abc9: break SCC by setting (* keep *) on output wires

This commit is contained in:
Eddie Hung 2020-01-13 21:45:27 -08:00
parent a2c4d98da7
commit 2c65e1abac
4 changed files with 23 additions and 35 deletions

View File

@ -436,15 +436,22 @@ struct XAigerWriter
for (const auto &bit : output_bits) {
ordered_outputs[bit] = aig_o++;
int aig;
// For inout/keep bits only, the output bit
// should be driven by logic, not the PI,
// so temporarily swap that out
// Unlike bit2aig() which checks aig_map first, for
// inout/keep bits, since aig_map will point to
// the PI, first attempt to find the NOT/AND driver
// before resorting to an aig_map lookup (which
// could be another PO)
if (input_bits.count(bit)) {
auto it = aig_map.find(bit);
int input_aig = it->second;
aig_map.erase(it);
aig = bit2aig(bit);
aig_map.at(bit) = input_aig;
if (not_map.count(bit)) {
aig = bit2aig(not_map.at(bit)) ^ 1;
} else if (and_map.count(bit)) {
auto args = and_map.at(bit);
int a0 = bit2aig(args.first);
int a1 = bit2aig(args.second);
aig = mkgate(a0, a1);
}
else
aig = aig_map.at(bit);
}
else
aig = bit2aig(bit);

View File

@ -831,6 +831,7 @@ void AigerReader::post_process()
}
else {
wire->port_output = false;
existing->port_output = true;
module->connect(wire, existing);
wire = existing;
}
@ -845,8 +846,9 @@ void AigerReader::post_process()
wideports_cache[escaped_s] = std::max(wideports_cache[escaped_s], index);
}
else {
module->connect(wire, existing);
wire->port_output = false;
existing->port_output = true;
module->connect(wire, existing);
}
log_debug(" -> %s\n", log_id(indexed_name));
}

View File

@ -298,7 +298,7 @@ struct Abc9Pass : public ScriptPass
num_outputs);
if (num_outputs) {
run(stringf("%s -cwd %s", exe_cmd.str().c_str(), tempdir_name.c_str()));
run(stringf("read_aiger -xaiger -wideports -module_name %s$abc9 -map %s/input.sym %s/output.aig", log_id(mod->name), tempdir_name.c_str(), tempdir_name.c_str()));
run(stringf("read_aiger -xaiger -wideports -module_name %s$abc9 -map %s/input.sym %s/output.aig", log_id(mod), tempdir_name.c_str(), tempdir_name.c_str()));
run("abc9_ops -reintegrate");
}
else

View File

@ -53,30 +53,7 @@ void break_scc(RTLIL::Module *module)
if (cell->output(c.first)) {
SigBit b = c.second.as_bit();
Wire *w = b.wire;
if (w->port_input) {
// In this case, hopefully the loop break has been already created
// Get the non-prefixed wire
Wire *wo = module->wire(stringf("%s.abco", b.wire->name.c_str()));
log_assert(wo != nullptr);
log_assert(wo->port_output);
log_assert(b.offset < GetSize(wo));
c.second = RTLIL::SigBit(wo, b.offset);
}
else {
// Create a new output/input loop break
w->port_input = true;
w = module->wire(stringf("%s.abco", w->name.c_str()));
if (!w) {
w = module->addWire(stringf("%s.abco", b.wire->name.c_str()), GetSize(b.wire));
w->port_output = true;
}
else {
log_assert(w->port_input);
log_assert(b.offset < GetSize(w));
}
w->set_bool_attribute(ID(abc9_scc_break));
c.second = RTLIL::SigBit(w, b.offset);
}
w->set_bool_attribute(ID::keep);
}
}
}
@ -586,7 +563,9 @@ void reintegrate(RTLIL::Module *module)
}
if (cell->output(mapped_conn.first))
for (auto i : mapped_conn.second)
bit_drivers[i].insert(mapped_cell->name);
// Ignore inouts for topo ordering
if (i.wire && !(i.wire->port_input && i.wire->port_output))
bit_drivers[i].insert(mapped_cell->name);
}
}
else {