SigMap sigmap, sigmap_xmux;
ModWalker modwalker;
CellTypes cone_ct;
+ bool flag_widen;
// ------------------------------------------------------
// Consolidate write ports that write to the same address
+ // (or close enough to be merged to wide ports)
// ------------------------------------------------------
- RTLIL::SigSpec mask_en_naive(RTLIL::SigSpec do_mask, RTLIL::SigSpec bits, RTLIL::SigSpec mask_bits)
- {
- // this is the naive version of the function that does not care about grouping the EN bits.
-
- RTLIL::SigSpec inv_mask_bits = module->Not(NEW_ID, mask_bits);
- RTLIL::SigSpec inv_mask_bits_filtered = module->Mux(NEW_ID, RTLIL::SigSpec(RTLIL::State::S1, bits.size()), inv_mask_bits, do_mask);
- RTLIL::SigSpec result = module->And(NEW_ID, inv_mask_bits_filtered, bits);
- return result;
- }
-
- RTLIL::SigSpec mask_en_grouped(RTLIL::SigSpec do_mask, RTLIL::SigSpec bits, RTLIL::SigSpec mask_bits)
- {
- // this version of the function preserves the bit grouping in the EN bits.
-
- std::vector<RTLIL::SigBit> v_bits = bits;
- std::vector<RTLIL::SigBit> v_mask_bits = mask_bits;
-
- std::map<std::pair<RTLIL::SigBit, RTLIL::SigBit>, std::pair<int, std::vector<int>>> groups;
- RTLIL::SigSpec grouped_bits, grouped_mask_bits;
-
- for (int i = 0; i < bits.size(); i++) {
- std::pair<RTLIL::SigBit, RTLIL::SigBit> key(v_bits[i], v_mask_bits[i]);
- if (groups.count(key) == 0) {
- groups[key].first = grouped_bits.size();
- grouped_bits.append(v_bits[i]);
- grouped_mask_bits.append(v_mask_bits[i]);
- }
- groups[key].second.push_back(i);
- }
-
- std::vector<RTLIL::SigBit> grouped_result = mask_en_naive(do_mask, grouped_bits, grouped_mask_bits);
- RTLIL::SigSpec result;
-
- for (int i = 0; i < bits.size(); i++) {
- std::pair<RTLIL::SigBit, RTLIL::SigBit> key(v_bits[i], v_mask_bits[i]);
- result.append(grouped_result.at(groups.at(key).first));
- }
-
- return result;
- }
-
- void merge_en_data(RTLIL::SigSpec &merged_en, RTLIL::SigSpec &merged_data, RTLIL::SigSpec next_en, RTLIL::SigSpec next_data)
- {
- std::vector<RTLIL::SigBit> v_old_en = merged_en;
- std::vector<RTLIL::SigBit> v_next_en = next_en;
-
- // The new merged_en signal is just the old merged_en signal and next_en OR'ed together.
- // But of course we need to preserve the bit grouping..
-
- std::map<std::pair<RTLIL::SigBit, RTLIL::SigBit>, int> groups;
- std::vector<RTLIL::SigBit> grouped_old_en, grouped_next_en;
- RTLIL::SigSpec new_merged_en;
-
- for (int i = 0; i < int(v_old_en.size()); i++) {
- std::pair<RTLIL::SigBit, RTLIL::SigBit> key(v_old_en[i], v_next_en[i]);
- if (groups.count(key) == 0) {
- groups[key] = grouped_old_en.size();
- grouped_old_en.push_back(key.first);
- grouped_next_en.push_back(key.second);
- }
- }
-
- std::vector<RTLIL::SigBit> grouped_new_en = module->Or(NEW_ID, grouped_old_en, grouped_next_en);
-
- for (int i = 0; i < int(v_old_en.size()); i++) {
- std::pair<RTLIL::SigBit, RTLIL::SigBit> key(v_old_en[i], v_next_en[i]);
- new_merged_en.append(grouped_new_en.at(groups.at(key)));
- }
-
- // Create the new merged_data signal.
-
- RTLIL::SigSpec new_merged_data(RTLIL::State::Sx, merged_data.size());
-
- RTLIL::SigSpec old_data_set = module->And(NEW_ID, merged_en, merged_data);
- RTLIL::SigSpec old_data_unset = module->And(NEW_ID, merged_en, module->Not(NEW_ID, merged_data));
-
- RTLIL::SigSpec new_data_set = module->And(NEW_ID, next_en, next_data);
- RTLIL::SigSpec new_data_unset = module->And(NEW_ID, next_en, module->Not(NEW_ID, next_data));
-
- new_merged_data = module->Or(NEW_ID, new_merged_data, old_data_set);
- new_merged_data = module->And(NEW_ID, new_merged_data, module->Not(NEW_ID, old_data_unset));
-
- new_merged_data = module->Or(NEW_ID, new_merged_data, new_data_set);
- new_merged_data = module->And(NEW_ID, new_merged_data, module->Not(NEW_ID, new_data_unset));
-
- // Update merged_* signals
-
- merged_en = new_merged_en;
- merged_data = new_merged_data;
- }
-
- void consolidate_wr_by_addr(Mem &mem)
+ bool consolidate_wr_by_addr(Mem &mem)
{
if (GetSize(mem.wr_ports) <= 1)
- return;
+ return false;
log("Consolidating write ports of memory %s.%s by address:\n", log_id(module), log_id(mem.memid));
- std::map<RTLIL::SigSpec, int> last_port_by_addr;
- std::vector<std::vector<bool>> active_bits_on_port;
-
- bool cache_clk_enable = false;
- bool cache_clk_polarity = false;
- RTLIL::SigSpec cache_clk;
- int cache_wide_log2 = 0;
-
bool changed = false;
-
for (int i = 0; i < GetSize(mem.wr_ports); i++)
{
- auto &port = mem.wr_ports[i];
- RTLIL::SigSpec addr = sigmap_xmux(port.addr);
-
- if (port.clk_enable != cache_clk_enable ||
- port.wide_log2 != cache_wide_log2 ||
- (cache_clk_enable && (sigmap(port.clk) != cache_clk ||
- port.clk_polarity != cache_clk_polarity)))
- {
- cache_clk_enable = port.clk_enable;
- cache_clk_polarity = port.clk_polarity;
- cache_clk = sigmap(port.clk);
- cache_wide_log2 = port.wide_log2;
- last_port_by_addr.clear();
-
- if (cache_clk_enable)
- log(" New clock domain: %s %s\n", cache_clk_polarity ? "posedge" : "negedge", log_signal(cache_clk));
- else
- log(" New clock domain: unclocked\n");
- }
-
- log(" Port %d has addr %s.\n", i, log_signal(addr));
-
- log(" Active bits: ");
- std::vector<RTLIL::SigBit> en_bits = sigmap(port.en);
- active_bits_on_port.push_back(std::vector<bool>(en_bits.size()));
- for (int k = int(en_bits.size())-1; k >= 0; k--) {
- active_bits_on_port[i][k] = en_bits[k].wire != NULL || en_bits[k].data != RTLIL::State::S0;
- log("%c", active_bits_on_port[i][k] ? '1' : '0');
- }
- log("\n");
-
- if (last_port_by_addr.count(addr))
+ auto &port1 = mem.wr_ports[i];
+ if (port1.removed)
+ continue;
+ if (!port1.clk_enable)
+ continue;
+ for (int j = i + 1; j < GetSize(mem.wr_ports); j++)
{
- int last_i = last_port_by_addr.at(addr);
- log(" Merging port %d into this one.\n", last_i);
-
- bool found_overlapping_bits = false;
- for (int k = 0; k < int(en_bits.size()); k++) {
- if (active_bits_on_port[i][k] && active_bits_on_port[last_i][k])
- found_overlapping_bits = true;
- active_bits_on_port[i][k] = active_bits_on_port[i][k] || active_bits_on_port[last_i][k];
- }
-
- // Force this ports addr input to addr directly (skip don't care muxes)
-
- port.addr = addr;
-
- // If any of the ports between `last_i' and `i' write to the same address, this
- // will have priority over whatever `last_i` wrote. So we need to revisit those
- // ports and mask the EN bits accordingly.
-
- RTLIL::SigSpec merged_en = sigmap(mem.wr_ports[last_i].en);
-
- for (int j = last_i+1; j < i; j++)
- {
- if (mem.wr_ports[j].removed)
+ auto &port2 = mem.wr_ports[j];
+ if (port2.removed)
+ continue;
+ if (!port2.clk_enable)
+ continue;
+ if (port1.clk != port2.clk)
+ continue;
+ if (port1.clk_polarity != port2.clk_polarity)
+ continue;
+ // If the width of the ports doesn't match, they can still be
+ // merged by widening the narrow one. Check if the conditions
+ // hold for that.
+ int wide_log2 = std::max(port1.wide_log2, port2.wide_log2);
+ if (GetSize(port1.addr) <= wide_log2)
+ continue;
+ if (GetSize(port2.addr) <= wide_log2)
+ continue;
+ if (!port1.addr.extract(0, wide_log2).is_fully_const())
+ continue;
+ if (!port2.addr.extract(0, wide_log2).is_fully_const())
+ continue;
+ if (sigmap_xmux(port1.addr.extract_end(wide_log2)) != sigmap_xmux(port2.addr.extract_end(wide_log2))) {
+ // Incompatible addresses after widening. Last chance — widen both
+ // ports by one more bit to merge them.
+ if (!flag_widen)
+ continue;
+ wide_log2++;
+ if (sigmap_xmux(port1.addr.extract_end(wide_log2)) != sigmap_xmux(port2.addr.extract_end(wide_log2)))
+ continue;
+ if (!port1.addr.extract(0, wide_log2).is_fully_const())
+ continue;
+ if (!port2.addr.extract(0, wide_log2).is_fully_const())
continue;
-
- for (int k = 0; k < int(en_bits.size()); k++)
- if (active_bits_on_port[i][k] && active_bits_on_port[j][k])
- goto found_overlapping_bits_i_j;
-
- if (0) {
- found_overlapping_bits_i_j:
- log(" Creating collosion-detect logic for port %d.\n", j);
- RTLIL::SigSpec is_same_addr = module->addWire(NEW_ID);
- module->addEq(NEW_ID, addr, mem.wr_ports[j].addr, is_same_addr);
- merged_en = mask_en_grouped(is_same_addr, merged_en, sigmap(mem.wr_ports[j].en));
- }
}
-
- // Then we need to merge the (masked) EN and the DATA signals.
-
- RTLIL::SigSpec merged_data = mem.wr_ports[last_i].data;
- if (found_overlapping_bits) {
- log(" Creating logic for merging DATA and EN ports.\n");
- merge_en_data(merged_en, merged_data, sigmap(port.en), sigmap(port.data));
- } else {
- RTLIL::SigSpec cell_en = sigmap(port.en);
- RTLIL::SigSpec cell_data = sigmap(port.data);
- for (int k = 0; k < int(en_bits.size()); k++)
- if (!active_bits_on_port[last_i][k]) {
- merged_en.replace(k, cell_en.extract(k, 1));
- merged_data.replace(k, cell_data.extract(k, 1));
- }
+ log(" Merging ports %d, %d (address %s).\n", i, j, log_signal(port1.addr));
+ mem.prepare_wr_merge(i, j);
+ port1.addr = sigmap_xmux(port1.addr);
+ port2.addr = sigmap_xmux(port2.addr);
+ mem.widen_wr_port(i, wide_log2);
+ mem.widen_wr_port(j, wide_log2);
+ int pos = 0;
+ while (pos < GetSize(port1.data)) {
+ int epos = pos;
+ while (epos < GetSize(port1.data) && port1.en[epos] == port1.en[pos] && port2.en[epos] == port2.en[pos])
+ epos++;
+ int width = epos - pos;
+ SigBit new_en;
+ if (port2.en[pos] == State::S0) {
+ new_en = port1.en[pos];
+ } else if (port1.en[pos] == State::S0) {
+ port1.data.replace(pos, port2.data.extract(pos, width));
+ new_en = port2.en[pos];
+ } else {
+ port1.data.replace(pos, module->Mux(NEW_ID, port1.data.extract(pos, width), port2.data.extract(pos, width), port2.en[pos]));
+ new_en = module->Or(NEW_ID, port1.en[pos], port2.en[pos]);
+ }
+ for (int k = pos; k < epos; k++)
+ port1.en[k] = new_en;
+ pos = epos;
}
-
- // Connect the new EN and DATA signals and remove the old write port.
-
- port.en = merged_en;
- port.data = merged_data;
-
- mem.wr_ports[last_i].removed = true;
changed = true;
-
- log(" Active bits: ");
- std::vector<RTLIL::SigBit> en_bits = sigmap(port.en);
- active_bits_on_port.push_back(std::vector<bool>(en_bits.size()));
- for (int k = int(en_bits.size())-1; k >= 0; k--)
- log("%c", active_bits_on_port[i][k] ? '1' : '0');
- log("\n");
+ port2.removed = true;
}
-
- last_port_by_addr[addr] = i;
}
if (changed)
mem.emit();
+
+ return changed;
}
// Setup and run
// -------------
- MemoryShareWorker(RTLIL::Design *design) : design(design), modwalker(design) {}
+ MemoryShareWorker(RTLIL::Design *design, bool flag_widen) : design(design), modwalker(design), flag_widen(flag_widen) {}
void operator()(RTLIL::Module* module)
{
}
}
- for (auto &mem : memories)
- consolidate_wr_by_addr(mem);
+ for (auto &mem : memories) {
+ while (consolidate_wr_by_addr(mem));
+ }
cone_ct.setup_internals();
cone_ct.cell_types.erase(ID($mul));
}
void execute(std::vector<std::string> args, RTLIL::Design *design) override {
log_header(design, "Executing MEMORY_SHARE pass (consolidating $memrd/$memwr cells).\n");
+ // TODO: expose when wide ports are actually supported.
+ bool flag_widen = false;
extra_args(args, 1, design);
- MemoryShareWorker msw(design);
+ MemoryShareWorker msw(design, flag_widen);
for (auto module : design->selected_modules())
msw(module);