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timing: Fix domain init when loops are present

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Signed-off-by: gatecat <gatecat@ds0.me>
This commit is contained in:
gatecat 2021-04-13 09:23:08 +01:00
parent 5cd2a7f9c2
commit ece10c3e04
2 changed files with 73 additions and 58 deletions
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129
common/timing.cc
View File

@ -185,6 +185,7 @@ void TimingAnalyser::topo_sort()
}
}
}
have_loops = !no_loops;
std::swap(topological_order, topo.sorted);
}
@ -195,66 +196,77 @@ void TimingAnalyser::setup_port_domains()
d.endpoints.clear();
}
// Go forward through the topological order (domains from the PoV of arrival time)
for (auto port : topological_order) {
auto &pd = ports.at(port);
auto &pi = port_info(port);
if (pi.type == PORT_OUT) {
for (auto &fanin : pd.cell_arcs) {
if (fanin.type != CellArc::CLK_TO_Q)
continue;
// registered outputs are startpoints
auto dom = domain_id(port.cell, fanin.other_port, fanin.edge);
// create per-domain data
pd.arrival[dom];
domains.at(dom).startpoints.emplace_back(port, fanin.other_port);
}
// copy domains across routing
if (pi.net != nullptr)
for (auto &usr : pi.net->users)
copy_domains(port, CellPortKey(usr), false);
} else {
// copy domains from input to output
for (auto &fanout : pd.cell_arcs) {
if (fanout.type != CellArc::COMBINATIONAL)
continue;
copy_domains(port, CellPortKey(port.cell, fanout.other_port), false);
bool first_iter = true;
do {
updated_domains = false;
for (auto port : topological_order) {
auto &pd = ports.at(port);
auto &pi = port_info(port);
if (pi.type == PORT_OUT) {
if (first_iter) {
for (auto &fanin : pd.cell_arcs) {
if (fanin.type != CellArc::CLK_TO_Q)
continue;
// registered outputs are startpoints
auto dom = domain_id(port.cell, fanin.other_port, fanin.edge);
// create per-domain data
pd.arrival[dom];
domains.at(dom).startpoints.emplace_back(port, fanin.other_port);
}
}
// copy domains across routing
if (pi.net != nullptr)
for (auto &usr : pi.net->users)
copy_domains(port, CellPortKey(usr), false);
} else {
// copy domains from input to output
for (auto &fanout : pd.cell_arcs) {
if (fanout.type != CellArc::COMBINATIONAL)
continue;
copy_domains(port, CellPortKey(port.cell, fanout.other_port), false);
}
}
}
}
// Go backward through the topological order (domains from the PoV of required time)
for (auto port : reversed_range(topological_order)) {
auto &pd = ports.at(port);
auto &pi = port_info(port);
if (pi.type == PORT_OUT) {
// copy domains from output to input
for (auto &fanin : pd.cell_arcs) {
if (fanin.type != CellArc::COMBINATIONAL)
continue;
copy_domains(port, CellPortKey(port.cell, fanin.other_port), true);
// Go backward through the topological order (domains from the PoV of required time)
for (auto port : reversed_range(topological_order)) {
auto &pd = ports.at(port);
auto &pi = port_info(port);
if (pi.type == PORT_OUT) {
// copy domains from output to input
for (auto &fanin : pd.cell_arcs) {
if (fanin.type != CellArc::COMBINATIONAL)
continue;
copy_domains(port, CellPortKey(port.cell, fanin.other_port), true);
}
} else {
if (first_iter) {
for (auto &fanout : pd.cell_arcs) {
if (fanout.type != CellArc::SETUP)
continue;
// registered inputs are endpoints
auto dom = domain_id(port.cell, fanout.other_port, fanout.edge);
// create per-domain data
pd.required[dom];
domains.at(dom).endpoints.emplace_back(port, fanout.other_port);
}
}
// copy port to driver
if (pi.net != nullptr && pi.net->driver.cell != nullptr)
copy_domains(port, CellPortKey(pi.net->driver), true);
}
} else {
for (auto &fanout : pd.cell_arcs) {
if (fanout.type != CellArc::SETUP)
continue;
// registered inputs are startpoints
auto dom = domain_id(port.cell, fanout.other_port, fanout.edge);
// create per-domain data
pd.required[dom];
domains.at(dom).endpoints.emplace_back(port, fanout.other_port);
}
// copy port to driver
if (pi.net != nullptr && pi.net->driver.cell != nullptr)
copy_domains(port, CellPortKey(pi.net->driver), true);
}
}
// Iterate over ports and find domain paris
for (auto port : topological_order) {
auto &pd = ports.at(port);
for (auto &arr : pd.arrival)
for (auto &req : pd.required) {
pd.domain_pairs[domain_pair_id(arr.first, req.first)];
}
}
// Iterate over ports and find domain paris
for (auto port : topological_order) {
auto &pd = ports.at(port);
for (auto &arr : pd.arrival)
for (auto &req : pd.required) {
pd.domain_pairs[domain_pair_id(arr.first, req.first)];
}
}
first_iter = false;
// If there are loops, repeat the process until a fixed point is reached, as there might be unusual ways to
// visit points, which would result in a missing domain key and therefore crash later on
} while (have_loops && updated_domains);
}
void TimingAnalyser::reset_times()
@ -561,8 +573,9 @@ domain_id_t TimingAnalyser::domain_pair_id(domain_id_t launch, domain_id_t captu
void TimingAnalyser::copy_domains(const CellPortKey &from, const CellPortKey &to, bool backward)
{
auto &f = ports.at(from), &t = ports.at(to);
for (auto &dom : (backward ? f.required : f.arrival))
(backward ? t.required : t.arrival)[dom.first];
for (auto &dom : (backward ? f.required : f.arrival)) {
updated_domains |= (backward ? t.required : t.arrival).emplace(dom.first, ArrivReqTime{}).second;
}
}
CellInfo *TimingAnalyser::cell_info(const CellPortKey &key) { return ctx->cells.at(key.cell).get(); }

2
common/timing.h
View File

@ -142,6 +142,8 @@ struct TimingAnalyser
bool setup_only = false;
bool verbose_mode = false;
bool have_loops = false;
bool updated_domains = false;
private:
void init_ports();