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

timing: Add support for critical path printing

Browse Source 
Signed-off-by: gatecat <gatecat@ds0.me>
This commit is contained in:
gatecat 2021-03-03 13:01:54 +00:00
parent e681e0f14c
commit bbf5a7d461
2 changed files with 69 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

62
common/timing.cc
View File

@ -43,6 +43,7 @@ void TimingAnalyser::setup()
compute_slack();
compute_criticality();
print_fmax();
print_report();
}
void TimingAnalyser::init_ports()
@ -457,6 +458,67 @@ void TimingAnalyser::compute_criticality()
}
}
std::vector<CellPortKey> TimingAnalyser::get_failing_eps(domain_id_t domain_pair, int count)
{
std::vector<CellPortKey> failing_eps;
delay_t last_slack = std::numeric_limits<delay_t>::min();
auto &dp = domain_pairs.at(domain_pair);
auto &cap_d = domains.at(dp.key.capture);
while (int(failing_eps.size()) < count) {
CellPortKey next;
delay_t next_slack = std::numeric_limits<delay_t>::max();
for (auto ep : cap_d.endpoints) {
auto &pd = ports.at(ep.first);
if (!pd.domain_pairs.count(domain_pair))
continue;
delay_t ep_slack = pd.domain_pairs.at(domain_pair).setup_slack;
if (ep_slack < next_slack && ep_slack > last_slack) {
next = ep.first;
next_slack = ep_slack;
}
}
if (next == CellPortKey())
break;
failing_eps.push_back(next);
last_slack = next_slack;
}
return failing_eps;
}
void TimingAnalyser::print_critical_path(CellPortKey endpoint, domain_id_t domain_pair)
{
CellPortKey cursor = endpoint;
auto &dp = domain_pairs.at(domain_pair);
log(" endpoint %s.%s (slack %.02fns):\n", ctx->nameOf(cursor.cell), ctx->nameOf(cursor.port),
ctx->getDelayNS(ports.at(cursor).domain_pairs.at(domain_pair).setup_slack));
while (cursor != CellPortKey()) {
log(" %s.%s (net %s)\n", ctx->nameOf(cursor.cell), ctx->nameOf(cursor.port),
ctx->nameOf(get_net_or_empty(ctx->cells.at(cursor.cell).get(), cursor.port)));
if (!ports.at(cursor).arrival.count(dp.key.launch))
break;
cursor = ports.at(cursor).arrival.at(dp.key.launch).bwd_max;
}
}
namespace {
const char *edge_name(ClockEdge edge) { return (edge == FALLING_EDGE) ? "negedge" : "posedge"; }
} // namespace
void TimingAnalyser::print_report()
{
for (int i = 0; i < int(domain_pairs.size()); i++) {
auto &dp = domain_pairs.at(i);
auto &launch = domains.at(dp.key.launch);
auto &capture = domains.at(dp.key.capture);
log("Worst endpoints for %s %s -> %s %s\n", edge_name(launch.key.edge), ctx->nameOf(launch.key.clock),
edge_name(capture.key.edge), ctx->nameOf(capture.key.clock));
auto failing_eps = get_failing_eps(i, 5);
for (auto &ep : failing_eps)
print_critical_path(ep, i);
log_break();
}
}
domain_id_t TimingAnalyser::domain_id(IdString cell, IdString clock_port, ClockEdge edge)
{
return domain_id(ctx->cells.at(cell)->ports.at(clock_port).net, edge);

7
common/timing.h
View File

@ -45,6 +45,7 @@ struct CellPortKey
}
};
inline bool operator==(const CellPortKey &other) const { return (cell == other.cell) && (port == other.port); }
inline bool operator!=(const CellPortKey &other) const { return (cell != other.cell) || (port != other.port); }
inline bool operator<(const CellPortKey &other) const
{
return cell == other.cell ? port < other.port : cell < other.cell;
@ -145,6 +146,12 @@ struct TimingAnalyser
void compute_criticality();
void print_fmax();
void print_report();
// get the N most failing endpoints for a given domain pair
std::vector<CellPortKey> get_failing_eps(domain_id_t domain_pair, int count);
// print the critical path for an endpoint and domain pair
void print_critical_path(CellPortKey endpoint, domain_id_t domain_pair);
const DelayPair init_delay{std::numeric_limits<delay_t>::max(), std::numeric_limits<delay_t>::lowest()};