Function remove_unreachable_bbs

tools/transform.cpp:1627–1667

}

static void remove_unreachable_bbs(Function &f) {
  vector<BasicBlock*> wl = { &f.getFirstBB() };
  set<BasicBlock*> reachable;

  do {
    auto bb = wl.back();
    wl.pop_back();
    if (!reachable.emplace(bb).second || bb->empty())
      continue;

    if (auto instr = dynamic_cast<JumpInstr*>(&bb->back())) {
      for (auto &target : instr->targets()) {
        wl.emplace_back(const_cast<BasicBlock*>(&target));
      }
    }
  } while (!wl.empty());

  auto all_bbs = f.getBBs(); // copy intended
  vector<string> unreachable;
  vector<const Value*> removed_instrs;
  for (auto bb : all_bbs) {
    if (!reachable.count(bb)) {
      unreachable.emplace_back(bb->getName());
      for (auto &i : bb->instrs()) {
        removed_instrs.emplace_back(&i);
      }
      f.removeBB(*bb);
    }
  }

  for (auto &i : f.instrs()) {
    if (auto phi = dynamic_cast<const Phi*>(&i)) {
      for (auto &bb : unreachable) {
        const_cast<Phi*>(phi)->removeValue(bb);
      }
      for (auto &i : removed_instrs) {
        const_cast<Phi*>(phi)->removeValue(i);
      }
    }
  }
}

static void optimize_ptrcmp(Function &f) {
  auto is_inbounds = [](const Value &v) {