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-rw-r--r--passes/opt/opt_const.cc22
1 files changed, 21 insertions, 1 deletions
diff --git a/passes/opt/opt_const.cc b/passes/opt/opt_const.cc
index c5c159ae..2b2c83a5 100644
--- a/passes/opt/opt_const.cc
+++ b/passes/opt/opt_const.cc
@@ -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);