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Added support for inverter chains to opt_const

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This commit is contained in:
Clifford Wolf 2014-02-02 21:46:42 +01:00
parent f9c4d33909
commit bee4450c4c
1 changed files with 21 additions and 1 deletions
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22
passes/opt/opt_const.cc
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@ -48,18 +48,38 @@ void replace_const_cells(RTLIL::Design *design, RTLIL::Module *module, bool cons
return;
SigMap assign_map(module);
std::map<RTLIL::SigSpec, RTLIL::SigSpec> invert_map;
std::vector<RTLIL::Cell*> cells;
cells.reserve(module->cells.size());
for (auto &cell_it : module->cells)
if (design->selected(module, cell_it.second))
if (design->selected(module, cell_it.second)) {
if ((cell_it.second->type == "$_INV_" || cell_it.second->type == "$not" || cell_it.second->type == "$logic_not") &&
cell_it.second->connections["\\A"].width == 1 && cell_it.second->connections["\\Y"].width == 1)
invert_map[assign_map(cell_it.second->connections["\\Y"])] = assign_map(cell_it.second->connections["\\A"]);
cells.push_back(cell_it.second);
}
for (auto cell : cells)
{
#define ACTION_DO(_p_, _s_) do { replace_cell(module, cell, input.as_string(), _p_, _s_); goto next_cell; } while (0)
#define ACTION_DO_Y(_v_) ACTION_DO("\\Y", RTLIL::SigSpec(RTLIL::State::S ## _v_))
if ((cell->type == "$_INV_" || cell->type == "$not" || cell->type == "$logic_not") &&
invert_map.count(assign_map(cell->connections["\\A"])) != 0) {
replace_cell(module, cell, "double_invert", "\\Y", invert_map.at(assign_map(cell->connections["\\A"])));
goto next_cell;
}
if ((cell->type == "$_MUX_" || cell->type == "$mux") && invert_map.count(assign_map(cell->connections["\\S"])) != 0) {
RTLIL::SigSpec tmp = cell->connections["\\A"];
cell->connections["\\A"] = cell->connections["\\B"];
cell->connections["\\B"] = tmp;
cell->connections["\\S"] = invert_map.at(assign_map(cell->connections["\\S"]));
did_something = true;
goto next_cell;
}
if (cell->type == "$_INV_") {
RTLIL::SigSpec input = cell->connections["\\A"];
assign_map.apply(input);