On 06/20/2018 04:32 AM, Richard Sandiford wrote:
> vect_recog_rotate_pattern had code to prevent operations
> on invariants being vectorised unnecessarily:
>
> if (dt == vect_external_def
> && TREE_CODE (oprnd1) == SSA_NAME
> && is_a <loop_vec_info> (vinfo))
> {
> struct loop *loop = as_a <loop_vec_info> (vinfo)->loop;
> ext_def = loop_preheader_edge (loop);
> if (!SSA_NAME_IS_DEFAULT_DEF (oprnd1))
> {
> basic_block bb = gimple_bb (SSA_NAME_DEF_STMT (oprnd1));
> if (bb == NULL
> || !dominated_by_p (CDI_DOMINATORS, ext_def->dest, bb))
> ext_def = NULL;
> }
> }
> [..]
> if (ext_def)
> {
> basic_block new_bb
> = gsi_insert_on_edge_immediate (ext_def, def_stmt);
> gcc_assert (!new_bb);
> }
>
> This patch reuses the same idea for casts of invariants created
> during widening optimisations.
>
> One hitch was that vect_loop_versioning asserted that the vector loop
> preheader was still empty, although the cfg transformation it's doing
> should be correct either way.
>
> Tested on aarch64-linux-gnu and x86_64-linux-gnu. OK to install?
>
> Richard
>
>
> 2018-06-20 Richard Sandiford <richard.sandif...@arm.com>
>
> gcc/
> * tree-vect-patterns.c (vect_get_external_def_edge): New function,
> split out from...
> (vect_recog_rotate_pattern): ...here.
> (vect_convert_input): Try to insert casts of invariants in the
> preheader.
> * tree-vect-loop-manip.c (vect_loop_versioning): Don't require the
> preheader to be empty.
>
> gcc/testsuite/
> * gcc.dg/vect/vect-widen-mult-extern-1.c: New test.
OK
jeff
igned int *x2, unsigned short *y, unsigned char z)
> +{
> + unsigned short zu = z;
> + for (int i = 0; i < N; ++i)
> + {
> + unsigned short yi = y[i];
> + x1[i] = x1[i] > 10 ? yi * zu : x1[i] + 1;
> + x2[i] += 1;
> + }
> +}
>
