diff options
Diffstat (limited to 'passes/opt/opt_expr.cc')
-rw-r--r-- | passes/opt/opt_expr.cc | 1164 |
1 files changed, 1164 insertions, 0 deletions
diff --git a/passes/opt/opt_expr.cc b/passes/opt/opt_expr.cc new file mode 100644 index 000000000..9e713935d --- /dev/null +++ b/passes/opt/opt_expr.cc @@ -0,0 +1,1164 @@ +/* + * yosys -- Yosys Open SYnthesis Suite + * + * Copyright (C) 2012 Clifford Wolf <clifford@clifford.at> + * + * Permission to use, copy, modify, and/or distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + * + */ + +#include "kernel/register.h" +#include "kernel/sigtools.h" +#include "kernel/celltypes.h" +#include "kernel/utils.h" +#include "kernel/log.h" +#include <stdlib.h> +#include <stdio.h> +#include <algorithm> + +USING_YOSYS_NAMESPACE +PRIVATE_NAMESPACE_BEGIN + +bool did_something; + +void replace_undriven(RTLIL::Design *design, RTLIL::Module *module) +{ + CellTypes ct(design); + SigMap sigmap(module); + SigPool driven_signals; + SigPool used_signals; + SigPool all_signals; + + for (auto cell : module->cells()) + for (auto &conn : cell->connections()) { + if (!ct.cell_known(cell->type) || ct.cell_output(cell->type, conn.first)) + driven_signals.add(sigmap(conn.second)); + if (!ct.cell_known(cell->type) || ct.cell_input(cell->type, conn.first)) + used_signals.add(sigmap(conn.second)); + } + + for (auto wire : module->wires()) { + if (wire->port_input) + driven_signals.add(sigmap(wire)); + if (wire->port_output) + used_signals.add(sigmap(wire)); + all_signals.add(sigmap(wire)); + } + + all_signals.del(driven_signals); + RTLIL::SigSpec undriven_signals = all_signals.export_all(); + + for (auto &c : undriven_signals.chunks()) + { + RTLIL::SigSpec sig = c; + + if (c.wire->name[0] == '$') + sig = used_signals.extract(sig); + if (sig.size() == 0) + continue; + + log("Setting undriven signal in %s to undef: %s\n", RTLIL::id2cstr(module->name), log_signal(c)); + module->connect(RTLIL::SigSig(c, RTLIL::SigSpec(RTLIL::State::Sx, c.width))); + did_something = true; + } +} + +void replace_cell(SigMap &assign_map, RTLIL::Module *module, RTLIL::Cell *cell, std::string info, std::string out_port, RTLIL::SigSpec out_val) +{ + RTLIL::SigSpec Y = cell->getPort(out_port); + out_val.extend_u0(Y.size(), false); + + log("Replacing %s cell `%s' (%s) in module `%s' with constant driver `%s = %s'.\n", + cell->type.c_str(), cell->name.c_str(), info.c_str(), + module->name.c_str(), log_signal(Y), log_signal(out_val)); + // log_cell(cell); + assign_map.add(Y, out_val); + module->connect(Y, out_val); + module->remove(cell); + did_something = true; +} + +bool group_cell_inputs(RTLIL::Module *module, RTLIL::Cell *cell, bool commutative, SigMap &sigmap) +{ + std::string b_name = cell->hasPort("\\B") ? "\\B" : "\\A"; + + bool a_signed = cell->parameters.at("\\A_SIGNED").as_bool(); + bool b_signed = cell->parameters.at(b_name + "_SIGNED").as_bool(); + + RTLIL::SigSpec sig_a = sigmap(cell->getPort("\\A")); + RTLIL::SigSpec sig_b = sigmap(cell->getPort(b_name)); + RTLIL::SigSpec sig_y = sigmap(cell->getPort("\\Y")); + + sig_a.extend_u0(sig_y.size(), a_signed); + sig_b.extend_u0(sig_y.size(), b_signed); + + std::vector<RTLIL::SigBit> bits_a = sig_a, bits_b = sig_b, bits_y = sig_y; + + enum { GRP_DYN, GRP_CONST_A, GRP_CONST_B, GRP_CONST_AB, GRP_N }; + std::map<std::pair<RTLIL::SigBit, RTLIL::SigBit>, std::set<RTLIL::SigBit>> grouped_bits[GRP_N]; + + for (int i = 0; i < GetSize(bits_y); i++) + { + int group_idx = GRP_DYN; + RTLIL::SigBit bit_a = bits_a[i], bit_b = bits_b[i]; + + if (cell->type == "$or" && (bit_a == RTLIL::State::S1 || bit_b == RTLIL::State::S1)) + bit_a = bit_b = RTLIL::State::S1; + + if (cell->type == "$and" && (bit_a == RTLIL::State::S0 || bit_b == RTLIL::State::S0)) + bit_a = bit_b = RTLIL::State::S0; + + if (bit_a.wire == NULL && bit_b.wire == NULL) + group_idx = GRP_CONST_AB; + else if (bit_a.wire == NULL) + group_idx = GRP_CONST_A; + else if (bit_b.wire == NULL && commutative) + group_idx = GRP_CONST_A, std::swap(bit_a, bit_b); + else if (bit_b.wire == NULL) + group_idx = GRP_CONST_B; + + grouped_bits[group_idx][std::pair<RTLIL::SigBit, RTLIL::SigBit>(bit_a, bit_b)].insert(bits_y[i]); + } + + for (int i = 0; i < GRP_N; i++) + if (GetSize(grouped_bits[i]) == GetSize(bits_y)) + return false; + + log("Replacing %s cell `%s' in module `%s' with cells using grouped bits:\n", + log_id(cell->type), log_id(cell), log_id(module)); + + for (int i = 0; i < GRP_N; i++) + { + if (grouped_bits[i].empty()) + continue; + + RTLIL::Wire *new_y = module->addWire(NEW_ID, GetSize(grouped_bits[i])); + RTLIL::SigSpec new_a, new_b; + RTLIL::SigSig new_conn; + + for (auto &it : grouped_bits[i]) { + for (auto &bit : it.second) { + new_conn.first.append_bit(bit); + new_conn.second.append_bit(RTLIL::SigBit(new_y, new_a.size())); + } + new_a.append_bit(it.first.first); + new_b.append_bit(it.first.second); + } + + RTLIL::Cell *c = module->addCell(NEW_ID, cell->type); + + c->setPort("\\A", new_a); + c->parameters["\\A_WIDTH"] = new_a.size(); + c->parameters["\\A_SIGNED"] = false; + + if (b_name == "\\B") { + c->setPort("\\B", new_b); + c->parameters["\\B_WIDTH"] = new_b.size(); + c->parameters["\\B_SIGNED"] = false; + } + + c->setPort("\\Y", new_y); + c->parameters["\\Y_WIDTH"] = new_y->width; + c->check(); + + module->connect(new_conn); + + log(" New cell `%s': A=%s", log_id(c), log_signal(new_a)); + if (b_name == "\\B") + log(", B=%s", log_signal(new_b)); + log("\n"); + } + + cover_list("opt.opt_expr.fine.group", "$not", "$pos", "$and", "$or", "$xor", "$xnor", cell->type.str()); + + module->remove(cell); + did_something = true; + return true; +} + +void handle_polarity_inv(Cell *cell, IdString port, IdString param, const SigMap &assign_map, const dict<RTLIL::SigSpec, RTLIL::SigSpec> &invert_map) +{ + SigSpec sig = assign_map(cell->getPort(port)); + if (invert_map.count(sig)) { + log("Inverting %s of %s cell `%s' in module `%s': %s -> %s\n", + log_id(port), log_id(cell->type), log_id(cell), log_id(cell->module), + log_signal(sig), log_signal(invert_map.at(sig))); + cell->setPort(port, (invert_map.at(sig))); + cell->setParam(param, !cell->getParam(param).as_bool()); + } +} + +void handle_clkpol_celltype_swap(Cell *cell, string type1, string type2, IdString port, const SigMap &assign_map, const dict<RTLIL::SigSpec, RTLIL::SigSpec> &invert_map) +{ + log_assert(GetSize(type1) == GetSize(type2)); + string cell_type = cell->type.str(); + + if (GetSize(type1) != GetSize(cell_type)) + return; + + for (int i = 0; i < GetSize(type1); i++) { + log_assert((type1[i] == '?') == (type2[i] == '?')); + if (type1[i] == '?') { + if (cell_type[i] != '0' && cell_type[i] != '1' && cell_type[i] != 'N' && cell_type[i] != 'P') + return; + type1[i] = cell_type[i]; + type2[i] = cell_type[i]; + } + } + + if (cell->type.in(type1, type2)) { + SigSpec sig = assign_map(cell->getPort(port)); + if (invert_map.count(sig)) { + log("Inverting %s of %s cell `%s' in module `%s': %s -> %s\n", + log_id(port), log_id(cell->type), log_id(cell), log_id(cell->module), + log_signal(sig), log_signal(invert_map.at(sig))); + cell->setPort(port, (invert_map.at(sig))); + cell->type = cell->type == type1 ? type2 : type1; + } + } +} + +bool is_one_or_minus_one(const Const &value, bool is_signed, bool &is_negative) +{ + bool all_bits_one = true; + bool last_bit_one = true; + + if (GetSize(value.bits) < 1) + return false; + + if (GetSize(value.bits) == 1) { + if (value.bits[0] != State::S1) + return false; + if (is_signed) + is_negative = true; + return true; + } + + for (int i = 0; i < GetSize(value.bits); i++) { + if (value.bits[i] != State::S1) + all_bits_one = false; + if (value.bits[i] != (i ? State::S0 : State::S1)) + last_bit_one = false; + } + + if (all_bits_one && is_signed) { + is_negative = true; + return true; + } + + return last_bit_one; +} + +void replace_const_cells(RTLIL::Design *design, RTLIL::Module *module, bool consume_x, bool mux_undef, bool mux_bool, bool do_fine, bool keepdc, bool clkinv) +{ + if (!design->selected(module)) + return; + + CellTypes ct_combinational; + ct_combinational.setup_internals(); + ct_combinational.setup_stdcells(); + + SigMap assign_map(module); + dict<RTLIL::SigSpec, RTLIL::SigSpec> invert_map; + + TopoSort<RTLIL::Cell*, RTLIL::IdString::compare_ptr_by_name<RTLIL::Cell>> cells; + dict<RTLIL::Cell*, std::set<RTLIL::SigBit>> cell_to_inbit; + dict<RTLIL::SigBit, std::set<RTLIL::Cell*>> outbit_to_cell; + + for (auto cell : module->cells()) + if (design->selected(module, cell) && cell->type[0] == '$') { + if ((cell->type == "$_NOT_" || cell->type == "$not" || cell->type == "$logic_not") && + cell->getPort("\\A").size() == 1 && cell->getPort("\\Y").size() == 1) + invert_map[assign_map(cell->getPort("\\Y"))] = assign_map(cell->getPort("\\A")); + if ((cell->type == "$mux" || cell->type == "$_MUX_") && cell->getPort("\\A") == SigSpec(State::S1) && cell->getPort("\\B") == SigSpec(State::S0)) + invert_map[assign_map(cell->getPort("\\Y"))] = assign_map(cell->getPort("\\S")); + if (ct_combinational.cell_known(cell->type)) + for (auto &conn : cell->connections()) { + RTLIL::SigSpec sig = assign_map(conn.second); + sig.remove_const(); + if (ct_combinational.cell_input(cell->type, conn.first)) + cell_to_inbit[cell].insert(sig.begin(), sig.end()); + if (ct_combinational.cell_output(cell->type, conn.first)) + for (auto &bit : sig) + outbit_to_cell[bit].insert(cell); + } + cells.node(cell); + } + + for (auto &it_right : cell_to_inbit) + for (auto &it_sigbit : it_right.second) + for (auto &it_left : outbit_to_cell[it_sigbit]) + cells.edge(it_left, it_right.first); + + cells.sort(); + + for (auto cell : cells.sorted) + { +#define ACTION_DO(_p_, _s_) do { cover("opt.opt_expr.action_" S__LINE__); replace_cell(assign_map, module, cell, input.as_string(), _p_, _s_); goto next_cell; } while (0) +#define ACTION_DO_Y(_v_) ACTION_DO("\\Y", RTLIL::SigSpec(RTLIL::State::S ## _v_)) + + if (clkinv) + { + if (cell->type.in("$dff", "$dffe", "$dffsr", "$adff", "$fsm", "$memrd", "$memwr")) + handle_polarity_inv(cell, "\\CLK", "\\CLK_POLARITY", assign_map, invert_map); + + if (cell->type.in("$sr", "$dffsr", "$dlatchsr")) { + handle_polarity_inv(cell, "\\SET", "\\SET_POLARITY", assign_map, invert_map); + handle_polarity_inv(cell, "\\CLR", "\\CLR_POLARITY", assign_map, invert_map); + } + + if (cell->type.in("$dffe", "$dlatch", "$dlatchsr")) + handle_polarity_inv(cell, "\\EN", "\\EN_POLARITY", assign_map, invert_map); + + handle_clkpol_celltype_swap(cell, "$_SR_N?_", "$_SR_P?_", "\\S", assign_map, invert_map); + handle_clkpol_celltype_swap(cell, "$_SR_?N_", "$_SR_?P_", "\\R", assign_map, invert_map); + + handle_clkpol_celltype_swap(cell, "$_DFF_N_", "$_DFF_P_", "\\C", assign_map, invert_map); + + handle_clkpol_celltype_swap(cell, "$_DFFE_N?_", "$_DFFE_P?_", "\\C", assign_map, invert_map); + handle_clkpol_celltype_swap(cell, "$_DFFE_?N_", "$_DFFE_?P_", "\\E", assign_map, invert_map); + + handle_clkpol_celltype_swap(cell, "$_DFF_N??_", "$_DFF_P??_", "\\C", assign_map, invert_map); + handle_clkpol_celltype_swap(cell, "$_DFF_?N?_", "$_DFF_?P?_", "\\R", assign_map, invert_map); + + handle_clkpol_celltype_swap(cell, "$_DFFSR_N??_", "$_DFFSR_P??_", "\\C", assign_map, invert_map); + handle_clkpol_celltype_swap(cell, "$_DFFSR_?N?_", "$_DFFSR_?P?_", "\\S", assign_map, invert_map); + handle_clkpol_celltype_swap(cell, "$_DFFSR_??N_", "$_DFFSR_??P_", "\\R", assign_map, invert_map); + + handle_clkpol_celltype_swap(cell, "$_DLATCH_N_", "$_DLATCH_P_", "\\E", assign_map, invert_map); + + handle_clkpol_celltype_swap(cell, "$_DLATCHSR_N??_", "$_DLATCHSR_P??_", "\\E", assign_map, invert_map); + handle_clkpol_celltype_swap(cell, "$_DLATCHSR_?N?_", "$_DLATCHSR_?P?_", "\\S", assign_map, invert_map); + handle_clkpol_celltype_swap(cell, "$_DLATCHSR_??N_", "$_DLATCHSR_??P_", "\\R", assign_map, invert_map); + } + + if (do_fine) + { + if (cell->type == "$not" || cell->type == "$pos" || + cell->type == "$and" || cell->type == "$or" || cell->type == "$xor" || cell->type == "$xnor") + if (group_cell_inputs(module, cell, true, assign_map)) + goto next_cell; + + if (cell->type == "$reduce_and") + { + RTLIL::SigSpec sig_a = assign_map(cell->getPort("\\A")); + + RTLIL::State new_a = RTLIL::State::S1; + for (auto &bit : sig_a.to_sigbit_vector()) + if (bit == RTLIL::State::Sx) { + if (new_a == RTLIL::State::S1) + new_a = RTLIL::State::Sx; + } else if (bit == RTLIL::State::S0) { + new_a = RTLIL::State::S0; + break; + } else if (bit.wire != NULL) { + new_a = RTLIL::State::Sm; + } + + if (new_a != RTLIL::State::Sm && RTLIL::SigSpec(new_a) != sig_a) { + cover("opt.opt_expr.fine.$reduce_and"); + log("Replacing port A of %s cell `%s' in module `%s' with constant driver: %s -> %s\n", + cell->type.c_str(), cell->name.c_str(), module->name.c_str(), log_signal(sig_a), log_signal(new_a)); + cell->setPort("\\A", sig_a = new_a); + cell->parameters.at("\\A_WIDTH") = 1; + did_something = true; + } + } + + if (cell->type == "$logic_not" || cell->type == "$logic_and" || cell->type == "$logic_or" || cell->type == "$reduce_or" || cell->type == "$reduce_bool") + { + RTLIL::SigSpec sig_a = assign_map(cell->getPort("\\A")); + + RTLIL::State new_a = RTLIL::State::S0; + for (auto &bit : sig_a.to_sigbit_vector()) + if (bit == RTLIL::State::Sx) { + if (new_a == RTLIL::State::S0) + new_a = RTLIL::State::Sx; + } else if (bit == RTLIL::State::S1) { + new_a = RTLIL::State::S1; + break; + } else if (bit.wire != NULL) { + new_a = RTLIL::State::Sm; + } + + if (new_a != RTLIL::State::Sm && RTLIL::SigSpec(new_a) != sig_a) { + cover_list("opt.opt_expr.fine.A", "$logic_not", "$logic_and", "$logic_or", "$reduce_or", "$reduce_bool", cell->type.str()); + log("Replacing port A of %s cell `%s' in module `%s' with constant driver: %s -> %s\n", + cell->type.c_str(), cell->name.c_str(), module->name.c_str(), log_signal(sig_a), log_signal(new_a)); + cell->setPort("\\A", sig_a = new_a); + cell->parameters.at("\\A_WIDTH") = 1; + did_something = true; + } + } + + if (cell->type == "$logic_and" || cell->type == "$logic_or") + { + RTLIL::SigSpec sig_b = assign_map(cell->getPort("\\B")); + + RTLIL::State new_b = RTLIL::State::S0; + for (auto &bit : sig_b.to_sigbit_vector()) + if (bit == RTLIL::State::Sx) { + if (new_b == RTLIL::State::S0) + new_b = RTLIL::State::Sx; + } else if (bit == RTLIL::State::S1) { + new_b = RTLIL::State::S1; + break; + } else if (bit.wire != NULL) { + new_b = RTLIL::State::Sm; + } + + if (new_b != RTLIL::State::Sm && RTLIL::SigSpec(new_b) != sig_b) { + cover_list("opt.opt_expr.fine.B", "$logic_and", "$logic_or", cell->type.str()); + log("Replacing port B of %s cell `%s' in module `%s' with constant driver: %s -> %s\n", + cell->type.c_str(), cell->name.c_str(), module->name.c_str(), log_signal(sig_b), log_signal(new_b)); + cell->setPort("\\B", sig_b = new_b); + cell->parameters.at("\\B_WIDTH") = 1; + did_something = true; + } + } + } + + if (cell->type == "$logic_or" && (assign_map(cell->getPort("\\A")) == RTLIL::State::S1 || assign_map(cell->getPort("\\B")) == RTLIL::State::S1)) { + cover("opt.opt_expr.one_high"); + replace_cell(assign_map, module, cell, "one high", "\\Y", RTLIL::State::S1); + goto next_cell; + } + + if (cell->type == "$logic_and" && (assign_map(cell->getPort("\\A")) == RTLIL::State::S0 || assign_map(cell->getPort("\\B")) == RTLIL::State::S0)) { + cover("opt.opt_expr.one_low"); + replace_cell(assign_map, module, cell, "one low", "\\Y", RTLIL::State::S0); + goto next_cell; + } + + if (cell->type == "$reduce_xor" || cell->type == "$reduce_xnor" || cell->type == "$shift" || cell->type == "$shiftx" || + cell->type == "$shl" || cell->type == "$shr" || cell->type == "$sshl" || cell->type == "$sshr" || + cell->type == "$lt" || cell->type == "$le" || cell->type == "$ge" || cell->type == "$gt" || + cell->type == "$neg" || cell->type == "$add" || cell->type == "$sub" || + cell->type == "$mul" || cell->type == "$div" || cell->type == "$mod" || cell->type == "$pow") + { + RTLIL::SigSpec sig_a = assign_map(cell->getPort("\\A")); + RTLIL::SigSpec sig_b = cell->hasPort("\\B") ? assign_map(cell->getPort("\\B")) : RTLIL::SigSpec(); + + if (cell->type == "$shl" || cell->type == "$shr" || cell->type == "$sshl" || cell->type == "$sshr" || cell->type == "$shift" || cell->type == "$shiftx") + sig_a = RTLIL::SigSpec(); + + for (auto &bit : sig_a.to_sigbit_vector()) + if (bit == RTLIL::State::Sx) + goto found_the_x_bit; + + for (auto &bit : sig_b.to_sigbit_vector()) + if (bit == RTLIL::State::Sx) + goto found_the_x_bit; + + if (0) { + found_the_x_bit: + cover_list("opt.opt_expr.xbit", "$reduce_xor", "$reduce_xnor", "$shl", "$shr", "$sshl", "$sshr", "$shift", "$shiftx", + "$lt", "$le", "$ge", "$gt", "$neg", "$add", "$sub", "$mul", "$div", "$mod", "$pow", cell->type.str()); + if (cell->type == "$reduce_xor" || cell->type == "$reduce_xnor" || + cell->type == "$lt" || cell->type == "$le" || cell->type == "$ge" || cell->type == "$gt") + replace_cell(assign_map, module, cell, "x-bit in input", "\\Y", RTLIL::State::Sx); + else + replace_cell(assign_map, module, cell, "x-bit in input", "\\Y", RTLIL::SigSpec(RTLIL::State::Sx, cell->getPort("\\Y").size())); + goto next_cell; + } + } + + if ((cell->type == "$_NOT_" || cell->type == "$not" || cell->type == "$logic_not") && cell->getPort("\\Y").size() == 1 && + invert_map.count(assign_map(cell->getPort("\\A"))) != 0) { + cover_list("opt.opt_expr.invert.double", "$_NOT_", "$not", "$logic_not", cell->type.str()); + replace_cell(assign_map, module, cell, "double_invert", "\\Y", invert_map.at(assign_map(cell->getPort("\\A")))); + goto next_cell; + } + + if ((cell->type == "$_MUX_" || cell->type == "$mux") && invert_map.count(assign_map(cell->getPort("\\S"))) != 0) { + cover_list("opt.opt_expr.invert.muxsel", "$_MUX_", "$mux", cell->type.str()); + log("Optimizing away select inverter for %s cell `%s' in module `%s'.\n", log_id(cell->type), log_id(cell), log_id(module)); + RTLIL::SigSpec tmp = cell->getPort("\\A"); + cell->setPort("\\A", cell->getPort("\\B")); + cell->setPort("\\B", tmp); + cell->setPort("\\S", invert_map.at(assign_map(cell->getPort("\\S")))); + did_something = true; + goto next_cell; + } + + if (cell->type == "$_NOT_") { + RTLIL::SigSpec input = cell->getPort("\\A"); + assign_map.apply(input); + if (input.match("1")) ACTION_DO_Y(0); + if (input.match("0")) ACTION_DO_Y(1); + if (input.match("*")) ACTION_DO_Y(x); + } + + if (cell->type == "$_AND_") { + RTLIL::SigSpec input; + input.append(cell->getPort("\\B")); + input.append(cell->getPort("\\A")); + assign_map.apply(input); + if (input.match(" 0")) ACTION_DO_Y(0); + if (input.match("0 ")) ACTION_DO_Y(0); + if (input.match("11")) ACTION_DO_Y(1); + if (input.match("**")) ACTION_DO_Y(x); + if (input.match("1*")) ACTION_DO_Y(x); + if (input.match("*1")) ACTION_DO_Y(x); + if (consume_x) { + if (input.match(" *")) ACTION_DO_Y(0); + if (input.match("* ")) ACTION_DO_Y(0); + } + if (input.match(" 1")) ACTION_DO("\\Y", input.extract(1, 1)); + if (input.match("1 ")) ACTION_DO("\\Y", input.extract(0, 1)); + } + + if (cell->type == "$_OR_") { + RTLIL::SigSpec input; + input.append(cell->getPort("\\B")); + input.append(cell->getPort("\\A")); + assign_map.apply(input); + if (input.match(" 1")) ACTION_DO_Y(1); + if (input.match("1 ")) ACTION_DO_Y(1); + if (input.match("00")) ACTION_DO_Y(0); + if (input.match("**")) ACTION_DO_Y(x); + if (input.match("0*")) ACTION_DO_Y(x); + if (input.match("*0")) ACTION_DO_Y(x); + if (consume_x) { + if (input.match(" *")) ACTION_DO_Y(1); + if (input.match("* ")) ACTION_DO_Y(1); + } + if (input.match(" 0")) ACTION_DO("\\Y", input.extract(1, 1)); + if (input.match("0 ")) ACTION_DO("\\Y", input.extract(0, 1)); + } + + if (cell->type == "$_XOR_") { + RTLIL::SigSpec input; + input.append(cell->getPort("\\B")); + input.append(cell->getPort("\\A")); + assign_map.apply(input); + if (input.match("00")) ACTION_DO_Y(0); + if (input.match("01")) ACTION_DO_Y(1); + if (input.match("10")) ACTION_DO_Y(1); + if (input.match("11")) ACTION_DO_Y(0); + if (input.match(" *")) ACTION_DO_Y(x); + if (input.match("* ")) ACTION_DO_Y(x); + if (input.match(" 0")) ACTION_DO("\\Y", input.extract(1, 1)); + if (input.match("0 ")) ACTION_DO("\\Y", input.extract(0, 1)); + } + + if (cell->type == "$_MUX_") { + RTLIL::SigSpec input; + input.append(cell->getPort("\\S")); + input.append(cell->getPort("\\B")); + input.append(cell->getPort("\\A")); + assign_map.apply(input); + if (input.extract(2, 1) == input.extract(1, 1)) + ACTION_DO("\\Y", input.extract(2, 1)); + if (input.match(" 0")) ACTION_DO("\\Y", input.extract(2, 1)); + if (input.match(" 1")) ACTION_DO("\\Y", input.extract(1, 1)); + if (input.match("01 ")) ACTION_DO("\\Y", input.extract(0, 1)); + if (input.match("10 ")) { + cover("opt.opt_expr.mux_to_inv"); + cell->type = "$_NOT_"; + cell->setPort("\\A", input.extract(0, 1)); + cell->unsetPort("\\B"); + cell->unsetPort("\\S"); + goto next_cell; + } + if (input.match("11 ")) ACTION_DO_Y(1); + if (input.match("00 ")) ACTION_DO_Y(0); + if (input.match("** ")) ACTION_DO_Y(x); + if (input.match("01*")) ACTION_DO_Y(x); + if (input.match("10*")) ACTION_DO_Y(x); + if (mux_undef) { + if (input.match("* ")) ACTION_DO("\\Y", input.extract(1, 1)); + if (input.match(" * ")) ACTION_DO("\\Y", input.extract(2, 1)); + if (input.match(" *")) ACTION_DO("\\Y", input.extract(2, 1)); + } + } + + if (cell->type == "$eq" || cell->type == "$ne" || cell->type == "$eqx" || cell->type == "$nex") + { + RTLIL::SigSpec a = cell->getPort("\\A"); + RTLIL::SigSpec b = cell->getPort("\\B"); + + if (cell->parameters["\\A_WIDTH"].as_int() != cell->parameters["\\B_WIDTH"].as_int()) { + int width = max(cell->parameters["\\A_WIDTH"].as_int(), cell->parameters["\\B_WIDTH"].as_int()); + a.extend_u0(width, cell->parameters["\\A_SIGNED"].as_bool() && cell->parameters["\\B_SIGNED"].as_bool()); + b.extend_u0(width, cell->parameters["\\A_SIGNED"].as_bool() && cell->parameters["\\B_SIGNED"].as_bool()); + } + + RTLIL::SigSpec new_a, new_b; + + log_assert(GetSize(a) == GetSize(b)); + for (int i = 0; i < GetSize(a); i++) { + if (a[i].wire == NULL && b[i].wire == NULL && a[i] != b[i] && a[i].data <= RTLIL::State::S1 && b[i].data <= RTLIL::State::S1) { + cover_list("opt.opt_expr.eqneq.isneq", "$eq", "$ne", "$eqx", "$nex", cell->type.str()); + RTLIL::SigSpec new_y = RTLIL::SigSpec((cell->type == "$eq" || cell->type == "$eqx") ? RTLIL::State::S0 : RTLIL::State::S1); + new_y.extend_u0(cell->parameters["\\Y_WIDTH"].as_int(), false); + replace_cell(assign_map, module, cell, "isneq", "\\Y", new_y); + goto next_cell; + } + if (a[i] == b[i]) + continue; + new_a.append(a[i]); + new_b.append(b[i]); + } + + if (new_a.size() == 0) { + cover_list("opt.opt_expr.eqneq.empty", "$eq", "$ne", "$eqx", "$nex", cell->type.str()); + RTLIL::SigSpec new_y = RTLIL::SigSpec((cell->type == "$eq" || cell->type == "$eqx") ? RTLIL::State::S1 : RTLIL::State::S0); + new_y.extend_u0(cell->parameters["\\Y_WIDTH"].as_int(), false); + replace_cell(assign_map, module, cell, "empty", "\\Y", new_y); + goto next_cell; + } + + if (new_a.size() < a.size() || new_b.size() < b.size()) { + cover_list("opt.opt_expr.eqneq.resize", "$eq", "$ne", "$eqx", "$nex", cell->type.str()); + cell->setPort("\\A", new_a); + cell->setPort("\\B", new_b); + cell->parameters["\\A_WIDTH"] = new_a.size(); + cell->parameters["\\B_WIDTH"] = new_b.size(); + } + } + + if ((cell->type == "$eq" || cell->type == "$ne") && cell->parameters["\\Y_WIDTH"].as_int() == 1 && + cell->parameters["\\A_WIDTH"].as_int() == 1 && cell->parameters["\\B_WIDTH"].as_int() == 1) + { + RTLIL::SigSpec a = assign_map(cell->getPort("\\A")); + RTLIL::SigSpec b = assign_map(cell->getPort("\\B")); + + if (a.is_fully_const() && !b.is_fully_const()) { + cover_list("opt.opt_expr.eqneq.swapconst", "$eq", "$ne", cell->type.str()); + cell->setPort("\\A", b); + cell->setPort("\\B", a); + std::swap(a, b); + } + + if (b.is_fully_const()) { + if (b.as_bool() == (cell->type == "$eq")) { + RTLIL::SigSpec input = b; + ACTION_DO("\\Y", cell->getPort("\\A")); + } else { + cover_list("opt.opt_expr.eqneq.isnot", "$eq", "$ne", cell->type.str()); + log("Replacing %s cell `%s' in module `%s' with inverter.\n", log_id(cell->type), log_id(cell), log_id(module)); + cell->type = "$not"; + cell->parameters.erase("\\B_WIDTH"); + cell->parameters.erase("\\B_SIGNED"); + cell->unsetPort("\\B"); + did_something = true; + } + goto next_cell; + } + } + + if ((cell->type == "$eq" || cell->type == "$ne") && + (assign_map(cell->getPort("\\A")).is_fully_zero() || assign_map(cell->getPort("\\B")).is_fully_zero())) + { + cover_list("opt.opt_expr.eqneq.cmpzero", "$eq", "$ne", cell->type.str()); + log("Replacing %s cell `%s' in module `%s' with %s.\n", log_id(cell->type), log_id(cell), + log_id(module), "$eq" ? "$logic_not" : "$reduce_bool"); + cell->type = cell->type == "$eq" ? "$logic_not" : "$reduce_bool"; + if (assign_map(cell->getPort("\\A")).is_fully_zero()) { + cell->setPort("\\A", cell->getPort("\\B")); + cell->setParam("\\A_SIGNED", cell->getParam("\\B_SIGNED")); + cell->setParam("\\A_WIDTH", cell->getParam("\\B_WIDTH")); + } + cell->unsetPort("\\B"); + cell->unsetParam("\\B_SIGNED"); + cell->unsetParam("\\B_WIDTH"); + did_something = true; + goto next_cell; + } + + if (cell->type.in("$shl", "$shr", "$sshl", "$sshr", "$shift", "$shiftx") && assign_map(cell->getPort("\\B")).is_fully_const()) + { + bool sign_ext = cell->type == "$sshr" && cell->getParam("\\A_SIGNED").as_bool(); + int shift_bits = assign_map(cell->getPort("\\B")).as_int(cell->type.in("$shift", "$shiftx") && cell->getParam("\\B_SIGNED").as_bool()); + + if (cell->type.in("$shl", "$sshl")) + shift_bits *= -1; + + RTLIL::SigSpec sig_a = assign_map(cell->getPort("\\A")); + RTLIL::SigSpec sig_y(cell->type == "$shiftx" ? RTLIL::State::Sx : RTLIL::State::S0, cell->getParam("\\Y_WIDTH").as_int()); + + if (GetSize(sig_a) < GetSize(sig_y)) + sig_a.extend_u0(GetSize(sig_y), cell->getParam("\\A_SIGNED").as_bool()); + + for (int i = 0; i < GetSize(sig_y); i++) { + int idx = i + shift_bits; + if (0 <= idx && idx < GetSize(sig_a)) + sig_y[i] = sig_a[idx]; + else if (GetSize(sig_a) <= idx && sign_ext) + sig_y[i] = sig_a[GetSize(sig_a)-1]; + } + + cover_list("opt.opt_expr.constshift", "$shl", "$shr", "$sshl", "$sshr", "$shift", "$shiftx", cell->type.str()); + + log("Replacing %s cell `%s' (B=%s, SHR=%d) in module `%s' with fixed wiring: %s\n", + log_id(cell->type), log_id(cell), log_signal(assign_map(cell->getPort("\\B"))), shift_bits, log_id(module), log_signal(sig_y)); + + module->connect(cell->getPort("\\Y"), sig_y); + module->remove(cell); + + did_something = true; + goto next_cell; + } + + if (!keepdc) + { + bool identity_wrt_a = false; + bool identity_wrt_b = false; + bool arith_inverse = false; + + if (cell->type == "$add" || cell->type == "$sub" || cell->type == "$or" || cell->type == "$xor") + { + RTLIL::SigSpec a = assign_map(cell->getPort("\\A")); + RTLIL::SigSpec b = assign_map(cell->getPort("\\B")); + + if (cell->type != "$sub" && a.is_fully_const() && a.as_bool() == false) + identity_wrt_b = true; + + if (b.is_fully_const() && b.as_bool() == false) + identity_wrt_a = true; + } + + if (cell->type == "$shl" || cell->type == "$shr" || cell->type == "$sshl" || cell->type == "$sshr" || cell->type == "$shift" || cell->type == "$shiftx") + { + RTLIL::SigSpec b = assign_map(cell->getPort("\\B")); + + if (b.is_fully_const() && b.as_bool() == false) + identity_wrt_a = true; + } + + if (cell->type == "$mul") + { + RTLIL::SigSpec a = assign_map(cell->getPort("\\A")); + RTLIL::SigSpec b = assign_map(cell->getPort("\\B")); + + if (a.is_fully_const() && is_one_or_minus_one(a.as_const(), cell->getParam("\\A_SIGNED").as_bool(), arith_inverse)) + identity_wrt_b = true; + else + if (b.is_fully_const() && is_one_or_minus_one(b.as_const(), cell->getParam("\\B_SIGNED").as_bool(), arith_inverse)) + identity_wrt_a = true; + } + + if (cell->type == "$div") + { + RTLIL::SigSpec b = assign_map(cell->getPort("\\B")); + + if (b.is_fully_const() && b.size() <= 32 && b.as_int() == 1) + identity_wrt_a = true; + } + + if (identity_wrt_a || identity_wrt_b) + { + if (identity_wrt_a) + cover_list("opt.opt_expr.identwrt.a", "$add", "$sub", "$or", "$xor", "$shl", "$shr", "$sshl", "$sshr", "$shift", "$shiftx", "$mul", "$div", cell->type.str()); + if (identity_wrt_b) + cover_list("opt.opt_expr.identwrt.b", "$add", "$sub", "$or", "$xor", "$shl", "$shr", "$sshl", "$sshr", "$shift", "$shiftx", "$mul", "$div", cell->type.str()); + + log("Replacing %s cell `%s' in module `%s' with identity for port %c.\n", + cell->type.c_str(), cell->name.c_str(), module->name.c_str(), identity_wrt_a ? 'A' : 'B'); + + if (!identity_wrt_a) { + cell->setPort("\\A", cell->getPort("\\B")); + cell->parameters.at("\\A_WIDTH") = cell->parameters.at("\\B_WIDTH"); + cell->parameters.at("\\A_SIGNED") = cell->parameters.at("\\B_SIGNED"); + } + + cell->type = arith_inverse ? "$neg" : "$pos"; + cell->unsetPort("\\B"); + cell->parameters.erase("\\B_WIDTH"); + cell->parameters.erase("\\B_SIGNED"); + cell->check(); + + did_something = true; + goto next_cell; + } + } + + if (mux_bool && (cell->type == "$mux" || cell->type == "$_MUX_") && + cell->getPort("\\A") == RTLIL::SigSpec(0, 1) && cell->getPort("\\B") == RTLIL::SigSpec(1, 1)) { + cover_list("opt.opt_expr.mux_bool", "$mux", "$_MUX_", cell->type.str()); + replace_cell(assign_map, module, cell, "mux_bool", "\\Y", cell->getPort("\\S")); + goto next_cell; + } + + if (mux_bool && (cell->type == "$mux" || cell->type == "$_MUX_") && + cell->getPort("\\A") == RTLIL::SigSpec(1, 1) && cell->getPort("\\B") == RTLIL::SigSpec(0, 1)) { + cover_list("opt.opt_expr.mux_invert", "$mux", "$_MUX_", cell->type.str()); + log("Replacing %s cell `%s' in module `%s' with inverter.\n", log_id(cell->type), log_id(cell), log_id(module)); + cell->setPort("\\A", cell->getPort("\\S")); + cell->unsetPort("\\B"); + cell->unsetPort("\\S"); + if (cell->type == "$mux") { + Const width = cell->parameters["\\WIDTH"]; + cell->parameters["\\A_WIDTH"] = width; + cell->parameters["\\Y_WIDTH"] = width; + cell->parameters["\\A_SIGNED"] = 0; + cell->parameters.erase("\\WIDTH"); + cell->type = "$not"; + } else + cell->type = "$_NOT_"; + did_something = true; + goto next_cell; + } + + if (consume_x && mux_bool && (cell->type == "$mux" || cell->type == "$_MUX_") && cell->getPort("\\A") == RTLIL::SigSpec(0, 1)) { + cover_list("opt.opt_expr.mux_and", "$mux", "$_MUX_", cell->type.str()); + log("Replacing %s cell `%s' in module `%s' with and-gate.\n", log_id(cell->type), log_id(cell), log_id(module)); + cell->setPort("\\A", cell->getPort("\\S")); + cell->unsetPort("\\S"); + if (cell->type == "$mux") { + Const width = cell->parameters["\\WIDTH"]; + cell->parameters["\\A_WIDTH"] = width; + cell->parameters["\\B_WIDTH"] = width; + cell->parameters["\\Y_WIDTH"] = width; + cell->parameters["\\A_SIGNED"] = 0; + cell->parameters["\\B_SIGNED"] = 0; + cell->parameters.erase("\\WIDTH"); + cell->type = "$and"; + } else + cell->type = "$_AND_"; + did_something = true; + goto next_cell; + } + + if (consume_x && mux_bool && (cell->type == "$mux" || cell->type == "$_MUX_") && cell->getPort("\\B") == RTLIL::SigSpec(1, 1)) { + cover_list("opt.opt_expr.mux_or", "$mux", "$_MUX_", cell->type.str()); + log("Replacing %s cell `%s' in module `%s' with or-gate.\n", log_id(cell->type), log_id(cell), log_id(module)); + cell->setPort("\\B", cell->getPort("\\S")); + cell->unsetPort("\\S"); + if (cell->type == "$mux") { + Const width = cell->parameters["\\WIDTH"]; + cell->parameters["\\A_WIDTH"] = width; + cell->parameters["\\B_WIDTH"] = width; + cell->parameters["\\Y_WIDTH"] = width; + cell->parameters["\\A_SIGNED"] = 0; + cell->parameters["\\B_SIGNED"] = 0; + cell->parameters.erase("\\WIDTH"); + cell->type = "$or"; + } else + cell->type = "$_OR_"; + did_something = true; + goto next_cell; + } + + if (mux_undef && (cell->type == "$mux" || cell->type == "$pmux")) { + RTLIL::SigSpec new_a, new_b, new_s; + int width = cell->getPort("\\A").size(); + if ((cell->getPort("\\A").is_fully_undef() && cell->getPort("\\B").is_fully_undef()) || + cell->getPort("\\S").is_fully_undef()) { + cover_list("opt.opt_expr.mux_undef", "$mux", "$pmux", cell->type.str()); + replace_cell(assign_map, module, cell, "mux_undef", "\\Y", cell->getPort("\\A")); + goto next_cell; + } + for (int i = 0; i < cell->getPort("\\S").size(); i++) { + RTLIL::SigSpec old_b = cell->getPort("\\B").extract(i*width, width); + RTLIL::SigSpec old_s = cell->getPort("\\S").extract(i, 1); + if (old_b.is_fully_undef() || old_s.is_fully_undef()) + continue; + new_b.append(old_b); + new_s.append(old_s); + } + new_a = cell->getPort("\\A"); + if (new_a.is_fully_undef() && new_s.size() > 0) { + new_a = new_b.extract((new_s.size()-1)*width, width); + new_b = new_b.extract(0, (new_s.size()-1)*width); + new_s = new_s.extract(0, new_s.size()-1); + } + if (new_s.size() == 0) { + cover_list("opt.opt_expr.mux_empty", "$mux", "$pmux", cell->type.str()); + replace_cell(assign_map, module, cell, "mux_empty", "\\Y", new_a); + goto next_cell; + } + if (new_a == RTLIL::SigSpec(RTLIL::State::S0) && new_b == RTLIL::SigSpec(RTLIL::State::S1)) { + cover_list("opt.opt_expr.mux_sel01", "$mux", "$pmux", cell->type.str()); + replace_cell(assign_map, module, cell, "mux_sel01", "\\Y", new_s); + goto next_cell; + } + if (cell->getPort("\\S").size() != new_s.size()) { + cover_list("opt.opt_expr.mux_reduce", "$mux", "$pmux", cell->type.str()); + log("Optimized away %d select inputs of %s cell `%s' in module `%s'.\n", + GetSize(cell->getPort("\\S")) - GetSize(new_s), log_id(cell->type), log_id(cell), log_id(module)); + cell->setPort("\\A", new_a); + cell->setPort("\\B", new_b); + cell->setPort("\\S", new_s); + if (new_s.size() > 1) { + cell->type = "$pmux"; + cell->parameters["\\S_WIDTH"] = new_s.size(); + } else { + cell->type = "$mux"; + cell->parameters.erase("\\S_WIDTH"); + } + did_something = true; + } + } + +#define FOLD_1ARG_CELL(_t) \ + if (cell->type == "$" #_t) { \ + RTLIL::SigSpec a = cell->getPort("\\A"); \ + assign_map.apply(a); \ + if (a.is_fully_const()) { \ + RTLIL::Const dummy_arg(RTLIL::State::S0, 1); \ + RTLIL::SigSpec y(RTLIL::const_ ## _t(a.as_const(), dummy_arg, \ + cell->parameters["\\A_SIGNED"].as_bool(), false, \ + cell->parameters["\\Y_WIDTH"].as_int())); \ + cover("opt.opt_expr.const.$" #_t); \ + replace_cell(assign_map, module, cell, stringf("%s", log_signal(a)), "\\Y", y); \ + goto next_cell; \ + } \ + } +#define FOLD_2ARG_CELL(_t) \ + if (cell->type == "$" #_t) { \ + RTLIL::SigSpec a = cell->getPort("\\A"); \ + RTLIL::SigSpec b = cell->getPort("\\B"); \ + assign_map.apply(a), assign_map.apply(b); \ + if (a.is_fully_const() && b.is_fully_const()) { \ + RTLIL::SigSpec y(RTLIL::const_ ## _t(a.as_const(), b.as_const(), \ + cell->parameters["\\A_SIGNED"].as_bool(), \ + cell->parameters["\\B_SIGNED"].as_bool(), \ + cell->parameters["\\Y_WIDTH"].as_int())); \ + cover("opt.opt_expr.const.$" #_t); \ + replace_cell(assign_map, module, cell, stringf("%s, %s", log_signal(a), log_signal(b)), "\\Y", y); \ + goto next_cell; \ + } \ + } + + FOLD_1ARG_CELL(not) + FOLD_2ARG_CELL(and) + FOLD_2ARG_CELL(or) + FOLD_2ARG_CELL(xor) + FOLD_2ARG_CELL(xnor) + + FOLD_1ARG_CELL(reduce_and) + FOLD_1ARG_CELL(reduce_or) + FOLD_1ARG_CELL(reduce_xor) + FOLD_1ARG_CELL(reduce_xnor) + FOLD_1ARG_CELL(reduce_bool) + + FOLD_1ARG_CELL(logic_not) + FOLD_2ARG_CELL(logic_and) + FOLD_2ARG_CELL(logic_or) + + FOLD_2ARG_CELL(shl) + FOLD_2ARG_CELL(shr) + FOLD_2ARG_CELL(sshl) + FOLD_2ARG_CELL(sshr) + FOLD_2ARG_CELL(shift) + FOLD_2ARG_CELL(shiftx) + + FOLD_2ARG_CELL(lt) + FOLD_2ARG_CELL(le) + FOLD_2ARG_CELL(eq) + FOLD_2ARG_CELL(ne) + FOLD_2ARG_CELL(gt) + FOLD_2ARG_CELL(ge) + + FOLD_2ARG_CELL(add) + FOLD_2ARG_CELL(sub) + FOLD_2ARG_CELL(mul) + FOLD_2ARG_CELL(div) + FOLD_2ARG_CELL(mod) + FOLD_2ARG_CELL(pow) + + FOLD_1ARG_CELL(pos) + FOLD_1ARG_CELL(neg) + + // be very conservative with optimizing $mux cells as we do not want to break mux trees + if (cell->type == "$mux") { + RTLIL::SigSpec input = assign_map(cell->getPort("\\S")); + RTLIL::SigSpec inA = assign_map(cell->getPort("\\A")); + RTLIL::SigSpec inB = assign_map(cell->getPort("\\B")); + if (input.is_fully_const()) + ACTION_DO("\\Y", input.as_bool() ? cell->getPort("\\B") : cell->getPort("\\A")); + else if (inA == inB) + ACTION_DO("\\Y", cell->getPort("\\A")); + } + + if (!keepdc && cell->type == "$mul") + { + bool a_signed = cell->parameters["\\A_SIGNED"].as_bool(); + bool b_signed = cell->parameters["\\B_SIGNED"].as_bool(); + bool swapped_ab = false; + + RTLIL::SigSpec sig_a = assign_map(cell->getPort("\\A")); + RTLIL::SigSpec sig_b = assign_map(cell->getPort("\\B")); + RTLIL::SigSpec sig_y = assign_map(cell->getPort("\\Y")); + + if (sig_b.is_fully_const() && sig_b.size() <= 32) + std::swap(sig_a, sig_b), std::swap(a_signed, b_signed), swapped_ab = true; + + if (sig_a.is_fully_def() && sig_a.size() <= 32) + { + int a_val = sig_a.as_int(); + + if (a_val == 0) + { + cover("opt.opt_expr.mul_shift.zero"); + + log("Replacing multiply-by-zero cell `%s' in module `%s' with zero-driver.\n", + cell->name.c_str(), module->name.c_str()); + + module->connect(RTLIL::SigSig(sig_y, RTLIL::SigSpec(0, sig_y.size()))); + module->remove(cell); + + did_something = true; + goto next_cell; + } + + for (int i = 1; i < (a_signed ? sig_a.size()-1 : sig_a.size()); i++) + if (a_val == (1 << i)) + { + if (swapped_ab) + cover("opt.opt_expr.mul_shift.swapped"); + else + cover("opt.opt_expr.mul_shift.unswapped"); + + log("Replacing multiply-by-%d cell `%s' in module `%s' with shift-by-%d.\n", + a_val, cell->name.c_str(), module->name.c_str(), i); + + if (!swapped_ab) { + cell->setPort("\\A", cell->getPort("\\B")); + cell->parameters.at("\\A_WIDTH") = cell->parameters.at("\\B_WIDTH"); + cell->parameters.at("\\A_SIGNED") = cell->parameters.at("\\B_SIGNED"); + } + + std::vector<RTLIL::SigBit> new_b = RTLIL::SigSpec(i, 6); + + while (GetSize(new_b) > 1 && new_b.back() == RTLIL::State::S0) + new_b.pop_back(); + + cell->type = "$shl"; + cell->parameters["\\B_WIDTH"] = GetSize(new_b); + cell->parameters["\\B_SIGNED"] = false; + cell->setPort("\\B", new_b); + cell->check(); + + did_something = true; + goto next_cell; + } + } + } + + next_cell:; +#undef ACTION_DO +#undef ACTION_DO_Y +#undef FOLD_1ARG_CELL +#undef FOLD_2ARG_CELL + } +} + +struct OptExprPass : public Pass { + OptExprPass() : Pass("opt_expr", "perform const folding and simple expression rewriting") { } + virtual void help() + { + // |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---| + log("\n"); + log(" opt_expr [options] [selection]\n"); + log("\n"); + log("This pass performs const folding on internal cell types with constant inputs.\n"); + log("It also performs some simple expression rewritring.\n"); + log("\n"); + log(" -mux_undef\n"); + log(" remove 'undef' inputs from $mux, $pmux and $_MUX_ cells\n"); + log("\n"); + log(" -mux_bool\n"); + log(" replace $mux cells with inverters or buffers when possible\n"); + log("\n"); + log(" -undriven\n"); + log(" replace undriven nets with undef (x) constants\n"); + log("\n"); + log(" -clkinv\n"); + log(" optimize clock inverters by changing FF types\n"); + log("\n"); + log(" -fine\n"); + log(" perform fine-grain optimizations\n"); + log("\n"); + log(" -full\n"); + log(" alias for -mux_undef -mux_bool -undriven -fine\n"); + log("\n"); + log(" -keepdc\n"); + log(" some optimizations change the behavior of the circuit with respect to\n"); + log(" don't-care bits. for example in 'a+0' a single x-bit in 'a' will cause\n"); + log(" all result bits to be set to x. this behavior changes when 'a+0' is\n"); + log(" replaced by 'a'. the -keepdc option disables all such optimizations.\n"); + log("\n"); + } + virtual void execute(std::vector<std::string> args, RTLIL::Design *design) + { + bool mux_undef = false; + bool mux_bool = false; + bool undriven = false; + bool clkinv = false; + bool do_fine = false; + bool keepdc = false; + + log_header("Executing OPT_EXPR pass (perform const folding).\n"); + log_push(); + + size_t argidx; + for (argidx = 1; argidx < args.size(); argidx++) { + if (args[argidx] == "-mux_undef") { + mux_undef = true; + continue; + } + if (args[argidx] == "-mux_bool") { + mux_bool = true; + continue; + } + if (args[argidx] == "-undriven") { + undriven = true; + continue; + } + if (args[argidx] == "-clkinv") { + clkinv = true; + continue; + } + if (args[argidx] == "-fine") { + do_fine = true; + continue; + } + if (args[argidx] == "-full") { + mux_undef = true; + mux_bool = true; + undriven = true; + do_fine = true; + continue; + } + if (args[argidx] == "-keepdc") { + keepdc = true; + continue; + } + break; + } + extra_args(args, argidx, design); + + for (auto module : design->selected_modules()) + { + if (undriven) + replace_undriven(design, module); + + do { + do { + did_something = false; + replace_const_cells(design, module, false, mux_undef, mux_bool, do_fine, keepdc, clkinv); + if (did_something) + design->scratchpad_set_bool("opt.did_something", true); + } while (did_something); + replace_const_cells(design, module, true, mux_undef, mux_bool, do_fine, keepdc, clkinv); + } while (did_something); + } + + log_pop(); + } +} OptExprPass; + +PRIVATE_NAMESPACE_END |