diff options
Diffstat (limited to 'passes/equiv/equiv_make.cc')
-rw-r--r-- | passes/equiv/equiv_make.cc | 86 |
1 files changed, 81 insertions, 5 deletions
diff --git a/passes/equiv/equiv_make.cc b/passes/equiv/equiv_make.cc index b1f88d55..dbd8682e 100644 --- a/passes/equiv/equiv_make.cc +++ b/passes/equiv/equiv_make.cc @@ -40,6 +40,16 @@ struct EquivMakeWorker pool<SigBit> undriven_bits; SigMap assign_map; + dict<SigBit, pool<Cell*>> bit2driven; // map: bit <--> and its driven cells + + CellTypes comb_ct; + + EquivMakeWorker() + { + comb_ct.setup_internals(); + comb_ct.setup_stdcells(); + } + void read_blacklists() { for (auto fn : blacklists) @@ -278,16 +288,31 @@ struct EquivMakeWorker } } + init_bit2driven(); + + pool<Cell*> visited_cells; for (auto c : cells_list) for (auto &conn : c->connections()) if (!ct.cell_output(c->type, conn.first)) { SigSpec old_sig = assign_map(conn.second); SigSpec new_sig = rd_signal_map(old_sig); - if (old_sig != new_sig) { - log("Changing input %s of cell %s (%s): %s -> %s\n", - log_id(conn.first), log_id(c), log_id(c->type), - log_signal(old_sig), log_signal(new_sig)); - c->setPort(conn.first, new_sig); + + if(old_sig != new_sig) { + SigSpec tmp_sig = old_sig; + for (int i = 0; i < GetSize(old_sig); i++) { + SigBit old_bit = old_sig[i], new_bit = new_sig[i]; + + visited_cells.clear(); + if (check_signal_in_fanout(visited_cells, old_bit, new_bit)) + continue; + + log("Changing input %s of cell %s (%s): %s -> %s\n", + log_id(conn.first), log_id(c), log_id(c->type), + log_signal(old_bit), log_signal(new_bit)); + + tmp_sig[i] = new_bit; + } + c->setPort(conn.first, tmp_sig); } } @@ -378,6 +403,57 @@ struct EquivMakeWorker } } + void init_bit2driven() + { + for (auto cell : equiv_mod->cells()) { + if (!ct.cell_known(cell->type) && !cell->type.in("$dff", "$_DFF_P_", "$_DFF_N_", "$ff", "$_FF_")) + continue; + for (auto &conn : cell->connections()) + { + if (yosys_celltypes.cell_input(cell->type, conn.first)) + for (auto bit : assign_map(conn.second)) + { + bit2driven[bit].insert(cell); + } + } + } + } + + bool check_signal_in_fanout(pool<Cell*> & visited_cells, SigBit source_bit, SigBit target_bit) + { + if (source_bit == target_bit) + return true; + + if (bit2driven.count(source_bit) == 0) + return false; + + auto driven_cells = bit2driven.at(source_bit); + for (auto driven_cell: driven_cells) + { + bool is_comb = comb_ct.cell_known(driven_cell->type); + if (!is_comb) + continue; + + if (visited_cells.count(driven_cell) > 0) + continue; + visited_cells.insert(driven_cell); + + for (auto &conn: driven_cell->connections()) + { + if (yosys_celltypes.cell_input(driven_cell->type, conn.first)) + continue; + + for (auto bit: conn.second) { + bool is_in_fanout = check_signal_in_fanout(visited_cells, bit, target_bit); + if (is_in_fanout == true) + return true; + } + } + } + + return false; + } + void run() { copy_to_equiv(); |