g++ optimization makes the program unable to run - c++

Question

I implemented a path planning algorithm based on D*-Lite. When I do not turn on optimization (-O0), the program can run normally. But when I turn on the optimization level (-O1/2/3), the program cannot be terminated. In Visual Studio, both debug mode and release mode can run normally. In the above cases, the codes are the same.I don’t know how to find the problem, can anyone help me?
class DstarLite {
public:
DstarLite() = delete;
DstarLite(GridStatus* a, GridStatus* b, FILE* fp)
: k_m_(0), start_(a), last_(start_), goal_(b), open_close_(fp) {}
void calculateKey(GridStatus* s);
void updateVertex(GridStatus* u);
void initialize();
void computeShortestPath();
void rePlanning(vector<pair<GridStatus*, int>>& node_change);
GridStatus* getStart();
void setStart(GridStatus* val);
GridStatus* getGoal();
private:
Fib frontier_;
double k_m_;
unordered_map<GridStatus*, handle_t>
heap_map_;
GridStatus* start_;
GridStatus* last_;
GridStatus* goal_;
FILE* open_close_;
};
void DstarLite::calculateKey(GridStatus* s) {
s->f = min(s->g, s->rhs) + heuristic(start_, s) + k_m_;
s->k2 = min(s->g, s->rhs);
}
void DstarLite::initialize() {
fprintf(open_close_, "%d %d\n", start_->x, start_->y);
fprintf(open_close_, "%d %d\n", goal_->x, goal_->y);
goal_->rhs = 0;
calculateKey(goal_);
handle_t hand = frontier_.push(goal_);
heap_map_[goal_] = hand;
}
void DstarLite::updateVertex(GridStatus* u) {
bool heap_in = heap_map_.find(u) != heap_map_.end();
if (u->g != u->rhs && heap_in) {
calculateKey(u);
frontier_.update(heap_map_[u]);
} else if (u->g != u->rhs && !heap_in) {
calculateKey(u);
handle_t hand = frontier_.push(u);
heap_map_[u] = hand;
} else if (u->g == u->rhs && heap_in) {
calculateKey(u);
frontier_.erase(heap_map_[u]);
heap_map_.erase(u);
}
}
void DstarLite::computeShortestPath() {
int count = 0;
while (smaller(frontier_.top(), start_) || !myEqual(start_->rhs, start_->g)) {
count++;
auto u = frontier_.top();
pair<double, double> k_old = {u->f, u->k2};
pair<double, double> k_new;
k_new.first = min(u->g, u->rhs) + heuristic(start_, u) + k_m_;
k_new.second = min(u->g, u->rhs);
if (k_old < k_new) {
calculateKey(u);
frontier_.update(heap_map_[u]);
} else if (myGreater(u->g, u->rhs)) {
u->g = u->rhs;
frontier_.pop();
heap_map_.erase(u);
for (auto s : neighbors(u)) {
if (s->rhs > u->g + cost(u, s)) {
s->next = u;
s->rhs = u->g + cost(u, s);
updateVertex(s);
}
}
} else {
double g_old = u->g;
u->g = kDoubleInfinity;
auto neighbor = neighbors(u);
neighbor.push_back(u);
for (auto s : neighbor) {
if (myEqual(s->rhs, cost(s, u) + g_old)) {
if (!equal(s, goal_)) {
double pp_s = kDoubleInfinity;
for (auto succ : neighbors(s)) {
double dis = succ->g + cost(succ, s);
if (dis < pp_s) {
pp_s = dis;
s->next = succ;
}
}
s->rhs = pp_s;
}
}
updateVertex(s);
}
}
}
cout << "Dstar visited nodes : " << count << endl;
}
void DstarLite::rePlanning(vector<pair<GridStatus*, int>>& node_change) {
k_m_ += heuristic(last_, start_);
last_ = start_;
for (auto change : node_change) {
GridStatus* u = change.first;
int old_threat = u->threat;
int new_threat = change.second;
double c_old;
double c_new;
u->threat = new_threat;
u->rhs += (new_threat - old_threat) * threat_factor;
updateVertex(u);
for (auto v : neighbors(u)) {
u->threat = old_threat;
c_old = cost(v, u);
u->threat = new_threat;
c_new = cost(v, u);
if (c_old > c_new) {
if (v != goal_) {
if (v->rhs > u->g + c_new) {
v->next = u;
v->rhs = u->g + c_new;
}
}
} else if (myEqual(v->rhs, c_old + u->g)) {
if (v != goal_) {
double pp_s = kDoubleInfinity;
for (auto pre : neighbors(v)) {
double dis = pre->g + cost(pre, v);
if (dis < pp_s) {
pp_s = dis;
v->next = pre;
}
}
v->rhs = pp_s;
}
}
updateVertex(v);
}
}
}
GridStatus* DstarLite::getStart() { return start_; }
void DstarLite::setStart(GridStatus* val) { start_ = val; }
GridStatus* DstarLite::getGoal() { return goal_; }
DstarLite dstar(start, goal, open_close);
dstar.initialize();
dstar.computeShortestPath();
Sorry, I think it is difficult to locate the problem in the code, so the code was not shown before. Now I have re-edited the question, but there are a lot of codes, and the main calling part is computeShortest().

Answer 1

As you did not provide any code, we can give you only some general hints to fix such problems.
As a first assumption your code has definitely one or more bugs which causes what we call undefined behaviour UB. As the result is undefined, it can be anything and is often changing behaviour with different optimization levels, compiler versions or platforms.
What you can do:
enable really ALL warnings and fix them all! Look especially for something like "comparison is always...", "use of xxx (sometimes) without initialization", " invalid pointer cast", ...
try to compile on different compilers. You should also try to use gcc and/or clang, even on windows. It is maybe hard in the first time to get the environment for these compilers run on windows plattforms, but it is really worth to do it. Different compilers will give different warnings. Fixing all warnings from all compilers is a really good help!
you should use memory tracers like valgrind. I have not much experience on windows, but I believe there are also such tools, maybe already integrated in your development suite. These tools are really good in finding "of by x" access, access freed memory and such problems.
if you still run into such trouble, static code analyser tools may help. Typically not as much as managers believe, because today's compilers are much better by detecting flaws as expected by dinosaur programmers. The additional findings are often false positives, especially if you use modern C++. Typically you can save the money and take a class for your own education!
Review, Review, Review with other people!
snip the problem small! You should spend most of your development time by setting up good automated unit tests. Check every path, every function in every file. It is good to see at minimum 95% of all branches covered by tests. Typically these tests will also fail if you have UB in your code if you change optimizer levels and or compiler and platforms.
using a debugger can be frustrating. In high optimized code you jump through all and nothing and you may not really see where you are and what is the relation to your code. And if in lower optimizer level the bug is not present, you have not really much chance to see find the underlying problem.
last but not least: "printf debugging". But this may change the behaviour also. In worst case the code will run always if you add a debug output. But it is a chance!
use thread and memory sanitizers from your compiler.

Answer 2

The problem is caused by the comparison of floating-point numbers. I deliberately put aside this question when I wrote the code before :). Now it can operate normally after being fixed.