On Fri, Jan 10, 2020 at 4:04 PM Richard Sandiford
<richard.sandif...@arm.com> wrote:
>
> Having the "same" vector types with different modes means that we can
> end up vectorising a constructor with a different mode from the lhs.
> This patch adds a VIEW_CONVERT_EXPR in that case.
>
> This showed up on existing tests when testing with fixed-length
> -msve-vector-bits=128.
>
> Tested on aarch64-linux-gnu and x86_64-linux-gnu. OK to install?
OK.
Richard.
> Richard
>
>
> 2020-01-10 Richard Sandiford <richard.sandif...@arm.com>
>
> gcc/
> * tree-vect-slp.c (vectorize_slp_instance_root_stmt): Use a
> VIEW_CONVERT_EXPR if the vectorized constructor has a diffeent
> type from the lhs.
>
> Index: gcc/tree-vect-slp.c
> ===================================================================
> --- gcc/tree-vect-slp.c 2020-01-06 17:59:49.126752227 +0000
> +++ gcc/tree-vect-slp.c 2020-01-10 15:01:13.780190287 +0000
> @@ -4306,6 +4306,10 @@ vectorize_slp_instance_root_stmt (slp_tr
> {
> tree vect_lhs = gimple_get_lhs (child_stmt_info->stmt);
> tree root_lhs = gimple_get_lhs (instance->root_stmt->stmt);
> + if (!useless_type_conversion_p (TREE_TYPE (root_lhs),
> + TREE_TYPE (vect_lhs)))
> + vect_lhs = build1 (VIEW_CONVERT_EXPR, TREE_TYPE (root_lhs),
> + vect_lhs);
> rstmt = gimple_build_assign (root_lhs, vect_lhs);
> break;
> }
