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Improve opt_expr and opt_clean handling of (partially) undriven and/or unused wires, fixes #981

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Signed-off-by: Clifford Wolf <clifford@clifford.at>
This commit is contained in:
Clifford Wolf 2019-05-03 14:24:53 +02:00
parent 98925f6c4b
commit 42190207b4
2 changed files with 83 additions and 46 deletions
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116
passes/opt/opt_clean.cc
View file

@ -274,50 +274,53 @@ void rmunused_module_signals(RTLIL::Module *module, bool purge_mode, bool verbos
std::vector<RTLIL::Wire*> maybe_del_wires; std::vector<RTLIL::Wire*> maybe_del_wires;
for (auto wire : module->wires()) for (auto wire : module->wires())
{ {
SigSpec s1 = SigSpec(wire), s2 = assign_map(s1);
log_assert(GetSize(s1) == GetSize(s2));
bool maybe_del = false;
if ((!purge_mode && check_public_name(wire->name)) || wire->port_id != 0 || wire->get_bool_attribute("\\keep") || wire->attributes.count("\\init")) { if ((!purge_mode && check_public_name(wire->name)) || wire->port_id != 0 || wire->get_bool_attribute("\\keep") || wire->attributes.count("\\init")) {
RTLIL::SigSpec s1 = RTLIL::SigSpec(wire), s2 = s1; if (!used_signals.check_any(s2) && wire->port_id == 0 && !wire->get_bool_attribute("\\keep"))
assign_map.apply(s2); maybe_del = true;
if (!used_signals.check_any(s2) && wire->port_id == 0 && !wire->get_bool_attribute("\\keep")) {
maybe_del_wires.push_back(wire);
} else {
log_assert(GetSize(s1) == GetSize(s2));
Const initval;
if (wire->attributes.count("\\init"))
initval = wire->attributes.at("\\init");
if (GetSize(initval) != GetSize(wire))
initval.bits.resize(GetSize(wire), State::Sx);
RTLIL::SigSig new_conn;
for (int i = 0; i < GetSize(s1); i++)
if (s1[i] != s2[i]) {
if (s2[i] == State::Sx && (initval[i] == State::S0 || initval[i] == State::S1)) {
s2[i] = initval[i];
initval[i] = State::Sx;
}
new_conn.first.append_bit(s1[i]);
new_conn.second.append_bit(s2[i]);
}
if (new_conn.first.size() > 0) {
if (initval.is_fully_undef())
wire->attributes.erase("\\init");
else
wire->attributes.at("\\init") = initval;
used_signals.add(new_conn.first);
used_signals.add(new_conn.second);
module->connect(new_conn);
}
}
} else { } else {
if (!used_signals.check_any(RTLIL::SigSpec(wire))) if (!used_signals.check_any(s2))
maybe_del_wires.push_back(wire); maybe_del = true;
} }
RTLIL::SigSpec sig = assign_map(RTLIL::SigSpec(wire)); if (maybe_del) {
if (!used_signals_nodrivers.check_any(sig)) { maybe_del_wires.push_back(wire);
} else {
Const initval;
if (wire->attributes.count("\\init"))
initval = wire->attributes.at("\\init");
if (GetSize(initval) != GetSize(wire))
initval.bits.resize(GetSize(wire), State::Sx);
RTLIL::SigSig new_conn;
for (int i = 0; i < GetSize(s1); i++)
if (s1[i] != s2[i]) {
if (s2[i] == State::Sx && (initval[i] == State::S0 || initval[i] == State::S1)) {
s2[i] = initval[i];
initval[i] = State::Sx;
}
new_conn.first.append_bit(s1[i]);
new_conn.second.append_bit(s2[i]);
}
if (new_conn.first.size() > 0) {
if (initval.is_fully_undef())
wire->attributes.erase("\\init");
else
wire->attributes.at("\\init") = initval;
used_signals.add(new_conn.first);
used_signals.add(new_conn.second);
module->connect(new_conn);
}
}
if (!used_signals_nodrivers.check_all(s2)) {
std::string unused_bits; std::string unused_bits;
for (int i = 0; i < GetSize(sig); i++) { for (int i = 0; i < GetSize(s2); i++) {
if (sig[i].wire == NULL) if (s2[i].wire == NULL)
continue; continue;
if (!used_signals_nodrivers.check(sig[i])) { if (!used_signals_nodrivers.check(s2[i])) {
if (!unused_bits.empty()) if (!unused_bits.empty())
unused_bits += " "; unused_bits += " ";
unused_bits += stringf("%d", i); unused_bits += stringf("%d", i);
@ -336,14 +339,40 @@ void rmunused_module_signals(RTLIL::Module *module, bool purge_mode, bool verbos
pool<RTLIL::Wire*> del_wires; pool<RTLIL::Wire*> del_wires;
int del_wires_count = 0; int del_wires_count = 0;
for (auto wire : maybe_del_wires) for (auto wire : maybe_del_wires) {
if (!used_signals.check_any(RTLIL::SigSpec(wire))) { SigSpec s1 = SigSpec(wire);
if (check_public_name(wire->name) && verbose) { if (used_signals.check_any(s1)) {
SigSpec s2 = assign_map(s1);
Const initval;
if (wire->attributes.count("\\init"))
initval = wire->attributes.at("\\init");
if (GetSize(initval) != GetSize(wire))
initval.bits.resize(GetSize(wire), State::Sx);
RTLIL::SigSig new_conn;
for (int i = 0; i < GetSize(s1); i++)
if (s1[i] != s2[i]) {
if (s2[i] == State::Sx && (initval[i] == State::S0 || initval[i] == State::S1)) {
s2[i] = initval[i];
initval[i] = State::Sx;
}
new_conn.first.append_bit(s1[i]);
new_conn.second.append_bit(s2[i]);
}
if (new_conn.first.size() > 0) {
if (initval.is_fully_undef())
wire->attributes.erase("\\init");
else
wire->attributes.at("\\init") = initval;
module->connect(new_conn);
}
} else {
if (ys_debug() || (check_public_name(wire->name) && verbose)) {
log_debug(" removing unused non-port wire %s.\n", wire->name.c_str()); log_debug(" removing unused non-port wire %s.\n", wire->name.c_str());
} }
del_wires.insert(wire); del_wires.insert(wire);
del_wires_count++; del_wires_count++;
} }
}
module->remove(del_wires); module->remove(del_wires);
count_rm_wires += del_wires.size(); count_rm_wires += del_wires.size();
@ -496,6 +525,9 @@ struct OptCleanPass : public Pass {
ct_all.setup(design); ct_all.setup(design);
count_rm_cells = 0;
count_rm_wires = 0;
for (auto module : design->selected_whole_modules_warn()) { for (auto module : design->selected_whole_modules_warn()) {
if (module->has_processes_warn()) if (module->has_processes_warn())
continue; continue;
@ -561,7 +593,7 @@ struct CleanPass : public Pass {
for (auto module : design->selected_whole_modules()) { for (auto module : design->selected_whole_modules()) {
if (module->has_processes()) if (module->has_processes())
continue; continue;
rmunused_module(module, purge_mode, false, false); rmunused_module(module, purge_mode, ys_debug(), false);
} }
log_suppressed(); log_suppressed();

13
passes/opt/opt_expr.cc
View file

@ -61,7 +61,7 @@ void replace_undriven(RTLIL::Design *design, RTLIL::Module *module)
} }
if (wire->port_input) if (wire->port_input)
driven_signals.add(sigmap(wire)); driven_signals.add(sigmap(wire));
if (wire->port_output) if (wire->port_output || wire->get_bool_attribute("\\keep"))
used_signals.add(sigmap(wire)); used_signals.add(sigmap(wire));
all_signals.add(sigmap(wire)); all_signals.add(sigmap(wire));
} }
@ -88,7 +88,7 @@ void replace_undriven(RTLIL::Design *design, RTLIL::Module *module)
} }
} }
log_debug("Setting undriven signal in %s to constant: %s = %s\n", RTLIL::id2cstr(module->name), log_signal(sig), log_signal(val)); log_debug("Setting undriven signal in %s to constant: %s = %s\n", log_id(module), log_signal(sig), log_signal(val));
module->connect(sig, val); module->connect(sig, val);
did_something = true; did_something = true;
} }
@ -104,10 +104,15 @@ void replace_undriven(RTLIL::Design *design, RTLIL::Module *module)
if (SigBit(initval[i]) == sig[i]) if (SigBit(initval[i]) == sig[i])
initval[i] = State::Sx; initval[i] = State::Sx;
} }
if (initval.is_fully_undef()) if (initval.is_fully_undef()) {
log_debug("Removing init attribute from %s/%s.\n", log_id(module), log_id(wire));
wire->attributes.erase("\\init"); wire->attributes.erase("\\init");
else did_something = true;
} else if (initval != wire->attributes.at("\\init")) {
log_debug("Updating init attribute on %s/%s: %s\n", log_id(module), log_id(wire), log_signal(initval));
wire->attributes["\\init"] = initval; wire->attributes["\\init"] = initval;
did_something = true;
}
} }
} }
} }