mirrors/yosys
3
0
Fork 0
mirror of https://github.com/YosysHQ/yosys synced 2025-12-27 14:36:38 +00:00
Code Activity

opt_dff: skip convertion to dffe for keep wires

Browse source
This commit is contained in:
Philippe Sauter 2025-12-15 15:46:09 +01:00
parent bd514df0df
commit 9c0e8875f1
1 changed files with 12 additions and 2 deletions
Download patch file Download diff file Expand all files Collapse all files

14
passes/opt/opt_dff.cc
View file

@ -52,6 +52,7 @@ struct OptDffWorker
FfInitVals initvals;
dict<SigBit, int> bitusers;
dict<SigBit, cell_int_t> bit2mux;
pool<SigBit> kept_bits;
typedef std::map<RTLIL::SigBit, bool> pattern_t;
typedef std::set<pattern_t> patterns_t;
@ -69,6 +70,10 @@ struct OptDffWorker
for (auto wire : module->wires())
{
if (wire->get_bool_attribute(ID::keep))
for (auto bit : sigmap(wire))
kept_bits.insert(bit);
if (wire->port_output)
for (auto bit : sigmap(wire))
bitusers[bit]++;
@ -77,8 +82,13 @@ struct OptDffWorker
for (auto cell : module->cells()) {
if (cell->type.in(ID($mux), ID($pmux), ID($_MUX_))) {
RTLIL::SigSpec sig_y = sigmap(cell->getPort(ID::Y));
for (int i = 0; i < GetSize(sig_y); i++)
bit2mux[sig_y[i]] = cell_int_t(cell, i);
for (int i = 0; i < GetSize(sig_y); i++) {
SigBit bit = sig_y[i];
// skip optimization for wires marked as 'keep'
if (kept_bits.count(bit))
continue;
bit2mux[bit] = cell_int_t(cell, i);
}
}
for (auto conn : cell->connections()) {