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yosys/passes/opt/opt_expr.cc
whitequark efa278e232 Fix typographical and grammatical errors and inconsistencies. 
The initial list of hits was generated with the codespell command
below, and each hit was evaluated and fixed manually while taking
context into consideration.

    DIRS="kernel/ frontends/ backends/ passes/ techlibs/"
    DIRS="${DIRS} libs/ezsat/ libs/subcircuit"
    codespell $DIRS -S *.o -L upto,iff,thru,synopsys,uint

More hits were found by looking through comments and strings manually.
2019-01-02 13:12:17 +00:00

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/*
* 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;
}
// if the signal has only one bit set, return the index of that bit.
// otherwise return -1
int get_onehot_bit_index(RTLIL::SigSpec signal)
{
int bit_index = -1;
for (int i = 0; i < GetSize(signal); i++)
{
if (signal[i] == RTLIL::State::S0)
continue;
if (signal[i] != RTLIL::State::S1)
return -1;
if (bit_index != -1)
return -1;
bit_index = i;
}
return bit_index;
}
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);
}
bool detect_const_and = false;
bool detect_const_or = false;
if (cell->type.in("$reduce_and", "$_AND_"))
detect_const_and = true;
if (cell->type.in("$and", "$logic_and") && GetSize(cell->getPort("\\A")) == 1 && GetSize(cell->getPort("\\B")) == 1 && !cell->getParam("\\A_SIGNED").as_bool())
detect_const_and = true;
if (cell->type.in("$reduce_or", "$reduce_bool", "$_OR_"))
detect_const_or = true;
if (cell->type.in("$or", "$logic_or") && GetSize(cell->getPort("\\A")) == 1 && GetSize(cell->getPort("\\B")) == 1 && !cell->getParam("\\A_SIGNED").as_bool())
detect_const_or = true;
if (detect_const_and || detect_const_or)
{
pool<SigBit> input_bits = assign_map(cell->getPort("\\A")).to_sigbit_pool();
bool found_zero = false, found_one = false, found_undef = false, found_inv = false, many_conconst = false;
SigBit non_const_input = State::Sm;
if (cell->hasPort("\\B")) {
vector<SigBit> more_bits = assign_map(cell->getPort("\\B")).to_sigbit_vector();
input_bits.insert(more_bits.begin(), more_bits.end());
}
for (auto bit : input_bits) {
if (bit.wire) {
if (invert_map.count(bit) && input_bits.count(invert_map.at(bit)))
found_inv = true;
if (non_const_input != State::Sm)
many_conconst = true;
non_const_input = many_conconst ? State::Sm : bit;
} else {
if (bit == State::S0)
found_zero = true;
else if (bit == State::S1)
found_one = true;
else
found_undef = true;
}
}
if (detect_const_and && (found_zero || found_inv)) {
cover("opt.opt_expr.const_and");
replace_cell(assign_map, module, cell, "const_and", "\\Y", RTLIL::State::S0);
goto next_cell;
}
if (detect_const_or && (found_one || found_inv)) {
cover("opt.opt_expr.const_or");
replace_cell(assign_map, module, cell, "const_or", "\\Y", RTLIL::State::S1);
goto next_cell;
}
if (non_const_input != State::Sm && !found_undef) {
cover("opt.opt_expr.and_or_buffer");
replace_cell(assign_map, module, cell, "and_or_buffer", "\\Y", non_const_input);
goto next_cell;
}
}
if (cell->type.in("$reduce_and", "$reduce_or", "$reduce_bool", "$reduce_xor", "$reduce_xnor", "$neg") &&
GetSize(cell->getPort("\\A")) == 1 && GetSize(cell->getPort("\\Y")) == 1)
{
if (cell->type == "$reduce_xnor") {
cover("opt.opt_expr.reduce_xnor_not");
log("Replacing %s cell `%s' in module `%s' with $not cell.\n",
log_id(cell->type), log_id(cell->name), log_id(module));
cell->type = "$not";
} else {
cover("opt.opt_expr.unary_buffer");
replace_cell(assign_map, module, cell, "unary_buffer", "\\Y", cell->getPort("\\A"));
}
goto next_cell;
}
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 == "$logic_not" || cell->type == "$logic_and" || cell->type == "$logic_or" ||
cell->type == "$reduce_or" || cell->type == "$reduce_and" || cell->type == "$reduce_bool")
{
SigBit neutral_bit = cell->type == "$reduce_and" ? State::S1 : State::S0;
RTLIL::SigSpec sig_a = assign_map(cell->getPort("\\A"));
RTLIL::SigSpec new_sig_a;
for (auto bit : sig_a)
if (bit != neutral_bit) new_sig_a.append(bit);
if (GetSize(new_sig_a) == 0)
new_sig_a.append(neutral_bit);
if (GetSize(new_sig_a) < GetSize(sig_a)) {
cover_list("opt.opt_expr.fine.neutral_A", "$logic_not", "$logic_and", "$logic_or", "$reduce_or", "$reduce_and", "$reduce_bool", cell->type.str());
log("Replacing port A of %s cell `%s' in module `%s' with shorter expression: %s -> %s\n",
cell->type.c_str(), cell->name.c_str(), module->name.c_str(), log_signal(sig_a), log_signal(new_sig_a));
cell->setPort("\\A", new_sig_a);
cell->parameters.at("\\A_WIDTH") = GetSize(new_sig_a);
did_something = true;
}
}
if (cell->type == "$logic_and" || cell->type == "$logic_or")
{
SigBit neutral_bit = State::S0;
RTLIL::SigSpec sig_b = assign_map(cell->getPort("\\B"));
RTLIL::SigSpec new_sig_b;
for (auto bit : sig_b)
if (bit != neutral_bit) new_sig_b.append(bit);
if (GetSize(new_sig_b) == 0)
new_sig_b.append(neutral_bit);
if (GetSize(new_sig_b) < GetSize(sig_b)) {
cover_list("opt.opt_expr.fine.neutral_B", "$logic_and", "$logic_or", cell->type.str());
log("Replacing port B of %s cell `%s' in module `%s' with shorter expression: %s -> %s\n",
cell->type.c_str(), cell->name.c_str(), module->name.c_str(), log_signal(sig_b), log_signal(new_sig_b));
cell->setPort("\\B", new_sig_b);
cell->parameters.at("\\B_WIDTH") = GetSize(new_sig_b);
did_something = true;
}
}
if (cell->type == "$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", "$logic_or", cell->type.str());
log("Replacing port B of %s cell `%s' in module `%s' with constant driver: %s -> %s\n",
cell->type.c_str(), cell->name.c_str(), module->name.c_str(), log_signal(sig_b), log_signal(new_b));
cell->setPort("\\B", sig_b = new_b);
cell->parameters.at("\\B_WIDTH") = 1;
did_something = true;
}
}
}
if (cell->type == "$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 = "$_NOT_";
cell->setPort("\\A", input.extract(0, 1));
cell->unsetPort("\\B");
cell->unsetPort("\\S");
goto next_cell;
}
if (input.match("11 ")) ACTION_DO_Y(1);
if (input.match("00 ")) ACTION_DO_Y(0);
if (input.match("** ")) ACTION_DO_Y(x);
if (input.match("01*")) ACTION_DO_Y(x);
if (input.match("10*")) ACTION_DO_Y(x);
if (mux_undef) {
if (input.match("* ")) ACTION_DO("\\Y", input.extract(1, 1));
if (input.match(" * ")) ACTION_DO("\\Y", input.extract(2, 1));
if (input.match(" *")) ACTION_DO("\\Y", input.extract(2, 1));
}
}
if (cell->type == "$_TBUF_" || cell->type == "$tribuf") {
RTLIL::SigSpec input = cell->getPort(cell->type == "$_TBUF_" ? "\\E" : "\\EN");
RTLIL::SigSpec a = cell->getPort("\\A");
assign_map.apply(input);
assign_map.apply(a);
if (input == State::S1)
ACTION_DO("\\Y", cell->getPort("\\A"));
if (input == State::S0 && !a.is_fully_undef()) {
cover("opt.opt_expr.action_" S__LINE__);
log("Replacing data input of %s cell `%s' in module `%s' with constant undef.\n",
cell->type.c_str(), cell->name.c_str(), module->name.c_str());
cell->setPort("\\A", SigSpec(State::Sx, GetSize(a)));
did_something = true;
goto next_cell;
}
}
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;
}
}
}
if (!keepdc && cell->type.in("$div", "$mod"))
{
bool b_signed = cell->parameters["\\B_SIGNED"].as_bool();
SigSpec sig_b = assign_map(cell->getPort("\\B"));
SigSpec sig_y = assign_map(cell->getPort("\\Y"));
if (sig_b.is_fully_def() && sig_b.size() <= 32)
{
int b_val = sig_b.as_int();
if (b_val == 0)
{
cover("opt.opt_expr.divmod_zero");
log("Replacing divide-by-zero cell `%s' in module `%s' with undef-driver.\n",
cell->name.c_str(), module->name.c_str());
module->connect(RTLIL::SigSig(sig_y, RTLIL::SigSpec(State::Sx, sig_y.size())));
module->remove(cell);
did_something = true;
goto next_cell;
}
for (int i = 1; i < (b_signed ? sig_b.size()-1 : sig_b.size()); i++)
if (b_val == (1 << i))
{
if (cell->type == "$div")
{
cover("opt.opt_expr.div_shift");
log("Replacing divide-by-%d cell `%s' in module `%s' with shift-by-%d.\n",
b_val, cell->name.c_str(), module->name.c_str(), i);
std::vector<RTLIL::SigBit> new_b = RTLIL::SigSpec(i, 6);
while (GetSize(new_b) > 1 && new_b.back() == RTLIL::State::S0)
new_b.pop_back();
cell->type = "$shr";
cell->parameters["\\B_WIDTH"] = GetSize(new_b);
cell->parameters["\\B_SIGNED"] = false;
cell->setPort("\\B", new_b);
cell->check();
}
else
{
cover("opt.opt_expr.mod_mask");
log("Replacing modulo-by-%d cell `%s' in module `%s' with bitmask.\n",
b_val, cell->name.c_str(), module->name.c_str());
std::vector<RTLIL::SigBit> new_b = RTLIL::SigSpec(State::S1, i);
if (b_signed)
new_b.push_back(State::S0);
cell->type = "$and";
cell->parameters["\\B_WIDTH"] = GetSize(new_b);
cell->setPort("\\B", new_b);
cell->check();
}
did_something = true;
goto next_cell;
}
}
}
// remove redundant pairs of bits in ==, ===, !=, and !==
// replace cell with const driver if inputs can't be equal
if (do_fine && cell->type.in("$eq", "$ne", "$eqx", "$nex"))
{
pool<pair<SigBit, SigBit>> redundant_cache;
mfp<SigBit> contradiction_cache;
contradiction_cache.promote(State::S0);
contradiction_cache.promote(State::S1);
int a_width = cell->getParam("\\A_WIDTH").as_int();
int b_width = cell->getParam("\\B_WIDTH").as_int();
bool is_signed = cell->getParam("\\A_SIGNED").as_bool();
int width = is_signed ? std::min(a_width, b_width) : std::max(a_width, b_width);
SigSpec sig_a = cell->getPort("\\A");
SigSpec sig_b = cell->getPort("\\B");
int redundant_bits = 0;
for (int i = width-1; i >= 0; i--)
{
SigBit bit_a = i < a_width ? assign_map(sig_a[i]) : State::S0;
SigBit bit_b = i < b_width ? assign_map(sig_b[i]) : State::S0;
if (bit_a != State::Sx && bit_a != State::Sz &&
bit_b != State::Sx && bit_b != State::Sz)
contradiction_cache.merge(bit_a, bit_b);
if (bit_b < bit_a)
std::swap(bit_a, bit_b);
pair<SigBit, SigBit> key(bit_a, bit_b);
if (redundant_cache.count(key)) {
if (i < a_width) sig_a.remove(i);
if (i < b_width) sig_b.remove(i);
redundant_bits++;
continue;
}
redundant_cache.insert(key);
}
if (contradiction_cache.find(State::S0) == contradiction_cache.find(State::S1))
{
SigSpec y_sig = cell->getPort("\\Y");
Const y_value(cell->type.in("$eq", "$eqx") ? 0 : 1, GetSize(y_sig));
log("Replacing cell `%s' in module `%s' with constant driver %s.\n",
log_id(cell), log_id(module), log_signal(y_value));
module->connect(y_sig, y_value);
module->remove(cell);
did_something = true;
goto next_cell;
}
if (redundant_bits)
{
log("Removed %d redundant input bits from %s cell `%s' in module `%s'.\n",
redundant_bits, log_id(cell->type), log_id(cell), log_id(module));
cell->setPort("\\A", sig_a);
cell->setPort("\\B", sig_b);
cell->setParam("\\A_WIDTH", GetSize(sig_a));
cell->setParam("\\B_WIDTH", GetSize(sig_b));
did_something = true;
goto next_cell;
}
}
// replace a<0 or a>=0 with the top bit of a
if (do_fine && (cell->type == "$lt" || cell->type == "$ge" || cell->type == "$gt" || cell->type == "$le"))
{
//used to decide whether the signal needs to be negated
bool is_lt = false;
//references the variable signal in the comparison
RTLIL::SigSpec sigVar;
//references the constant signal in the comparison
RTLIL::SigSpec sigConst;
// note that this signal must be constant for the optimization
// to take place, but it is not checked beforehand.
// If new passes are added, this signal must be checked for const-ness
//width of the variable port
int width;
int const_width;
bool var_signed;
if (cell->type == "$lt" || cell->type == "$ge") {
is_lt = cell->type == "$lt" ? 1 : 0;
sigVar = cell->getPort("\\A");
sigConst = cell->getPort("\\B");
width = cell->parameters["\\A_WIDTH"].as_int();
const_width = cell->parameters["\\B_WIDTH"].as_int();
var_signed = cell->parameters["\\A_SIGNED"].as_bool();
} else
if (cell->type == "$gt" || cell->type == "$le") {
is_lt = cell->type == "$gt" ? 1 : 0;
sigVar = cell->getPort("\\B");
sigConst = cell->getPort("\\A");
width = cell->parameters["\\B_WIDTH"].as_int();
const_width = cell->parameters["\\A_WIDTH"].as_int();
var_signed = cell->parameters["\\B_SIGNED"].as_bool();
} else
log_abort();
// replace a(signed) < 0 with the high bit of a
if (sigConst.is_fully_const() && sigConst.is_fully_zero() && var_signed == true)
{
RTLIL::SigSpec a_prime(RTLIL::State::S0, cell->parameters["\\Y_WIDTH"].as_int());
a_prime[0] = sigVar[width - 1];
if (is_lt) {
log("Replacing %s cell `%s' (implementing X<0) with X[%d]: %s\n",
log_id(cell->type), log_id(cell), width-1, log_signal(a_prime));
module->connect(cell->getPort("\\Y"), a_prime);
module->remove(cell);
} else {
log("Replacing %s cell `%s' (implementing X>=0) with ~X[%d]: %s\n",
log_id(cell->type), log_id(cell), width-1, log_signal(a_prime));
module->addNot(NEW_ID, a_prime, cell->getPort("\\Y"));
module->remove(cell);
}
did_something = true;
goto next_cell;
} else
if (sigConst.is_fully_const() && sigConst.is_fully_def() && var_signed == false)
{
if (sigConst.is_fully_zero()) {
RTLIL::SigSpec a_prime(RTLIL::State::S0, GetSize(cell->getPort("\\Y")));
if (is_lt) {
log("Replacing %s cell `%s' (implementing unsigned X<0) with constant false.\n",
log_id(cell->type), log_id(cell));
a_prime[0] = RTLIL::State::S0;
} else {
log("Replacing %s cell `%s' (implementing unsigned X>=0) with constant true.\n",
log_id(cell->type), log_id(cell));
a_prime[0] = RTLIL::State::S1;
}
module->connect(cell->getPort("\\Y"), a_prime);
module->remove(cell);
did_something = true;
goto next_cell;
}
int const_bit_set = get_onehot_bit_index(sigConst);
if (const_bit_set >= 0 && const_bit_set < width) {
int bit_set = const_bit_set;
RTLIL::SigSpec a_prime(RTLIL::State::S0, width - bit_set);
for (int i = bit_set; i < width; i++) {
a_prime[i - bit_set] = sigVar[i];
}
if (is_lt) {
log("Replacing %s cell `%s' (implementing unsigned X<%s) with !X[%d:%d]: %s.\n",
log_id(cell->type), log_id(cell), log_signal(sigConst), width - 1, bit_set, log_signal(a_prime));
module->addLogicNot(NEW_ID, a_prime, cell->getPort("\\Y"));
} else {
log("Replacing %s cell `%s' (implementing unsigned X>=%s) with |X[%d:%d]: %s.\n",
log_id(cell->type), log_id(cell), log_signal(sigConst), width - 1, bit_set, log_signal(a_prime));
module->addReduceOr(NEW_ID, a_prime, cell->getPort("\\Y"));
}
module->remove(cell);
did_something = true;
goto next_cell;
}
else if(const_bit_set >= width && const_bit_set >= 0){
RTLIL::SigSpec a_prime(RTLIL::State::S0, 1);
if(is_lt){
a_prime[0] = RTLIL::State::S1;
log("Replacing %s cell `%s' (implementing unsigned X[%d:0] < %s[%d:0]) with constant 0.\n", log_id(cell->type), log_id(cell), width-1, log_signal(sigConst),const_width-1);
}
else{
log("Replacing %s cell `%s' (implementing unsigned X[%d:0]>= %s[%d:0]) with constant 1.\n", log_id(cell->type), log_id(cell), width-1, log_signal(sigConst),const_width-1);
}
module->connect(cell->getPort("\\Y"), a_prime);
module->remove(cell);
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") { }
void help() YS_OVERRIDE
{
// |---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 rewriting.\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");
}
void execute(std::vector<std::string> args, RTLIL::Design *design) YS_OVERRIDE
{
bool mux_undef = false;
bool mux_bool = false;
bool undriven = false;
bool clkinv = false;
bool do_fine = false;
bool keepdc = false;
log_header(design, "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
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