Peeling loops at tree level?

[Richard Guenther]

On Mon, 13 Sep 2004 16:09:03 +0200 (CEST), Richard Guenther
<rguenth@tat.physik.uni-tuebingen.de> wrote:
> Hi!
> 
> Do we (I suspect not) peel small loops at tree level yet?  This seems
> to inhibit further (tree) optimization of inlined dimension-unaware
> code like:
> 
> template <int Dim>
> struct Vector
> {
>         int operator[](int i) const { return val[i]; }
>         int val[Dim];
> };
> 
> template <int Dim>
> inline int foo(const Vector<Dim>& x)
> {
>         int res;
>         for (int i=0; i<Dim; ++i)
>                 res += x[i];
>         return res;
> }
> 
> int bar(const Vector<3>& x)
> {
>         return foo(x);
> }

Btw. lno from g++ (GCC) 3.5-tree-ssa-lno 20040630 (merged 20040612)
seems to do the trick:

;; Function int bar(constVector<3>&) (_Z3barRK6VectorILi3EE)

int bar(constVector<3>&) (x)
{
[...]
<bb 0>:
  return *&x->val[2] + x->val[1] + x->val[0] + res;

}

So I guess we'll get this feature during further merge of lno?

Thanks,
Richard.