Re: Add VIEW_CONVERT_EXPR to operand_equal_p

[Richard Biener <richard.guenther@gmail.com>]

On Fri, Oct 23, 2015 at 7:19 AM, Jan Hubicka <hubicka@ucw.cz> wrote:
> Hello,
> this is a variant of patch I tested.  After looking into the issue more, I think we don't really need
> to check types to be compatible (or we want to check it in other references, too).  It seems to me
> that we should be able to drop
>               /* Verify that access happens in similar types.  */
>               if (!types_compatible_p (TREE_TYPE (arg0), TREE_TYPE (arg1)))
>                 return 0;
> from MEM_REF, too.

Yeah.

> I had bit hard time creating a testcase running into an ICE
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68062
> With C FE I only know how to produce VCEs by vector conversions.  Will play
> with it more tomorrow.  The code patch hits about 1k times during bootstrap.
>
> Bootstrapped/regtested ppc64-linux, OK?

Ok.

Thanks,
Richard.

> Index: fold-const.c
> ===================================================================
> --- fold-const.c        (revision 228933)
> +++ fold-const.c        (working copy)
> @@ -2960,6 +2962,7 @@ operand_equal_p (const_tree arg0, const_
>
>         case REALPART_EXPR:
>         case IMAGPART_EXPR:
> +       case VIEW_CONVERT_EXPR:
>           return OP_SAME (0);
>
>         case TARGET_MEM_REF: