[Bug middle-end/82083] New: sanitizer detects signed integer overflow in tree-data-ref.c with -O3

[zeccav at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82083

            Bug ID: 82083
           Summary: sanitizer detects signed integer overflow in
                    tree-data-ref.c with -O3
           Product: gcc
           Version: 8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
          Assignee: unassigned at gcc dot gnu.org
          Reporter: zeccav at gmail dot com
  Target Milestone: ---
              Host: x86_64-pc-linux-gnu
             Build: trunk 251201

// from test case pr60183.c
// must be compiled with -O3 option
// signed integer overflow in tree-data-ref.c
int j = 2;

void
foo (unsigned long *x, unsigned char *y)
{
  int i;
  unsigned long w = x[0];
  for (i = 0; i < j; i++)
    {
      w += *y;
      y += 0x10000;
      w += *y;
    }
  x[1] = w;
}
/*../../gcc/gcc/tree-data-ref.c:3427:16: runtime error: signed integer
overflow: 65536 * -65536 cannot be represented in type 'int'
../../gcc/gcc/tree-data-ref.c:3350:16: runtime error: signed integer overflow:
1073741824 + 1073741824 cannot be represented in type 'int'
../../gcc/gcc/tree-data-ref.c:3429:7: runtime error: negation of -2147483648
cannot be represented in type 'int'; cast to an unsigned type to negate this
value to itself
../../gcc/gcc/tree-data-ref.c:3428:7: runtime error: negation of -2147483648
cannot be represented in type 'int'; cast to an unsigned type to negate this
value to itself*/