From 42190207b4a5ae37240e58652d173c7164f025f7 Mon Sep 17 00:00:00 2001 From: Clifford Wolf Date: Fri, 3 May 2019 14:24:53 +0200 Subject: [PATCH] Improve opt_expr and opt_clean handling of (partially) undriven and/or unused wires, fixes #981 Signed-off-by: Clifford Wolf --- passes/opt/opt_clean.cc | 116 +++++++++++++++++++++++++--------------- passes/opt/opt_expr.cc | 13 +++-- 2 files changed, 83 insertions(+), 46 deletions(-) diff --git a/passes/opt/opt_clean.cc b/passes/opt/opt_clean.cc index 5d95c4f1a..96118e906 100644 --- a/passes/opt/opt_clean.cc +++ b/passes/opt/opt_clean.cc @@ -274,50 +274,53 @@ void rmunused_module_signals(RTLIL::Module *module, bool purge_mode, bool verbos std::vector maybe_del_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")) { - RTLIL::SigSpec s1 = RTLIL::SigSpec(wire), s2 = s1; - assign_map.apply(s2); - 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); - } - } + if (!used_signals.check_any(s2) && wire->port_id == 0 && !wire->get_bool_attribute("\\keep")) + maybe_del = true; } else { - if (!used_signals.check_any(RTLIL::SigSpec(wire))) - maybe_del_wires.push_back(wire); + if (!used_signals.check_any(s2)) + maybe_del = true; } - RTLIL::SigSpec sig = assign_map(RTLIL::SigSpec(wire)); - if (!used_signals_nodrivers.check_any(sig)) { + if (maybe_del) { + 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; - for (int i = 0; i < GetSize(sig); i++) { - if (sig[i].wire == NULL) + for (int i = 0; i < GetSize(s2); i++) { + if (s2[i].wire == NULL) continue; - if (!used_signals_nodrivers.check(sig[i])) { + if (!used_signals_nodrivers.check(s2[i])) { if (!unused_bits.empty()) unused_bits += " "; unused_bits += stringf("%d", i); @@ -336,14 +339,40 @@ void rmunused_module_signals(RTLIL::Module *module, bool purge_mode, bool verbos pool del_wires; int del_wires_count = 0; - for (auto wire : maybe_del_wires) - if (!used_signals.check_any(RTLIL::SigSpec(wire))) { - if (check_public_name(wire->name) && verbose) { + for (auto wire : maybe_del_wires) { + SigSpec s1 = SigSpec(wire); + 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()); } del_wires.insert(wire); del_wires_count++; } + } module->remove(del_wires); count_rm_wires += del_wires.size(); @@ -496,6 +525,9 @@ struct OptCleanPass : public Pass { ct_all.setup(design); + count_rm_cells = 0; + count_rm_wires = 0; + for (auto module : design->selected_whole_modules_warn()) { if (module->has_processes_warn()) continue; @@ -561,7 +593,7 @@ struct CleanPass : public Pass { for (auto module : design->selected_whole_modules()) { if (module->has_processes()) continue; - rmunused_module(module, purge_mode, false, false); + rmunused_module(module, purge_mode, ys_debug(), false); } log_suppressed(); diff --git a/passes/opt/opt_expr.cc b/passes/opt/opt_expr.cc index b445afdc8..512ef0cbf 100644 --- a/passes/opt/opt_expr.cc +++ b/passes/opt/opt_expr.cc @@ -61,7 +61,7 @@ void replace_undriven(RTLIL::Design *design, RTLIL::Module *module) } if (wire->port_input) driven_signals.add(sigmap(wire)); - if (wire->port_output) + if (wire->port_output || wire->get_bool_attribute("\\keep")) used_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); did_something = true; } @@ -104,10 +104,15 @@ void replace_undriven(RTLIL::Design *design, RTLIL::Module *module) if (SigBit(initval[i]) == sig[i]) 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"); - 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; + did_something = true; + } } } }