log("Merge synchronous set/reset $_MUX_ cells to create $__DFFS_[NP][NP][01], to be run before\n");
log("dff2dffe for SR over CE priority.\n");
log("\n");
+ log(" -match-init\n");
+ log(" Disallow merging synchronous set/reset that has polarity opposite of the\n");
+ log(" output wire's init attribute (if any).\n");
+ log("\n");
}
void execute(std::vector<std::string> args, RTLIL::Design *design) YS_OVERRIDE
{
log_header(design, "Executing dff2dffs pass (merge synchronous set/reset into FF cells).\n");
+ bool match_init = false;
size_t argidx;
for (argidx = 1; argidx < args.size(); argidx++)
{
// singleton_mode = true;
// continue;
// }
+ if (args[argidx] == "-match-init") {
+ match_init = true;
+ continue;
+ }
break;
}
extra_args(args, argidx, design);
if (cell->type != ID($_MUX_))
continue;
- SigBit bit_a = sigmap(cell->getPort(ID(A)));
- SigBit bit_b = sigmap(cell->getPort(ID(B)));
+ SigBit bit_a = sigmap(cell->getPort(ID::A));
+ SigBit bit_b = sigmap(cell->getPort(ID::B));
if (bit_a.wire == nullptr || bit_b.wire == nullptr)
- sr_muxes[sigmap(cell->getPort(ID(Y)))] = cell;
+ sr_muxes[sigmap(cell->getPort(ID::Y))] = cell;
}
for (auto cell : ff_cells)
continue;
Cell *mux_cell = sr_muxes.at(bit_d);
- SigBit bit_a = sigmap(mux_cell->getPort(ID(A)));
- SigBit bit_b = sigmap(mux_cell->getPort(ID(B)));
+ SigBit bit_a = sigmap(mux_cell->getPort(ID::A));
+ SigBit bit_b = sigmap(mux_cell->getPort(ID::B));
SigBit bit_s = sigmap(mux_cell->getPort(ID(S)));
- log(" Merging %s (A=%s, B=%s, S=%s) into %s (%s).\n", log_id(mux_cell),
- log_signal(bit_a), log_signal(bit_b), log_signal(bit_s), log_id(cell), log_id(cell->type));
-
SigBit sr_val, sr_sig;
bool invert_sr;
sr_sig = bit_s;
invert_sr = false;
}
+ if (match_init) {
+ SigBit bit_q = cell->getPort(ID(Q));
+ if (bit_q.wire) {
+ auto it = bit_q.wire->attributes.find(ID(init));
+ if (it != bit_q.wire->attributes.end()) {
+ auto init_val = it->second[bit_q.offset];
+ if (init_val == State::S1 && sr_val != State::S1)
+ continue;
+ if (init_val == State::S0 && sr_val != State::S0)
+ continue;
+ }
+ }
+ }
+
+ log(" Merging %s (A=%s, B=%s, S=%s) into %s (%s).\n", log_id(mux_cell),
+ log_signal(bit_a), log_signal(bit_b), log_signal(bit_s), log_id(cell), log_id(cell->type));
+
if (sr_val == State::S1) {
if (cell->type == ID($_DFF_N_)) {
if (invert_sr) cell->type = ID($__DFFS_NN1_);