Why does loop-35.c store motion testcase fail for AVR?

[Andy H]

Help !

gcc.dg/tree-ssa/loop-35.c is a test that looks for "Executing store motion" in 
dump-tree-lim-details

As the load and store of memory location should be pulled out of loop.


This works for 3 out of 4 tescases. But on AVR target test3() will fail.

The only difference between this and test1() is that index is unsigned long 
rather than int.
Index of char or int work fine.

Why????

Even considering pointers and int are only HImode, I cant see why a long 
(SImode) should affect this.



void test3(unsigned long b)
{
unsigned i;

/* And here.  */
for (i = 0; i < 100; i++)
  {
    arr[b+8].X += i;
    arr[b+9].X += i;
  }
}