diff options
Diffstat (limited to 'passes/opt/wreduce.cc')
| -rw-r--r-- | passes/opt/wreduce.cc | 65 |
1 files changed, 52 insertions, 13 deletions
diff --git a/passes/opt/wreduce.cc b/passes/opt/wreduce.cc index 70a40e960..4f08da675 100644 --- a/passes/opt/wreduce.cc +++ b/passes/opt/wreduce.cc @@ -37,7 +37,7 @@ struct WreduceConfig "$and", "$or", "$xor", "$xnor", "$shl", "$shr", "$sshl", "$sshr", "$shift", "$shiftx", "$lt", "$le", "$eq", "$ne", "$eqx", "$nex", "$ge", "$gt", - "$add", "$sub", // "$mul", "$div", "$mod", "$pow", + "$add", "$sub", "$mul", // "$div", "$mod", "$pow", "$mux", "$pmux" }); } @@ -51,6 +51,7 @@ struct WreduceWorker std::set<Cell*, IdString::compare_ptr_by_name<Cell>> work_queue_cells; std::set<SigBit> work_queue_bits; + pool<SigBit> keep_bits; WreduceWorker(WreduceConfig *config, Module *module) : config(config), module(module), mi(module) { } @@ -65,10 +66,13 @@ struct WreduceWorker SigSpec sig_y = mi.sigmap(cell->getPort("\\Y")); std::vector<SigBit> bits_removed; + if (sig_y.has_const()) + return; + for (int i = GetSize(sig_y)-1; i >= 0; i--) { auto info = mi.query(sig_y[i]); - if (!info->is_output && GetSize(info->ports) <= 1) { + if (!info->is_output && GetSize(info->ports) <= 1 && !keep_bits.count(mi.sigmap(sig_y[i]))) { bits_removed.push_back(Sx); continue; } @@ -172,6 +176,11 @@ struct WreduceWorker if (cell->type.in("$mux", "$pmux")) return run_cell_mux(cell); + SigSpec sig = mi.sigmap(cell->getPort("\\Y")); + + if (sig.has_const()) + return; + // Reduce size of ports A and B based on constant input bits and size of output port @@ -179,8 +188,8 @@ struct WreduceWorker int max_port_b_size = cell->hasPort("\\B") ? GetSize(cell->getPort("\\B")) : -1; if (cell->type.in("$not", "$pos", "$neg", "$and", "$or", "$xor", "$add", "$sub")) { - max_port_a_size = std::min(max_port_a_size, GetSize(cell->getPort("\\Y"))); - max_port_b_size = std::min(max_port_b_size, GetSize(cell->getPort("\\Y"))); + max_port_a_size = min(max_port_a_size, GetSize(sig)); + max_port_b_size = min(max_port_b_size, GetSize(sig)); } bool port_a_signed = false; @@ -192,10 +201,33 @@ struct WreduceWorker if (max_port_b_size >= 0) run_reduce_inport(cell, 'B', max_port_b_size, port_b_signed, did_something); + if (cell->hasPort("\\A") && cell->hasPort("\\B") && port_a_signed && port_b_signed) { + SigSpec sig_a = mi.sigmap(cell->getPort("\\A")), sig_b = mi.sigmap(cell->getPort("\\B")); + if (GetSize(sig_a) > 0 && sig_a[GetSize(sig_a)-1] == State::S0 && + GetSize(sig_b) > 0 && sig_b[GetSize(sig_b)-1] == State::S0) { + log("Converting cell %s.%s (%s) from signed to unsigned.\n", + log_id(module), log_id(cell), log_id(cell->type)); + cell->setParam("\\A_SIGNED", 0); + cell->setParam("\\B_SIGNED", 0); + port_a_signed = false; + port_b_signed = false; + did_something = true; + } + } + + if (cell->hasPort("\\A") && !cell->hasPort("\\B") && port_a_signed) { + SigSpec sig_a = mi.sigmap(cell->getPort("\\A")); + if (GetSize(sig_a) > 0 && sig_a[GetSize(sig_a)-1] == State::S0) { + log("Converting cell %s.%s (%s) from signed to unsigned.\n", + log_id(module), log_id(cell), log_id(cell->type)); + cell->setParam("\\A_SIGNED", 0); + port_a_signed = false; + did_something = true; + } + } - // Reduce size of port Y based on sizes for A and B and unused bits in Y - SigSpec sig = mi.sigmap(cell->getPort("\\Y")); + // Reduce size of port Y based on sizes for A and B and unused bits in Y int bits_removed = 0; if (port_a_signed && cell->type == "$shr") { @@ -221,7 +253,7 @@ struct WreduceWorker if (cell->hasPort("\\A")) a_size = GetSize(cell->getPort("\\A")); if (cell->hasPort("\\B")) b_size = GetSize(cell->getPort("\\B")); - int max_y_size = std::max(a_size, b_size); + int max_y_size = max(a_size, b_size); if (cell->type == "$add") max_y_size++; @@ -265,6 +297,11 @@ struct WreduceWorker void run() { + for (auto w : module->wires()) + if (w->get_bool_attribute("\\keep")) + for (auto bit : mi.sigmap(w)) + keep_bits.insert(bit); + for (auto c : module->selected_cells()) work_queue_cells.insert(c); @@ -348,14 +385,16 @@ struct WreducePass : public Pass { continue; for (auto c : module->selected_cells()) - if (c->type.in({"$reduce_and", "$reduce_or", "$reduce_xor", "$reduce_xnor", "$reduce_bool", + if (c->type.in("$reduce_and", "$reduce_or", "$reduce_xor", "$reduce_xnor", "$reduce_bool", "$lt", "$le", "$eq", "$ne", "$eqx", "$nex", "$ge", "$gt", - "$logic_not", "$logic_and", "$logic_or"}) && GetSize(c->getPort("\\Y")) > 1) { + "$logic_not", "$logic_and", "$logic_or") && GetSize(c->getPort("\\Y")) > 1) { SigSpec sig = c->getPort("\\Y"); - c->setPort("\\Y", sig[0]); - c->setParam("\\Y_WIDTH", 1); - sig.remove(0); - module->connect(sig, Const(0, GetSize(sig))); + if (!sig.has_const()) { + c->setPort("\\Y", sig[0]); + c->setParam("\\Y_WIDTH", 1); + sig.remove(0); + module->connect(sig, Const(0, GetSize(sig))); + } } WreduceWorker worker(&config, module); |