OpenFPGA/yosys/passes/opt/opt_clean.cc

636 lines
17 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 "kernel/register.h"
#include "kernel/sigtools.h"
#include "kernel/log.h"
#include "kernel/celltypes.h"
#include <stdlib.h>
#include <stdio.h>
#include <set>
USING_YOSYS_NAMESPACE
PRIVATE_NAMESPACE_BEGIN
using RTLIL::id2cstr;
struct keep_cache_t
{
Design *design;
dict<Module*, bool> cache;
void reset(Design *design = nullptr)
{
this->design = design;
cache.clear();
}
bool query(Module *module)
{
log_assert(design != nullptr);
if (module == nullptr)
return false;
if (cache.count(module))
return cache.at(module);
cache[module] = true;
if (!module->get_bool_attribute("\\keep")) {
bool found_keep = false;
for (auto cell : module->cells())
if (query(cell)) found_keep = true;
cache[module] = found_keep;
}
return cache[module];
}
bool query(Cell *cell)
{
if (cell->type.in("$memwr", "$meminit", "$assert", "$assume", "$live", "$fair", "$cover", "$specify2", "$specify3", "$specrule"))
return true;
if (cell->has_keep_attr())
return true;
if (cell->module && cell->module->design)
return query(cell->module->design->module(cell->type));
return false;
}
};
keep_cache_t keep_cache;
CellTypes ct_reg, ct_all;
int count_rm_cells, count_rm_wires;
void rmunused_module_cells(Module *module, bool verbose)
{
SigMap sigmap(module);
pool<Cell*> queue, unused;
pool<SigBit> used_raw_bits;
dict<SigBit, pool<Cell*>> wire2driver;
dict<SigBit, vector<string>> driver_driver_logs;
SigMap raw_sigmap;
for (auto &it : module->connections_) {
for (int i = 0; i < GetSize(it.second); i++) {
if (it.second[i].wire != nullptr)
raw_sigmap.add(it.first[i], it.second[i]);
}
}
for (auto &it : module->cells_) {
Cell *cell = it.second;
for (auto &it2 : cell->connections()) {
if (ct_all.cell_known(cell->type) && !ct_all.cell_output(cell->type, it2.first))
continue;
for (auto raw_bit : it2.second) {
if (raw_bit.wire == nullptr)
continue;
auto bit = sigmap(raw_bit);
if (bit.wire == nullptr && ct_all.cell_known(cell->type))
driver_driver_logs[raw_sigmap(raw_bit)].push_back(stringf("Driver-driver conflict "
"for %s between cell %s.%s and constant %s in %s: Resolved using constant.",
log_signal(raw_bit), log_id(cell), log_id(it2.first), log_signal(bit), log_id(module)));
if (bit.wire != nullptr)
wire2driver[bit].insert(cell);
}
}
if (keep_cache.query(cell))
queue.insert(cell);
else
unused.insert(cell);
}
for (auto &it : module->wires_) {
Wire *wire = it.second;
if (wire->port_output || wire->get_bool_attribute("\\keep")) {
for (auto bit : sigmap(wire))
for (auto c : wire2driver[bit])
queue.insert(c), unused.erase(c);
for (auto raw_bit : SigSpec(wire))
used_raw_bits.insert(raw_sigmap(raw_bit));
}
}
while (!queue.empty())
{
pool<SigBit> bits;
for (auto cell : queue)
for (auto &it : cell->connections())
if (!ct_all.cell_known(cell->type) || ct_all.cell_input(cell->type, it.first))
for (auto bit : sigmap(it.second))
bits.insert(bit);
queue.clear();
for (auto bit : bits)
for (auto c : wire2driver[bit])
if (unused.count(c))
queue.insert(c), unused.erase(c);
}
unused.sort(RTLIL::sort_by_name_id<RTLIL::Cell>());
for (auto cell : unused) {
if (verbose)
log_debug(" removing unused `%s' cell `%s'.\n", cell->type.c_str(), cell->name.c_str());
module->design->scratchpad_set_bool("opt.did_something", true);
module->remove(cell);
count_rm_cells++;
}
for (auto &it : module->cells_) {
Cell *cell = it.second;
for (auto &it2 : cell->connections()) {
if (ct_all.cell_known(cell->type) && !ct_all.cell_input(cell->type, it2.first))
continue;
for (auto raw_bit : raw_sigmap(it2.second))
used_raw_bits.insert(raw_bit);
}
}
for (auto it : driver_driver_logs) {
if (used_raw_bits.count(it.first))
for (auto msg : it.second)
log_warning("%s\n", msg.c_str());
}
}
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;
}
bool compare_signals(RTLIL::SigBit &s1, RTLIL::SigBit &s2, SigPool &regs, SigPool &conns, pool<RTLIL::Wire*> &direct_wires)
{
RTLIL::Wire *w1 = s1.wire;
RTLIL::Wire *w2 = s2.wire;
if (w1 == NULL || w2 == NULL)
return w2 == NULL;
if (w1->port_input != w2->port_input)
return w2->port_input;
if ((w1->port_input && w1->port_output) != (w2->port_input && w2->port_output))
return !(w2->port_input && w2->port_output);
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) != 0;
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 strcmp(w2->name.c_str(), w1->name.c_str()) < 0;
}
bool check_public_name(RTLIL::IdString id)
{
const std::string &id_str = id.str();
if (id_str[0] == '$')
return false;
if (id_str.substr(0, 2) == "\\_" && (id_str[id_str.size()-1] == '_' || id_str.find("_[") != std::string::npos))
return false;
if (id_str.find(".$") != std::string::npos)
return false;
return true;
}
bool 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);
pool<RTLIL::SigSpec> direct_sigs;
pool<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::SigBit s1 = RTLIL::SigBit(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 raw_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);
raw_used_signals.add(it2.second);
used_signals.add(it2.second);
if (!ct_all.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);
raw_used_signals.add(sig);
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);
}
}
pool<RTLIL::Wire*> del_wires_queue;
for (auto wire : module->wires())
{
SigSpec s1 = SigSpec(wire), s2 = assign_map(s1);
log_assert(GetSize(s1) == GetSize(s2));
Const initval;
if (wire->attributes.count("\\init"))
initval = wire->attributes.at("\\init");
if (GetSize(initval) != GetSize(wire))
initval.bits.resize(GetSize(wire), State::Sx);
if (initval.is_fully_undef())
wire->attributes.erase("\\init");
if (GetSize(wire) == 0) {
// delete zero-width wires, unless they are module ports
if (wire->port_id == 0)
goto delete_this_wire;
} else
if (wire->port_id != 0 || wire->get_bool_attribute("\\keep") || !initval.is_fully_undef()) {
// do not delete anything with "keep" or module ports or initialized wires
} else
if (!purge_mode && check_public_name(wire->name) && (raw_used_signals.check_any(s1) || used_signals.check_any(s2) || s1 != s2)) {
// do not get rid of public names unless in purge mode or if the wire is entirely unused, not even aliased
} else
if (!raw_used_signals.check_any(s1)) {
// delete wires that aren't used by anything directly
goto delete_this_wire;
} else
if (!used_signals.check_any(s2)) {
// delete wires that aren't used by anything indirectly, even though other wires may alias it
goto delete_this_wire;
}
if (0)
{
delete_this_wire:
del_wires_queue.insert(wire);
}
else
{
RTLIL::SigSig new_conn;
for (int i = 0; i < GetSize(s1); i++)
if (s1[i] != s2[i]) {
if (s2[i] == State::Sx && (initval[i] == State::S0 || initval[i] == State::S1)) {
s2[i] = initval[i];
initval[i] = State::Sx;
}
new_conn.first.append_bit(s1[i]);
new_conn.second.append_bit(s2[i]);
}
if (new_conn.first.size() > 0) {
if (initval.is_fully_undef())
wire->attributes.erase("\\init");
else
wire->attributes.at("\\init") = initval;
used_signals.add(new_conn.first);
used_signals.add(new_conn.second);
module->connect(new_conn);
}
if (!used_signals_nodrivers.check_all(s2)) {
std::string unused_bits;
for (int i = 0; i < GetSize(s2); i++) {
if (s2[i].wire == NULL)
continue;
if (!used_signals_nodrivers.check(s2[i])) {
if (!unused_bits.empty())
unused_bits += " ";
unused_bits += stringf("%d", 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_temp_wires_count = 0;
for (auto wire : del_wires_queue) {
if (ys_debug() || (check_public_name(wire->name) && verbose))
log_debug(" removing unused non-port wire %s.\n", wire->name.c_str());
else
del_temp_wires_count++;
}
module->remove(del_wires_queue);
count_rm_wires += GetSize(del_wires_queue);
if (verbose && del_temp_wires_count)
log_debug(" removed %d unused temporary wires.\n", del_temp_wires_count);
return !del_wires_queue.empty();
}
bool rmunused_module_init(RTLIL::Module *module, bool purge_mode, bool verbose)
{
bool did_something = false;
CellTypes fftypes;
fftypes.setup_internals_mem();
SigMap sigmap(module);
dict<SigBit, State> qbits;
for (auto cell : module->cells())
if (fftypes.cell_known(cell->type) && cell->hasPort("\\Q"))
{
SigSpec sig = cell->getPort("\\Q");
for (int i = 0; i < GetSize(sig); i++)
{
SigBit bit = sig[i];
if (bit.wire == nullptr || bit.wire->attributes.count("\\init") == 0)
continue;
Const init = bit.wire->attributes.at("\\init");
if (i >= GetSize(init) || init[i] == State::Sx || init[i] == State::Sz)
continue;
sigmap.add(bit);
qbits[bit] = init[i];
}
}
for (auto wire : module->wires())
{
if (!purge_mode && wire->name[0] == '\\')
continue;
if (wire->attributes.count("\\init") == 0)
continue;
Const init = wire->attributes.at("\\init");
for (int i = 0; i < GetSize(wire) && i < GetSize(init); i++)
{
if (init[i] == State::Sx || init[i] == State::Sz)
continue;
SigBit wire_bit = SigBit(wire, i);
SigBit mapped_wire_bit = sigmap(wire_bit);
if (wire_bit == mapped_wire_bit)
goto next_wire;
if (qbits.count(sigmap(SigBit(wire, i))) == 0)
goto next_wire;
if (qbits.at(sigmap(SigBit(wire, i))) != init[i])
goto next_wire;
}
if (verbose)
log_debug(" removing redundant init attribute on %s.\n", log_id(wire));
wire->attributes.erase("\\init");
did_something = true;
next_wire:;
}
return did_something;
}
void rmunused_module(RTLIL::Module *module, bool purge_mode, bool verbose, bool rminit)
{
if (verbose)
log("Finding unused cells or wires in module %s..\n", module->name.c_str());
std::vector<RTLIL::Cell*> delcells;
for (auto cell : module->cells())
if (cell->type.in("$pos", "$_BUF_") && !cell->has_keep_attr()) {
bool is_signed = cell->type == "$pos" && cell->getParam("\\A_SIGNED").as_bool();
RTLIL::SigSpec a = cell->getPort("\\A");
RTLIL::SigSpec y = cell->getPort("\\Y");
a.extend_u0(GetSize(y), is_signed);
module->connect(y, a);
delcells.push_back(cell);
}
for (auto cell : delcells) {
if (verbose)
log_debug(" removing buffer cell `%s': %s = %s\n", cell->name.c_str(),
log_signal(cell->getPort("\\Y")), log_signal(cell->getPort("\\A")));
module->remove(cell);
}
if (!delcells.empty())
module->design->scratchpad_set_bool("opt.did_something", true);
rmunused_module_cells(module, verbose);
while (rmunused_module_signals(module, purge_mode, verbose)) { }
if (rminit && rmunused_module_init(module, purge_mode, verbose))
while (rmunused_module_signals(module, purge_mode, verbose)) { }
}
struct OptCleanPass : public Pass {
OptCleanPass() : Pass("opt_clean", "remove unused cells and wires") { }
void help() YS_OVERRIDE
{
// |---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");
}
void execute(std::vector<std::string> args, RTLIL::Design *design) YS_OVERRIDE
{
bool purge_mode = false;
log_header(design, "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);
keep_cache.reset(design);
ct_reg.setup_internals_mem();
ct_reg.setup_stdcells_mem();
ct_all.setup(design);
count_rm_cells = 0;
count_rm_wires = 0;
for (auto module : design->selected_whole_modules_warn()) {
if (module->has_processes_warn())
continue;
rmunused_module(module, purge_mode, true, true);
}
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);
design->optimize();
design->sort();
design->check();
keep_cache.reset();
ct_reg.clear();
ct_all.clear();
log_pop();
}
} OptCleanPass;
struct CleanPass : public Pass {
CleanPass() : Pass("clean", "remove unused cells and wires") { }
void help() YS_OVERRIDE
{
// |---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 separated using the ';;' token, this command will be executed\n");
log("between the commands.\n");
log("\n");
log("When commands are separated using the ';;;' token, this command will be executed\n");
log("in -purge mode between the commands.\n");
log("\n");
}
void execute(std::vector<std::string> args, RTLIL::Design *design) YS_OVERRIDE
{
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);
keep_cache.reset(design);
ct_reg.setup_internals_mem();
ct_reg.setup_stdcells_mem();
ct_all.setup(design);
count_rm_cells = 0;
count_rm_wires = 0;
for (auto module : design->selected_whole_modules()) {
if (module->has_processes())
continue;
rmunused_module(module, purge_mode, ys_debug(), false);
}
log_suppressed();
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);
design->optimize();
design->sort();
design->check();
keep_cache.reset();
ct_reg.clear();
ct_all.clear();
}
} CleanPass;
PRIVATE_NAMESPACE_END