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Try way that doesn't involve creating a new wire

This commit is contained in:
Eddie Hung 2019-06-11 15:48:20 -07:00
parent e1fff34dde
commit 5ff75b1cdc
1 changed files with 15 additions and 10 deletions
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25
passes/techmap/shregmap.cc
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@ -141,12 +141,8 @@ struct ShregmapWorker
if (opts.init || sigbit_init.count(q_bit) == 0) if (opts.init || sigbit_init.count(q_bit) == 0)
{ {
auto r = sigbit_chain_next.insert(std::make_pair(d_bit, cell)); auto r = sigbit_chain_next.insert(std::make_pair(d_bit, cell));
if (!r.second) { if (!r.second)
sigbit_with_non_chain_users.insert(d_bit); sigbit_with_non_chain_users.insert(d_bit);
Wire *wire = module->addWire(NEW_ID);
module->connect(wire, d_bit);
sigbit_chain_next.insert(std::make_pair(wire, cell));
}
sigbit_chain_prev[q_bit] = cell; sigbit_chain_prev[q_bit] = cell;
continue; continue;
@ -164,14 +160,14 @@ struct ShregmapWorker
{ {
for (auto it : sigbit_chain_next) for (auto it : sigbit_chain_next)
{ {
Cell *c1, *c2 = it.second;
if (opts.tech == nullptr && sigbit_with_non_chain_users.count(it.first)) if (opts.tech == nullptr && sigbit_with_non_chain_users.count(it.first))
goto start_cell; goto start_cell;
if (sigbit_chain_prev.count(it.first) != 0) c1 = sigbit_chain_prev.at(it.first, nullptr);
if (c1 != nullptr)
{ {
Cell *c1 = sigbit_chain_prev.at(it.first);
Cell *c2 = it.second;
if (c1->type != c2->type) if (c1->type != c2->type)
goto start_cell; goto start_cell;
@ -181,6 +177,15 @@ struct ShregmapWorker
IdString d_port = opts.ffcells.at(c1->type).first; IdString d_port = opts.ffcells.at(c1->type).first;
IdString q_port = opts.ffcells.at(c1->type).second; IdString q_port = opts.ffcells.at(c1->type).second;
// If the previous cell's D has other non chain users,
// then it is possible that this previous cell could
// be a start of the chain
SigBit d_bit = sigmap(c1->getPort(d_port).as_bit());
if (sigbit_with_non_chain_users.count(d_bit)) {
c2 = c1;
goto start_cell;
}
auto c1_conn = c1->connections(); auto c1_conn = c1->connections();
auto c2_conn = c1->connections(); auto c2_conn = c1->connections();
@ -197,7 +202,7 @@ struct ShregmapWorker
} }
start_cell: start_cell:
chain_start_cells.insert(it.second); chain_start_cells.insert(c2);
} }
} }