[Bug tree-optimization/112721] New: [14 Regression] Wrong code at -O1/s on x86_64-linux-gnu since r14-5831-gaae723d360c

[shaohua.li at inf dot ethz.ch]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112721

            Bug ID: 112721
           Summary: [14 Regression] Wrong code at -O1/s on
                    x86_64-linux-gnu since r14-5831-gaae723d360c
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Keywords: wrong-code
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: shaohua.li at inf dot ethz.ch
                CC: mjambor at suse dot cz
  Target Milestone: ---

gcc at -O1/s produces the wrong code.

Bisected to r14-5831-gaae723d360c

Compiler explorer: https://godbolt.org/z/671M9YPPj

$ cat a.c
int printf(const char *, ...);
struct a {
  int b;
};
int c, e;
long d;
unsigned *f(unsigned *g) {
  for (; c;)
    e = d;
  return g;
}
int main() {
  int *h;
  struct a i = {8};
  int *j = &i.b;
  h = f(j);
  *h = 0;
  printf("%d\n", i.b);
}
$
$ gcc -O0 a.c && ./a.out
0
$ gcc -O1 a.c && ./a.out
8
$