gcc/testsuite/gcc.dg/tree-ssa/pr31966.c

   1 /* Contributed by Jack Lloyd  <lloyd@randombit.net> */
   2
   3 /* { dg-do run } */
   4 /* { dg-options "-O2 -ftree-vectorize" } */
   5 /* { dg-options "-O2 -ftree-vectorize -march=nocona" { target { i?86-*-* x86_64-*-* } } } */
   6
   7 typedef unsigned long long word;
   8
   9 const unsigned int MP_WORD_BITS = 64;
  10 const word MP_WORD_MASK = ~((word)0);
  11 const word MP_WORD_TOP_BIT = (word)1 << (8*sizeof(word) - 1);
  12
  13 extern void abort (void);
  14
  15 word do_div(word n1, word n0, word d)
  16 {
  17   word high = n1 % d, quotient = 0;
  18   unsigned int j;
  19
  20   for(j = 0; j != MP_WORD_BITS; ++j)
  21     {
  22       word high_top_bit = (high & MP_WORD_TOP_BIT);
  23
  24       high <<= 1;
  25       high |= (n0 >> (MP_WORD_BITS-1-j)) & 1;
  26       quotient <<= 1;
  27
  28       if(high_top_bit || high >= d)
  29         {
  30           high -= d;
  31           quotient |= 1;
  32         }
  33     }
  34
  35   return quotient;
  36 }
  37
  38 int main()
  39 {
  40   word result;
  41
  42   result = do_div(0x0000000000200000ll,
  43                   0x0000000000000000ll,
  44                   0x86E53497CE000000ll);
  45
  46
  47   if (result != 0x3CBA83)
  48     abort ();
  49
  50   return 0;
  51 }