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author | Bogdan Vukobratovic <bogdan.vukobratovic@gmail.com> | 2019-08-04 19:06:38 +0200 |
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committer | Bogdan Vukobratovic <bogdan.vukobratovic@gmail.com> | 2019-08-04 19:06:38 +0200 |
commit | 6a796accc09bc2c8ef98c068185de13d3e01890a (patch) | |
tree | 856a9939e89e757d8cc8dbf45514996c87f78287 /passes/opt/opt_share.cc | |
parent | d8be5ce6ba11ec78d0f7925d488fad09a3eaba2c (diff) | |
download | yosys-6a796accc09bc2c8ef98c068185de13d3e01890a.tar.gz yosys-6a796accc09bc2c8ef98c068185de13d3e01890a.tar.bz2 yosys-6a796accc09bc2c8ef98c068185de13d3e01890a.zip |
Support various binary operators in opt_share
Diffstat (limited to 'passes/opt/opt_share.cc')
-rw-r--r-- | passes/opt/opt_share.cc | 586 |
1 files changed, 392 insertions, 194 deletions
diff --git a/passes/opt/opt_share.cc b/passes/opt/opt_share.cc index 25b07cbbd..e8f44749a 100644 --- a/passes/opt/opt_share.cc +++ b/passes/opt/opt_share.cc @@ -32,37 +32,36 @@ PRIVATE_NAMESPACE_BEGIN SigMap assign_map; -struct InPort { +struct OpMuxConn { RTLIL::SigSpec sig; - RTLIL::Cell *pmux; - int port_id; - RTLIL::Cell *alu; + RTLIL::Cell *mux; + RTLIL::Cell *op; + int mux_port_id; + int mux_port_offset; + int op_outsig_offset; + + bool operator<(const OpMuxConn &other) const + { + if (mux != other.mux) + return mux < other.mux; + + if (mux_port_id != other.mux_port_id) + return mux_port_id < other.mux_port_id; - InPort(RTLIL::SigSpec s, RTLIL::Cell *c, int p, RTLIL::Cell *a = NULL) : sig(s), pmux(c), port_id(p), alu(a) {} + return mux_port_offset < other.mux_port_offset; + } }; -// Helper class that to track whether a SigSpec is signed and whether it is -// connected to the \\B port of the $sub cell, which makes its sign prefix -// negative. +// Helper class to track additiona information about a SigSpec, like whether it is signed and the semantics of the port it is connected to struct ExtSigSpec { RTLIL::SigSpec sig; RTLIL::SigSpec sign; bool is_signed; + RTLIL::IdString semantics; ExtSigSpec() {} - ExtSigSpec(RTLIL::SigSpec s, bool sign = false, bool is_signed = false) : sig(s), sign(sign), is_signed(is_signed) {} - - ExtSigSpec(RTLIL::Cell *cell, RTLIL::IdString port_name, SigMap *sigmap) - { - sign = (port_name == "\\B") ? cell->getPort("\\BI") : RTLIL::Const(0, 1); - sig = (*sigmap)(cell->getPort(port_name)); - - is_signed = false; - if (cell->hasParam(port_name.str() + "_SIGNED")) { - is_signed = cell->getParam(port_name.str() + "_SIGNED").as_bool(); - } - } + ExtSigSpec(RTLIL::SigSpec s, RTLIL::SigSpec sign = RTLIL::Const(0, 1), bool is_signed = false, RTLIL::IdString semantics = RTLIL::IdString()) : sig(s), sign(sign), is_signed(is_signed), semantics(semantics) {} bool empty() const { return sig.empty(); } @@ -74,42 +73,136 @@ struct ExtSigSpec { if (sign != other.sign) return sign < other.sign; - return is_signed < other.is_signed; + if (is_signed != other.is_signed) + return is_signed < other.is_signed; + + return semantics < other.semantics; } bool operator==(const RTLIL::SigSpec &other) const { return (sign != RTLIL::Const(0, 1)) ? false : sig == other; } - bool operator==(const ExtSigSpec &other) const { return is_signed == other.is_signed && sign == other.sign && sig == other.sig; } + bool operator==(const ExtSigSpec &other) const { return is_signed == other.is_signed && sign == other.sign && sig == other.sig && semantics == other.semantics; } }; -void merge_operators(RTLIL::Module *module, RTLIL::Cell *mux, const std::vector<InPort> &ports, int offset, int width, - const ExtSigSpec &operand) +#define BITWISE_OPS "$_AND_", "$_NAND_", "$_OR_", "$_NOR_", "$_XOR_", "$_XNOR_", "$_ANDNOT_", "$_ORNOT_", "$and", "$or", "$xor", "$xnor" + +#define REDUCTION_OPS "$reduce_and", "$reduce_or", "$reduce_xor", "$reduce_xnor", "$reduce_bool", "$reduce_nand" + +#define LOGICAL_OPS "$logic_and", "$logic_or" + +#define SHIFT_OPS "$shl", "$shr", "$sshl", "$sshr", "$shift", "$shiftx" + +#define RELATIONAL_OPS "$lt", "$le", "$eq", "$ne", "$eqx", "$nex", "$ge", "$gt" + +bool cell_supported(RTLIL::Cell *cell) +{ + + if (cell->type.in("$alu")) { + RTLIL::SigSpec sig_bi = cell->getPort("\\BI"); + RTLIL::SigSpec sig_ci = cell->getPort("\\CI"); + + if (sig_bi.is_fully_const() && sig_ci.is_fully_const() && sig_bi == sig_ci) + return true; + } else if (cell->type.in(LOGICAL_OPS, SHIFT_OPS, BITWISE_OPS, RELATIONAL_OPS, "$add", "$sub", "$mul", "$div", "$mod", "$concat")) { + return true; + } + + return false; +} + +std::map<std::string, std::string> mergeable_type_map{ + {"$sub", "$add"}, +}; + +bool mergeable(RTLIL::Cell *a, RTLIL::Cell *b) +{ + auto a_type = a->type; + if (mergeable_type_map.count(a_type.str())) + a_type = mergeable_type_map.at(a_type.str()); + + auto b_type = b->type; + if (mergeable_type_map.count(b_type.str())) + b_type = mergeable_type_map.at(b_type.str()); + + return a_type == b_type; +} + +RTLIL::IdString decode_port_semantics(RTLIL::Cell *cell, RTLIL::IdString port_name) +{ + if (cell->type.in("$lt", "$le", "$ge", "$gt", "$div", "$mod", "$concat", SHIFT_OPS) && port_name == "\\B") + return port_name; + + return ""; +} + +RTLIL::SigSpec decode_port_sign(RTLIL::Cell *cell, RTLIL::IdString port_name) { + + if (cell->type == "$alu" && port_name == "\\B") + return cell->getPort("\\BI"); + else if (cell->type == "$sub" && port_name == "\\B") + return RTLIL::Const(1, 1); + + return RTLIL::Const(0, 1); +} + +bool decode_port_signed(RTLIL::Cell *cell, RTLIL::IdString port_name) +{ + if (cell->type.in(BITWISE_OPS, LOGICAL_OPS)) + return false; + + if (cell->hasParam(port_name.str() + "_SIGNED")) + return cell->getParam(port_name.str() + "_SIGNED").as_bool(); + + return false; + +} + +ExtSigSpec decode_port(RTLIL::Cell *cell, RTLIL::IdString port_name, SigMap *sigmap) +{ + auto sig = (*sigmap)(cell->getPort(port_name)); + + RTLIL::SigSpec sign = decode_port_sign(cell, port_name); + RTLIL::IdString semantics = decode_port_semantics(cell, port_name); + + bool is_signed = decode_port_signed(cell, port_name); + + return ExtSigSpec(sig, sign, is_signed, semantics); +} + +void merge_operators(RTLIL::Module *module, RTLIL::Cell *mux, const std::vector<OpMuxConn> &ports, const ExtSigSpec &operand) { std::vector<ExtSigSpec> muxed_operands; int max_width = 0; for (const auto& p : ports) { - auto op = p.alu; + auto op = p.op; - for (RTLIL::IdString port_name : {"\\A", "\\B"}) { - if (op->getPort(port_name) != operand.sig) { - auto operand = ExtSigSpec(op, port_name, &assign_map); - if (operand.sig.size() > max_width) { - max_width = operand.sig.size(); - } + RTLIL::IdString muxed_port_name = "\\A"; + if (op->getPort("\\A") == operand.sig) { + muxed_port_name = "\\B"; + } - muxed_operands.push_back(operand); - } + auto operand = decode_port(op, muxed_port_name, &assign_map); + if (operand.sig.size() > max_width) { + max_width = operand.sig.size(); } + + muxed_operands.push_back(operand); } + auto shared_op = ports[0].op; + + if (std::any_of(muxed_operands.begin(), muxed_operands.end(), [&](ExtSigSpec &op) { return op.sign != muxed_operands[0].sign; })) + if (max_width < shared_op->getParam("\\Y_WIDTH").as_int()) + max_width = shared_op->getParam("\\Y_WIDTH").as_int(); + + for (auto &operand : muxed_operands) { operand.sig.extend_u0(max_width, operand.is_signed); } - auto shared_op = ports[0].alu; for (const auto& p : ports) { - auto op = p.alu; + auto op = p.op; if (op == shared_op) continue; module->remove(op); @@ -126,40 +219,47 @@ void merge_operators(RTLIL::Module *module, RTLIL::Cell *mux, const std::vector< RTLIL::SigSpec mux_b = mux->getPort("\\B"); RTLIL::SigSpec mux_s = mux->getPort("\\S"); - RTLIL::SigSpec alu_x = shared_op->getPort("\\X"); - RTLIL::SigSpec alu_co = shared_op->getPort("\\CO"); - RTLIL::SigSpec shared_pmux_a = RTLIL::Const(RTLIL::State::Sx, max_width); RTLIL::SigSpec shared_pmux_b; RTLIL::SigSpec shared_pmux_s; - shared_op->setPort("\\Y", shared_op->getPort("\\Y").extract(0, width)); + int conn_width = ports[0].sig.size(); + int conn_offset = ports[0].mux_port_offset; + + shared_op->setPort("\\Y", shared_op->getPort("\\Y").extract(0, conn_width)); if (mux->type == "$pmux") { shared_pmux_s = RTLIL::SigSpec(); - for (const auto&p: ports) { - shared_pmux_s.append(mux_s[p.port_id]); - mux_b.replace(p.port_id * mux_a.size() + offset, shared_op->getPort("\\Y")); + for (const auto &p : ports) { + shared_pmux_s.append(mux_s[p.mux_port_id]); + mux_b.replace(p.mux_port_id * mux_a.size() + conn_offset, shared_op->getPort("\\Y")); } } else { shared_pmux_s = RTLIL::SigSpec{mux_s, module->Not(NEW_ID, mux_s)}; - mux_a.replace(offset, shared_op->getPort("\\Y")); - mux_b.replace(offset, shared_op->getPort("\\Y")); + mux_a.replace(conn_offset, shared_op->getPort("\\Y")); + mux_b.replace(conn_offset, shared_op->getPort("\\Y")); } + mux->setPort("\\A", mux_a); + mux->setPort("\\B", mux_b); mux->setPort("\\Y", mux_y); mux->setPort("\\S", mux_s); - mux->setPort("\\B", mux_b); for (const auto &op : muxed_operands) shared_pmux_b.append(op.sig); auto mux_to_oper = module->Pmux(NEW_ID, shared_pmux_a, shared_pmux_b, shared_pmux_s); - shared_op->setPort("\\X", alu_x.extract(0, width)); - shared_op->setPort("\\CO", alu_co.extract(0, width)); - shared_op->setParam("\\Y_WIDTH", width); + if (shared_op->type.in("$alu")) { + RTLIL::SigSpec alu_x = shared_op->getPort("\\X"); + RTLIL::SigSpec alu_co = shared_op->getPort("\\CO"); + + shared_op->setPort("\\X", alu_x.extract(0, conn_width)); + shared_op->setPort("\\CO", alu_co.extract(0, conn_width)); + } + + shared_op->setParam("\\Y_WIDTH", conn_width); if (shared_op->getPort("\\A") == operand.sig) { shared_op->setPort("\\B", mux_to_oper); @@ -173,11 +273,9 @@ void merge_operators(RTLIL::Module *module, RTLIL::Cell *mux, const std::vector< typedef struct { RTLIL::Cell *mux; - std::vector<InPort> ports; - int offset; - int width; + std::vector<OpMuxConn> ports; ExtSigSpec shared_operand; -} shared_op_t; +} merged_op_t; template <typename T> void remove_val(std::vector<T> &v, const std::vector<T> &vals) @@ -190,86 +288,60 @@ template <typename T> void remove_val(std::vector<T> &v, const std::vector<T> &v } } -bool find_op_res_width(int offset, int &width, std::vector<InPort*>& ports, const dict<RTLIL::SigBit, RTLIL::SigSpec> &op_outbit_to_outsig) +void check_muxed_operands(std::vector<const OpMuxConn *> &ports, const ExtSigSpec &shared_operand) { - std::vector<RTLIL::SigSpec> op_outsigs; - dict<int, std::set<InPort*>> op_outsig_span; - - std::transform(ports.begin(), ports.end(), std::back_inserter(op_outsigs), [&](InPort *p) { return op_outbit_to_outsig.at(p->sig[offset]); }); - - std::vector<bool> finished(ports.size(), false); + auto it = ports.begin(); + ExtSigSpec seed; - width = 0; + while (it != ports.end()) { + auto p = *it; + auto op = p->op; - std::function<bool()> all_finished = [&] { return std::find(std::begin(finished), std::end(finished), false) == end(finished);}; - - while (!all_finished()) - { - ++offset; - ++width; - - if (offset >= ports[0]->sig.size()) { - for (size_t i = 0; i < op_outsigs.size(); ++i) { - if (finished[i]) - continue; - - op_outsig_span[width].insert(ports[i]); - finished[i] = true; - } - - break; + RTLIL::IdString muxed_port_name = "\\A"; + if (op->getPort("\\A") == shared_operand.sig) { + muxed_port_name = "\\B"; } - for (size_t i = 0; i < op_outsigs.size(); ++i) { - if (finished[i]) - continue; + auto operand = decode_port(op, muxed_port_name, &assign_map); - if ((width >= op_outsigs[i].size()) || (ports[i]->sig[offset] != op_outsigs[i][width])) { - op_outsig_span[width].insert(ports[i]); - finished[i] = true; - } - } - } - - for (auto w: op_outsig_span) { - if (w.second.size() > 1) { - width = w.first; + if (seed.empty()) + seed = operand; - ports.erase(std::remove_if(ports.begin(), ports.end(), [&](InPort *p) { return !w.second.count(p); }), ports.end()); - - return true; + if (operand.is_signed != seed.is_signed) { + ports.erase(it); + } else { + ++it; } } - - return false; } -ExtSigSpec find_shared_operand(InPort* seed, std::vector<InPort *> &ports, const std::map<ExtSigSpec, std::set<RTLIL::Cell *>> &operand_to_users) +ExtSigSpec find_shared_operand(const OpMuxConn* seed, std::vector<const OpMuxConn *> &ports, const std::map<ExtSigSpec, std::set<RTLIL::Cell *>> &operand_to_users) { - std::set<RTLIL::Cell *> alus_using_operand; - std::set<RTLIL::Cell *> alus_set; + std::set<RTLIL::Cell *> ops_using_operand; + std::set<RTLIL::Cell *> ops_set; for(const auto& p: ports) - alus_set.insert(p->alu); + ops_set.insert(p->op); ExtSigSpec oper; - auto op_a = seed->alu; + auto op_a = seed->op; for (RTLIL::IdString port_name : {"\\A", "\\B"}) { - oper = ExtSigSpec(op_a, port_name, &assign_map); + oper = decode_port(op_a, port_name, &assign_map); auto operand_users = operand_to_users.at(oper); if (operand_users.size() == 1) continue; - alus_using_operand.clear(); - std::set_intersection(operand_users.begin(), operand_users.end(), alus_set.begin(), alus_set.end(), - std::inserter(alus_using_operand, alus_using_operand.begin())); + ops_using_operand.clear(); + for (auto mux_ops: ops_set) + if (operand_users.count(mux_ops)) + ops_using_operand.insert(mux_ops); - if (alus_using_operand.size() > 1) { - ports.erase(std::remove_if(ports.begin(), ports.end(), [&](InPort *p) { return !alus_using_operand.count(p->alu); }), - ports.end()); + if (ops_using_operand.size() > 1) { + ports.erase(std::remove_if(ports.begin(), ports.end(), [&](const OpMuxConn *p) { return !ops_using_operand.count(p->op); }), + ports.end()); return oper; } } @@ -277,40 +349,135 @@ ExtSigSpec find_shared_operand(InPort* seed, std::vector<InPort *> &ports, const return ExtSigSpec(); } -void remove_multi_user_outbits(RTLIL::Module *module, dict<RTLIL::SigBit, RTLIL::SigSpec> &op_outbit_to_outsig) +dict<RTLIL::SigSpec, OpMuxConn> find_valid_op_mux_conns(RTLIL::Module *module, dict<RTLIL::SigBit, RTLIL::SigSpec> &op_outbit_to_outsig, + dict<RTLIL::SigSpec, RTLIL::Cell *> outsig_to_operator, + dict<RTLIL::SigBit, RTLIL::SigSpec> &op_aux_to_outsig) { - dict<RTLIL::SigBit, int> op_outbit_user_cnt; + dict<RTLIL::SigSpec, int> op_outsig_user_track; + dict<RTLIL::SigSpec, OpMuxConn> op_mux_conn_map; - std::function<void(SigSpec)> update_op_outbit_user_cnt = [&](SigSpec sig) { - auto outsig = assign_map(sig); - for (auto outbit : outsig) { - if (!op_outbit_to_outsig.count(outbit)) - continue; + std::function<void(RTLIL::SigSpec)> remove_outsig = [&](RTLIL::SigSpec outsig) { + for (auto op_outbit : outsig) + op_outbit_to_outsig.erase(op_outbit); + + if (op_mux_conn_map.count(outsig)) + op_mux_conn_map.erase(outsig); + }; - if (++op_outbit_user_cnt[outbit] > 1) { - auto alu_outsig = op_outbit_to_outsig.at(outbit); + std::function<void(RTLIL::SigBit)> remove_outsig_from_aux_bit = [&](RTLIL::SigBit auxbit) { + auto aux_outsig = op_aux_to_outsig.at(auxbit); + auto op = outsig_to_operator.at(aux_outsig); + auto op_outsig = assign_map(op->getPort("\\Y")); + remove_outsig(op_outsig); - for (auto outbit : alu_outsig) - op_outbit_to_outsig.erase(outbit); + for (auto aux_outbit : aux_outsig) + op_aux_to_outsig.erase(aux_outbit); + }; + + std::function<void(RTLIL::Cell *)> + find_op_mux_conns = [&](RTLIL::Cell *mux) { + RTLIL::SigSpec sig; + int mux_port_size; + + if (mux->type.in("$mux", "$_MUX_")) { + mux_port_size = mux->getPort("\\A").size(); + sig = RTLIL::SigSpec{mux->getPort("\\B"), mux->getPort("\\A")}; + } else { + mux_port_size = mux->getPort("\\A").size(); + sig = mux->getPort("\\B"); + } + + auto mux_insig = assign_map(sig); + + for (int i = 0; i < mux_insig.size(); ++i) { + if (op_aux_to_outsig.count(mux_insig[i])) { + remove_outsig_from_aux_bit(mux_insig[i]); + continue; + } + + if (!op_outbit_to_outsig.count(mux_insig[i])) + continue; + + auto op_outsig = op_outbit_to_outsig.at(mux_insig[i]); + + if (op_mux_conn_map.count(op_outsig)) { + remove_outsig(op_outsig); + continue; + } + + int mux_port_id = i / mux_port_size; + int mux_port_offset = i % mux_port_size; + + int op_outsig_offset; + for (op_outsig_offset = 0; op_outsig[op_outsig_offset] != mux_insig[i]; ++op_outsig_offset) + ; + + int j = op_outsig_offset; + do { + if (!op_outbit_to_outsig.count(mux_insig[i])) + break; + + if (op_outbit_to_outsig.at(mux_insig[i]) != op_outsig) + break; + + ++i; + ++j; + } while ((i / mux_port_size == mux_port_id) && (j < op_outsig.size())); + + int op_conn_width = j - op_outsig_offset; + OpMuxConn inp = { + op_outsig.extract(op_outsig_offset, op_conn_width), + mux, + outsig_to_operator.at(op_outsig), + mux_port_id, + mux_port_offset, + op_outsig_offset, + }; + + op_mux_conn_map[op_outsig] = inp; + + --i; + } + }; + + std::function<void(RTLIL::SigSpec)> remove_connected_ops = [&](RTLIL::SigSpec sig) { + auto mux_insig = assign_map(sig); + for (auto outbit : mux_insig) { + if (op_aux_to_outsig.count(outbit)) { + remove_outsig_from_aux_bit(outbit); + continue; } + + if (!op_outbit_to_outsig.count(outbit)) + continue; + + remove_outsig(op_outbit_to_outsig.at(outbit)); } }; - for (auto cell : module->cells()) - for (auto &conn : cell->connections()) - if (cell->input(conn.first)) - update_op_outbit_user_cnt(conn.second); + for (auto cell : module->cells()) { + if (cell->type.in("$mux", "$_MUX_", "$pmux")) { + remove_connected_ops(cell->getPort("\\S")); + find_op_mux_conns(cell); + } else { + for (auto &conn : cell->connections()) + if (cell->input(conn.first)) + remove_connected_ops(conn.second); + } + } for (auto w : module->wires()) { if (!w->port_output) continue; - update_op_outbit_user_cnt(w); + remove_connected_ops(w); } + + return op_mux_conn_map; } struct OptSharePass : public Pass { - OptSharePass() : Pass("opt_share", "merge arithmetic operators that share an operand") {} + OptSharePass() : Pass("opt_share", "merge mutually exclusive cells of the same type that share an input signal") {} void help() YS_OVERRIDE { // |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---| @@ -318,18 +485,19 @@ struct OptSharePass : public Pass { log(" opt_share [selection]\n"); log("\n"); - log("This pass identifies mutually exclusive $alu arithmetic cells that:\n"); - log(" (a) share an input operand\n"); + log("This pass identifies mutually exclusive cells of the same type that:\n"); + log(" (a) share an input signal\n"); log(" (b) drive the same $mux, $_MUX_, or $pmux multiplexing cell allowing\n"); - log(" the $alu cell to be merged and the multiplexer to be moved from\n"); - log(" multiplexing its output to multiplexing the non-shared input operands.\n"); + log(" the cell to be merged and the multiplexer to be moved from\n"); + log(" multiplexing its output to multiplexing the non-shared input signals.\n"); log("\n"); } - void execute(std::vector<std::string>, RTLIL::Design *design) YS_OVERRIDE + void execute(std::vector<std::string> args, RTLIL::Design *design) YS_OVERRIDE { log_header(design, "Executing OPT_SHARE pass.\n"); + extra_args(args, 1, design); for (auto module : design->selected_modules()) { assign_map.clear(); assign_map.set(module); @@ -337,28 +505,30 @@ struct OptSharePass : public Pass { std::map<ExtSigSpec, std::set<RTLIL::Cell *>> operand_to_users; dict<RTLIL::SigSpec, RTLIL::Cell *> outsig_to_operator; dict<RTLIL::SigBit, RTLIL::SigSpec> op_outbit_to_outsig; + dict<RTLIL::SigBit, RTLIL::SigSpec> op_aux_to_outsig; bool any_shared_operands = false; std::vector<ExtSigSpec> op_insigs; for (auto cell : module->cells()) { - if (!cell->type.in("$alu")) + if (!cell_supported(cell)) continue; - RTLIL::SigSpec sig_bi = cell->getPort("\\BI"); - RTLIL::SigSpec sig_ci = cell->getPort("\\CI"); - - if ((!sig_bi.is_fully_const()) || (!sig_ci.is_fully_const()) || (sig_bi != sig_ci)) - continue; - - RTLIL::SigSpec sig_y = cell->getPort("\\A"); + if (cell->type == "$alu") { + for (RTLIL::IdString port_name : {"\\X", "\\CO"}) { + auto mux_insig = assign_map(cell->getPort(port_name)); + outsig_to_operator[mux_insig] = cell; + for (auto outbit : mux_insig) + op_aux_to_outsig[outbit] = mux_insig; + } + } - auto outsig = assign_map(cell->getPort("\\Y")); - outsig_to_operator[outsig] = cell; - for (auto outbit : outsig) - op_outbit_to_outsig[outbit] = outsig; + auto mux_insig = assign_map(cell->getPort("\\Y")); + outsig_to_operator[mux_insig] = cell; + for (auto outbit : mux_insig) + op_outbit_to_outsig[outbit] = mux_insig; for (RTLIL::IdString port_name : {"\\A", "\\B"}) { - auto op_insig = ExtSigSpec(cell, port_name, &assign_map); + auto op_insig = decode_port(cell, port_name, &assign_map); op_insigs.push_back(op_insig); operand_to_users[op_insig].insert(cell); if (operand_to_users[op_insig].size() > 1) @@ -371,89 +541,117 @@ struct OptSharePass : public Pass { // Operator outputs need to be exclusively connected to the $mux inputs in order to be mergeable. Hence we count to // how many points are operator output bits connected. - remove_multi_user_outbits(module, op_outbit_to_outsig); + dict<RTLIL::SigSpec, OpMuxConn> op_mux_conn_map = + find_valid_op_mux_conns(module, op_outbit_to_outsig, outsig_to_operator, op_aux_to_outsig); - std::vector<shared_op_t> shared_ops; - for (auto cell : module->cells()) { - if (!cell->type.in("$mux", "$_MUX_", "$pmux")) - continue; + // Group op connections connected to same ports of the same $mux. Sort them in ascending order of their port offset + dict<RTLIL::Cell*, std::vector<std::set<OpMuxConn>>> mux_port_op_conns; + for (auto& val: op_mux_conn_map) { + OpMuxConn p = val.second; + auto& mux_port_conns = mux_port_op_conns[p.mux]; - RTLIL::SigSpec sig_a = cell->getPort("\\A"); - RTLIL::SigSpec sig_b = cell->getPort("\\B"); - RTLIL::SigSpec sig_s = cell->getPort("\\S"); + if (mux_port_conns.size() == 0) { + int mux_port_num; - std::vector<InPort> ports; + if (p.mux->type.in("$mux", "$_MUX_")) + mux_port_num = 2; + else + mux_port_num = p.mux->getPort("\\S").size(); - if (cell->type.in("$mux", "$_MUX_")) { - ports.push_back(InPort(assign_map(sig_a), cell, 0)); - ports.push_back(InPort(assign_map(sig_b), cell, 1)); - } else { - RTLIL::SigSpec sig_s = cell->getPort("\\S"); - for (int i = 0; i < sig_s.size(); i++) { - auto inp = sig_b.extract(i * sig_a.size(), sig_a.size()); - ports.push_back(InPort(assign_map(inp), cell, i)); - } + mux_port_conns.resize(mux_port_num); } + mux_port_conns[p.mux_port_id].insert(p); + } + + std::vector<merged_op_t> merged_ops; + for (auto& val: mux_port_op_conns) { + + RTLIL::Cell* cell = val.first; + auto &mux_port_conns = val.second; + + const OpMuxConn *seed = NULL; + // Look through the bits of the $mux inputs and see which of them are connected to the operator // results. Operator results can be concatenated with other signals before led to the $mux. - for (int i = 0; i < sig_a.size(); ++i) { - std::vector<InPort*> alu_ports; - for (auto& p: ports) - if (op_outbit_to_outsig.count(p.sig[i])) { - p.alu = outsig_to_operator.at(op_outbit_to_outsig.at(p.sig[i])); - alu_ports.push_back(&p); - } + while (true) { - int alu_port_width = 0; + // Remove either the merged ports from the last iteration or the seed that failed to yield a merger + if (seed != NULL) { + mux_port_conns[seed->mux_port_id].erase(*seed); + seed = NULL; + } - while (alu_ports.size() > 1) { - std::vector<InPort*> shared_ports(alu_ports); + // For a new merger, find the seed op connection that starts at lowest port offset among port connections + for (auto &port_conns : mux_port_conns) { + if (!port_conns.size()) + continue; - auto seed = alu_ports[0]; - alu_ports.erase(alu_ports.begin()); + const OpMuxConn *next_p = &(*port_conns.begin()); - // Find ports whose $alu-s share an operand with $alu connected to the seed port - auto shared_operand = find_shared_operand(seed, shared_ports, operand_to_users); + if ((seed == NULL) || (seed->mux_port_offset > next_p->mux_port_offset)) + seed = next_p; + } - if (shared_operand.empty()) + // Cannot find the seed -> nothing to do for this $mux anymore + if (seed == NULL) + break; + + // Find all other op connections that start from the same port offset, and whose ops can be merged with the seed op + std::vector<const OpMuxConn *> mergeable_conns; + for (auto &port_conns : mux_port_conns) { + if (!port_conns.size()) continue; - // Some bits of the operator results might be unconnected. Calculate the number of conneted - // bits. - if (!find_op_res_width(i, alu_port_width, shared_ports, op_outbit_to_outsig)) - break; + const OpMuxConn *next_p = &(*port_conns.begin()); + + if ((next_p->op_outsig_offset == seed->op_outsig_offset) && + (next_p->mux_port_offset == seed->mux_port_offset) && mergeable(next_p->op, seed->op) && + next_p->sig.size() == seed->sig.size()) + mergeable_conns.push_back(next_p); + } + + // We need at least two mergeable connections for the merger + if (mergeable_conns.size() < 2) + continue; - if (shared_ports.size() < 2) - break; + // Filter mergeable connections whose ops share an operand with seed connection's op + auto shared_operand = find_shared_operand(seed, mergeable_conns, operand_to_users); - // Remember the combination for the merger - std::vector<InPort> shared_p; - for (auto p: shared_ports) - shared_p.push_back(*p); + if (shared_operand.empty()) + continue; - shared_ops.push_back(shared_op_t{cell, shared_p, i, alu_port_width, shared_operand}); + check_muxed_operands(mergeable_conns, shared_operand); - // Remove merged ports from the list and try to find other mergers for the mux - remove_val(alu_ports, shared_ports); + if (mergeable_conns.size() < 2) + continue; + + // Remember the combination for the merger + std::vector<OpMuxConn> merged_ports; + for (auto p : mergeable_conns) { + merged_ports.push_back(*p); + mux_port_conns[p->mux_port_id].erase(*p); } - if (alu_port_width) - i += alu_port_width - 1; + seed = NULL; + + merged_ops.push_back(merged_op_t{cell, merged_ports, shared_operand}); + + design->scratchpad_set_bool("opt.did_something", true); } } - for (auto &shared : shared_ops) { - log(" Found arithmetic cells that share an operand and can be merged by moving the %s %s in front " + for (auto &shared : merged_ops) { + log(" Found cells that share an operand and can be merged by moving the %s %s in front " "of " "them:\n", log_id(shared.mux->type), log_id(shared.mux)); for (const auto& op : shared.ports) - log(" %s\n", log_id(op.alu)); + log(" %s\n", log_id(op.op)); log("\n"); - merge_operators(module, shared.mux, shared.ports, shared.offset, shared.width, shared.shared_operand); + merge_operators(module, shared.mux, shared.ports, shared.shared_operand); } } } |