| Issue |
76789
|
| Summary |
Wrong code at -O1 on x86_64-linux_gnu since LLVM-13
|
| Labels |
new issue
|
| Assignees |
|
| Reporter |
shao-hua-li
|
Clang at -O1 produces the wrong code since LLVM-13.
Bisected to 8f3d16905d75b07a933d01dc29677fe5867c1b3e, which was committed by @efriedma-quic
Compiler explorer: https://godbolt.org/z/35no4xxfK
```console
% cat a.c
int printf(const char *, ...);
char a;
short b;
static short *c = &b;
static short **f = &c;
int g;
int h(char *j, long k) {
int d = 0;
char *e = j + k;
for (; j < e; j++)
d = (d << 4) + *j;
return d;
}
int l(char j, long k) {
int i = h(&j, k);
return i;
}
int m(void);
void n() { m(); }
int m() {
int o;
char p = b = 4;
for (;;) {
g = 0;
for (; g <= 4; g++) {
p = 0;
for (; p <= 5; p++)
o = l(1, **f - 3);
a = (6 || 0) & o;
}
break;
}
short ***s = &f, ***q = s;
return &s != &q;
}
int main() {
n();
printf("%d\n", a);
}
%
% clang -O0 a.c && ./a.out
1
% clang -O1 a.c && ./a.out
0
%
```
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