caiyu/nextpnr
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

router2: Binding nextpnr wires/pips

Browse Source 
Signed-off-by: David Shah <dave@ds0.me>
This commit is contained in:
David Shah 2019-11-15 11:30:39 +00:00
parent 599236bbc6
commit fa217a50a5
1 changed files with 90 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

96
common/router2.cc
View File

@ -372,6 +372,8 @@ struct Router2
bool did_something = false;
for (auto uh : ctx->getPipsUphill(cursor)) {
did_something = true;
if (!ctx->checkPipAvail(uh) && ctx->getBoundPipNet(uh) != net)
continue;
if (cpip != PipId() && cpip != uh)
continue; // don't allow multiple pips driving a wire with a net
WireId next = ctx->getPipSrcWire(uh);
@ -442,6 +444,8 @@ struct Router2
#else
if (is_bb && !hit_test_pip(ad.bb, ctx->getPipLocation(dh)))
continue;
if (!ctx->checkPipAvail(dh) && ctx->getBoundPipNet(dh) != net)
continue;
#endif
// Evaluate score of next wire
WireId next = ctx->getPipDstWire(dh);
@ -540,14 +544,14 @@ struct Router2
int overused_wires = 0;
int total_overuse = 0;
std::vector<int> route_queue;
std::set<int> congested_nets;
std::set<int> failed_nets;
void update_congestion()
{
total_overuse = 0;
overused_wires = 0;
total_wire_use = 0;
congested_nets.clear();
failed_nets.clear();
for (auto &wire : wires) {
total_wire_use += int(wire.second.bound_nets.size());
int overuse = int(wire.second.bound_nets.size()) - 1;
@ -556,11 +560,86 @@ struct Router2
total_overuse += overuse;
overused_wires += 1;
for (auto &bound : wire.second.bound_nets)
congested_nets.insert(bound.first);
failed_nets.insert(bound.first);
}
}
}
bool bind_and_check(NetInfo *net, int usr_idx)
{
bool success = true;
auto &nd = nets.at(net->udata);
auto &ad = nd.arcs.at(usr_idx);
auto &usr = net->users.at(usr_idx);
WireId src = ctx->getNetinfoSourceWire(net);
WireId dst = ctx->getNetinfoSinkWire(net, usr);
WireId cursor = dst;
std::vector<PipId> to_bind;
while (cursor != src) {
if (!ctx->checkWireAvail(cursor)) {
if (ctx->getBoundWireNet(cursor) == net)
break; // hit the part of the net that is already bound
else {
success = false;
break;
}
}
if (!ad.wires.count(cursor)) {
log("Failure details:\n");
log(" Cursor: %s\n", ctx->nameOfWire(cursor));
log(" route backtrace: \n");
for (auto w : ad.wires)
log(" %s: %s (src: %s)\n", ctx->nameOfWire(w.first), ctx->nameOfPip(w.second),
ctx->nameOfWire(ctx->getPipSrcWire(w.second)));
log_error("Internal error; incomplete route tree for arc %d of net %s.\n", usr_idx, ctx->nameOf(net));
}
auto &p = ad.wires.at(cursor);
if (!ctx->checkPipAvail(p)) {
success = false;
break;
} else {
to_bind.push_back(p);
}
cursor = ctx->getPipSrcWire(p);
}
if (success) {
if (ctx->getBoundWireNet(src) == nullptr)
ctx->bindWire(src, net, STRENGTH_WEAK);
for (auto tb : to_bind)
ctx->bindPip(tb, net, STRENGTH_WEAK);
} else {
ripup_arc(net, usr_idx);
failed_nets.insert(net->udata);
}
return success;
}
int arch_fail = 0;
bool bind_and_check_all()
{
bool success = true;
std::vector<WireId> net_wires;
for (auto net : nets_by_udata) {
// Ripup wires and pips used by the net in nextpnr's structures
net_wires.clear();
for (auto &w : net->wires)
net_wires.push_back(w.first);
for (auto w : net_wires)
ctx->unbindWire(w);
// Bind the arcs using the routes we have discovered
for (size_t i = 0; i < net->users.size(); i++) {
if (!bind_and_check(net, i)) {
++arch_fail;
success = false;
}
}
}
return success;
}
void router_test()
{
setup_nets();
@ -582,12 +661,17 @@ struct Router2
}
route_queue.clear();
update_congestion();
for (auto cn : congested_nets)
if (overused_wires == 0) {
// Try and actually bind nextpnr Arch API wires
bind_and_check_all();
}
for (auto cn : failed_nets)
route_queue.push_back(cn);
log_info("iter=%d wires=%d overused=%d overuse=%d\n", iter, total_wire_use, overused_wires, total_overuse);
log_info("iter=%d wires=%d overused=%d overuse=%d archfail=%s\n", iter, total_wire_use, overused_wires,
total_overuse, overused_wires > 0 ? "NA" : std::to_string(arch_fail).c_str());
++iter;
curr_cong_weight *= 2;
} while (total_overuse > 0);
} while (!failed_nets.empty());
}
};
} // namespace