From 53695e6729e8ae603be7e7cd9bc8b29758d61a11 Mon Sep 17 00:00:00 2001
From: Bogdan Vukobratovic <bogdan.vukobratovic@gmail.com>
Date: Fri, 14 Jun 2019 11:39:24 +0200
Subject: [PATCH] Prepare for situation when port of the signal cannot be found
---
kernel/algo.h | 8 +++++++-
passes/opt/opt_rmdff.cc | 2 +-
2 files changed, 8 insertions(+), 2 deletions(-)
diff --git a/kernel/algo.h b/kernel/algo.h
index 9626c780e..f029ad6ab 100644
--- a/kernel/algo.h
+++ b/kernel/algo.h
@@ -58,10 +58,14 @@ struct Netlist {
return sigbit_driver_map.at(sig);
}
- RTLIL::SigBit& driver_port(RTLIL::SigBit sig)
+ RTLIL::SigSpec driver_port(RTLIL::SigBit sig)
{
RTLIL::Cell *cell = driver_cell(sig);
+ if (!cell) {
+ return RTLIL::SigSpec();
+ }
+
for (auto &port : cell->connections_) {
if (ct.cell_output(cell->type, port.first)) {
RTLIL::SigSpec port_sig = sigmap(port.second);
@@ -72,6 +76,8 @@ struct Netlist {
}
}
}
+
+ return RTLIL::SigSpec();
}
void setup_netlist(RTLIL::Module *module, const CellTypes &ct)
diff --git a/passes/opt/opt_rmdff.cc b/passes/opt/opt_rmdff.cc
index 41bbdcd57..cf89ac096 100644
--- a/passes/opt/opt_rmdff.cc
+++ b/passes/opt/opt_rmdff.cc
@@ -503,7 +503,7 @@ bool handle_dff(RTLIL::Module *mod, RTLIL::Cell *dff)
// If the register bit cannot change, we can replace it with a constant
if (!counter_example_found) {
- RTLIL::SigBit &driver_port = net.driver_port(q_sigbit);
+ RTLIL::SigSpec driver_port = net.driver_port(q_sigbit);
RTLIL::Wire *dummy_wire = mod->addWire(NEW_ID, 1);
for (auto &conn : mod->connections_)