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Add merging of "past FFs" to verific importer

This commit is contained in:
Clifford Wolf 2017-07-29 00:07:02 +02:00
parent e7d1277a2c
commit 15073790bf
1 changed files with 76 additions and 2 deletions
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78
frontends/verific/verific.cc
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@ -636,6 +636,73 @@ struct VerificImporter
return false;
}
void merge_past_ffs_clock(pool<RTLIL::Cell*> &candidates, SigBit clock, bool clock_pol)
{
bool keep_running = true;
SigMap sigmap;
while (keep_running)
{
keep_running = false;
dict<SigBit, pool<RTLIL::Cell*>> dbits_db;
SigSpec dbits;
for (auto cell : candidates) {
SigBit bit = sigmap(cell->getPort("\\D"));
dbits_db[bit].insert(cell);
dbits.append(bit);
}
dbits.sort_and_unify();
for (auto chunk : dbits.chunks())
{
SigSpec sig_d = chunk;
if (chunk.wire == nullptr || GetSize(sig_d) == 1)
continue;
SigSpec sig_q = module->addWire(NEW_ID, GetSize(sig_d));
RTLIL::Cell *new_ff = module->addDff(NEW_ID, clock, sig_d, sig_q, clock_pol);
if (verbose)
log(" merging single-bit past_ffs into new %d-bit ff %s.\n", GetSize(sig_d), log_id(new_ff));
for (int i = 0; i < GetSize(sig_d); i++)
for (auto old_ff : dbits_db[sig_d[i]])
{
if (verbose)
log(" replacing old ff %s on bit %d.\n", log_id(old_ff), i);
SigBit old_q = old_ff->getPort("\\Q");
SigBit new_q = sig_q[i];
sigmap.add(old_q, new_q);
module->connect(old_q, new_q);
candidates.erase(old_ff);
module->remove(old_ff);
keep_running = true;
}
}
}
}
void merge_past_ffs(pool<RTLIL::Cell*> &candidates)
{
dict<pair<SigBit, int>, pool<RTLIL::Cell*>> database;
for (auto cell : candidates)
{
SigBit clock = cell->getPort("\\CLK");
bool clock_pol = cell->getParam("\\CLK_POLARITY").as_bool();
database[make_pair(clock, int(clock_pol))].insert(cell);
}
for (auto it : database)
merge_past_ffs_clock(it.second, it.first.first, it.first.second);
}
void import_netlist(RTLIL::Design *design, Netlist *nl, std::set<Netlist*> &nl_todo)
{
std::string module_name = nl->IsOperator() ? std::string("$verific$") + nl->Owner()->Name() : RTLIL::escape_id(nl->Owner()->Name());
@ -947,6 +1014,8 @@ struct VerificImporter
pool<Instance*, hash_ptr_ops> sva_assumes;
pool<Instance*, hash_ptr_ops> sva_covers;
pool<RTLIL::Cell*> past_ffs;
FOREACH_INSTANCE_OF_NETLIST(nl, mi, inst)
{
RTLIL::IdString inst_name = module->uniquify(mode_names || inst->IsUserDeclared() ? RTLIL::escape_id(inst->Name()) : NEW_ID);
@ -1078,7 +1147,7 @@ struct VerificImporter
log(" %sedge FF with D=%s, Q=%s, C=%s.\n", clock_edge.posedge ? "pos" : "neg",
log_signal(sig_d), log_signal(sig_q), log_signal(clock_edge.clock_sig));
module->addDff(NEW_ID, clock_edge.clock_sig, sig_d, sig_q, clock_edge.posedge);
past_ffs.insert(module->addDff(NEW_ID, clock_edge.clock_sig, sig_d, sig_q, clock_edge.posedge));
if (!mode_keep)
continue;
@ -1103,7 +1172,10 @@ struct VerificImporter
log(" %sedge FF with D=%s, Q=%s, C=%s.\n", clock_edge.posedge ? "pos" : "neg",
log_signal(sig_d), log_signal(sig_q), log_signal(clock_edge.clock_sig));
module->addDff(NEW_ID, clock_edge.clock_sig, sig_d, sig_q, clock_edge.posedge);
RTLIL::Cell *ff = module->addDff(NEW_ID, clock_edge.clock_sig, sig_d, sig_q, clock_edge.posedge);
if (inst->InputSize() == 1)
past_ffs.insert(ff);
if (!mode_keep)
continue;
@ -1178,6 +1250,8 @@ struct VerificImporter
for (auto inst : sva_covers)
import_sva_cover(this, inst);
merge_past_ffs(past_ffs);
}
}
};