https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106135
Bug ID: 106135
Summary: Found a bug in gcc
Product: gcc
Version: 10.3.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: 85811545 at qq dot com
Target Milestone: ---
This code will output wrong result when execute g++ code.cpp -o code -lm -O2
-DONLINE_JUDGE -std=c++11 using g++10.3.0, on Ubuntu 20.04，64bits.
#include <bits/stdc++.h>
using namespace std;
vector<pair<int,int>>f;
int mg(pair<int,int>x,pair<int,int>y)
{
return max(x.second,y.second);
}
int main()
{
f={{0,-11}};
for(int J=0;J<=0;J++)
{
f[J]=f[0];
if(J==0)f[J]={0,2};
cout<<mg({0,-8},f[J])<<endl;
}
return 0;
}
The correct result is 2 (don't use -O2 or add ''cout<<"" ' in code) but it
output -8 (using -O2)
