Re: [PATCH, rs6000] Improve TREE_TYPE comparisons in fold_mergehl_helper()

[Segher Boessenkool <segher@kernel.crashing.org>]

Hi Will,

On Mon, Aug 20, 2018 at 04:40:35PM -0500, Will Schmidt wrote:
> This is a follow-up to an earlier patch that enabled gimple folding of
> vec_mergeh and vec_mergel for the float and double data types.
> 
> Per feedback from Richard, use the types_compatible_p helper to ensure
> we also catch any qualified types matching the V2DF_ or V4SF_ types.

That looks fine; if no one hollers, please commit.  Thanks!

I note we use lang_hooks.types_compatible_p a lot, which is a totally
different thing?  How confusing :-/


Segher


> 2018-08-20  Will Schmidt  <will_schmidt@vnet.ibm.com>
> 
> 	* config/rs6000/rs6000.c (fold_mergehl_helper): Add types_compatible_p
> 	wrappers around TREE_TYPE comparisons.
> 
> diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
> index 97b922f..5f77afd 100644
> --- a/gcc/config/rs6000/rs6000.c
> +++ b/gcc/config/rs6000/rs6000.c
> @@ -15135,13 +15135,15 @@ fold_mergehl_helper (gimple_stmt_iterator *gsi, gimple *stmt, int use_high)
>    tree permute_type;
>    if (INTEGRAL_TYPE_P (TREE_TYPE (lhs_type)))
>      permute_type = lhs_type;
>    else
>      {
> -      if (TREE_TYPE (lhs_type) == TREE_TYPE (V2DF_type_node))
> +      if (types_compatible_p (TREE_TYPE (lhs_type),
> +			      TREE_TYPE (V2DF_type_node)))
>  	permute_type = V2DI_type_node;
> -      else if (TREE_TYPE (lhs_type) == TREE_TYPE (V4SF_type_node))
> +      else if (types_compatible_p (TREE_TYPE (lhs_type),
> +				   TREE_TYPE (V4SF_type_node)))
>  	permute_type = V4SI_type_node;
>        else
>  	gcc_unreachable ();
>      }
>    tree_vector_builder elts (permute_type, VECTOR_CST_NELTS (arg0), 1);
>