yosys/passes/sat/sim.cc

885 lines
21 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/yosys.h"
#include "kernel/sigtools.h"
#include "kernel/celltypes.h"
#include "kernel/mem.h"
#include <ctime>
USING_YOSYS_NAMESPACE
PRIVATE_NAMESPACE_BEGIN
struct SimShared
{
bool debug = false;
bool hide_internal = true;
bool writeback = false;
bool zinit = false;
int rstlen = 1;
};
void zinit(State &v)
{
if (v != State::S1)
v = State::S0;
}
void zinit(Const &v)
{
for (auto &bit : v.bits)
zinit(bit);
}
struct SimInstance
{
SimShared *shared;
Module *module;
Cell *instance;
SimInstance *parent;
dict<Cell*, SimInstance*> children;
SigMap sigmap;
dict<SigBit, State> state_nets;
dict<SigBit, pool<Cell*>> upd_cells;
dict<SigBit, pool<Wire*>> upd_outports;
pool<SigBit> dirty_bits;
pool<Cell*> dirty_cells;
pool<IdString> dirty_memories;
pool<SimInstance*, hash_ptr_ops> dirty_children;
struct ff_state_t
{
State past_clock;
Const past_d;
};
struct mem_state_t
{
Mem *mem;
std::vector<Const> past_wr_clk;
std::vector<Const> past_wr_en;
std::vector<Const> past_wr_addr;
std::vector<Const> past_wr_data;
Const data;
};
dict<Cell*, ff_state_t> ff_database;
dict<IdString, mem_state_t> mem_database;
pool<Cell*> formal_database;
dict<Cell*, IdString> mem_cells;
std::vector<Mem> memories;
dict<Wire*, pair<int, Const>> vcd_database;
SimInstance(SimShared *shared, Module *module, Cell *instance = nullptr, SimInstance *parent = nullptr) :
shared(shared), module(module), instance(instance), parent(parent), sigmap(module)
{
log_assert(module);
if (parent) {
log_assert(parent->children.count(instance) == 0);
parent->children[instance] = this;
}
for (auto wire : module->wires())
{
SigSpec sig = sigmap(wire);
for (int i = 0; i < GetSize(sig); i++) {
if (state_nets.count(sig[i]) == 0)
state_nets[sig[i]] = State::Sx;
if (wire->port_output) {
upd_outports[sig[i]].insert(wire);
dirty_bits.insert(sig[i]);
}
}
if (wire->attributes.count(ID::init)) {
Const initval = wire->attributes.at(ID::init);
for (int i = 0; i < GetSize(sig) && i < GetSize(initval); i++)
if (initval[i] == State::S0 || initval[i] == State::S1) {
state_nets[sig[i]] = initval[i];
dirty_bits.insert(sig[i]);
}
}
}
memories = Mem::get_all_memories(module);
for (auto &mem : memories) {
auto &mdb = mem_database[mem.memid];
mdb.mem = &mem;
for (auto &port : mem.wr_ports) {
mdb.past_wr_clk.push_back(Const(State::Sx));
mdb.past_wr_en.push_back(Const(State::Sx, GetSize(port.en)));
mdb.past_wr_addr.push_back(Const(State::Sx, GetSize(port.addr)));
mdb.past_wr_data.push_back(Const(State::Sx, GetSize(port.data)));
}
mdb.data = mem.get_init_data();
}
for (auto cell : module->cells())
{
Module *mod = module->design->module(cell->type);
if (mod != nullptr) {
dirty_children.insert(new SimInstance(shared, mod, cell, this));
}
for (auto &port : cell->connections()) {
if (cell->input(port.first))
for (auto bit : sigmap(port.second)) {
upd_cells[bit].insert(cell);
// Make sure cell inputs connected to constants are updated in the first cycle
if (bit.wire == nullptr)
dirty_bits.insert(bit);
}
}
if (cell->type.in(ID($dff))) {
ff_state_t ff;
ff.past_clock = State::Sx;
ff.past_d = Const(State::Sx, cell->getParam(ID::WIDTH).as_int());
ff_database[cell] = ff;
}
if (cell->type.in(ID($mem), ID($meminit), ID($memwr), ID($memrd)))
{
mem_cells[cell] = cell->parameters.at(ID::MEMID).decode_string();
}
if (cell->type.in(ID($assert), ID($cover), ID($assume))) {
formal_database.insert(cell);
}
}
if (shared->zinit)
{
for (auto &it : ff_database)
{
Cell *cell = it.first;
ff_state_t &ff = it.second;
zinit(ff.past_d);
SigSpec qsig = cell->getPort(ID::Q);
Const qdata = get_state(qsig);
zinit(qdata);
set_state(qsig, qdata);
}
for (auto &it : mem_database) {
mem_state_t &mem = it.second;
for (auto &val : mem.past_wr_en)
zinit(val);
zinit(mem.data);
}
}
}
~SimInstance()
{
for (auto child : children)
delete child.second;
}
IdString name() const
{
if (instance != nullptr)
return instance->name;
return module->name;
}
std::string hiername() const
{
if (instance != nullptr)
return parent->hiername() + "." + log_id(instance->name);
return log_id(module->name);
}
Const get_state(SigSpec sig)
{
Const value;
for (auto bit : sigmap(sig))
if (bit.wire == nullptr)
value.bits.push_back(bit.data);
else if (state_nets.count(bit))
value.bits.push_back(state_nets.at(bit));
else
value.bits.push_back(State::Sz);
if (shared->debug)
log("[%s] get %s: %s\n", hiername().c_str(), log_signal(sig), log_signal(value));
return value;
}
bool set_state(SigSpec sig, Const value)
{
bool did_something = false;
sig = sigmap(sig);
log_assert(GetSize(sig) <= GetSize(value));
for (int i = 0; i < GetSize(sig); i++)
if (state_nets.at(sig[i]) != value[i]) {
state_nets.at(sig[i]) = value[i];
dirty_bits.insert(sig[i]);
did_something = true;
}
if (shared->debug)
log("[%s] set %s: %s\n", hiername().c_str(), log_signal(sig), log_signal(value));
return did_something;
}
void update_cell(Cell *cell)
{
if (ff_database.count(cell))
return;
if (formal_database.count(cell))
return;
if (mem_cells.count(cell))
{
dirty_memories.insert(mem_cells[cell]);
return;
}
if (children.count(cell))
{
auto child = children.at(cell);
for (auto &conn: cell->connections())
if (cell->input(conn.first) && GetSize(conn.second)) {
Const value = get_state(conn.second);
child->set_state(child->module->wire(conn.first), value);
}
dirty_children.insert(child);
return;
}
if (yosys_celltypes.cell_evaluable(cell->type))
{
RTLIL::SigSpec sig_a, sig_b, sig_c, sig_d, sig_s, sig_y;
bool has_a, has_b, has_c, has_d, has_s, has_y;
has_a = cell->hasPort(ID::A);
has_b = cell->hasPort(ID::B);
has_c = cell->hasPort(ID::C);
has_d = cell->hasPort(ID::D);
has_s = cell->hasPort(ID::S);
has_y = cell->hasPort(ID::Y);
if (has_a) sig_a = cell->getPort(ID::A);
if (has_b) sig_b = cell->getPort(ID::B);
if (has_c) sig_c = cell->getPort(ID::C);
if (has_d) sig_d = cell->getPort(ID::D);
if (has_s) sig_s = cell->getPort(ID::S);
if (has_y) sig_y = cell->getPort(ID::Y);
if (shared->debug)
log("[%s] eval %s (%s)\n", hiername().c_str(), log_id(cell), log_id(cell->type));
// Simple (A -> Y) and (A,B -> Y) cells
if (has_a && !has_c && !has_d && !has_s && has_y) {
set_state(sig_y, CellTypes::eval(cell, get_state(sig_a), get_state(sig_b)));
return;
}
// (A,B,C -> Y) cells
if (has_a && has_b && has_c && !has_d && !has_s && has_y) {
set_state(sig_y, CellTypes::eval(cell, get_state(sig_a), get_state(sig_b), get_state(sig_c)));
return;
}
// (A,B,S -> Y) cells
if (has_a && has_b && !has_c && !has_d && has_s && has_y) {
set_state(sig_y, CellTypes::eval(cell, get_state(sig_a), get_state(sig_b), get_state(sig_s)));
return;
}
log_warning("Unsupported evaluable cell type: %s (%s.%s)\n", log_id(cell->type), log_id(module), log_id(cell));
return;
}
log_error("Unsupported cell type: %s (%s.%s)\n", log_id(cell->type), log_id(module), log_id(cell));
}
void update_memory(IdString id) {
auto &mdb = mem_database[id];
auto &mem = *mdb.mem;
for (int port_idx = 0; port_idx < GetSize(mem.rd_ports); port_idx++)
{
auto &port = mem.rd_ports[port_idx];
Const addr = get_state(port.addr);
Const data = Const(State::Sx, mem.width);
if (port.clk_enable)
log_error("Memory %s.%s has clocked read ports. Run 'memory' with -nordff.\n", log_id(module), log_id(mem.memid));
if (addr.is_fully_def()) {
int index = addr.as_int() - mem.start_offset;
if (index >= 0 && index < mem.size)
data = mdb.data.extract(index*mem.width, mem.width);
}
set_state(port.data, data);
}
}
void update_ph1()
{
pool<Cell*> queue_cells;
pool<Wire*> queue_outports;
queue_cells.swap(dirty_cells);
while (1)
{
for (auto bit : dirty_bits)
{
if (upd_cells.count(bit))
for (auto cell : upd_cells.at(bit))
queue_cells.insert(cell);
if (upd_outports.count(bit) && parent != nullptr)
for (auto wire : upd_outports.at(bit))
queue_outports.insert(wire);
}
dirty_bits.clear();
if (!queue_cells.empty())
{
for (auto cell : queue_cells)
update_cell(cell);
queue_cells.clear();
continue;
}
for (auto &memid : dirty_memories)
update_memory(memid);
dirty_memories.clear();
for (auto wire : queue_outports)
if (instance->hasPort(wire->name)) {
Const value = get_state(wire);
parent->set_state(instance->getPort(wire->name), value);
}
queue_outports.clear();
for (auto child : dirty_children)
child->update_ph1();
dirty_children.clear();
if (dirty_bits.empty())
break;
}
}
bool update_ph2()
{
bool did_something = false;
for (auto &it : ff_database)
{
Cell *cell = it.first;
ff_state_t &ff = it.second;
if (cell->type.in(ID($dff)))
{
bool clkpol = cell->getParam(ID::CLK_POLARITY).as_bool();
State current_clock = get_state(cell->getPort(ID::CLK))[0];
if (clkpol ? (ff.past_clock == State::S1 || current_clock != State::S1) :
(ff.past_clock == State::S0 || current_clock != State::S0))
continue;
if (set_state(cell->getPort(ID::Q), ff.past_d))
did_something = true;
}
}
for (auto &it : mem_database)
{
mem_state_t &mdb = it.second;
auto &mem = *mdb.mem;
for (int port_idx = 0; port_idx < GetSize(mem.wr_ports); port_idx++)
{
auto &port = mem.wr_ports[port_idx];
Const addr, data, enable;
if (!port.clk_enable)
{
addr = get_state(port.addr);
data = get_state(port.data);
enable = get_state(port.en);
}
else
{
if (port.clk_polarity ?
(mdb.past_wr_clk[port_idx] == State::S1 || get_state(port.clk) != State::S1) :
(mdb.past_wr_clk[port_idx] == State::S0 || get_state(port.clk) != State::S0))
continue;
addr = mdb.past_wr_addr[port_idx];
data = mdb.past_wr_data[port_idx];
enable = mdb.past_wr_en[port_idx];
}
if (addr.is_fully_def())
{
int index = addr.as_int() - mem.start_offset;
if (index >= 0 && index < mem.size)
for (int i = 0; i < mem.width; i++)
if (enable[i] == State::S1 && mdb.data.bits.at(index*mem.width+i) != data[i]) {
mdb.data.bits.at(index*mem.width+i) = data[i];
dirty_memories.insert(mem.memid);
did_something = true;
}
}
}
}
for (auto it : children)
if (it.second->update_ph2()) {
dirty_children.insert(it.second);
did_something = true;
}
return did_something;
}
void update_ph3()
{
for (auto &it : ff_database)
{
Cell *cell = it.first;
ff_state_t &ff = it.second;
if (cell->type.in(ID($dff))) {
ff.past_clock = get_state(cell->getPort(ID::CLK))[0];
ff.past_d = get_state(cell->getPort(ID::D));
}
}
for (auto &it : mem_database)
{
mem_state_t &mem = it.second;
for (int i = 0; i < GetSize(mem.mem->wr_ports); i++) {
auto &port = mem.mem->wr_ports[i];
mem.past_wr_clk[i] = get_state(port.clk);
mem.past_wr_en[i] = get_state(port.en);
mem.past_wr_addr[i] = get_state(port.addr);
mem.past_wr_data[i] = get_state(port.data);
}
}
for (auto cell : formal_database)
{
string label = log_id(cell);
if (cell->attributes.count(ID::src))
label = cell->attributes.at(ID::src).decode_string();
State a = get_state(cell->getPort(ID::A))[0];
State en = get_state(cell->getPort(ID::EN))[0];
if (cell->type == ID($cover) && en == State::S1 && a != State::S1)
log("Cover %s.%s (%s) reached.\n", hiername().c_str(), log_id(cell), label.c_str());
if (cell->type == ID($assume) && en == State::S1 && a != State::S1)
log("Assumption %s.%s (%s) failed.\n", hiername().c_str(), log_id(cell), label.c_str());
if (cell->type == ID($assert) && en == State::S1 && a != State::S1)
log_warning("Assert %s.%s (%s) failed.\n", hiername().c_str(), log_id(cell), label.c_str());
}
for (auto it : children)
it.second->update_ph3();
}
void writeback(pool<Module*> &wbmods)
{
if (wbmods.count(module))
log_error("Instance %s of module %s is not unique: Writeback not possible. (Fix by running 'uniquify'.)\n", hiername().c_str(), log_id(module));
wbmods.insert(module);
for (auto wire : module->wires())
wire->attributes.erase(ID::init);
for (auto &it : ff_database)
{
Cell *cell = it.first;
SigSpec sig_q = cell->getPort(ID::Q);
Const initval = get_state(sig_q);
for (int i = 0; i < GetSize(sig_q); i++)
{
Wire *w = sig_q[i].wire;
if (w->attributes.count(ID::init) == 0)
w->attributes[ID::init] = Const(State::Sx, GetSize(w));
w->attributes[ID::init][sig_q[i].offset] = initval[i];
}
}
for (auto &it : mem_database)
{
mem_state_t &mem = it.second;
mem.mem->clear_inits();
MemInit minit;
minit.addr = mem.mem->start_offset;
minit.data = mem.data;
mem.mem->inits.push_back(minit);
mem.mem->emit();
}
for (auto it : children)
it.second->writeback(wbmods);
}
void write_vcd_header(std::ofstream &f, int &id)
{
f << stringf("$scope module %s $end\n", log_id(name()));
for (auto wire : module->wires())
{
if (shared->hide_internal && wire->name[0] == '$')
continue;
f << stringf("$var wire %d n%d %s%s $end\n", GetSize(wire), id, wire->name[0] == '$' ? "\\" : "", log_id(wire));
vcd_database[wire] = make_pair(id++, Const());
}
for (auto child : children)
child.second->write_vcd_header(f, id);
f << stringf("$upscope $end\n");
}
void write_vcd_step(std::ofstream &f)
{
for (auto &it : vcd_database)
{
Wire *wire = it.first;
Const value = get_state(wire);
int id = it.second.first;
if (it.second.second == value)
continue;
it.second.second = value;
f << "b";
for (int i = GetSize(value)-1; i >= 0; i--) {
switch (value[i]) {
case State::S0: f << "0"; break;
case State::S1: f << "1"; break;
case State::Sx: f << "x"; break;
default: f << "z";
}
}
f << stringf(" n%d\n", id);
}
for (auto child : children)
child.second->write_vcd_step(f);
}
};
struct SimWorker : SimShared
{
SimInstance *top = nullptr;
std::ofstream vcdfile;
pool<IdString> clock, clockn, reset, resetn;
std::string timescale;
~SimWorker()
{
delete top;
}
void write_vcd_header()
{
if (!vcdfile.is_open())
return;
vcdfile << stringf("$version %s $end\n", yosys_version_str);
std::time_t t = std::time(nullptr);
char mbstr[255];
if (std::strftime(mbstr, sizeof(mbstr), "%c", std::localtime(&t))) {
vcdfile << stringf("$date ") << mbstr << stringf(" $end\n");
}
if (!timescale.empty())
vcdfile << stringf("$timescale %s $end\n", timescale.c_str());
int id = 1;
top->write_vcd_header(vcdfile, id);
vcdfile << stringf("$enddefinitions $end\n");
}
void write_vcd_step(int t)
{
if (!vcdfile.is_open())
return;
vcdfile << stringf("#%d\n", t);
top->write_vcd_step(vcdfile);
}
void update()
{
while (1)
{
if (debug)
log("\n-- ph1 --\n");
top->update_ph1();
if (debug)
log("\n-- ph2 --\n");
if (!top->update_ph2())
break;
}
if (debug)
log("\n-- ph3 --\n");
top->update_ph3();
}
void set_inports(pool<IdString> ports, State value)
{
for (auto portname : ports)
{
Wire *w = top->module->wire(portname);
if (w == nullptr)
log_error("Can't find port %s on module %s.\n", log_id(portname), log_id(top->module));
top->set_state(w, value);
}
}
void run(Module *topmod, int numcycles)
{
log_assert(top == nullptr);
top = new SimInstance(this, topmod);
if (debug)
log("\n===== 0 =====\n");
else
log("Simulating cycle 0.\n");
set_inports(reset, State::S1);
set_inports(resetn, State::S0);
set_inports(clock, State::Sx);
set_inports(clockn, State::Sx);
update();
write_vcd_header();
write_vcd_step(0);
for (int cycle = 0; cycle < numcycles; cycle++)
{
if (debug)
log("\n===== %d =====\n", 10*cycle + 5);
set_inports(clock, State::S0);
set_inports(clockn, State::S1);
update();
write_vcd_step(10*cycle + 5);
if (debug)
log("\n===== %d =====\n", 10*cycle + 10);
else
log("Simulating cycle %d.\n", cycle+1);
set_inports(clock, State::S1);
set_inports(clockn, State::S0);
if (cycle+1 == rstlen) {
set_inports(reset, State::S0);
set_inports(resetn, State::S1);
}
update();
write_vcd_step(10*cycle + 10);
}
write_vcd_step(10*numcycles + 2);
if (writeback) {
pool<Module*> wbmods;
top->writeback(wbmods);
}
}
};
struct SimPass : public Pass {
SimPass() : Pass("sim", "simulate the circuit") { }
void help() override
{
// |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
log("\n");
log(" sim [options] [top-level]\n");
log("\n");
log("This command simulates the circuit using the given top-level module.\n");
log("\n");
log(" -vcd <filename>\n");
log(" write the simulation results to the given VCD file\n");
log("\n");
log(" -clock <portname>\n");
log(" name of top-level clock input\n");
log("\n");
log(" -clockn <portname>\n");
log(" name of top-level clock input (inverse polarity)\n");
log("\n");
log(" -reset <portname>\n");
log(" name of top-level reset input (active high)\n");
log("\n");
log(" -resetn <portname>\n");
log(" name of top-level inverted reset input (active low)\n");
log("\n");
log(" -rstlen <integer>\n");
log(" number of cycles reset should stay active (default: 1)\n");
log("\n");
log(" -zinit\n");
log(" zero-initialize all uninitialized regs and memories\n");
log("\n");
log(" -timescale <string>\n");
log(" include the specified timescale declaration in the vcd\n");
log("\n");
log(" -n <integer>\n");
log(" number of cycles to simulate (default: 20)\n");
log("\n");
log(" -a\n");
log(" include all nets in VCD output, not just those with public names\n");
log("\n");
log(" -w\n");
log(" writeback mode: use final simulation state as new init state\n");
log("\n");
log(" -d\n");
log(" enable debug output\n");
log("\n");
}
void execute(std::vector<std::string> args, RTLIL::Design *design) override
{
SimWorker worker;
int numcycles = 20;
log_header(design, "Executing SIM pass (simulate the circuit).\n");
size_t argidx;
for (argidx = 1; argidx < args.size(); argidx++) {
if (args[argidx] == "-vcd" && argidx+1 < args.size()) {
std::string vcd_filename = args[++argidx];
rewrite_filename(vcd_filename);
worker.vcdfile.open(vcd_filename.c_str());
continue;
}
if (args[argidx] == "-n" && argidx+1 < args.size()) {
numcycles = atoi(args[++argidx].c_str());
continue;
}
if (args[argidx] == "-rstlen" && argidx+1 < args.size()) {
worker.rstlen = atoi(args[++argidx].c_str());
continue;
}
if (args[argidx] == "-clock" && argidx+1 < args.size()) {
worker.clock.insert(RTLIL::escape_id(args[++argidx]));
continue;
}
if (args[argidx] == "-clockn" && argidx+1 < args.size()) {
worker.clockn.insert(RTLIL::escape_id(args[++argidx]));
continue;
}
if (args[argidx] == "-reset" && argidx+1 < args.size()) {
worker.reset.insert(RTLIL::escape_id(args[++argidx]));
continue;
}
if (args[argidx] == "-resetn" && argidx+1 < args.size()) {
worker.resetn.insert(RTLIL::escape_id(args[++argidx]));
continue;
}
if (args[argidx] == "-timescale" && argidx+1 < args.size()) {
worker.timescale = args[++argidx];
continue;
}
if (args[argidx] == "-a") {
worker.hide_internal = false;
continue;
}
if (args[argidx] == "-d") {
worker.debug = true;
continue;
}
if (args[argidx] == "-w") {
worker.writeback = true;
continue;
}
if (args[argidx] == "-zinit") {
worker.zinit = true;
continue;
}
break;
}
extra_args(args, argidx, design);
Module *top_mod = nullptr;
if (design->full_selection()) {
top_mod = design->top_module();
if (!top_mod)
log_cmd_error("Design has no top module, use the 'hierarchy' command to specify one.\n");
} else {
auto mods = design->selected_whole_modules();
if (GetSize(mods) != 1)
log_cmd_error("Only one top module must be selected.\n");
top_mod = mods.front();
}
worker.run(top_mod, numcycles);
}
} SimPass;
PRIVATE_NAMESPACE_END