OpenFPGA/yosys/passes/fsm/fsm_map.cc

356 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 "kernel/log.h"
#include "kernel/register.h"
#include "kernel/sigtools.h"
#include "kernel/consteval.h"
#include "kernel/celltypes.h"
#include "fsmdata.h"
#include <string.h>
USING_YOSYS_NAMESPACE
PRIVATE_NAMESPACE_BEGIN
static bool pattern_is_subset(const RTLIL::Const &super_pattern, const RTLIL::Const &sub_pattern)
{
log_assert(GetSize(super_pattern.bits) == GetSize(sub_pattern.bits));
for (int i = 0; i < GetSize(super_pattern.bits); i++)
if (sub_pattern.bits[i] == RTLIL::State::S0 || sub_pattern.bits[i] == RTLIL::State::S1) {
if (super_pattern.bits[i] == RTLIL::State::S0 || super_pattern.bits[i] == RTLIL::State::S1) {
if (super_pattern.bits[i] != sub_pattern.bits[i])
return false;
} else
return false;
}
return true;
}
static void implement_pattern_cache(RTLIL::Module *module, std::map<RTLIL::Const, std::set<int>> &pattern_cache, std::set<int> &fullstate_cache, int num_states, RTLIL::Wire *state_onehot, RTLIL::SigSpec &ctrl_in, RTLIL::SigSpec output)
{
RTLIL::SigSpec cases_vector;
for (int in_state : fullstate_cache)
cases_vector.append(RTLIL::SigSpec(state_onehot, in_state));
for (auto &it : pattern_cache)
{
RTLIL::Const pattern = it.first;
RTLIL::SigSpec eq_sig_a, eq_sig_b, or_sig;
for (size_t j = 0; j < pattern.bits.size(); j++)
if (pattern.bits[j] == RTLIL::State::S0 || pattern.bits[j] == RTLIL::State::S1) {
eq_sig_a.append(ctrl_in.extract(j, 1));
eq_sig_b.append(RTLIL::SigSpec(pattern.bits[j]));
}
for (int in_state : it.second)
if (fullstate_cache.count(in_state) == 0)
or_sig.append(RTLIL::SigSpec(state_onehot, in_state));
if (or_sig.size() == 0)
continue;
RTLIL::SigSpec and_sig;
if (eq_sig_a.size() > 0)
{
RTLIL::Wire *eq_wire = module->addWire(NEW_ID);
and_sig.append(RTLIL::SigSpec(eq_wire));
RTLIL::Cell *eq_cell = module->addCell(NEW_ID, "$eq");
eq_cell->setPort("\\A", eq_sig_a);
eq_cell->setPort("\\B", eq_sig_b);
eq_cell->setPort("\\Y", RTLIL::SigSpec(eq_wire));
eq_cell->parameters["\\A_SIGNED"] = RTLIL::Const(false);
eq_cell->parameters["\\B_SIGNED"] = RTLIL::Const(false);
eq_cell->parameters["\\A_WIDTH"] = RTLIL::Const(eq_sig_a.size());
eq_cell->parameters["\\B_WIDTH"] = RTLIL::Const(eq_sig_b.size());
eq_cell->parameters["\\Y_WIDTH"] = RTLIL::Const(1);
}
std::set<int> complete_in_state_cache = it.second;
for (auto &it2 : pattern_cache)
if (pattern_is_subset(pattern, it2.first))
complete_in_state_cache.insert(it2.second.begin(), it2.second.end());
if (GetSize(complete_in_state_cache) < num_states)
{
if (or_sig.size() == 1)
{
and_sig.append(or_sig);
}
else
{
RTLIL::Wire *or_wire = module->addWire(NEW_ID);
and_sig.append(RTLIL::SigSpec(or_wire));
RTLIL::Cell *or_cell = module->addCell(NEW_ID, "$reduce_or");
or_cell->setPort("\\A", or_sig);
or_cell->setPort("\\Y", RTLIL::SigSpec(or_wire));
or_cell->parameters["\\A_SIGNED"] = RTLIL::Const(false);
or_cell->parameters["\\A_WIDTH"] = RTLIL::Const(or_sig.size());
or_cell->parameters["\\Y_WIDTH"] = RTLIL::Const(1);
}
}
switch (and_sig.size())
{
case 2:
{
RTLIL::Wire *and_wire = module->addWire(NEW_ID);
cases_vector.append(RTLIL::SigSpec(and_wire));
RTLIL::Cell *and_cell = module->addCell(NEW_ID, "$and");
and_cell->setPort("\\A", and_sig.extract(0, 1));
and_cell->setPort("\\B", and_sig.extract(1, 1));
and_cell->setPort("\\Y", RTLIL::SigSpec(and_wire));
and_cell->parameters["\\A_SIGNED"] = RTLIL::Const(false);
and_cell->parameters["\\B_SIGNED"] = RTLIL::Const(false);
and_cell->parameters["\\A_WIDTH"] = RTLIL::Const(1);
and_cell->parameters["\\B_WIDTH"] = RTLIL::Const(1);
and_cell->parameters["\\Y_WIDTH"] = RTLIL::Const(1);
break;
}
case 1:
cases_vector.append(and_sig);
break;
case 0:
cases_vector.append(RTLIL::SigSpec(1, 1));
break;
default:
log_abort();
}
}
if (cases_vector.size() > 1) {
RTLIL::Cell *or_cell = module->addCell(NEW_ID, "$reduce_or");
or_cell->setPort("\\A", cases_vector);
or_cell->setPort("\\Y", output);
or_cell->parameters["\\A_SIGNED"] = RTLIL::Const(false);
or_cell->parameters["\\A_WIDTH"] = RTLIL::Const(cases_vector.size());
or_cell->parameters["\\Y_WIDTH"] = RTLIL::Const(1);
} else if (cases_vector.size() == 1) {
module->connect(RTLIL::SigSig(output, cases_vector));
} else {
module->connect(RTLIL::SigSig(output, RTLIL::SigSpec(0, 1)));
}
}
static void map_fsm(RTLIL::Cell *fsm_cell, RTLIL::Module *module)
{
log("Mapping FSM `%s' from module `%s'.\n", fsm_cell->name.c_str(), module->name.c_str());
FsmData fsm_data;
fsm_data.copy_from_cell(fsm_cell);
RTLIL::SigSpec ctrl_in = fsm_cell->getPort("\\CTRL_IN");
RTLIL::SigSpec ctrl_out = fsm_cell->getPort("\\CTRL_OUT");
// create state register
RTLIL::Wire *state_wire = module->addWire(module->uniquify(fsm_cell->parameters["\\NAME"].decode_string()), fsm_data.state_bits);
RTLIL::Wire *next_state_wire = module->addWire(NEW_ID, fsm_data.state_bits);
RTLIL::Cell *state_dff = module->addCell(NEW_ID, "");
if (fsm_cell->getPort("\\ARST").is_fully_const()) {
state_dff->type = "$dff";
} else {
state_dff->type = "$adff";
state_dff->parameters["\\ARST_POLARITY"] = fsm_cell->parameters["\\ARST_POLARITY"];
state_dff->parameters["\\ARST_VALUE"] = fsm_data.state_table[fsm_data.reset_state];
for (auto &bit : state_dff->parameters["\\ARST_VALUE"].bits)
if (bit != RTLIL::State::S1)
bit = RTLIL::State::S0;
state_dff->setPort("\\ARST", fsm_cell->getPort("\\ARST"));
}
state_dff->parameters["\\WIDTH"] = RTLIL::Const(fsm_data.state_bits);
state_dff->parameters["\\CLK_POLARITY"] = fsm_cell->parameters["\\CLK_POLARITY"];
state_dff->setPort("\\CLK", fsm_cell->getPort("\\CLK"));
state_dff->setPort("\\D", RTLIL::SigSpec(next_state_wire));
state_dff->setPort("\\Q", RTLIL::SigSpec(state_wire));
// decode state register
bool encoding_is_onehot = true;
RTLIL::Wire *state_onehot = module->addWire(NEW_ID, fsm_data.state_table.size());
for (size_t i = 0; i < fsm_data.state_table.size(); i++)
{
RTLIL::Const state = fsm_data.state_table[i];
RTLIL::SigSpec sig_a, sig_b;
for (size_t j = 0; j < state.bits.size(); j++)
if (state.bits[j] == RTLIL::State::S0 || state.bits[j] == RTLIL::State::S1) {
sig_a.append(RTLIL::SigSpec(state_wire, j));
sig_b.append(RTLIL::SigSpec(state.bits[j]));
}
if (sig_b == RTLIL::SigSpec(RTLIL::State::S1))
{
module->connect(RTLIL::SigSig(RTLIL::SigSpec(state_onehot, i), sig_a));
}
else
{
encoding_is_onehot = false;
RTLIL::Cell *eq_cell = module->addCell(NEW_ID, "$eq");
eq_cell->setPort("\\A", sig_a);
eq_cell->setPort("\\B", sig_b);
eq_cell->setPort("\\Y", RTLIL::SigSpec(state_onehot, i));
eq_cell->parameters["\\A_SIGNED"] = RTLIL::Const(false);
eq_cell->parameters["\\B_SIGNED"] = RTLIL::Const(false);
eq_cell->parameters["\\A_WIDTH"] = RTLIL::Const(sig_a.size());
eq_cell->parameters["\\B_WIDTH"] = RTLIL::Const(sig_b.size());
eq_cell->parameters["\\Y_WIDTH"] = RTLIL::Const(1);
}
}
if (encoding_is_onehot)
state_wire->set_bool_attribute("\\onehot");
// generate next_state signal
if (GetSize(fsm_data.state_table) == 1)
{
module->connect(next_state_wire, fsm_data.state_table.front());
}
else
{
RTLIL::Wire *next_state_onehot = module->addWire(NEW_ID, fsm_data.state_table.size());
for (size_t i = 0; i < fsm_data.state_table.size(); i++)
{
std::map<RTLIL::Const, std::set<int>> pattern_cache;
std::set<int> fullstate_cache;
for (size_t j = 0; j < fsm_data.state_table.size(); j++)
fullstate_cache.insert(j);
for (auto &tr : fsm_data.transition_table) {
if (tr.state_out == int(i))
pattern_cache[tr.ctrl_in].insert(tr.state_in);
else
fullstate_cache.erase(tr.state_in);
}
implement_pattern_cache(module, pattern_cache, fullstate_cache, fsm_data.state_table.size(), state_onehot, ctrl_in, RTLIL::SigSpec(next_state_onehot, i));
}
if (encoding_is_onehot)
{
RTLIL::SigSpec next_state_sig(RTLIL::State::Sm, next_state_wire->width);
for (size_t i = 0; i < fsm_data.state_table.size(); i++) {
RTLIL::Const state = fsm_data.state_table[i];
int bit_idx = -1;
for (size_t j = 0; j < state.bits.size(); j++)
if (state.bits[j] == RTLIL::State::S1)
bit_idx = j;
if (bit_idx >= 0)
next_state_sig.replace(bit_idx, RTLIL::SigSpec(next_state_onehot, i));
}
log_assert(!next_state_sig.has_marked_bits());
module->connect(RTLIL::SigSig(next_state_wire, next_state_sig));
}
else
{
RTLIL::SigSpec sig_a(RTLIL::State::Sx, next_state_wire->width);
RTLIL::SigSpec sig_b, sig_s;
int reset_state = fsm_data.reset_state;
if (reset_state < 0)
reset_state = 0;
for (size_t i = 0; i < fsm_data.state_table.size(); i++) {
RTLIL::Const state = fsm_data.state_table[i];
if (int(i) == fsm_data.reset_state) {
sig_a = RTLIL::SigSpec(state);
} else {
sig_b.append(RTLIL::SigSpec(state));
sig_s.append(RTLIL::SigSpec(next_state_onehot, i));
}
}
RTLIL::Cell *mux_cell = module->addCell(NEW_ID, "$pmux");
mux_cell->setPort("\\A", sig_a);
mux_cell->setPort("\\B", sig_b);
mux_cell->setPort("\\S", sig_s);
mux_cell->setPort("\\Y", RTLIL::SigSpec(next_state_wire));
mux_cell->parameters["\\WIDTH"] = RTLIL::Const(sig_a.size());
mux_cell->parameters["\\S_WIDTH"] = RTLIL::Const(sig_s.size());
}
}
// Generate ctrl_out signal
for (int i = 0; i < fsm_data.num_outputs; i++)
{
std::map<RTLIL::Const, std::set<int>> pattern_cache;
std::set<int> fullstate_cache;
for (size_t j = 0; j < fsm_data.state_table.size(); j++)
fullstate_cache.insert(j);
for (auto &tr : fsm_data.transition_table) {
if (tr.ctrl_out.bits[i] == RTLIL::State::S1)
pattern_cache[tr.ctrl_in].insert(tr.state_in);
else
fullstate_cache.erase(tr.state_in);
}
implement_pattern_cache(module, pattern_cache, fullstate_cache, fsm_data.state_table.size(), state_onehot, ctrl_in, ctrl_out.extract(i, 1));
}
// Remove FSM cell
module->remove(fsm_cell);
}
struct FsmMapPass : public Pass {
FsmMapPass() : Pass("fsm_map", "mapping FSMs to basic logic") { }
virtual void help()
{
// |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
log("\n");
log(" fsm_map [selection]\n");
log("\n");
log("This pass translates FSM cells to flip-flops and logic.\n");
log("\n");
}
virtual void execute(std::vector<std::string> args, RTLIL::Design *design)
{
log_header(design, "Executing FSM_MAP pass (mapping FSMs to basic logic).\n");
extra_args(args, 1, design);
for (auto &mod_it : design->modules_) {
if (!design->selected(mod_it.second))
continue;
std::vector<RTLIL::Cell*> fsm_cells;
for (auto &cell_it : mod_it.second->cells_)
if (cell_it.second->type == "$fsm" && design->selected(mod_it.second, cell_it.second))
fsm_cells.push_back(cell_it.second);
for (auto cell : fsm_cells)
map_fsm(cell, mod_it.second);
}
}
} FsmMapPass;
PRIVATE_NAMESPACE_END