Added translation from read-feedback to en-signals in memory_share
authorClifford Wolf <clifford@clifford.at>
Fri, 18 Jul 2014 14:46:40 +0000 (16:46 +0200)
committerClifford Wolf <clifford@clifford.at>
Fri, 18 Jul 2014 14:46:40 +0000 (16:46 +0200)
passes/memory/memory.cc
passes/memory/memory_share.cc
tests/memories/implicit_en.v [new file with mode: 0644]

index a0c89a4d66282bd9b084990545a7f0ba150b5199..fc30955358ef1aa69ea5da9d8cd9b207672673d7 100644 (file)
@@ -33,7 +33,9 @@ struct MemoryPass : public Pass {
                log("This pass calls all the other memory_* passes in a useful order:\n");
                log("\n");
                log("    memory_dff\n");
+               log("    opt_clean\n");
                log("    memory_share\n");
+               log("    opt_clean\n");
                log("    memory_collect\n");
                log("    memory_map          (skipped if called with -nomap)\n");
                log("\n");
@@ -59,7 +61,9 @@ struct MemoryPass : public Pass {
                extra_args(args, argidx, design);
 
                Pass::call(design, "memory_dff");
+               Pass::call(design, "opt_clean");
                Pass::call(design, "memory_share");
+               Pass::call(design, "opt_clean");
                Pass::call(design, "memory_collect");
 
                if (!flag_nomap)
index 140a418492e7409d58438c6a9b9edc5589db988e..e2fa168c3575270adac153ef32f7e64c1c55c4bb 100644 (file)
@@ -36,7 +36,209 @@ struct MemoryShareWorker
 {
        RTLIL::Design *design;
        RTLIL::Module *module;
-       SigMap sigmap;
+       SigMap sigmap, sigmap_xmux;
+
+       std::map<RTLIL::SigBit, std::pair<RTLIL::Cell*, int>> sig_to_mux;
+       std::map<std::set<std::map<RTLIL::SigBit, bool>>, RTLIL::SigBit> conditions_logic_cache;
+
+
+       // -----------------------------------------------------------------
+       // Converting feedbacks to async read ports to proper enable signals
+       // -----------------------------------------------------------------
+
+       bool find_data_feedback(const std::set<RTLIL::SigBit> &async_rd_bits, RTLIL::SigBit sig,
+                       std::map<RTLIL::SigBit, bool> &state, std::set<std::map<RTLIL::SigBit, bool>> &conditions)
+       {
+               if (async_rd_bits.count(sig)) {
+                       conditions.insert(state);
+                       return true;
+               }
+
+               if (sig_to_mux.count(sig) == 0)
+                       return false;
+
+               RTLIL::Cell *cell = sig_to_mux.at(sig).first;
+               int bit_idx = sig_to_mux.at(sig).second;
+
+               std::vector<RTLIL::SigBit> sig_a = sigmap(cell->connections.at("\\A"));
+               std::vector<RTLIL::SigBit> sig_b = sigmap(cell->connections.at("\\B"));
+               std::vector<RTLIL::SigBit> sig_s = sigmap(cell->connections.at("\\S"));
+               std::vector<RTLIL::SigBit> sig_y = sigmap(cell->connections.at("\\Y"));
+               log_assert(sig_y.at(bit_idx) == sig);
+
+               for (int i = 0; i < int(sig_s.size()); i++)
+                       if (state.count(sig_s[i]) && state.at(sig_s[i]) == true) {
+                               if (find_data_feedback(async_rd_bits, sig_b.at(bit_idx + i*sig_y.size()), state, conditions))
+                                       cell->connections.at("\\B").replace(bit_idx + i*sig_y.size(), RTLIL::State::Sx);
+                               return false;
+                       }
+                               
+
+               for (int i = 0; i < int(sig_s.size()); i++)
+               {
+                       if (state.count(sig_s[i]) && state.at(sig_s[i]) == false)
+                               continue;
+
+                       std::map<RTLIL::SigBit, bool> new_state = state;
+                       new_state[sig_s[i]] = true;
+
+                       if (find_data_feedback(async_rd_bits, sig_b.at(bit_idx + i*sig_y.size()), new_state, conditions))
+                               cell->connections.at("\\B").replace(bit_idx + i*sig_y.size(), RTLIL::State::Sx);
+               }
+
+               std::map<RTLIL::SigBit, bool> new_state = state;
+               for (int i = 0; i < int(sig_s.size()); i++)
+                       new_state[sig_s[i]] = false;
+
+               if (find_data_feedback(async_rd_bits, sig_a.at(bit_idx), new_state, conditions))
+                       cell->connections.at("\\A").replace(bit_idx, RTLIL::State::Sx);
+
+               return false;
+       }
+
+       RTLIL::SigBit conditions_to_logic(std::set<std::map<RTLIL::SigBit, bool>> &conditions, int &created_conditions)
+       {
+               if (conditions_logic_cache.count(conditions))
+                       return conditions_logic_cache.at(conditions);
+
+               RTLIL::SigSpec terms;
+               for (auto &cond : conditions) {
+                       RTLIL::SigSpec sig1, sig2;
+                       for (auto &it : cond) {
+                               sig1.append_bit(it.first);
+                               sig2.append_bit(it.second ? RTLIL::State::S1 : RTLIL::State::S0);
+                       }
+                       terms.append(module->Ne(NEW_ID, sig1, sig2));
+                       created_conditions++;
+               }
+
+               if (terms.width > 1)
+                       terms = module->ReduceAnd(NEW_ID, terms);
+
+               return conditions_logic_cache[conditions] = terms;
+       }
+
+       void translate_rd_feedback_to_en(std::string memid, std::vector<RTLIL::Cell*> &rd_ports, std::vector<RTLIL::Cell*> &wr_ports)
+       {
+               std::vector<std::set<RTLIL::SigBit>> async_rd_bits;
+               std::map<RTLIL::SigBit, std::set<RTLIL::SigBit>> muxtree_upstream_map;
+               std::set<RTLIL::SigBit> non_feedback_nets;
+
+               for (auto wire_it : module->wires)
+                       if (wire_it.second->port_output) {
+                               std::vector<RTLIL::SigBit> bits = RTLIL::SigSpec(wire_it.second);
+                               non_feedback_nets.insert(bits.begin(), bits.end());
+                       }
+
+               for (auto cell_it : module->cells)
+               {
+                       RTLIL::Cell *cell = cell_it.second;
+                       bool ignore_data_port = false;
+
+                       if (cell->type == "$mux" || cell->type == "$pmux")
+                       {
+                               std::vector<RTLIL::SigBit> sig_a = sigmap(cell->connections.at("\\A"));
+                               std::vector<RTLIL::SigBit> sig_b = sigmap(cell->connections.at("\\B"));
+                               std::vector<RTLIL::SigBit> sig_s = sigmap(cell->connections.at("\\S"));
+                               std::vector<RTLIL::SigBit> sig_y = sigmap(cell->connections.at("\\Y"));
+
+                               non_feedback_nets.insert(sig_s.begin(), sig_s.end());
+
+                               for (int i = 0; i < int(sig_y.size()); i++) {
+                                       muxtree_upstream_map[sig_y[i]].insert(sig_a[i]);
+                                       for (int j = 0; j < int(sig_s.size()); j++)
+                                               muxtree_upstream_map[sig_y[i]].insert(sig_b[i + j*sig_y.size()]);
+                               }
+
+                               continue;
+                       }
+
+                       if ((cell->type == "$memwr" || cell->type == "$memrd") &&
+                                       cell->parameters.at("\\MEMID").decode_string() == memid)
+                               ignore_data_port = true;
+
+                       for (auto conn : cell_it.second->connections)
+                       {
+                               if (ignore_data_port && conn.first == "\\DATA")
+                                       continue;
+                               std::vector<RTLIL::SigBit> bits = sigmap(conn.second);
+                               non_feedback_nets.insert(bits.begin(), bits.end());
+                       }
+               }
+
+               std::set<RTLIL::SigBit> expand_non_feedback_nets = non_feedback_nets;
+               while (!expand_non_feedback_nets.empty())
+               {
+                       std::set<RTLIL::SigBit> new_expand_non_feedback_nets;
+
+                       for (auto &bit : expand_non_feedback_nets)
+                               if (muxtree_upstream_map.count(bit))
+                                       for (auto &new_bit : muxtree_upstream_map.at(bit))
+                                               if (!non_feedback_nets.count(new_bit)) {
+                                                       non_feedback_nets.insert(new_bit);
+                                                       new_expand_non_feedback_nets.insert(new_bit);
+                                               }
+
+                       expand_non_feedback_nets.swap(new_expand_non_feedback_nets);
+               }
+
+               for (auto cell : rd_ports)
+               {
+                       if (cell->parameters.at("\\CLK_ENABLE").as_bool())
+                               continue;
+
+                       std::vector<RTLIL::SigBit> sig_data = sigmap(cell->connections.at("\\DATA"));
+
+                       for (int i = 0; i < int(sig_data.size()); i++)
+                               if (non_feedback_nets.count(sig_data[i]))
+                                       goto not_pure_feedback_port;
+
+                       async_rd_bits.resize(std::max(async_rd_bits.size(), sig_data.size()));
+                       for (int i = 0; i < int(sig_data.size()); i++)
+                               async_rd_bits[i].insert(sig_data[i]);
+
+               not_pure_feedback_port:;
+               }
+
+               if (async_rd_bits.empty())
+                       return;
+
+               log("Populating enable bits on write ports of memory %s with aync read feedback:\n", log_id(memid));
+
+               for (auto cell : wr_ports)
+               {
+                       log("  Analyzing write port %s.\n", log_id(cell));
+
+                       std::vector<RTLIL::SigBit> cell_data = cell->connections.at("\\DATA");
+                       std::vector<RTLIL::SigBit> cell_en = cell->connections.at("\\EN");
+
+                       int created_conditions = 0;
+                       for (int i = 0; i < int(cell_data.size()); i++)
+                               if (cell_en[i] != RTLIL::SigBit(RTLIL::State::S0))
+                               {
+                                       std::map<RTLIL::SigBit, bool> state;
+                                       std::set<std::map<RTLIL::SigBit, bool>> conditions;
+
+                                       if (cell_en[i].wire != NULL) {
+                                               state[cell_en[i]] = false;
+                                               conditions.insert(state);
+                                       }
+
+                                       find_data_feedback(async_rd_bits.at(i), cell_data[i], state, conditions);
+                                       cell_en[i] = conditions_to_logic(conditions, created_conditions);
+                               }
+
+                       if (created_conditions) {
+                               log("    Added enable logic for %d different cases.\n", created_conditions);
+                               cell->connections.at("\\EN") = cell_en;
+                       }
+               }
+       }
+
+
+       // ------------------------------------------------------
+       // Consolidate write ports that write to the same address
+       // ------------------------------------------------------
 
        RTLIL::SigSpec mask_en_naive(RTLIL::SigSpec do_mask, RTLIL::SigSpec bits, RTLIL::SigSpec mask_bits)
        {
@@ -143,7 +345,7 @@ struct MemoryShareWorker
                for (int i = 0; i < int(wr_ports.size()); i++)
                {
                        RTLIL::Cell *cell = wr_ports.at(i);
-                       RTLIL::SigSpec addr = sigmap(cell->connections.at("\\ADDR"));
+                       RTLIL::SigSpec addr = sigmap_xmux(cell->connections.at("\\ADDR"));
 
                        if (cell->parameters.at("\\CLK_ENABLE").as_bool() != cache_clk_enable ||
                                        (cache_clk_enable && (sigmap(cell->connections.at("\\CLK")) != cache_clk ||
@@ -212,17 +414,18 @@ struct MemoryShareWorker
                                }
 
                                // Then we need to merge the (masked) EN and the DATA signals.
-                               // Note that we intentionally do not use sigmap() on the DATA ports.
 
                                RTLIL::SigSpec merged_data = wr_ports[last_i]->connections.at("\\DATA");
                                if (found_overlapping_bits) {
                                        log("      Creating logic for merging DATA and EN ports.\n");
-                                       merge_en_data(merged_en, merged_data, sigmap(cell->connections.at("\\EN")), cell->connections.at("\\DATA"));
+                                       merge_en_data(merged_en, merged_data, sigmap(cell->connections.at("\\EN")), sigmap(cell->connections.at("\\DATA")));
                                } else {
+                                       RTLIL::SigSpec cell_en = sigmap(cell->connections.at("\\EN"));
+                                       RTLIL::SigSpec cell_data = sigmap(cell->connections.at("\\DATA"));
                                        for (int k = 0; k < int(en_bits.size()); k++)
                                                if (!active_bits_on_port[last_i][k]) {
-                                                       merged_en.replace(k, cell->connections.at("\\EN").extract(k, 1));
-                                                       merged_data.replace(k, cell->connections.at("\\DATA").extract(k, 1));
+                                                       merged_en.replace(k, cell_en.extract(k, 1));
+                                                       merged_data.replace(k, cell_data.extract(k, 1));
                                                }
                                        merged_en.optimize();
                                        merged_data.optimize();
@@ -247,13 +450,28 @@ struct MemoryShareWorker
 
                        last_port_by_addr[addr] = i;
                }
+
+               // Clean up `wr_ports': remove all NULL entries
+
+               std::vector<RTLIL::Cell*> wr_ports_with_nulls;
+               wr_ports_with_nulls.swap(wr_ports);
+
+               for (auto cell : wr_ports_with_nulls)
+                       if (cell != NULL)
+                               wr_ports.push_back(cell);
        }
 
+
+       // -------------
+       // Setup and run
+       // -------------
+
        MemoryShareWorker(RTLIL::Design *design, RTLIL::Module *module) :
                        design(design), module(module), sigmap(module)
        {
                std::map<std::string, std::pair<std::vector<RTLIL::Cell*>, std::vector<RTLIL::Cell*>>> memindex;
 
+               sigmap_xmux = sigmap;
                for (auto &it : module->cells)
                {
                        RTLIL::Cell *cell = it.second;
@@ -266,19 +484,27 @@ struct MemoryShareWorker
 
                        if (cell->type == "$mux")
                        {
-                               RTLIL::SigSpec sig_a = sigmap(cell->connections.at("\\A"));
-                               RTLIL::SigSpec sig_b = sigmap(cell->connections.at("\\B"));
+                               RTLIL::SigSpec sig_a = sigmap_xmux(cell->connections.at("\\A"));
+                               RTLIL::SigSpec sig_b = sigmap_xmux(cell->connections.at("\\B"));
 
                                if (sig_a.is_fully_undef())
-                                       sigmap.add(cell->connections.at("\\Y"), sig_b);
+                                       sigmap_xmux.add(cell->connections.at("\\Y"), sig_b);
                                else if (sig_b.is_fully_undef())
-                                       sigmap.add(cell->connections.at("\\Y"), sig_a);
+                                       sigmap_xmux.add(cell->connections.at("\\Y"), sig_a);
+                       }
+
+                       if (cell->type == "$mux" || cell->type == "$pmux")
+                       {
+                               std::vector<RTLIL::SigBit> sig_y = sigmap(cell->connections.at("\\Y"));
+                               for (int i = 0; i < int(sig_y.size()); i++)
+                                       sig_to_mux[sig_y[i]] = std::pair<RTLIL::Cell*, int>(cell, i);
                        }
                }
 
                for (auto &it : memindex) {
                        std::sort(it.second.first.begin(), it.second.first.end(), memcells_cmp);
                        std::sort(it.second.second.begin(), it.second.second.end(), memcells_cmp);
+                       translate_rd_feedback_to_en(it.first, it.second.first, it.second.second);
                        consolidate_wr_by_addr(it.first, it.second.second);
                }
        }
diff --git a/tests/memories/implicit_en.v b/tests/memories/implicit_en.v
new file mode 100644 (file)
index 0000000..cfce378
--- /dev/null
@@ -0,0 +1,24 @@
+// expect-wr-ports 1
+// expect-rd-ports 1
+
+module test(clk, rd_addr, rd_data, wr_addr, wr_en, wr_data);
+
+input clk;
+
+input [3:0] rd_addr;
+output reg [31:0] rd_data;
+
+input [3:0] wr_addr, wr_en;
+input [31:0] wr_data;
+
+reg [31:0] mem [0:15];
+
+always @(posedge clk) begin
+       mem[wr_addr][ 7: 0] <= wr_en[0] ? wr_data[ 7: 0] : mem[wr_addr][ 7: 0];
+       mem[wr_addr][15: 8] <= wr_en[1] ? wr_data[15: 8] : mem[wr_addr][15: 8];
+       mem[wr_addr][23:16] <= wr_en[2] ? wr_data[23:16] : mem[wr_addr][23:16];
+       mem[wr_addr][31:24] <= wr_en[3] ? wr_data[31:24] : mem[wr_addr][31:24];
+       rd_data <= mem[rd_addr];
+end
+
+endmodule