Subversion Repositories openrisc_2011-10-31

/* { dg-do compile { target i?86-*-* x86_64-*-* } } */
/* { dg-require-effective-target ilp32 } */
/* { dg-options "-O2 --param min-insn-to-prefetch-ratio=5 -fprefetch-loop-arrays -march=athlon -fdump-tree-aprefetch-details" } */
 
/* These are common idioms for writing variable-length arrays at the end
   of structures.  We should not deduce anything about the number of iterations
   of the loops from them.  */
 
struct tail0
{
  int xxx;
  int yyy[0];
};
 
int loop0 (int n, struct tail0 *x)
{
  int i, s = 0;
 
  for (i = 0; i < n; i++)
    s += x->yyy[i];
 
  return s;
}
 
struct tail1
{
  int xxx;
  int yyy[1];
};
int loop1 (int n, struct tail1 *x)
{
  int i, s = 0;
 
  for (i = 0; i < n; i++)
    s += x->yyy[i];
 
  return s;
}
 
/* It is unlikely that this should be a tail array.  We may deduce that most
   likely, the loop iterates about 5 times, and the array is not worth prefetching.  */
 
struct tail5
{
  int xxx;
  int yyy[5];
};
int loop5 (int n, struct tail5 *x)
{
  int i, s = 0;
 
  for (i = 0; i < n; i++)
    s += x->yyy[i];
 
  return s;
}
 
/* { dg-final { scan-tree-dump-times "Issued prefetch" 2 "aprefetch" } } */
/* { dg-final { scan-tree-dump-times "Not prefetching" 1 "aprefetch" } } */
/* { dg-final { cleanup-tree-dump "aprefetch" } } */