Improved comments on topological sort in edif backend

This commit is contained in:
Clifford Wolf 2013-11-04 08:34:15 +01:00
parent 1325514d33
commit ba305a7ca6
1 changed files with 4 additions and 3 deletions

View File

@ -209,16 +209,17 @@ struct EdifBackend : public Backend {
module_deps[mod_it.second].insert(design->modules.at(cell_it.second->type));
}
// bubble-sort equivialent to topological sort..
// simple good-enough topological sort
// (O(n*m) on n elements and depth m)
while (module_deps.size() > 0) {
size_t sorted_modules_idx = sorted_modules.size();
for (auto &it : module_deps) {
for (auto &dep : it.second)
if (module_deps.count(dep) > 0)
goto no_ready_yet;
goto not_ready_yet;
// log("Next in topological sort: %s\n", RTLIL::id2cstr(it.first->name));
sorted_modules.push_back(it.first);
no_ready_yet:;
not_ready_yet:;
}
if (sorted_modules_idx == sorted_modules.size())
log_error("Cyclic dependency between modules found! Cycle includes module %s.\n", RTLIL::id2cstr(module_deps.begin()->first->name));