--- /dev/null
+/*
+ * 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"
+
+USING_YOSYS_NAMESPACE
+PRIVATE_NAMESPACE_BEGIN
+
+struct MuxcoverWorker
+{
+ Module *module;
+ SigMap sigmap;
+
+ struct newmux_t
+ {
+ int cost;
+ vector<SigBit> inputs, selects;
+ newmux_t() : cost(0) {}
+ };
+
+ struct tree_t
+ {
+ SigBit root;
+ dict<SigBit, Cell*> muxes;
+ dict<SigBit, newmux_t> newmuxes;
+ };
+
+ vector<tree_t> tree_list;
+
+ bool use_mux4;
+ bool use_mux8;
+ bool use_mux16;
+ bool nodecode;
+
+ MuxcoverWorker(Module *module) : module(module), sigmap(module)
+ {
+ use_mux4 = false;
+ use_mux8 = false;
+ use_mux16 = false;
+ nodecode = false;
+ }
+
+ void treeify()
+ {
+ pool<SigBit> roots;
+ pool<SigBit> used_once;
+ dict<SigBit, Cell*> sig_to_mux;
+
+ for (auto wire : module->wires()) {
+ if (!wire->port_output)
+ continue;
+ for (auto bit : sigmap(wire))
+ roots.insert(bit);
+ }
+
+ for (auto cell : module->cells()) {
+ for (auto conn : cell->connections()) {
+ if (!cell->input(conn.first))
+ continue;
+ for (auto bit : sigmap(conn.second)) {
+ if (used_once.count(bit) || cell->type != "$_MUX_" || conn.first == "\\S")
+ roots.insert(bit);
+ used_once.insert(bit);
+ }
+ }
+ if (cell->type == "$_MUX_")
+ sig_to_mux[sigmap(cell->getPort("\\Y"))] = cell;
+ }
+
+ roots.sort();
+ for (auto rootsig : roots)
+ {
+ tree_t tree;
+ tree.root = rootsig;
+
+ pool<SigBit> wavefront;
+ wavefront.insert(rootsig);
+
+ while (!wavefront.empty()) {
+ SigBit bit = wavefront.pop();
+ if (sig_to_mux.count(bit) && (bit == rootsig || !roots.count(bit))) {
+ Cell *c = sig_to_mux.at(bit);
+ tree.muxes[bit] = c;
+ wavefront.insert(sigmap(c->getPort("\\A")));
+ wavefront.insert(sigmap(c->getPort("\\B")));
+ }
+ }
+
+ if (!tree.muxes.empty()) {
+ log("Found tree with %d MUXes at root %s.\n", GetSize(tree.muxes), log_signal(tree.root));
+ tree_list.push_back(tree);
+ }
+ }
+
+ log("Finished treeification: Found %d trees.\n", GetSize(tree_list));
+ }
+
+ bool follow_muxtree(SigBit &ret_bit, tree_t &tree, SigBit bit, const char *path)
+ {
+ if (*path) {
+ if (tree.muxes.count(bit) == 0)
+ return false;
+ char port_name[3] = {'\\', *path, 0};
+ return follow_muxtree(ret_bit, tree, sigmap(tree.muxes.at(bit)->getPort(port_name)), path+1);
+ } else {
+ ret_bit = bit;
+ return true;
+ }
+ }
+
+ int find_best_cover(tree_t &tree, SigBit bit)
+ {
+ if (tree.newmuxes.count(bit)) {
+ return tree.newmuxes.at(bit).cost;
+ }
+
+ SigBit A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P;
+ SigBit S1, S2, S3, S4, S5, S6, S7, S8;
+ SigBit T1, T2, T3, T4;
+ SigBit U1, U2;
+ SigBit V1;
+
+ newmux_t best_mux;
+ bool ok = true;
+
+ // 2-Input MUX
+
+ ok = ok && follow_muxtree(A, tree, bit, "A");
+ ok = ok && follow_muxtree(B, tree, bit, "B");
+
+ ok = ok && follow_muxtree(S1, tree, bit, "S");
+
+ if (ok)
+ {
+ newmux_t mux;
+
+ mux.inputs.push_back(A);
+ mux.inputs.push_back(B);
+ mux.selects.push_back(S1);
+
+ mux.cost += 10;
+ mux.cost += find_best_cover(tree, A);
+ mux.cost += find_best_cover(tree, B);
+
+ best_mux = mux;
+ }
+
+ // 4-Input MUX
+
+ if (use_mux4)
+ {
+ ok = ok && follow_muxtree(A, tree, bit, "AA");
+ ok = ok && follow_muxtree(B, tree, bit, "AB");
+ ok = ok && follow_muxtree(C, tree, bit, "BA");
+ ok = ok && follow_muxtree(D, tree, bit, "BB");
+
+ ok = ok && follow_muxtree(S1, tree, bit, "AS");
+ ok = ok && follow_muxtree(S2, tree, bit, "BS");
+
+ if (nodecode)
+ ok = ok && S1 == S2;
+
+ ok = ok && follow_muxtree(T1, tree, bit, "S");
+
+ if (ok)
+ {
+ newmux_t mux;
+
+ mux.inputs.push_back(A);
+ mux.inputs.push_back(B);
+ mux.inputs.push_back(C);
+ mux.inputs.push_back(D);
+
+ mux.selects.push_back(S1);
+ mux.selects.push_back(T1);
+
+ mux.cost += 10;
+ mux.cost += find_best_cover(tree, A);
+ mux.cost += find_best_cover(tree, B);
+ mux.cost += find_best_cover(tree, C);
+ mux.cost += find_best_cover(tree, D);
+
+ if (best_mux.cost > mux.cost)
+ best_mux = mux;
+ }
+ }
+
+ // 8-Input MUX
+
+ if (use_mux8)
+ {
+ ok = ok && follow_muxtree(A, tree, bit, "AAA");
+ ok = ok && follow_muxtree(B, tree, bit, "AAB");
+ ok = ok && follow_muxtree(C, tree, bit, "ABA");
+ ok = ok && follow_muxtree(D, tree, bit, "ABB");
+ ok = ok && follow_muxtree(E, tree, bit, "BAA");
+ ok = ok && follow_muxtree(F, tree, bit, "BAB");
+ ok = ok && follow_muxtree(G, tree, bit, "BBA");
+ ok = ok && follow_muxtree(H, tree, bit, "BBB");
+
+ ok = ok && follow_muxtree(S1, tree, bit, "AAS");
+ ok = ok && follow_muxtree(S2, tree, bit, "ABS");
+ ok = ok && follow_muxtree(S3, tree, bit, "BAS");
+ ok = ok && follow_muxtree(S4, tree, bit, "BBS");
+
+ if (nodecode)
+ ok = ok && S1 == S2 && S2 == S3 && S3 == S4;
+
+ ok = ok && follow_muxtree(T1, tree, bit, "AS");
+ ok = ok && follow_muxtree(T2, tree, bit, "BS");
+
+ if (nodecode)
+ ok = ok && T1 == T2;
+
+ ok = ok && follow_muxtree(U1, tree, bit, "S");
+
+ if (ok)
+ {
+ newmux_t mux;
+
+ mux.inputs.push_back(A);
+ mux.inputs.push_back(B);
+ mux.inputs.push_back(C);
+ mux.inputs.push_back(D);
+ mux.inputs.push_back(E);
+ mux.inputs.push_back(F);
+ mux.inputs.push_back(G);
+ mux.inputs.push_back(H);
+
+ mux.selects.push_back(S1);
+ mux.selects.push_back(T1);
+ mux.selects.push_back(U1);
+
+ mux.cost += 10;
+ mux.cost += find_best_cover(tree, A);
+ mux.cost += find_best_cover(tree, B);
+ mux.cost += find_best_cover(tree, C);
+ mux.cost += find_best_cover(tree, D);
+ mux.cost += find_best_cover(tree, E);
+ mux.cost += find_best_cover(tree, F);
+ mux.cost += find_best_cover(tree, G);
+ mux.cost += find_best_cover(tree, H);
+
+ if (best_mux.cost > mux.cost)
+ best_mux = mux;
+ }
+ }
+
+ // 16-Input MUX
+
+ if (use_mux16)
+ {
+ ok = ok && follow_muxtree(A, tree, bit, "AAAA");
+ ok = ok && follow_muxtree(B, tree, bit, "AAAB");
+ ok = ok && follow_muxtree(C, tree, bit, "AABA");
+ ok = ok && follow_muxtree(D, tree, bit, "AABB");
+ ok = ok && follow_muxtree(E, tree, bit, "ABAA");
+ ok = ok && follow_muxtree(F, tree, bit, "ABAB");
+ ok = ok && follow_muxtree(G, tree, bit, "ABBA");
+ ok = ok && follow_muxtree(H, tree, bit, "ABBB");
+ ok = ok && follow_muxtree(I, tree, bit, "BAAA");
+ ok = ok && follow_muxtree(J, tree, bit, "BAAB");
+ ok = ok && follow_muxtree(K, tree, bit, "BABA");
+ ok = ok && follow_muxtree(L, tree, bit, "BABB");
+ ok = ok && follow_muxtree(M, tree, bit, "BBAA");
+ ok = ok && follow_muxtree(N, tree, bit, "BBAB");
+ ok = ok && follow_muxtree(O, tree, bit, "BBBA");
+ ok = ok && follow_muxtree(P, tree, bit, "BBBB");
+
+ ok = ok && follow_muxtree(S1, tree, bit, "AAAS");
+ ok = ok && follow_muxtree(S2, tree, bit, "AABS");
+ ok = ok && follow_muxtree(S3, tree, bit, "ABAS");
+ ok = ok && follow_muxtree(S4, tree, bit, "ABBS");
+ ok = ok && follow_muxtree(S5, tree, bit, "BAAS");
+ ok = ok && follow_muxtree(S6, tree, bit, "BABS");
+ ok = ok && follow_muxtree(S7, tree, bit, "BBAS");
+ ok = ok && follow_muxtree(S8, tree, bit, "BBBS");
+
+ if (nodecode)
+ ok = ok && S1 == S2 && S2 == S3 && S3 == S4 && S4 == S5 && S5 == S6 && S6 == S7 && S7 == S8;
+
+ ok = ok && follow_muxtree(T1, tree, bit, "AAS");
+ ok = ok && follow_muxtree(T2, tree, bit, "ABS");
+ ok = ok && follow_muxtree(T3, tree, bit, "BAS");
+ ok = ok && follow_muxtree(T4, tree, bit, "BBS");
+
+ if (nodecode)
+ ok = ok && T1 == T2 && T2 == T3 && T3 == T4;
+
+ ok = ok && follow_muxtree(U1, tree, bit, "AS");
+ ok = ok && follow_muxtree(U2, tree, bit, "BS");
+
+ if (nodecode)
+ ok = ok && U1 == U2;
+
+ ok = ok && follow_muxtree(V1, tree, bit, "S");
+
+ if (ok)
+ {
+ newmux_t mux;
+
+ mux.inputs.push_back(A);
+ mux.inputs.push_back(B);
+ mux.inputs.push_back(C);
+ mux.inputs.push_back(D);
+ mux.inputs.push_back(E);
+ mux.inputs.push_back(F);
+ mux.inputs.push_back(G);
+ mux.inputs.push_back(H);
+ mux.inputs.push_back(I);
+ mux.inputs.push_back(J);
+ mux.inputs.push_back(K);
+ mux.inputs.push_back(L);
+ mux.inputs.push_back(M);
+ mux.inputs.push_back(N);
+ mux.inputs.push_back(O);
+ mux.inputs.push_back(P);
+
+ mux.selects.push_back(S1);
+ mux.selects.push_back(T1);
+ mux.selects.push_back(U1);
+ mux.selects.push_back(V1);
+
+ mux.cost += 10;
+ mux.cost += find_best_cover(tree, A);
+ mux.cost += find_best_cover(tree, B);
+ mux.cost += find_best_cover(tree, C);
+ mux.cost += find_best_cover(tree, D);
+ mux.cost += find_best_cover(tree, E);
+ mux.cost += find_best_cover(tree, F);
+ mux.cost += find_best_cover(tree, G);
+ mux.cost += find_best_cover(tree, H);
+ mux.cost += find_best_cover(tree, I);
+ mux.cost += find_best_cover(tree, J);
+ mux.cost += find_best_cover(tree, K);
+ mux.cost += find_best_cover(tree, L);
+ mux.cost += find_best_cover(tree, M);
+ mux.cost += find_best_cover(tree, N);
+ mux.cost += find_best_cover(tree, O);
+ mux.cost += find_best_cover(tree, P);
+
+ if (best_mux.cost > mux.cost)
+ best_mux = mux;
+ }
+ }
+
+ tree.newmuxes[bit] = best_mux;
+ return best_mux.cost;
+ }
+
+ void implement_best_cover(tree_t &tree, SigBit bit, int count_muxes_by_type[4])
+ {
+ newmux_t mux = tree.newmuxes.at(bit);
+
+ for (auto inbit : mux.inputs)
+ implement_best_cover(tree, inbit, count_muxes_by_type);
+
+ if (GetSize(mux.inputs) == 0)
+ return;
+
+ if (GetSize(mux.inputs) == 2) {
+ count_muxes_by_type[0]++;
+ Cell *cell = module->addCell(NEW_ID, "$_MUX_");
+ cell->setPort("\\A", mux.inputs[0]);
+ cell->setPort("\\B", mux.inputs[1]);
+ cell->setPort("\\S", mux.selects[0]);
+ cell->setPort("\\Y", bit);
+ return;
+ }
+
+ if (GetSize(mux.inputs) == 4) {
+ count_muxes_by_type[1]++;
+ Cell *cell = module->addCell(NEW_ID, "$_MUX4_");
+ cell->setPort("\\A", mux.inputs[0]);
+ cell->setPort("\\B", mux.inputs[1]);
+ cell->setPort("\\C", mux.inputs[2]);
+ cell->setPort("\\D", mux.inputs[3]);
+ cell->setPort("\\S", mux.selects[0]);
+ cell->setPort("\\T", mux.selects[1]);
+ cell->setPort("\\Y", bit);
+ return;
+ }
+
+ if (GetSize(mux.inputs) == 8) {
+ count_muxes_by_type[2]++;
+ Cell *cell = module->addCell(NEW_ID, "$_MUX8_");
+ cell->setPort("\\A", mux.inputs[0]);
+ cell->setPort("\\B", mux.inputs[1]);
+ cell->setPort("\\C", mux.inputs[2]);
+ cell->setPort("\\D", mux.inputs[3]);
+ cell->setPort("\\E", mux.inputs[4]);
+ cell->setPort("\\F", mux.inputs[5]);
+ cell->setPort("\\G", mux.inputs[6]);
+ cell->setPort("\\H", mux.inputs[7]);
+ cell->setPort("\\S", mux.selects[0]);
+ cell->setPort("\\T", mux.selects[1]);
+ cell->setPort("\\U", mux.selects[2]);
+ cell->setPort("\\Y", bit);
+ return;
+ }
+
+ if (GetSize(mux.inputs) == 16) {
+ count_muxes_by_type[3]++;
+ Cell *cell = module->addCell(NEW_ID, "$_MUX16_");
+ cell->setPort("\\A", mux.inputs[0]);
+ cell->setPort("\\B", mux.inputs[1]);
+ cell->setPort("\\C", mux.inputs[2]);
+ cell->setPort("\\D", mux.inputs[3]);
+ cell->setPort("\\E", mux.inputs[4]);
+ cell->setPort("\\F", mux.inputs[5]);
+ cell->setPort("\\G", mux.inputs[6]);
+ cell->setPort("\\H", mux.inputs[7]);
+ cell->setPort("\\I", mux.inputs[8]);
+ cell->setPort("\\J", mux.inputs[9]);
+ cell->setPort("\\K", mux.inputs[10]);
+ cell->setPort("\\L", mux.inputs[11]);
+ cell->setPort("\\M", mux.inputs[12]);
+ cell->setPort("\\N", mux.inputs[13]);
+ cell->setPort("\\O", mux.inputs[14]);
+ cell->setPort("\\P", mux.inputs[15]);
+ cell->setPort("\\S", mux.selects[0]);
+ cell->setPort("\\T", mux.selects[1]);
+ cell->setPort("\\U", mux.selects[2]);
+ cell->setPort("\\V", mux.selects[3]);
+ cell->setPort("\\Y", bit);
+ return;
+ }
+
+ log_abort();
+ }
+
+ void treecover(tree_t &tree)
+ {
+ int count_muxes_by_type[4] = {0, 0, 0, 0};
+ find_best_cover(tree, tree.root);
+ implement_best_cover(tree, tree.root, count_muxes_by_type);
+ log("Replaced tree at %s: %d MUX2, %d MUX4, %d MUX8, %d MUX16\n", log_signal(tree.root),
+ count_muxes_by_type[0], count_muxes_by_type[1], count_muxes_by_type[2], count_muxes_by_type[3]);
+ for (auto &it : tree.muxes)
+ module->remove(it.second);
+ }
+
+ void run()
+ {
+ log("Covering MUX trees in module %s..\n", log_id(module));
+
+ treeify();
+
+ for (auto &tree : tree_list)
+ treecover(tree);
+ }
+};
+
+struct MuxcoverPass : public Pass {
+ MuxcoverPass() : Pass("muxcover", "cover trees of MUX cells with wider MUXes") { }
+ virtual void help()
+ {
+ // |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
+ log("\n");
+ log(" muxcover [options] [selection]\n");
+ log("\n");
+ log("Cover trees of $_MUX_ cells with $_MUX{4,8,16}_ cells\n");
+ log("\n");
+ log(" -mux4, -mux8, -mux16\n");
+ log(" Use the specified types of MUXes. If none of those options are used,\n");
+ log(" the effect is the same as if all of them where used.\n");
+ log("\n");
+ // log(" -nodecode\n");
+ // log(" Do not insert decoder logic. This reduces the number of possible\n");
+ // log(" substitutions, but guarantees that the resulting circuit is not\n");
+ // log(" less efficient than the original circuit.\n");
+ // log("\n");
+ }
+ virtual void execute(std::vector<std::string> args, RTLIL::Design *design)
+ {
+ log_header("Executing MUXCOVER pass (mapping to wider MUXes).\n");
+
+ bool use_mux4 = false;
+ bool use_mux8 = false;
+ bool use_mux16 = false;
+ bool nodecode = true;
+
+ size_t argidx;
+ for (argidx = 1; argidx < args.size(); argidx++)
+ {
+ if (args[argidx] == "-mux4") {
+ use_mux4 = true;
+ continue;
+ }
+ if (args[argidx] == "-mux8") {
+ use_mux8 = true;
+ continue;
+ }
+ if (args[argidx] == "-mux16") {
+ use_mux16 = true;
+ continue;
+ }
+ if (args[argidx] == "-nodecode") {
+ nodecode = true;
+ continue;
+ }
+ break;
+ }
+ extra_args(args, argidx, design);
+
+ if (!use_mux4 && !use_mux8 && !use_mux16) {
+ use_mux4 = true;
+ use_mux8 = true;
+ use_mux16 = true;
+ }
+
+ for (auto module : design->selected_modules())
+ {
+ MuxcoverWorker worker(module);
+ worker.use_mux4 = use_mux4;
+ worker.use_mux8 = use_mux8;
+ worker.use_mux16 = use_mux16;
+ worker.nodecode = nodecode;
+ worker.run();
+ }
+ }
+} MuxcoverPass;
+
+PRIVATE_NAMESPACE_END
projects / yosys.git / commitdiff