Subversion Repositories openrisc

/* { dg-require-effective-target int32plus } */

typedef long unsigned int size_t;

extern void *memset (void *__s, int __c, size_t __n) __attribute__ ((__nothrow__)) __attribute__ ((__nonnull__ (1)));

static void

encode (words, low, hi)

     long *words;

     unsigned long low;

     long hi;

{

  words[0] = ((low) & (((unsigned long) 1 << (sizeof(unsigned long) / 2)) - 1));

  words[1] = ((unsigned long) (low) >> sizeof(unsigned long) / 2);

  words[2] = ((hi) & (((unsigned long) 1 << (sizeof(unsigned long) / 2)) - 1));

  words[3] = ((unsigned long) (hi) >> sizeof(unsigned long) / 2);

}

static void

decode (words, low, hi)

     long *words;

     unsigned long *low;

     long *hi;

{

  *low = words[0] + words[1] * ((unsigned long) 1 << sizeof(unsigned long) / 2);

  *hi = words[2] + words[3] * ((unsigned long) 1 << sizeof(unsigned long) / 2);

}

int

neg_double (l1, h1, lv, hv)

     unsigned long l1;

     long h1;

     unsigned long *lv;

     long *hv;

{

  if (l1 == 0)

    {

      *lv = 0;

      *hv = - h1;

      return (*hv & h1) < 0;

    }

  else

    {

      *lv = -l1;

      *hv = ~h1;

      return 0;

    }

}

int

add_double (l1, h1, l2, h2, lv, hv)

     unsigned long l1, l2;

     long h1, h2;

     unsigned long *lv;

     long *hv;

{

  unsigned long l;

  long h;

  l = l1 + l2;

  h = h1 + h2 + (l < l1);

  *lv = l;

  *hv = h;

  return ((~((h1) ^ (h2)) & ((h1) ^ (h))) < 0);

}

int

mul_double (l1, h1, l2, h2, lv, hv)

     unsigned long l1, l2;

     long h1, h2;

     unsigned long *lv;

     long *hv;

{

  long arg1[4];

  long arg2[4];

  long prod[4 * 2];

  unsigned long carry;

  int i, j, k;

  unsigned long toplow, neglow;

  long tophigh, neghigh;

  encode (arg1, l1, h1);

  encode (arg2, l2, h2);

  memset ((char *) prod, 0, sizeof prod);

  for (i = 0; i < 4; i++)

    {

      carry = 0;

      for (j = 0; j < 4; j++)

        {

          k = i + j;

          carry += arg1[i] * arg2[j];

          carry += prod[k];

          prod[k] = ((carry) & (((unsigned long) 1 << (sizeof(unsigned long) / 2)) - 1));

          carry = ((unsigned long) (carry) >> sizeof(unsigned long) / 2);

        }

      prod[i + 4] = carry;

    }

  decode (prod, lv, hv);

  decode (prod + 4, &toplow, &tophigh);

  if (h1 < 0)

    {

      neg_double (l2, h2, &neglow, &neghigh);

      add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);

    }

  if (h2 < 0)

    {

      neg_double (l1, h1, &neglow, &neghigh);

      add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);

    }

  return (*hv < 0 ? ~(toplow & tophigh) : toplow | tophigh) != 0;

}