yosys/passes/opt/opt_clean.cc

429 lines
12 KiB
C++

/*
* 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 "opt_status.h"
#include "kernel/register.h"
#include "kernel/sigtools.h"
#include "kernel/log.h"
#include "kernel/celltypes.h"
#include <stdlib.h>
#include <assert.h>
#include <stdio.h>
#include <set>
using RTLIL::id2cstr;
static CellTypes ct, ct_reg, ct_all;
static int count_rm_cells, count_rm_wires;
static void rmunused_module_cells(RTLIL::Module *module, bool verbose)
{
SigMap assign_map(module);
std::set<RTLIL::Cell*, RTLIL::sort_by_name<RTLIL::Cell>> queue, unused;
SigSet<RTLIL::Cell*> wire2driver;
for (auto &it : module->cells) {
RTLIL::Cell *cell = it.second;
for (auto &it2 : cell->connections) {
if (!ct.cell_input(cell->type, it2.first)) {
RTLIL::SigSpec sig = it2.second;
assign_map.apply(sig);
wire2driver.insert(sig, cell);
}
}
if (cell->type == "$memwr" || cell->type == "$assert" || cell->get_bool_attribute("\\keep"))
queue.insert(cell);
unused.insert(cell);
}
for (auto &it : module->wires) {
RTLIL::Wire *wire = it.second;
if (wire->port_output || wire->get_bool_attribute("\\keep")) {
std::set<RTLIL::Cell*> cell_list;
RTLIL::SigSpec sig = RTLIL::SigSpec(wire);
assign_map.apply(sig);
wire2driver.find(sig, cell_list);
for (auto cell : cell_list)
queue.insert(cell);
}
}
while (queue.size() > 0)
{
std::set<RTLIL::Cell*, RTLIL::sort_by_name<RTLIL::Cell>> new_queue;
for (auto cell : queue)
unused.erase(cell);
for (auto cell : queue) {
for (auto &it : cell->connections) {
if (!ct.cell_output(cell->type, it.first)) {
std::set<RTLIL::Cell*> cell_list;
RTLIL::SigSpec sig = it.second;
assign_map.apply(sig);
wire2driver.find(sig, cell_list);
for (auto cell : cell_list) {
if (unused.count(cell) > 0)
new_queue.insert(cell);
}
}
}
}
queue.swap(new_queue);
}
for (auto cell : unused) {
if (verbose)
log(" removing unused `%s' cell `%s'.\n", cell->type.c_str(), cell->name.c_str());
OPT_DID_SOMETHING = true;
module->cells.erase(cell->name);
count_rm_cells++;
delete cell;
}
}
static int count_nontrivial_wire_attrs(RTLIL::Wire *w)
{
int count = w->attributes.size();
count -= w->attributes.count("\\src");
count -= w->attributes.count("\\unused_bits");
return count;
}
static bool compare_signals(RTLIL::SigSpec &s1, RTLIL::SigSpec &s2, SigPool &regs, SigPool &conns, std::set<RTLIL::Wire*> &direct_wires)
{
assert(s1.size() == 1);
assert(s2.size() == 1);
assert(s1.chunks().size() == 1);
assert(s2.chunks().size() == 1);
RTLIL::Wire *w1 = s1.chunks()[0].wire;
RTLIL::Wire *w2 = s2.chunks()[0].wire;
if (w1 == NULL || w2 == NULL)
return w2 == NULL;
if (w1->port_input != w2->port_input)
return w2->port_input;
if (w1->name[0] == '\\' && w2->name[0] == '\\') {
if (regs.check_any(s1) != regs.check_any(s2))
return regs.check_any(s2);
if (direct_wires.count(w1) != direct_wires.count(w2))
return direct_wires.count(w2);
if (conns.check_any(s1) != conns.check_any(s2))
return conns.check_any(s2);
}
if (w1->port_output != w2->port_output)
return w2->port_output;
if (w1->name[0] != w2->name[0])
return w2->name[0] == '\\';
int attrs1 = count_nontrivial_wire_attrs(w1);
int attrs2 = count_nontrivial_wire_attrs(w2);
if (attrs1 != attrs2)
return attrs2 > attrs1;
return w2->name < w1->name;
}
static bool check_public_name(RTLIL::IdString id)
{
if (id[0] == '$')
return false;
if (id.substr(0, 2) == "\\_" && (id[id.size()-1] == '_' || id.find("_[") != std::string::npos))
return false;
if (id.find(".$") != std::string::npos)
return false;
return true;
}
static void rmunused_module_signals(RTLIL::Module *module, bool purge_mode, bool verbose)
{
SigPool register_signals;
SigPool connected_signals;
if (!purge_mode)
for (auto &it : module->cells) {
RTLIL::Cell *cell = it.second;
if (ct_reg.cell_known(cell->type))
for (auto &it2 : cell->connections)
if (ct_reg.cell_output(cell->type, it2.first))
register_signals.add(it2.second);
for (auto &it2 : cell->connections)
connected_signals.add(it2.second);
}
SigMap assign_map(module);
std::set<RTLIL::SigSpec> direct_sigs;
std::set<RTLIL::Wire*> direct_wires;
for (auto &it : module->cells) {
RTLIL::Cell *cell = it.second;
if (ct_all.cell_known(cell->type))
for (auto &it2 : cell->connections)
if (ct_all.cell_output(cell->type, it2.first))
direct_sigs.insert(assign_map(it2.second));
}
for (auto &it : module->wires) {
if (direct_sigs.count(assign_map(it.second)) || it.second->port_input)
direct_wires.insert(it.second);
}
for (auto &it : module->wires) {
RTLIL::Wire *wire = it.second;
for (int i = 0; i < wire->width; i++) {
RTLIL::SigSpec s1 = RTLIL::SigSpec(wire, i), s2 = assign_map(s1);
if (!compare_signals(s1, s2, register_signals, connected_signals, direct_wires))
assign_map.add(s1);
}
}
module->connections.clear();
SigPool used_signals;
SigPool used_signals_nodrivers;
for (auto &it : module->cells) {
RTLIL::Cell *cell = it.second;
for (auto &it2 : cell->connections) {
assign_map.apply(it2.second);
used_signals.add(it2.second);
if (!ct.cell_output(cell->type, it2.first))
used_signals_nodrivers.add(it2.second);
}
}
for (auto &it : module->wires) {
RTLIL::Wire *wire = it.second;
if (wire->port_id > 0) {
RTLIL::SigSpec sig = RTLIL::SigSpec(wire);
assign_map.apply(sig);
used_signals.add(sig);
if (!wire->port_input)
used_signals_nodrivers.add(sig);
}
if (wire->get_bool_attribute("\\keep")) {
RTLIL::SigSpec sig = RTLIL::SigSpec(wire);
assign_map.apply(sig);
used_signals.add(sig);
}
}
std::vector<RTLIL::Wire*> del_wires;
for (auto &it : module->wires) {
RTLIL::Wire *wire = it.second;
if ((!purge_mode && check_public_name(wire->name)) || wire->port_id != 0 || wire->get_bool_attribute("\\keep")) {
RTLIL::SigSpec s1 = RTLIL::SigSpec(wire), s2 = s1;
assign_map.apply(s2);
if (!used_signals.check_any(s2) && wire->port_id == 0 && !wire->get_bool_attribute("\\keep")) {
del_wires.push_back(wire);
} else {
s1.expand();
s2.expand();
assert(s1.chunks().size() == s2.chunks().size());
RTLIL::SigSig new_conn;
for (size_t i = 0; i < s1.chunks().size(); i++)
if (s1.chunks()[i] != s2.chunks()[i]) {
new_conn.first.append(s1.chunks()[i]);
new_conn.second.append(s2.chunks()[i]);
}
if (new_conn.first.size() > 0) {
new_conn.first.optimize();
new_conn.second.optimize();
used_signals.add(new_conn.first);
used_signals.add(new_conn.second);
module->connections.push_back(new_conn);
}
}
} else {
if (!used_signals.check_any(RTLIL::SigSpec(wire)))
del_wires.push_back(wire);
}
RTLIL::SigSpec sig = assign_map(RTLIL::SigSpec(wire));
if (!used_signals_nodrivers.check_any(sig)) {
std::string unused_bits;
sig.expand();
for (size_t i = 0; i < sig.chunks().size(); i++) {
if (sig.chunks()[i].wire == NULL)
continue;
if (!used_signals_nodrivers.check_any(sig)) {
if (!unused_bits.empty())
unused_bits += " ";
unused_bits += stringf("%zd", i);
}
}
if (unused_bits.empty() || wire->port_id != 0)
wire->attributes.erase("\\unused_bits");
else
wire->attributes["\\unused_bits"] = RTLIL::Const(unused_bits);
} else {
wire->attributes.erase("\\unused_bits");
}
}
int del_wires_count = 0;
for (auto wire : del_wires)
if (!used_signals.check_any(RTLIL::SigSpec(wire))) {
if (check_public_name(wire->name) && verbose) {
log(" removing unused non-port wire %s.\n", wire->name.c_str());
del_wires_count++;
}
module->wires.erase(wire->name);
count_rm_wires++;
delete wire;
}
if (del_wires_count > 0)
log(" removed %d unused temporary wires.\n", del_wires_count);
}
static void rmunused_module(RTLIL::Module *module, bool purge_mode, bool verbose)
{
if (verbose)
log("Finding unused cells or wires in module %s..\n", module->name.c_str());
rmunused_module_cells(module, verbose);
rmunused_module_signals(module, purge_mode, verbose);
}
struct OptCleanPass : public Pass {
OptCleanPass() : Pass("opt_clean", "remove unused cells and wires") { }
virtual void help()
{
// |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
log("\n");
log(" opt_clean [options] [selection]\n");
log("\n");
log("This pass identifies wires and cells that are unused and removes them. Other\n");
log("passes often remove cells but leave the wires in the design or reconnect the\n");
log("wires but leave the old cells in the design. This pass can be used to clean up\n");
log("after the passes that do the actual work.\n");
log("\n");
log("This pass only operates on completely selected modules without processes.\n");
log("\n");
log(" -purge\n");
log(" also remove internal nets if they have a public name\n");
log("\n");
}
virtual void execute(std::vector<std::string> args, RTLIL::Design *design)
{
bool purge_mode = false;
log_header("Executing OPT_CLEAN pass (remove unused cells and wires).\n");
log_push();
size_t argidx;
for (argidx = 1; argidx < args.size(); argidx++) {
if (args[argidx] == "-purge") {
purge_mode = true;
continue;
}
break;
}
extra_args(args, argidx, design);
ct.setup_internals();
ct.setup_internals_mem();
ct.setup_stdcells();
ct.setup_stdcells_mem();
ct_reg.setup_internals_mem();
ct_reg.setup_stdcells_mem();
for (auto &mod_it : design->modules) {
if (!design->selected_whole_module(mod_it.first)) {
if (design->selected(mod_it.second))
log("Skipping module %s as it is only partially selected.\n", id2cstr(mod_it.second->name));
continue;
}
if (mod_it.second->processes.size() > 0) {
log("Skipping module %s as it contains processes.\n", mod_it.second->name.c_str());
} else {
rmunused_module(mod_it.second, purge_mode, true);
}
}
ct.clear();
ct_reg.clear();
log_pop();
}
} OptCleanPass;
struct CleanPass : public Pass {
CleanPass() : Pass("clean", "remove unused cells and wires") { }
virtual void help()
{
// |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
log("\n");
log(" clean [options] [selection]\n");
log("\n");
log("This is identical to 'opt_clean', but less verbose.\n");
log("\n");
log("When commands are seperated using the ';;' token, this command will be executed\n");
log("between the commands.\n");
log("\n");
log("When commands are seperated using the ';;;' token, this command will be executed\n");
log("in -purge mode between the commands.\n");
log("\n");
}
virtual void execute(std::vector<std::string> args, RTLIL::Design *design)
{
bool purge_mode = false;
size_t argidx;
for (argidx = 1; argidx < args.size(); argidx++) {
if (args[argidx] == "-purge") {
purge_mode = true;
continue;
}
break;
}
if (argidx < args.size())
extra_args(args, argidx, design);
ct.setup_internals();
ct.setup_internals_mem();
ct.setup_stdcells();
ct.setup_stdcells_mem();
ct_reg.setup_internals_mem();
ct_reg.setup_stdcells_mem();
ct_all.setup(design);
count_rm_cells = 0;
count_rm_wires = 0;
for (auto &mod_it : design->modules) {
if (design->selected_whole_module(mod_it.first) && mod_it.second->processes.size() == 0)
do {
OPT_DID_SOMETHING = false;
rmunused_module(mod_it.second, purge_mode, false);
} while (OPT_DID_SOMETHING);
}
if (count_rm_cells > 0 || count_rm_wires > 0)
log("Removed %d unused cells and %d unused wires.\n", count_rm_cells, count_rm_wires);
ct.clear();
ct_reg.clear();
ct_all.clear();
}
} CleanPass;