-O2 Bug Infinite Loop

• 回報者: first_last
• 負責人: (無)
• 類型: Issues
• 狀態: 關閉
• 元件: GCC
• 里程碑: (無)
• 優先權: 1 - 最低
• 嚴重程度: 1 - 最低
• 處理結果: Rejected
• 檔案: 無

細節

This Piece of Code is getting Stuck In Infinite Loop when Using -O2 Flag

 #include <bits/stdc++.h>
 using namespace std;
 typedef long long int ll;
 
 ll f() {
 
   for (int i = 0; i < 3; i++) {
     for (int j = 0; j < 2; j++) {
      cout << i << " " << j << endl;
     }
   }
 }
 
 int main() {
   f();
 
   return 0;
 }

Ticket History (2/2 Histories)

2021-03-13 04:07 Updated by: first_last

• New Ticket "-O2 Bug Infinite Loop" created

2021-03-13 07:32 Updated by: keith

• 狀態 Update from 開啟 to 關閉
• 處理結果 Update from 無 to Rejected
• 里程碑 Update from Create a 64bit build environment for the MinGW.org project. to (無)
• 嚴重程度 Update from 9 - 最高 to 1 - 最低
• 優先權 Update from 9 - 最高 to 1 - 最低
• Details Updated

評語

Several comments:

1. What part of the instruction: "priority is to be assigned only by an approved MinGW developer" do you not understand? You are not such a developer. Thus your attempt to escalate priority guarantees that this ticket will be treated as lowest priority.
2. This is not specifically a MinGW bug. Yes, I can see that it misbehaves as you suggest, but it exhibits similar misbehaviour when I compile it as a native GNU/Linux application, (using GCC-10.2 on Manjaro Linux). If you want it pursued, you need to raise the issue on the GCC bug tracker.
3. You really should not use #include <bits/stdc++.h> directly in user code; that's an internal-use header. In this example, you should be using #include <iostream>.
4. If I compile your code, I see a warning about a missing return statement, in your non-void f() function. Address that warning, either by adding the missing return statement, or by declaring void f(), and the misbehaviour does not occur.

Given the above, I am not going to pursue this.