[Bug tree-optimization/101001] New: wrong code at -O3 on x86_64-linux-gnu

[qrzhang at gatech dot edu via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101001

            Bug ID: 101001
           Summary: wrong code at -O3 on x86_64-linux-gnu
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: qrzhang at gatech dot edu
  Target Milestone: ---

It affects gcc-8 to the trunk. Gcc-7 works fine.



$ gcc-trunk -v
gcc version 12.0.0 20210609 (experimental) [master revision
174e75a2107:3b61ba37fe1:5bfcfe3087eb05b76395c9efbfc1abbf3f9e1a03] (GCC)


$ gcc-trunk abc.c ; ./a.out
0


$ gcc-trunk -O3 abc.c ; ./a.out
Segmentation fault


$ cat abc.c
int a;
volatile char b;
int main() {
  char c;
  int d, f = 5;
  short e;
  e = 0;
  for (; e != -15; e--) {
    d = 0;
    for (; d > -16; d = d - 4) {
      f || b;
      c = 0;
      for (; c != 2; c = c - 3)
        f = 0;
    }
  }
  printf("%X\n", a);
}