gcc/testsuite/gcc.dg/tree-ssa/reassoc-28.c

   1 /* { dg-do run } */
   2 /* { dg-options "-O2" } */
   3
   4 #define LENGTH 4
   5 void abort (void);
   6 unsigned
   7 __attribute__ ((noinline))  foo (unsigned char *buf, int n)
   8 {
   9  unsigned sum = 0, i = 0;
  10  do {
  11    sum +=(buf)[n-1];
  12    /* Split the BB to test statements are correctly moved to
  13       satisfy dependences.  */
  14    if (n > LENGTH)
  15      i++;
  16    sum += buf[n-2];
  17    sum += buf[n-3];
  18    sum += buf[n-4];
  19    n = n-4;
  20  } while (n > 0);
  21
  22  return sum + i;
  23 }
  24
  25 unsigned char a[] = {1, 1, 1, 1};
  26
  27 int main() {
  28   int sum = foo (a, LENGTH);
  29   if (sum != 4)
  30     abort ();
  31   return 0;
  32 }