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Added simple $dlatch support to opt_rmdff

This commit is contained in:
Clifford Wolf 2015-05-23 09:45:48 +02:00
parent 264eb8eb6e
commit 4b6221478e
1 changed files with 35 additions and 0 deletions
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35
passes/opt/opt_rmdff.cc
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@ -29,6 +29,33 @@ PRIVATE_NAMESPACE_BEGIN
SigMap assign_map, dff_init_map;
SigSet<RTLIL::Cell*> mux_drivers;
bool handle_dlatch(RTLIL::Module *mod, RTLIL::Cell *dlatch)
{
SigSpec sig_e = dlatch->getPort("\\EN");
if (sig_e == State::S0)
{
RTLIL::Const val_init;
for (auto bit : dff_init_map(dlatch->getPort("\\Q")))
val_init.bits.push_back(bit.wire == NULL ? bit.data : State::Sx);
mod->connect(dlatch->getPort("\\Q"), val_init);
goto delete_dlatch;
}
if (sig_e == State::S1)
{
mod->connect(dlatch->getPort("\\Q"), dlatch->getPort("\\D"));
goto delete_dlatch;
}
return false;
delete_dlatch:
log("Removing %s (%s) from module %s.\n", dlatch->name.c_str(), dlatch->type.c_str(), mod->name.c_str());
mod->remove(dlatch);
return true;
}
bool handle_dff(RTLIL::Module *mod, RTLIL::Cell *dff)
{
RTLIL::SigSpec sig_d, sig_q, sig_c, sig_r;
@ -178,6 +205,7 @@ struct OptRmdffPass : public Pass {
mux_drivers.clear();
std::vector<RTLIL::IdString> dff_list;
std::vector<RTLIL::IdString> dlatch_list;
for (auto &it : mod_it.second->cells_) {
if (it.second->type == "$mux" || it.second->type == "$pmux") {
if (it.second->getPort("\\A").size() == it.second->getPort("\\B").size())
@ -198,6 +226,7 @@ struct OptRmdffPass : public Pass {
if (it.second->type == "$_DFF_PP1_") dff_list.push_back(it.first);
if (it.second->type == "$dff") dff_list.push_back(it.first);
if (it.second->type == "$adff") dff_list.push_back(it.first);
if (it.second->type == "$dlatch") dlatch_list.push_back(it.first);
}
for (auto &id : dff_list) {
@ -205,6 +234,12 @@ struct OptRmdffPass : public Pass {
handle_dff(mod_it.second, mod_it.second->cells_[id]))
total_count++;
}
for (auto &id : dlatch_list) {
if (mod_it.second->cells_.count(id) > 0 &&
handle_dlatch(mod_it.second, mod_it.second->cells_[id]))
total_count++;
}
}
assign_map.clear();