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sim/formalff: Clock handling for yw cosim

This commit is contained in:
Jannis Harder 2023-01-11 17:52:25 +01:00
parent 7ddec5093f
commit d6c7aa0e3d
5 changed files with 274 additions and 33 deletions

View file

@ -317,6 +317,172 @@ struct InitValWorker
}
};
struct ReplacedPort {
IdString name;
int offset;
bool clk_pol;
};
struct HierarchyWorker
{
Design *design;
pool<Module *> pending;
dict<Module *, std::vector<ReplacedPort>> replaced_clk_inputs;
HierarchyWorker(Design *design) :
design(design)
{
for (auto module : design->modules())
pending.insert(module);
}
void propagate();
const std::vector<ReplacedPort> &find_replaced_clk_inputs(IdString cell_type);
};
// Propagates replaced clock signals
struct PropagateWorker
{
HierarchyWorker &hierarchy;
Module *module;
SigMap sigmap;
dict<SigBit, bool> replaced_clk_bits;
dict<SigBit, SigBit> not_drivers;
std::vector<ReplacedPort> replaced_clk_inputs;
std::vector<std::pair<SigBit, bool>> pending;
PropagateWorker(Module *module, HierarchyWorker &hierarchy) :
hierarchy(hierarchy), module(module), sigmap(module)
{
hierarchy.pending.erase(module);
for (auto wire : module->wires())
if (wire->has_attribute(ID::replaced_by_gclk))
replace_clk_bit(SigBit(wire), wire->attributes[ID::replaced_by_gclk].bits.at(0) == State::S1, false);
for (auto cell : module->cells()) {
if (cell->type.in(ID($not), ID($_NOT_))) {
auto sig_a = cell->getPort(ID::A);
auto &sig_y = cell->getPort(ID::Y);
sig_a.extend_u0(GetSize(sig_y), cell->parameters.at(ID::A_SIGNED).as_bool());
for (int i = 0; i < GetSize(sig_a); i++)
if (sig_a[i].is_wire())
not_drivers.emplace(sigmap(sig_y[i]), sigmap(sig_a[i]));
} else {
for (auto &port_bit : hierarchy.find_replaced_clk_inputs(cell->type))
replace_clk_bit(cell->getPort(port_bit.name)[port_bit.offset], port_bit.clk_pol, true);
}
}
while (!pending.empty()) {
auto current = pending.back();
pending.pop_back();
auto it = not_drivers.find(current.first);
if (it == not_drivers.end())
continue;
replace_clk_bit(it->second, !current.second, true);
}
for (auto cell : module->cells()) {
if (cell->type.in(ID($not), ID($_NOT_)))
continue;
for (auto &conn : cell->connections()) {
if (!cell->output(conn.first))
continue;
for (SigBit bit : conn.second) {
sigmap.apply(bit);
if (replaced_clk_bits.count(bit))
log_error("derived signal %s driven by %s (%s) from module %s is used as clock, derived clocks are only supported with clk2fflogic.\n",
log_signal(bit), log_id(cell->name), log_id(cell->type), log_id(module));
}
}
}
for (auto port : module->ports) {
auto wire = module->wire(port);
if (!wire->port_input)
continue;
for (int i = 0; i < GetSize(wire); i++) {
SigBit bit(wire, i);
sigmap.apply(bit);
auto it = replaced_clk_bits.find(bit);
if (it == replaced_clk_bits.end())
continue;
replaced_clk_inputs.emplace_back(ReplacedPort {port, i, it->second});
if (it->second) {
bit = module->Not(NEW_ID, bit);
}
}
}
}
void replace_clk_bit(SigBit bit, bool polarity, bool add_attribute)
{
sigmap.apply(bit);
if (!bit.is_wire())
log_error("XXX todo\n");
auto it = replaced_clk_bits.find(bit);
if (it != replaced_clk_bits.end()) {
if (it->second != polarity)
log_error("signal %s from module %s is used as clock with different polarities, run clk2fflogic instead.\n",
log_signal(bit), log_id(module));
return;
}
replaced_clk_bits.emplace(bit, polarity);
if (add_attribute) {
Wire *clk_wire = bit.wire;
if (bit.offset != 0 || GetSize(bit.wire) != 1) {
clk_wire = module->addWire(NEW_ID);
module->connect(RTLIL::SigBit(clk_wire), bit);
}
clk_wire->attributes[ID::replaced_by_gclk] = polarity ? State::S1 : State::S0;
clk_wire->set_bool_attribute(ID::keep);
}
pending.emplace_back(bit, polarity);
}
};
const std::vector<ReplacedPort> &HierarchyWorker::find_replaced_clk_inputs(IdString cell_type)
{
static const std::vector<ReplacedPort> empty;
if (!cell_type.isPublic())
return empty;
Module *module = design->module(cell_type);
if (module == nullptr)
return empty;
auto it = replaced_clk_inputs.find(module);
if (it != replaced_clk_inputs.end())
return it->second;
if (pending.count(module)) {
PropagateWorker worker(module, *this);
return replaced_clk_inputs.emplace(module, std::move(worker.replaced_clk_inputs)).first->second;
}
return empty;
}
void HierarchyWorker::propagate()
{
while (!pending.empty())
PropagateWorker worker(pending.pop(), *this);
}
struct FormalFfPass : public Pass {
FormalFfPass() : Pass("formalff", "prepare FFs for formal") { }
void help() override
@ -362,6 +528,15 @@ struct FormalFfPass : public Pass {
log(" them. For -ff2anyinit, this reduces the number of generated $anyinit\n");
log(" cells that drive wires with private names.\n");
log("\n");
log(" -hierarchy\n");
log(" Propagates the 'replaced_by_gclk' attribute set by clk2ff upwards\n");
log(" through the design hierarchy towards the toplevel inputs. This option\n");
log(" works on the whole design and ignores the selection.\n");
log("\n");
log(" -assume\n");
log(" Add assumptions that constrain wires with the 'replaced_by_gclk'\n");
log(" attribute to the value they would have before an active clock edge.\n");
log("\n");
// TODO: An option to check whether all FFs use the same clock before changing it to the global clock
}
@ -372,6 +547,8 @@ struct FormalFfPass : public Pass {
bool flag_anyinit2ff = false;
bool flag_fine = false;
bool flag_setundef = false;
bool flag_hierarchy = false;
bool flag_assume = false;
log_header(design, "Executing FORMALFF pass.\n");
@ -398,12 +575,20 @@ struct FormalFfPass : public Pass {
flag_setundef = true;
continue;
}
if (args[argidx] == "-hierarchy") {
flag_hierarchy = true;
continue;
}
if (args[argidx] == "-assume") {
flag_assume = true;
continue;
}
break;
}
extra_args(args, argidx, design);
if (!(flag_clk2ff || flag_ff2anyinit || flag_anyinit2ff))
log_cmd_error("One of the options -clk2ff, -ff2anyinit, or -anyinit2ff must be specified.\n");
if (!(flag_clk2ff || flag_ff2anyinit || flag_anyinit2ff || flag_hierarchy || flag_assume))
log_cmd_error("One of the options -clk2ff, -ff2anyinit, -anyinit2ff, -hierarchy or -assume must be specified.\n");
if (flag_ff2anyinit && flag_anyinit2ff)
log_cmd_error("The options -ff2anyinit and -anyinit2ff are exclusive.\n");
@ -548,6 +733,33 @@ struct FormalFfPass : public Pass {
ff.emit();
}
}
if (flag_hierarchy) {
HierarchyWorker worker(design);
worker.propagate();
}
if (flag_assume) {
for (auto module : design->selected_modules()) {
std::vector<pair<SigBit, bool>> found;
for (auto wire : module->wires()) {
if (!wire->has_attribute(ID::replaced_by_gclk))
continue;
bool clk_pol = wire->attributes[ID::replaced_by_gclk].bits.at(0) == State::S1;
found.emplace_back(SigSpec(wire), clk_pol);
}
for (auto pair : found) {
SigBit clk = pair.first;
if (pair.second)
clk = module->Not(NEW_ID, clk);
module->addAssume(NEW_ID, clk, State::S1);
}
}
}
}
} FormalFfPass;

View file

@ -1655,28 +1655,25 @@ struct SimWorker : SimShared
};
struct YwHierarchy {
dict<IdPath, FoundYWPath> signal_paths;
dict<IdPath, FoundYWPath> clock_paths;
dict<IdPath, FoundYWPath> paths;
};
YwHierarchy prepare_yw_hierarchy(const ReadWitness &yw)
{
YwHierarchy hierarchy;
pool<IdPath> paths;
dict<IdPath, pool<IdString>> mem_paths;
for (auto &signal : yw.signals)
paths.insert(signal.path);
for (auto &clock : yw.clocks) {
if (paths.count(clock.path))
log_warning("Witness path `%s` is present as witness signal and as clock, treating as clock and ignoring signal data.\n", clock.path.str().c_str());
for (auto &clock : yw.clocks)
paths.insert(clock.path);
}
for (auto &path : paths)
if (path.has_address())
mem_paths[path.prefix()].insert(path.back());
YwHierarchy hierarchy;
witness_hierarchy(top->module, top, [&](IdPath const &path, WitnessHierarchyItem item, SimInstance *instance) {
if (item.cell != nullptr)
return instance->children.at(item.cell);
@ -1684,7 +1681,7 @@ struct SimWorker : SimShared
if (paths.count(path)) {
if (debug)
log("witness hierarchy: found wire %s\n", path.str().c_str());
bool inserted = hierarchy.signal_paths.emplace(path, {instance, item.wire, {}, INT_MIN}).second;
bool inserted = hierarchy.paths.emplace(path, {instance, item.wire, {}, INT_MIN}).second;
if (!inserted)
log_warning("Yosys witness path `%s` is ambiguous in this design\n", path.str().c_str());
}
@ -1701,7 +1698,7 @@ struct SimWorker : SimShared
word_path.get_address(addr);
if (addr < item.mem->start_offset || (addr - item.mem->start_offset) >= item.mem->size)
continue;
bool inserted = hierarchy.signal_paths.emplace(word_path, {instance, nullptr, item.mem->memid, addr}).second;
bool inserted = hierarchy.paths.emplace(word_path, {instance, nullptr, item.mem->memid, addr}).second;
if (!inserted)
log_warning("Yosys witness path `%s` is ambiguous in this design\n", path.str().c_str());
}
@ -1711,19 +1708,35 @@ struct SimWorker : SimShared
});
for (auto &path : paths)
if (!hierarchy.signal_paths.count(path))
if (!hierarchy.paths.count(path))
log_warning("Yosys witness path `%s` was not found in this design, ignoring\n", path.str().c_str());
dict<IdPath, dict<int, bool>> clock_inputs;
for (auto &clock : yw.clocks) {
auto found_path_it = hierarchy.signal_paths.find(clock.path);
if (found_path_it == hierarchy.signal_paths.end())
if (clock.is_negedge == clock.is_posedge)
continue;
hierarchy.clock_paths.insert(*found_path_it);
hierarchy.signal_paths.erase(found_path_it);
paths.insert(clock.path);
clock_inputs[clock.path].emplace(clock.offset, clock.is_posedge);
}
for (auto &signal : yw.signals) {
auto it = clock_inputs.find(signal.path);
if (it == clock_inputs.end())
continue;
for (auto &clock_input : it->second) {
int offset = clock_input.first;
if (offset >= signal.offset && (offset - signal.offset) < signal.width) {
int clock_bits_offset = signal.bits_offset + (offset - signal.offset);
State expected = clock_input.second ? State::S0 : State::S1;
for (int t = 0; t < GetSize(yw.steps); t++) {
if (yw.get_bits(t, clock_bits_offset, 1) != expected)
log_warning("Yosys witness trace has an unexpected value for the clock input `%s` in step %d.\n", signal.path.str().c_str(), t);
}
}
}
}
// TODO add checks and warnings for witness signals (toplevel inputs, $any*) not present in the witness file
return hierarchy;
@ -1736,8 +1749,8 @@ struct SimWorker : SimShared
for (auto &signal : yw.signals) {
if (signal.init_only && t >= 1)
continue;
auto found_path_it = hierarchy.signal_paths.find(signal.path);
if (found_path_it == hierarchy.signal_paths.end())
auto found_path_it = hierarchy.paths.find(signal.path);
if (found_path_it == hierarchy.paths.end())
continue;
auto &found_path = found_path_it->second;
@ -1767,8 +1780,8 @@ struct SimWorker : SimShared
for (auto &clock : yw.clocks) {
if (clock.is_negedge == clock.is_posedge)
continue;
auto found_path_it = hierarchy.clock_paths.find(clock.path);
if (found_path_it == hierarchy.clock_paths.end())
auto found_path_it = hierarchy.paths.find(clock.path);
if (found_path_it == hierarchy.paths.end())
continue;
auto &found_path = found_path_it->second;