mono/benchmark/regalloc-2.cs

   1 //
   2 // Idealy, we would fold the operations from a...h into one long xor chain,
   3 // we could then commute the xor operation.
   4 //
   5 // More realisticly, we should assign each of a...h to one reg, rather than making
   6 // the two swap between two registers:
   7 //       (stind.i4 regvar[%edi] (xor (ldind.i4 regoffset[-0x18(%ebp)]) iconst[1]))
   8 //       (stind.i4 regvar[%esi] (xor (ldind.i4 regvar[%edi]) iconst[2]))
   9 //       (stind.i4 regvar[%edi] (xor (ldind.i4 regvar[%esi]) iconst[3]))
  10 //       (stind.i4 regvar[%esi] (xor (ldind.i4 regvar[%edi]) iconst[4]))
  11 //
  12
  13 class T {
  14         static void Main ()
  15         {
  16                 int j = 0, k = 0, l = 0;
  17                 for (int i = 0; i < 50000000; i ++) {
  18                         int a = i ^ 1;
  19                         int b = a ^ 2;
  20                         int c = b ^ 3;
  21                         int d = c ^ 4;
  22                         int e = d ^ 5;
  23                         int f = e ^ 6;
  24                         int g = f ^ 7;
  25                         int h = g ^ 8;
  26
  27                         j ^= h;
  28                         k ^= h + 1;
  29                         l ^= h & 5;
  30
  31                         j ^= l;
  32                         k ^= k + 1;
  33                         l ^= j & 5;
  34
  35                         j ^= l;
  36                         k ^= k + 1;
  37                         l ^= j & 5;
  38                 }
  39         }
  40 }