx, scores, net_name, false);
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));
}
netCnt++;
Router router(ctx, scores, net_name, user_idx, false, false);
jobCnt++;
visitCnt += router.visitCnt;
revisitCnt += router.revisitCnt;
overtimeRevisitCnt += router.overtimeRevisitCnt;
@ -529,18 +759,20 @@ bool router1(Context *ctx)
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 && (netCnt % 100 == 0))
log_info(" processed %d nets. (%d routed, %d failed)\n", netCnt, netCnt - int(ripupQueue.size()),
int(ripupQueue.size()));
if ((ctx->verbose || iterCnt == 1) && !printNets && (jobCnt % 100 == 0))
log_info(" processed %d jobs. (%d routed, %d failed)\n", jobCnt, jobCnt - failedCnt, failedCnt);
}
int normalRouteCnt = netCnt - int(ripupQueue.size());
NPNR_ASSERT(jobQueue.empty());
jobCache.clear();
if ((ctx->verbose || iterCnt == 1) && (netCnt % 100 != 0))
log_info(" processed %d nets. (%d routed, %d failed)\n", netCnt, normalRouteCnt,
int(ripupQueue.size()));
if ((ctx->verbose || iterCnt == 1) && (jobCnt % 100 != 0))
log_info(" processed %d jobs. (%d routed, %d failed)\n", jobCnt, jobCnt - failedCnt, failedCnt);
if (ctx->verbose)
log_info(" visited %d PIPs (%.2f%% revisits, %.2f%% overtime "
@ -558,7 +790,7 @@ bool router1(Context *ctx)
visitCnt = 0;
revisitCnt = 0;
overtimeRevisitCnt = 0;
netCnt = 0;
int netCnt = 0;
int ripCnt = 0;
std::vector<IdString> ripupArray(ripupQueue.begin(), ripupQueue.end());
@ -569,7 +801,7 @@ bool router1(Context *ctx)
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, true, ripup_penalty);
Router router(ctx, scores, net_name, -1, false, true, ripup_penalty);
netCnt++;
visitCnt += router.visitCnt;
@ -580,7 +812,7 @@ bool router1(Context *ctx)
log_error("Net %s is impossible to route.\n", net_name.c_str(ctx));
for (auto it : router.rippedNets)
netsQueue.insert(it);
addFullNetRouteJob(ctx, it, jobCache, jobQueue);
if (printNets) {
if (router.rippedNets.size() < 10) {
@ -606,16 +838,16 @@ bool router1(Context *ctx)
"overtime revisits).\n",
visitCnt, (100.0 * revisitCnt) / visitCnt, (100.0 * overtimeRevisitCnt) / visitCnt);
if (ctx->verbose && !netsQueue.empty())
if (ctx->verbose && !jobQueue.empty())
log_info(" ripped up %d previously routed nets. continue "
"routing.\n",
int(netsQueue.size()));
int(jobQueue.size()));
}
if (!ctx->verbose)
log_info("iteration %d: routed %d nets without ripup, routed %d "
"nets with ripup.\n",
iterCnt, normalRouteCnt, int(ripupQueue.size()));
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;

1
ice40/picorv32.sh
View File

@ -4,3 +4,4 @@ rm -f picorv32.v
wget https://raw.githubusercontent.com/cliffordwolf/picorv32/master/picorv32.v
yosys -p 'synth_ice40 -json picorv32.json -top top' picorv32.v picorv32_top.v
../nextpnr-ice40 --hx8k --asc picorv32.asc --json picorv32.json
icetime -d hx8k -t picorv32.asc