mirror of https://github.com/YosysHQ/yosys.git
651 lines
19 KiB
C++
651 lines
19 KiB
C++
/*
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* yosys -- Yosys Open SYnthesis Suite
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*
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* Copyright (C) 2012 Clifford Wolf <clifford@clifford.at>
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* 2019 Bogdan Vukobratovic <bogdan.vukobratovic@gmail.com>
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*
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* Permission to use, copy, modify, and/or distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*
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*/
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#include "kernel/log.h"
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#include "kernel/register.h"
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#include "kernel/rtlil.h"
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#include "kernel/sigtools.h"
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#include <algorithm>
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#include <stdio.h>
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#include <stdlib.h>
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USING_YOSYS_NAMESPACE
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PRIVATE_NAMESPACE_BEGIN
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SigMap assign_map;
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struct OpMuxConn {
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RTLIL::SigSpec sig;
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RTLIL::Cell *mux;
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RTLIL::Cell *op;
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int mux_port_id;
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int mux_port_offset;
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int op_outsig_offset;
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bool operator<(const OpMuxConn &other) const
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{
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if (mux != other.mux)
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return mux < other.mux;
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if (mux_port_id != other.mux_port_id)
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return mux_port_id < other.mux_port_id;
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return mux_port_offset < other.mux_port_offset;
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}
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};
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// Helper class to track additiona information about a SigSpec, like whether it is signed and the semantics of the port it is connected to
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struct ExtSigSpec {
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RTLIL::SigSpec sig;
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RTLIL::SigSpec sign;
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bool is_signed;
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RTLIL::IdString semantics;
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ExtSigSpec() {}
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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) {}
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bool empty() const { return sig.empty(); }
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bool operator<(const ExtSigSpec &other) const
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{
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if (sig != other.sig)
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return sig < other.sig;
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if (sign != other.sign)
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return sign < other.sign;
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if (is_signed != other.is_signed)
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return is_signed < other.is_signed;
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return semantics < other.semantics;
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}
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bool operator==(const RTLIL::SigSpec &other) const { return (sign != RTLIL::Const(0, 1)) ? false : sig == other; }
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bool operator==(const ExtSigSpec &other) const { return is_signed == other.is_signed && sign == other.sign && sig == other.sig && semantics == other.semantics; }
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};
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#define BITWISE_OPS ID($_AND_), ID($_NAND_), ID($_OR_), ID($_NOR_), ID($_XOR_), ID($_XNOR_), ID($_ANDNOT_), ID($_ORNOT_), ID($and), ID($or), ID($xor), ID($xnor)
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#define REDUCTION_OPS ID($reduce_and), ID($reduce_or), ID($reduce_xor), ID($reduce_xnor), ID($reduce_bool), ID($reduce_nand)
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#define LOGICAL_OPS ID($logic_and), ID($logic_or)
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#define SHIFT_OPS ID($shl), ID($shr), ID($sshl), ID($sshr), ID($shift), ID($shiftx)
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#define RELATIONAL_OPS ID($lt), ID($le), ID($eq), ID($ne), ID($eqx), ID($nex), ID($ge), ID($gt)
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bool cell_supported(RTLIL::Cell *cell)
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{
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if (cell->type.in(ID($alu))) {
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RTLIL::SigSpec sig_bi = cell->getPort(ID(BI));
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RTLIL::SigSpec sig_ci = cell->getPort(ID(CI));
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if (sig_bi.is_fully_const() && sig_ci.is_fully_const() && sig_bi == sig_ci)
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return true;
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} else if (cell->type.in(LOGICAL_OPS, SHIFT_OPS, BITWISE_OPS, RELATIONAL_OPS, ID($add), ID($sub), ID($mul), ID($div), ID($mod), ID($concat))) {
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return true;
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}
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return false;
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}
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std::map<IdString, IdString> mergeable_type_map;
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bool mergeable(RTLIL::Cell *a, RTLIL::Cell *b)
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{
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if (mergeable_type_map.empty()) {
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mergeable_type_map.insert({ID($sub), ID($add)});
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}
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auto a_type = a->type;
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if (mergeable_type_map.count(a_type))
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a_type = mergeable_type_map.at(a_type);
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auto b_type = b->type;
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if (mergeable_type_map.count(b_type))
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b_type = mergeable_type_map.at(b_type);
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return a_type == b_type;
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}
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RTLIL::IdString decode_port_semantics(RTLIL::Cell *cell, RTLIL::IdString port_name)
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{
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if (cell->type.in(ID($lt), ID($le), ID($ge), ID($gt), ID($div), ID($mod), ID($concat), SHIFT_OPS) && port_name == ID::B)
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return port_name;
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return "";
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}
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RTLIL::SigSpec decode_port_sign(RTLIL::Cell *cell, RTLIL::IdString port_name) {
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if (cell->type == ID($alu) && port_name == ID::B)
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return cell->getPort(ID(BI));
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else if (cell->type == ID($sub) && port_name == ID::B)
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return RTLIL::Const(1, 1);
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return RTLIL::Const(0, 1);
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}
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bool decode_port_signed(RTLIL::Cell *cell, RTLIL::IdString port_name)
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{
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if (cell->type.in(BITWISE_OPS, LOGICAL_OPS))
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return false;
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if (cell->hasParam(port_name.str() + "_SIGNED"))
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return cell->getParam(port_name.str() + "_SIGNED").as_bool();
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return false;
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}
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ExtSigSpec decode_port(RTLIL::Cell *cell, RTLIL::IdString port_name, SigMap *sigmap)
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{
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auto sig = (*sigmap)(cell->getPort(port_name));
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RTLIL::SigSpec sign = decode_port_sign(cell, port_name);
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RTLIL::IdString semantics = decode_port_semantics(cell, port_name);
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bool is_signed = decode_port_signed(cell, port_name);
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return ExtSigSpec(sig, sign, is_signed, semantics);
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}
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void merge_operators(RTLIL::Module *module, RTLIL::Cell *mux, const std::vector<OpMuxConn> &ports, const ExtSigSpec &operand)
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{
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std::vector<ExtSigSpec> muxed_operands;
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int max_width = 0;
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for (const auto& p : ports) {
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auto op = p.op;
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RTLIL::IdString muxed_port_name = ID::A;
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if (decode_port(op, ID::A, &assign_map) == operand)
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muxed_port_name = ID::B;
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auto operand = decode_port(op, muxed_port_name, &assign_map);
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if (operand.sig.size() > max_width)
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max_width = operand.sig.size();
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muxed_operands.push_back(operand);
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}
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auto shared_op = ports[0].op;
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if (std::any_of(muxed_operands.begin(), muxed_operands.end(), [&](ExtSigSpec &op) { return op.sign != muxed_operands[0].sign; }))
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max_width = std::max(max_width, shared_op->getParam(ID(Y_WIDTH)).as_int());
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for (auto &operand : muxed_operands)
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operand.sig.extend_u0(max_width, operand.is_signed);
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for (const auto& p : ports) {
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auto op = p.op;
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if (op == shared_op)
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continue;
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module->remove(op);
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}
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for (auto &muxed_op : muxed_operands)
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if (muxed_op.sign != muxed_operands[0].sign)
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muxed_op = ExtSigSpec(module->Neg(NEW_ID, muxed_op.sig, muxed_op.is_signed));
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RTLIL::SigSpec mux_y = mux->getPort(ID::Y);
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RTLIL::SigSpec mux_a = mux->getPort(ID::A);
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RTLIL::SigSpec mux_b = mux->getPort(ID::B);
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RTLIL::SigSpec mux_s = mux->getPort(ID(S));
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RTLIL::SigSpec shared_pmux_a = RTLIL::Const(RTLIL::State::Sx, max_width);
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RTLIL::SigSpec shared_pmux_b;
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RTLIL::SigSpec shared_pmux_s;
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int conn_width = ports[0].sig.size();
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int conn_offset = ports[0].mux_port_offset;
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shared_op->setPort(ID::Y, shared_op->getPort(ID::Y).extract(0, conn_width));
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if (mux->type == ID($pmux)) {
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shared_pmux_s = RTLIL::SigSpec();
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for (const auto &p : ports) {
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shared_pmux_s.append(mux_s[p.mux_port_id]);
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mux_b.replace(p.mux_port_id * mux_a.size() + conn_offset, shared_op->getPort(ID::Y));
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}
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} else {
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shared_pmux_s = RTLIL::SigSpec{mux_s, module->Not(NEW_ID, mux_s)};
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mux_a.replace(conn_offset, shared_op->getPort(ID::Y));
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mux_b.replace(conn_offset, shared_op->getPort(ID::Y));
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}
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mux->setPort(ID::A, mux_a);
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mux->setPort(ID::B, mux_b);
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mux->setPort(ID::Y, mux_y);
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mux->setPort(ID(S), mux_s);
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for (const auto &op : muxed_operands)
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shared_pmux_b.append(op.sig);
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auto mux_to_oper = module->Pmux(NEW_ID, shared_pmux_a, shared_pmux_b, shared_pmux_s);
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if (shared_op->type.in(ID($alu))) {
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RTLIL::SigSpec alu_x = shared_op->getPort(ID(X));
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RTLIL::SigSpec alu_co = shared_op->getPort(ID(CO));
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shared_op->setPort(ID(X), alu_x.extract(0, conn_width));
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shared_op->setPort(ID(CO), alu_co.extract(0, conn_width));
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}
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shared_op->setParam(ID(Y_WIDTH), conn_width);
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if (decode_port(shared_op, ID::A, &assign_map) == operand) {
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shared_op->setPort(ID::B, mux_to_oper);
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shared_op->setParam(ID(B_WIDTH), max_width);
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} else {
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shared_op->setPort(ID::A, mux_to_oper);
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shared_op->setParam(ID(A_WIDTH), max_width);
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}
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}
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typedef struct {
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RTLIL::Cell *mux;
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std::vector<OpMuxConn> ports;
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ExtSigSpec shared_operand;
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} merged_op_t;
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template <typename T> void remove_val(std::vector<T> &v, const std::vector<T> &vals)
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{
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auto val_iter = vals.rbegin();
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for (auto i = v.rbegin(); i != v.rend(); ++i)
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if ((val_iter != vals.rend()) && (*i == *val_iter)) {
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v.erase(i.base() - 1);
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++val_iter;
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}
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}
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void check_muxed_operands(std::vector<const OpMuxConn *> &ports, const ExtSigSpec &shared_operand)
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{
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auto it = ports.begin();
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ExtSigSpec seed;
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while (it != ports.end()) {
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auto p = *it;
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auto op = p->op;
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RTLIL::IdString muxed_port_name = ID::A;
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if (decode_port(op, ID::A, &assign_map) == shared_operand) {
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muxed_port_name = ID::B;
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}
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auto operand = decode_port(op, muxed_port_name, &assign_map);
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if (seed.empty())
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seed = operand;
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if (operand.is_signed != seed.is_signed) {
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ports.erase(it);
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} else {
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++it;
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}
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}
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}
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ExtSigSpec find_shared_operand(const OpMuxConn* seed, std::vector<const OpMuxConn *> &ports, const std::map<ExtSigSpec, std::set<RTLIL::Cell *>> &operand_to_users)
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{
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std::set<RTLIL::Cell *> ops_using_operand;
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std::set<RTLIL::Cell *> ops_set;
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for(const auto& p: ports)
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ops_set.insert(p->op);
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ExtSigSpec oper;
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auto op_a = seed->op;
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for (RTLIL::IdString port_name : {ID::A, ID::B}) {
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oper = decode_port(op_a, port_name, &assign_map);
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auto operand_users = operand_to_users.at(oper);
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if (operand_users.size() == 1)
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continue;
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ops_using_operand.clear();
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for (auto mux_ops: ops_set)
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if (operand_users.count(mux_ops))
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ops_using_operand.insert(mux_ops);
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if (ops_using_operand.size() > 1) {
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ports.erase(std::remove_if(ports.begin(), ports.end(), [&](const OpMuxConn *p) { return !ops_using_operand.count(p->op); }),
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ports.end());
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return oper;
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}
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}
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return ExtSigSpec();
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}
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dict<RTLIL::SigSpec, OpMuxConn> find_valid_op_mux_conns(RTLIL::Module *module, dict<RTLIL::SigBit, RTLIL::SigSpec> &op_outbit_to_outsig,
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dict<RTLIL::SigSpec, RTLIL::Cell *> outsig_to_operator,
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dict<RTLIL::SigBit, RTLIL::SigSpec> &op_aux_to_outsig)
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{
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dict<RTLIL::SigSpec, int> op_outsig_user_track;
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dict<RTLIL::SigSpec, OpMuxConn> op_mux_conn_map;
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std::function<void(RTLIL::SigSpec)> remove_outsig = [&](RTLIL::SigSpec outsig) {
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for (auto op_outbit : outsig)
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op_outbit_to_outsig.erase(op_outbit);
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if (op_mux_conn_map.count(outsig))
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op_mux_conn_map.erase(outsig);
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};
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std::function<void(RTLIL::SigBit)> remove_outsig_from_aux_bit = [&](RTLIL::SigBit auxbit) {
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auto aux_outsig = op_aux_to_outsig.at(auxbit);
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auto op = outsig_to_operator.at(aux_outsig);
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auto op_outsig = assign_map(op->getPort(ID::Y));
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remove_outsig(op_outsig);
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for (auto aux_outbit : aux_outsig)
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op_aux_to_outsig.erase(aux_outbit);
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};
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std::function<void(RTLIL::Cell *)> find_op_mux_conns = [&](RTLIL::Cell *mux) {
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RTLIL::SigSpec sig;
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int mux_port_size;
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if (mux->type.in(ID($mux), ID($_MUX_))) {
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mux_port_size = mux->getPort(ID::A).size();
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sig = RTLIL::SigSpec{mux->getPort(ID::B), mux->getPort(ID::A)};
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} else {
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mux_port_size = mux->getPort(ID::A).size();
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sig = mux->getPort(ID::B);
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}
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auto mux_insig = assign_map(sig);
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for (int i = 0; i < mux_insig.size(); ++i) {
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if (op_aux_to_outsig.count(mux_insig[i])) {
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remove_outsig_from_aux_bit(mux_insig[i]);
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continue;
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}
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if (!op_outbit_to_outsig.count(mux_insig[i]))
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continue;
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auto op_outsig = op_outbit_to_outsig.at(mux_insig[i]);
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if (op_mux_conn_map.count(op_outsig)) {
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remove_outsig(op_outsig);
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continue;
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}
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int mux_port_id = i / mux_port_size;
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int mux_port_offset = i % mux_port_size;
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int op_outsig_offset;
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for (op_outsig_offset = 0; op_outsig[op_outsig_offset] != mux_insig[i]; ++op_outsig_offset)
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;
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int j = op_outsig_offset;
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do {
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if (!op_outbit_to_outsig.count(mux_insig[i]))
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break;
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if (op_outbit_to_outsig.at(mux_insig[i]) != op_outsig)
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break;
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++i;
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++j;
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} while ((i / mux_port_size == mux_port_id) && (j < op_outsig.size()));
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int op_conn_width = j - op_outsig_offset;
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OpMuxConn inp = {
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op_outsig.extract(op_outsig_offset, op_conn_width),
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mux,
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outsig_to_operator.at(op_outsig),
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mux_port_id,
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mux_port_offset,
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op_outsig_offset,
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};
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op_mux_conn_map[op_outsig] = inp;
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--i;
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}
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};
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std::function<void(RTLIL::SigSpec)> remove_connected_ops = [&](RTLIL::SigSpec sig) {
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auto mux_insig = assign_map(sig);
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for (auto outbit : mux_insig) {
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if (op_aux_to_outsig.count(outbit)) {
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remove_outsig_from_aux_bit(outbit);
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continue;
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}
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if (!op_outbit_to_outsig.count(outbit))
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continue;
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remove_outsig(op_outbit_to_outsig.at(outbit));
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}
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};
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for (auto cell : module->cells()) {
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if (cell->type.in(ID($mux), ID($_MUX_), ID($pmux))) {
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remove_connected_ops(cell->getPort(ID(S)));
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find_op_mux_conns(cell);
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} else {
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for (auto &conn : cell->connections())
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if (cell->input(conn.first))
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remove_connected_ops(conn.second);
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}
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}
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for (auto w : module->wires()) {
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if (!w->port_output)
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continue;
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|
|
|
remove_connected_ops(w);
|
|
}
|
|
|
|
return op_mux_conn_map;
|
|
}
|
|
|
|
struct OptSharePass : public Pass {
|
|
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---|
|
|
log("\n");
|
|
log(" opt_share [selection]\n");
|
|
log("\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 $pmux multiplexing cell,\n");
|
|
log("\n");
|
|
log("allowing the cell to be merged and the multiplexer to be moved from\n");
|
|
log("multiplexing its output to multiplexing the non-shared input signals.\n");
|
|
log("\n");
|
|
}
|
|
void execute(std::vector<std::string> args, RTLIL::Design *design) YS_OVERRIDE
|
|
{
|
|
|
|
log_header(design, "Executing OPT_SHARE pass.\n");
|
|
|
|
extra_args(args, 1, design);
|
|
for (auto module : design->selected_modules()) {
|
|
assign_map.clear();
|
|
assign_map.set(module);
|
|
|
|
std::map<ExtSigSpec, std::set<RTLIL::Cell *>> operand_to_users;
|
|
dict<RTLIL::SigSpec, RTLIL::Cell *> outsig_to_operator;
|
|
dict<RTLIL::SigBit, RTLIL::SigSpec> op_outbit_to_outsig;
|
|
dict<RTLIL::SigBit, RTLIL::SigSpec> op_aux_to_outsig;
|
|
bool any_shared_operands = false;
|
|
std::vector<ExtSigSpec> op_insigs;
|
|
|
|
for (auto cell : module->cells()) {
|
|
if (!cell_supported(cell))
|
|
continue;
|
|
|
|
if (cell->type == ID($alu)) {
|
|
for (RTLIL::IdString port_name : {ID(X), ID(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 mux_insig = assign_map(cell->getPort(ID::Y));
|
|
outsig_to_operator[mux_insig] = cell;
|
|
for (auto outbit : mux_insig)
|
|
op_outbit_to_outsig[outbit] = mux_insig;
|
|
|
|
for (RTLIL::IdString port_name : {ID::A, ID::B}) {
|
|
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)
|
|
any_shared_operands = true;
|
|
}
|
|
}
|
|
|
|
if (!any_shared_operands)
|
|
continue;
|
|
|
|
// 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.
|
|
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);
|
|
|
|
// Group op connections connected to same ports of the same $mux. Sort them in ascending order of their port offset
|
|
dict<RTLIL::Cell*, std::vector<std::set<OpMuxConn>>> mux_port_op_conns;
|
|
for (auto& val: op_mux_conn_map) {
|
|
OpMuxConn p = val.second;
|
|
auto& mux_port_conns = mux_port_op_conns[p.mux];
|
|
|
|
if (mux_port_conns.size() == 0) {
|
|
int mux_port_num;
|
|
|
|
if (p.mux->type.in(ID($mux), ID($_MUX_)))
|
|
mux_port_num = 2;
|
|
else
|
|
mux_port_num = p.mux->getPort(ID(S)).size();
|
|
|
|
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.
|
|
while (true) {
|
|
|
|
// 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;
|
|
}
|
|
|
|
// 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;
|
|
|
|
const OpMuxConn *next_p = &(*port_conns.begin());
|
|
|
|
if ((seed == NULL) || (seed->mux_port_offset > next_p->mux_port_offset))
|
|
seed = next_p;
|
|
}
|
|
|
|
// 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;
|
|
|
|
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;
|
|
|
|
// 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);
|
|
|
|
if (shared_operand.empty())
|
|
continue;
|
|
|
|
check_muxed_operands(mergeable_conns, shared_operand);
|
|
|
|
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);
|
|
}
|
|
|
|
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 : 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.op));
|
|
log("\n");
|
|
|
|
merge_operators(module, shared.mux, shared.ports, shared.shared_operand);
|
|
}
|
|
}
|
|
}
|
|
|
|
} OptSharePass;
|
|
|
|
PRIVATE_NAMESPACE_END
|