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Added "shregmap -zinit" and "shregmap -init"

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This commit is contained in:
Clifford Wolf 2016-04-18 11:44:10 +02:00
parent ce7c980ec7
commit 525651c8f6
1 changed files with 65 additions and 2 deletions
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67
passes/techmap/shregmap.cc
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@ -27,6 +27,7 @@ struct ShregmapOptions
{
int minlen, maxlen;
int keep_before, keep_after;
bool zinit, init;
dict<IdString, pair<IdString, IdString>> ffcells;
ShregmapOptions()
@ -35,6 +36,8 @@ struct ShregmapOptions
maxlen = 0;
keep_before = 0;
keep_after = 0;
zinit = false;
init = false;
}
};
@ -45,7 +48,9 @@ struct ShregmapWorker
const ShregmapOptions &opts;
int dff_count, shreg_count;
pool<Cell*> remove_cells;
pool<SigBit> remove_init;
dict<SigBit, bool> sigbit_init;
dict<SigBit, Cell*> sigbit_chain_next;
@ -66,7 +71,7 @@ struct ShregmapWorker
SigSpec initsig = sigmap(wire);
Const initval = wire->attributes.at("\\init");
for (int i = 0; i < GetSize(initsig) && i < GetSize(initval); i++)
if (initval[i] == State::S0)
if (initval[i] == State::S0 && !opts.zinit)
sigbit_init[initsig[i]] = false;
else if (initval[i] == State::S1)
sigbit_init[initsig[i]] = true;
@ -83,7 +88,7 @@ struct ShregmapWorker
SigBit d_bit = sigmap(cell->getPort(d_port).as_bit());
SigBit q_bit = sigmap(cell->getPort(q_port).as_bit());
if (sigbit_init.count(q_bit) == 0) {
if (opts.init || sigbit_init.count(q_bit) == 0) {
if (sigbit_chain_next.count(d_bit)) {
sigbit_with_non_chain_users.insert(d_bit);
} else
@ -195,6 +200,28 @@ struct ShregmapWorker
shreg_cell_type_str += first_cell->type.substr(1);
IdString q_port = opts.ffcells.at(first_cell->type).second;
if (opts.init) {
vector<State> initval;
for (int i = depth-1; i >= 0; i--) {
SigBit bit = sigmap(chain[cursor+i]->getPort(q_port).as_bit());
if (sigbit_init.count(bit) == 0)
initval.push_back(State::Sx);
else if (sigbit_init.at(bit))
initval.push_back(State::S1);
else
initval.push_back(State::S0);
remove_init.insert(bit);
}
first_cell->setParam("\\INIT", initval);
}
if (opts.zinit)
for (int i = depth-1; i >= 0; i--) {
SigBit bit = sigmap(chain[cursor+i]->getPort(q_port).as_bit());
remove_init.insert(bit);
}
first_cell->type = shreg_cell_type_str;
first_cell->setPort(q_port, last_cell->getPort(q_port));
first_cell->setParam("\\DEPTH", depth);
@ -210,6 +237,22 @@ struct ShregmapWorker
for (auto cell : remove_cells)
module->remove(cell);
for (auto wire : module->wires())
{
if (wire->attributes.count("\\init") == 0)
continue;
SigSpec initsig = sigmap(wire);
Const &initval = wire->attributes.at("\\init");
for (int i = 0; i < GetSize(initsig) && i < GetSize(initval); i++)
if (remove_init.count(initsig[i]))
initval[i] = State::Sx;
if (SigSpec(initval).is_fully_undef())
wire->attributes.erase("\\init");
}
remove_cells.clear();
sigbit_chain_next.clear();
sigbit_chain_prev.clear();
@ -272,6 +315,15 @@ struct ShregmapPass : public Pass {
log(" by default. E.g. the option '-clkpol pos' is just an alias for\n");
log(" '-match $_DFF_P_', which is an alias for '-match $_DFF_P_:D:Q'.\n");
log("\n");
log(" -zinit\n");
log(" assume the shift register is automatically zero-initialized, so it\n");
log(" becomes legal to merge zero initialized FFs into the shift register.\n");
log("\n");
log(" -init\n");
log(" map initialized registers to the shift reg, add an INIT parameter to\n");
log(" generated cells with the initialization value. (first bit to shift out\n");
log(" in LSB position)\n");
log("\n");
}
virtual void execute(std::vector<std::string> args, RTLIL::Design *design)
{
@ -319,10 +371,21 @@ struct ShregmapPass : public Pass {
opts.keep_after = atoi(args[++argidx].c_str());
continue;
}
if (args[argidx] == "-zinit") {
opts.zinit = true;
continue;
}
if (args[argidx] == "-init") {
opts.init = true;
continue;
}
break;
}
extra_args(args, argidx, design);
if (opts.zinit && opts.init)
log_cmd_error("Options -zinit and -init are exclusive!\n");
if (opts.ffcells.empty())
{
bool clk_pos = clkpol == "" || clkpol == "pos" || clkpol == "any";