[Bug tree-optimization/58553] New fail in PASS->FAIL: gcc.c-torture/execute/memcpy-2.c execution on arm and aarch64

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58553

--- Comment #7 from Richard Biener <rguenth at gcc dot gnu.org> ---
Testcase that also fails on x86_64:

#define MAX_LENGTH 96
#define SEQUENCE_LENGTH 31

static struct {
  char buf[MAX_LENGTH + 1];
} u1, u2;

extern void abort (void);

int main ()
{
  int i;
  char c;

  u1.buf[0] = '\0';
  for (i = 0, c = 'A'; i < MAX_LENGTH; i++, c++)
    {
      u1.buf[i] = 'a';
      if (c >= 'A' + SEQUENCE_LENGTH)
        c = 'A';
      u2.buf[i] = c;
    }
  if (u1.buf[MAX_LENGTH] != '\0')
    abort ();

  return 0;
}

jump threading rotates the loop in interesting ways.