https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117453
Bug ID: 117453
Summary: Miscompile with -O3 and -O0/1/2
Product: gcc
Version: 14.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: middle-end
Assignee: unassigned at gcc dot gnu.org
Reporter: yunboni at smail dot nju.edu.cn
Target Milestone: ---
When compiled with -O0/1/2, its output is 0. With -O3, it's 4.
It can be fixed with -fstack-reuse=none.
```c
int printf(const char *, ...);
int a[6];
int b, j, o;
char c;
char d[11];
char *e;
short f, g;
short *h = &f;
int main() {
char l[7];
int i = 0;
for (; i < 7; i++) {
{
char n[10];
int k = 15;
char *m = n;
e = d;
while (k)
*e++ = k /= 10;
while (e != d)
*m++ = *--e;
*m++ = '\0';
j = m - n - 1;
}
l[j] = 4;
}
g = l[2];
*h = g;
printf("%d\n", f);
for (; b; o++) {
b = c;
if (c)
b = a[b];
}
}
```
Details can be found here: https://godbolt.org/z/Pqzr9rbno
