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

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