[Bug tree-optimization/98211] New: [11 Regression] Wrong code at -O3 since r11-4482-gb626b00823af9ca9

[marxin at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98211

            Bug ID: 98211
           Summary: [11 Regression] Wrong code at -O3 since
                    r11-4482-gb626b00823af9ca9
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Keywords: wrong-code
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: marxin at gcc dot gnu.org
                CC: rguenth at gcc dot gnu.org
  Target Milestone: ---

Reduced from a yarpgen test-case. Started with r11-4482-gb626b00823af9ca9 when
a new SLP opportunity happens.

$ cat pr.C
unsigned long long seed;
void hash(unsigned long long *seed, int v) { *seed ^= v; }

long var_11 = -4439057030159136246;
short arr_19[8][2][16];
void test(unsigned long long, bool, unsigned long long);

void
__attribute__((noipa, optimize("-O0")))
calculate_hash(void)
{
  for (long i_0 = 0; i_0 < 8; ++i_0)
    for (long i_1 = 0; i_1 < 2; ++i_1)
      for (long i_2 = 0; i_2 < 16; ++i_2)
        hash(&seed, arr_19[i_0][i_1][i_2]);
}

int main() {
  test(407382096781995, 0, 4);
  calculate_hash ();

  __builtin_printf("%llu\n", seed);
  if (seed != 2570)
    __builtin_abort ();

  return 0;
}

long val_or_zero(long __b) {
  if (__b)
    return __b;
  return 0;
}

int test_var_3;
int counter = 0;

void test(unsigned long long var_1, bool var_9, unsigned long long var_12) {
  for (unsigned i_0 = 0; i_0 < 7; i_0 += 9)
    for (bool i_1 = 0; i_1 < (bool)var_1; i_1 += 4)
      for (unsigned i_5 = 0; i_5 < (int)val_or_zero(var_11) - 1940523515U;
i_5++)
        arr_19[i_0][i_1][i_5] = (test_var_3 ?: var_12) ? (short)var_11 : var_9;
}

$ gcc -O3 pr.C && ./a.out
0
Aborted (core dumped)

$ gcc pr.C && ./a.out
2570