[Bug rtl-optimization/69691] New: [6 Regression] wrong code at -O2 on x86_64-linux-gnu

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69691

            Bug ID: 69691
           Summary: [6 Regression] wrong code at -O2 on x86_64-linux-gnu
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: rtl-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: mpolacek at gcc dot gnu.org
  Target Milestone: ---

$ xgcc -O2 zz.c; ./a.out
Aborted (core dumped)

extern int tolower (int) __attribute__ ((leaf));

char *USHyphens[] = { ".ach4", 0 };

#define LCNT (26 + 1 + 4)
#define SEPCNT 10
typedef struct sHyphenNode
{
  char sepcnts[SEPCNT];
  struct sHyphenNode *Daughters[LCNT];
} THyphenNode, *PHyphenNode;

static PHyphenNode HyphenRoot = 0;

static int
GetIndex (char ch)
{
  if (ch == 0)
    __builtin_abort ();
  if ((tolower (ch) >= 'a' - 1) && (tolower (ch) <= 'z'))
    return (tolower (ch) - ('a' - 1));
  else if (ch == '.')
    return 0;
  else
    {
      __builtin_printf ("unallowed character %d\n", ch);
      return -1;
    }
}

static void
InitHyphenNode (PHyphenNode Node)
{
  int z;

  for (z = 0; z < LCNT; Node->Daughters[z++] = 0);
  for (z = 0; z < SEPCNT; Node->sepcnts[z++] = 0);
}

void
BuildTree (char **Patterns)
{
  char **run, ch, *pos, sing[500], *rrun;
  char RunCnts[SEPCNT];
  int z, l, rc, index;
  PHyphenNode Lauf;

  HyphenRoot = (PHyphenNode) __builtin_malloc (sizeof (THyphenNode));
  InitHyphenNode (HyphenRoot);

  for (run = Patterns; *run != 0; run++)
    {
      __builtin_strcpy (sing, *run);
      rrun = sing;
      do
        {
          pos = __builtin_strchr (rrun, ' ');
          if (pos)
            *pos = '\0';
          l = __builtin_strlen (rrun);
          rc = 0;
          Lauf = HyphenRoot;
          for (z = 0; z < SEPCNT; RunCnts[z++] = 0);
          for (z = 0; z < l; z++)
            {
              ch = rrun[z];
              if ((ch >= '0') && (ch <= '9'))
                RunCnts[rc] = ch - '0';
              else
                {
                  index = GetIndex (ch);
                  if (!Lauf->Daughters[index])
                    {
                      Lauf->Daughters[index] =
                        (PHyphenNode) __builtin_malloc (sizeof (THyphenNode));
                      InitHyphenNode (Lauf->Daughters[index]);
                    }
                  Lauf = Lauf->Daughters[index];
                  rc++;
                }
            }
          __builtin_memcpy (Lauf->sepcnts, RunCnts, SEPCNT);
          if (pos)
            rrun = pos + 1;
        }
      while (pos);
    }
}

void
DoHyphens (char *word)
{
  char Field[300];
  char Res[300];
  int z, z2, z3, l;
  PHyphenNode Lauf;

  l = __builtin_strlen (word);
  *Field = 'a' - 1;
  for (z = 0; z < l; z++)
    {
      Field[z + 1] = tolower ((unsigned int) word[z]);
      if (GetIndex (Field[z + 1]) <= 0)
        return;
    }
  Field[l + 1] = 'a' - 1;
  l += 2;
  for (z = 0; z <= l + 1; Res[z++] = 0);

  if (!HyphenRoot)
    return;

  for (z = 0; z < l; z++)
    {
      Lauf = HyphenRoot;
      for (z2 = z; z2 < l; z2++)
        {
          Lauf = Lauf->Daughters[GetIndex (Field[z2])];
          if (!Lauf)
            break;
          for (z3 = 0; z3 <= z2 - z + 2; z3++)
            if (Lauf->sepcnts[z3] > Res[z + z3])
              Res[z + z3] = Lauf->sepcnts[z3];
        }
    }
  for (z = 3; z < l - 2; z++)
    if ((Res[z] & 1) == 1)
     asm ("");
}

int
main ()
{
  BuildTree (USHyphens);
  DoHyphens ("aaaaa");
}