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Merge pull request #441 from YosysHQ/eddie/fix_topo

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Fix embarassing use of topographical when meaning topological
This commit is contained in:
Miodrag Milanović 2020-05-14 19:08:22 +02:00 committed by GitHub
commit f8cf206826
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1 changed files with 16 additions and 16 deletions
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32
common/timing.cc
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@ -123,9 +123,9 @@ struct Timing
{ {
const auto clk_period = ctx->getDelayFromNS(1.0e9 / ctx->setting<float>("target_freq")).maxDelay(); const auto clk_period = ctx->getDelayFromNS(1.0e9 / ctx->setting<float>("target_freq")).maxDelay();
// First, compute the topographical order of nets to walk through the circuit, assuming it is a _acyclic_ graph // First, compute the topological order of nets to walk through the circuit, assuming it is a _acyclic_ graph
// TODO(eddieh): Handle the case where it is cyclic, e.g. combinatorial loops // TODO(eddieh): Handle the case where it is cyclic, e.g. combinatorial loops
std::vector<NetInfo *> topographical_order; std::vector<NetInfo *> topological_order;
std::unordered_map<const NetInfo *, std::unordered_map<ClockEvent, TimingData>> net_data; std::unordered_map<const NetInfo *, std::unordered_map<ClockEvent, TimingData>> net_data;
// In lieu of deleting edges from the graph, simply count the number of fanins to each output port // In lieu of deleting edges from the graph, simply count the number of fanins to each output port
std::unordered_map<const PortInfo *, unsigned> port_fanin; std::unordered_map<const PortInfo *, unsigned> port_fanin;
@ -150,7 +150,7 @@ struct Timing
// If output port is influenced by a clock (e.g. FF output) then add it to the ordering as a timing // If output port is influenced by a clock (e.g. FF output) then add it to the ordering as a timing
// start-point // start-point
if (portClass == TMG_REGISTER_OUTPUT) { if (portClass == TMG_REGISTER_OUTPUT) {
topographical_order.emplace_back(o->net); topological_order.emplace_back(o->net);
for (int i = 0; i < clocks; i++) { for (int i = 0; i < clocks; i++) {
TimingClockingInfo clkInfo = ctx->getPortClockingInfo(cell.second.get(), o->name, i); TimingClockingInfo clkInfo = ctx->getPortClockingInfo(cell.second.get(), o->name, i);
const NetInfo *clknet = get_net_or_empty(cell.second.get(), clkInfo.clock_port); const NetInfo *clknet = get_net_or_empty(cell.second.get(), clkInfo.clock_port);
@ -161,7 +161,7 @@ struct Timing
} else { } else {
if (portClass == TMG_STARTPOINT || portClass == TMG_GEN_CLOCK || portClass == TMG_IGNORE) { if (portClass == TMG_STARTPOINT || portClass == TMG_GEN_CLOCK || portClass == TMG_IGNORE) {
topographical_order.emplace_back(o->net); topological_order.emplace_back(o->net);
TimingData td; TimingData td;
td.false_startpoint = (portClass == TMG_GEN_CLOCK || portClass == TMG_IGNORE); td.false_startpoint = (portClass == TMG_GEN_CLOCK || portClass == TMG_IGNORE);
td.max_arrival = 0; td.max_arrival = 0;
@ -185,7 +185,7 @@ struct Timing
} }
// If there is no fanin, add the port as a false startpoint // If there is no fanin, add the port as a false startpoint
if (!port_fanin.count(o) && !net_data.count(o->net)) { if (!port_fanin.count(o) && !net_data.count(o->net)) {
topographical_order.emplace_back(o->net); topological_order.emplace_back(o->net);
TimingData td; TimingData td;
td.false_startpoint = true; td.false_startpoint = true;
td.max_arrival = 0; td.max_arrival = 0;
@ -200,12 +200,12 @@ struct Timing
for (auto &p : ctx->ports) { for (auto &p : ctx->ports) {
if (p.second.type != PORT_IN || p.second.net == nullptr) if (p.second.type != PORT_IN || p.second.net == nullptr)
continue; continue;
topographical_order.emplace_back(p.second.net); topological_order.emplace_back(p.second.net);
} }
} }
std::deque<NetInfo *> queue(topographical_order.begin(), topographical_order.end()); std::deque<NetInfo *> queue(topological_order.begin(), topological_order.end());
// Now walk the design, from the start points identified previously, building up a topographical order // Now walk the design, from the start points identified previously, building up a topological order
while (!queue.empty()) { while (!queue.empty()) {
const auto net = queue.front(); const auto net = queue.front();
queue.pop_front(); queue.pop_front();
@ -229,12 +229,12 @@ struct Timing
bool is_path = ctx->getCellDelay(usr.cell, usr.port, port.first, comb_delay); bool is_path = ctx->getCellDelay(usr.cell, usr.port, port.first, comb_delay);
if (!is_path) if (!is_path)
continue; continue;
// Decrement the fanin count, and only add to topographical order if all its fanins have already // Decrement the fanin count, and only add to topological order if all its fanins have already
// been visited // been visited
auto it = port_fanin.find(&port.second); auto it = port_fanin.find(&port.second);
NPNR_ASSERT(it != port_fanin.end()); NPNR_ASSERT(it != port_fanin.end());
if (--it->second == 0) { if (--it->second == 0) {
topographical_order.emplace_back(port.second.net); topological_order.emplace_back(port.second.net);
queue.emplace_back(port.second.net); queue.emplace_back(port.second.net);
port_fanin.erase(it); port_fanin.erase(it);
} }
@ -266,8 +266,8 @@ struct Timing
"timing ports, etc.\n"); "timing ports, etc.\n");
} }
// Go forwards topographically to find the maximum arrival time and max path length for each net // Go forwards topologically to find the maximum arrival time and max path length for each net
for (auto net : topographical_order) { for (auto net : topological_order) {
if (!net_data.count(net)) if (!net_data.count(net))
continue; continue;
auto &nd_map = net_data.at(net); auto &nd_map = net_data.at(net);
@ -314,9 +314,9 @@ struct Timing
std::unordered_map<ClockPair, std::pair<delay_t, NetInfo *>> crit_nets; std::unordered_map<ClockPair, std::pair<delay_t, NetInfo *>> crit_nets;
// Now go backwards topographically to determine the minimum path slack, and to distribute all path slack evenly // Now go backwards topologically to determine the minimum path slack, and to distribute all path slack evenly
// between all nets on the path // between all nets on the path
for (auto net : boost::adaptors::reverse(topographical_order)) { for (auto net : boost::adaptors::reverse(topological_order)) {
if (!net_data.count(net)) if (!net_data.count(net))
continue; continue;
auto &nd_map = net_data.at(net); auto &nd_map = net_data.at(net);
@ -482,8 +482,8 @@ struct Timing
if (net_crit) { if (net_crit) {
NPNR_ASSERT(crit_path); NPNR_ASSERT(crit_path);
// Go through in reverse topographical order to set required times // Go through in reverse topological order to set required times
for (auto net : boost::adaptors::reverse(topographical_order)) { for (auto net : boost::adaptors::reverse(topological_order)) {
if (!net_data.count(net)) if (!net_data.count(net))
continue; continue;
auto &nd_map = net_data.at(net); auto &nd_map = net_data.at(net);