| Issue |
69293
|
| Summary |
Wrong code at -O1/2/s on x86_64-linux_gnu since 669ddd1
|
| Labels |
new issue
|
| Assignees |
|
| Reporter |
shao-hua-li
|
Clang at -O1/2/s produced the wrong code.
Bisected to 669ddd1e9b1226432b003dbba05b99f8e992285b, which was committed by @aeubanks
Compiler explorer: https://godbolt.org/z/sGM1v4jd1
```console
% cat a.c
int printf(const char *, ...);
long a;
int b, c, e, g, i;
long *d, *h;
char f = -26;
int main() {
long j;
c = 0;
for (; c != 7; ++c) {
long k=0;
long l = k;
long **m = &d;
for (; f + i!=0; i++)
h = &l;
g = h != (*m = &j);
int *n = &b;
*n = g;
for (; e;)
for (; a; a = a + 1)
;
}
printf("%d\n", b);
}
%
% clang -O0 a.c && ./a.out
1
%
% clang -fsanitize=address,undefined a.c && ./a.out
1
% clang -fsanitize=memory a.c && ./a.out
1
% clang -O1 a.c && ./a.out
0
%
```
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