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Properly clean up unused "init" attributes

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This commit is contained in:
Clifford Wolf 2015-08-18 13:50:15 +02:00
parent a7ab9172f9
commit f43815054e
2 changed files with 36 additions and 6 deletions
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22
passes/techmap/dffinit.cc
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@ -63,16 +63,26 @@ struct DffinitPass : public Pass {
SigMap sigmap(module);
dict<SigBit, State> init_bits;
pool<SigBit> cleanup_bits;
pool<SigBit> used_bits;
for (auto wire : module->selected_wires())
for (auto wire : module->selected_wires()) {
if (wire->attributes.count("\\init")) {
Const value = wire->attributes.at("\\init");
for (int i = 0; i < std::min(GetSize(value), GetSize(wire)); i++)
init_bits[sigmap(SigBit(wire, i))] = value[i];
}
if (wire->port_output)
for (auto bit : sigmap(wire))
used_bits.insert(bit);
}
for (auto cell : module->selected_cells())
{
for (auto it : cell->connections())
if (!cell->known() || cell->input(it.first))
for (auto bit : sigmap(it.second))
used_bits.insert(bit);
if (ff_types.count(cell->type) == 0)
continue;
@ -104,11 +114,15 @@ struct DffinitPass : public Pass {
for (auto wire : module->selected_wires())
if (wire->attributes.count("\\init")) {
Const value = wire->attributes.at("\\init");
Const &value = wire->attributes.at("\\init");
bool do_cleanup = true;
for (int i = 0; i < std::min(GetSize(value), GetSize(wire)); i++)
if (cleanup_bits.count(sigmap(SigBit(wire, i))) == 0)
for (int i = 0; i < std::min(GetSize(value), GetSize(wire)); i++) {
SigBit bit = sigmap(SigBit(wire, i));
if (cleanup_bits.count(bit) || !used_bits.count(bit))
value[i] = State::Sx;
else if (value[i] != State::Sx)
do_cleanup = false;
}
if (do_cleanup) {
log("Removing init attribute from wire %s.%s.\n", log_id(module), log_id(wire));
wire->attributes.erase("\\init");