[Bug tree-optimization/121556] New: wrong code at -O3 on x86_64-linux-gnu

[zhendong.su at inf dot ethz.ch via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121556

            Bug ID: 121556
           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: zhendong.su at inf dot ethz.ch
  Target Milestone: ---

Compiler Explorer: https://godbolt.org/z/eeasrbce7

Note:
- works: 9.* and earlier
- fails: 10.* and later
- -fno-tree-slsr makes it disappear

[519] % gcctk -v
Using built-in specs.
COLLECT_GCC=gcctk
COLLECT_LTO_WRAPPER=/local/home/suz/suz-local/software/local/gcc-trunk/bin/../libexec/gcc/x86_64-pc-linux-gnu/16.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../gcc-trunk/configure --disable-bootstrap
--enable-checking=yes --prefix=/local/suz-local/software/local/gcc-trunk
--enable-sanitizers --enable-languages=c,c++ --disable-werror --enable-multilib
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 16.0.0 20250814 (experimental) (GCC) 
[520] % 
[520] % gcctk -O3 small.c
[521] % ./a.out
Aborted
[522] % cat small.c
int printf (const char *, ...);
int a, b, c, d, f, g;
int e[] = { 0, 5, 5, -565230030, 2044508324, 0, 4, 1, 7,
  -655623580, 6, 4089016648, 453116029, 3, 107580753, 9, 0,
  2, 2, 6, 7, 5, 5, 7, 7073096, 6, 2, 2, 1006888145, 607687, 101629,
  3, 901097722, 9000684, 6, 8065728, 705015759, 5, 0, 6, 69554304, 1,
  5, 3099436303, 4, 4, 30930, 70347812, 3060149565, 2, 4, 2,
  4023717930, 907459465, 5, 3, 904427059, 2013776290, 6, 4, 0, 3, 3,
  9, 7, 802195444, 6, 8001368, 4066508878, 70925, 3092731, 5, 3,
  706088902, 314042704, 2, 2, 1, 7, 3, 5, 303535960, 6, 7007092,
  9037538, 70817, 1, 6, 909243462, 6, 7, 7, 1, 708648649, 42533948,
  876714000, 4, 909, 5, 10523913, 5, 4, 702138776, 0, 2,
  -1447152767, 3082640443, 3233442989, 4, 7068, 10842, 5, 1,
  70997, 3, 0, 596804, 0, 2053790376, 5, 3, 3, 2097651377, 4027552580,
  -1083300248, 2050814, 5, 5, 5, 507879, 6, 0, 6, 2, 708143, 5, 3,
  7, 604390888, 8, 5, 60999, 1068828381, 9, 0, 8, 906185462,
  1090812512, 3, 9, 5, 4, 60834842, 8085408, 6, 109, 8078467, 3,
  1426400815, 2, 4, 6, 1, 5, 3, 1541320221, 607071920, 0, 2, 40735498,
  5, 1, 3087877, 908371, 4, 803740692, 2075208622, 2, 3, 90285,
  2094854071, 1, 2029012, 0, 2, 0, 1, 5, 1, 7, 4, 200368, 4, 6,
  405801727, 5, 3736837829};
int h(int j, char k) { return (j >> 8 & 16777215) ^ e[(j ^ k) & 255]; }
int l(int j) {
  a = h (a, j >> 8);
  a = d = a >> 8 ^ e[0];
  a = h (a, j >> 24);
  return a;
}
int m() {
  f = l(0);
  return f;
}
void n(int j, int k) {
  int o = 1, i = 0;
  do {
    k = - --j;
    b = k - 3;
    o = -o;
  } while (m());
  k = -1000 - o + 1000 * b;
  g = -1000 - o - 999 * b;
  int p[] = {b, o, g, j, c, k};
  for (; i < 6; ++i)
    l (p[i]);
}
int main() {
  do {
    n (-2147460, 3);
  } while (!a);
  if (a != 31)
    __builtin_abort();
  return 0;
}