On Mon, 27 Nov 2023, Richard Sandiford wrote:
> can_duplicate_and_interleave_p checks whether we know a way of
> building a particular VLA SLP invariant. g:60034ecf25597bd515f
> skipped that test for booleans, to support MASK_LEN_GATHER_LOAD
> calls with a dummy all-ones mask. But there's nothing fundamentally
> different about VLA masks vs VLA data vectors. If we have a VLA mask
> that isn't all-ones, we need some way of loading it. This ultimately
> led to the ICE in the PR.
>
> This patch fixes it by applying can_duplicate_and_interleave_p
> to masks, while also adding a special path for uniform vectors
> (of all kinds) to support the MASK_LEN_GATHER_LOAD usage. This
> also fixes an XFAIL in pr36648.cc for SVE.
>
> The patch is mostly Richard's. My only changes were to skip
> redundant conversions and to use gimple_build_vector_from_val
> for all eligible vectors.
>
> Tested on aarch64-linux-gnu (with and without SVE) and x86_64-linux-gnu.
> OK to install?
OK.
Thanks for picking up.
Richard.
> Richard
>
>
> 2023-11-27 Richard Biener <rguent...@suse.de>
> Richard Sandiford <richard.sandif...@arm.com>
>
> gcc/
> PR tree-optimization/112661
> * tree-vect-slp.cc (vect_get_and_check_slp_defs): Defer duplicate-and-
> interleave test to...
> (vect_build_slp_tree_2): ...here, once we have all the operands.
> Skip the test for uniform vectors.
> (vect_create_constant_vectors): Detect uniform vectors. Avoid
> redundant conversions in that case. Use gimple_build_vector_from_val
> to build the vector.
>
> gcc/testsuite/
> * g++.dg/vect/pr36648.cc: Remove XFAIL for VLA load-lanes.
> ---
> gcc/testsuite/g++.dg/vect/pr36648.cc | 2 +-
> gcc/tree-vect-slp.cc | 56 +++++++++++++++++++---------
> 2 files changed, 40 insertions(+), 18 deletions(-)
>
> diff --git a/gcc/testsuite/g++.dg/vect/pr36648.cc
> b/gcc/testsuite/g++.dg/vect/pr36648.cc
> index 8d24d3d445d..7bda82899d0 100644
> --- a/gcc/testsuite/g++.dg/vect/pr36648.cc
> +++ b/gcc/testsuite/g++.dg/vect/pr36648.cc
> @@ -25,6 +25,6 @@ int main() { }
> targets, ! vect_no_align is a sufficient test. */
>
> /* { dg-final { scan-tree-dump-times "vectorized 1 loops" 1 "vect" { target
> { { { ! vect_no_align } && { ! powerpc*-*-* } } || { powerpc*-*-* &&
> vect_hw_misalign } } } } } */
> -/* { dg-final { scan-tree-dump-times "vectorizing stmts using SLP" 1 "vect"
> { target { { { ! vect_no_align } && { ! powerpc*-*-* } } || { powerpc*-*-* &&
> vect_hw_misalign } } xfail { vect_variable_length && vect_load_lanes } } } }
> */
> +/* { dg-final { scan-tree-dump-times "vectorizing stmts using SLP" 1 "vect"
> { target { { { ! vect_no_align } && { ! powerpc*-*-* } } || { powerpc*-*-* &&
> vect_hw_misalign } } } } } */
>
>
> diff --git a/gcc/tree-vect-slp.cc b/gcc/tree-vect-slp.cc
> index 4a09b3c2aca..6799b9375ae 100644
> --- a/gcc/tree-vect-slp.cc
> +++ b/gcc/tree-vect-slp.cc
> @@ -763,18 +763,6 @@ vect_get_and_check_slp_defs (vec_info *vinfo, unsigned
> char swap,
> {
> tree type = TREE_TYPE (oprnd);
> dt = dts[i];
> - if ((dt == vect_constant_def
> - || dt == vect_external_def)
> - && !GET_MODE_SIZE (vinfo->vector_mode).is_constant ()
> - && TREE_CODE (type) != BOOLEAN_TYPE
> - && !can_duplicate_and_interleave_p (vinfo, stmts.length (), type))
> - {
> - if (dump_enabled_p ())
> - dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
> - "Build SLP failed: invalid type of def "
> - "for variable-length SLP %T\n", oprnd);
> - return -1;
> - }
>
> /* For the swapping logic below force vect_reduction_def
> for the reduction op in a SLP reduction group. */
> @@ -2395,7 +2383,7 @@ out:
> /* Create SLP_TREE nodes for the definition node/s. */
> FOR_EACH_VEC_ELT (oprnds_info, i, oprnd_info)
> {
> - slp_tree child;
> + slp_tree child = nullptr;
> unsigned int j;
>
> /* We're skipping certain operands from processing, for example
> @@ -2443,6 +2431,29 @@ out:
> if (oprnd_info->first_dt == vect_external_def
> || oprnd_info->first_dt == vect_constant_def)
> {
> + if (!GET_MODE_SIZE (vinfo->vector_mode).is_constant ())
> + {
> + tree op0;
> + tree uniform_val = op0 = oprnd_info->ops[0];
> + for (j = 1; j < oprnd_info->ops.length (); ++j)
> + if (!operand_equal_p (uniform_val, oprnd_info->ops[j]))
> + {
> + uniform_val = NULL_TREE;
> + break;
> + }
> + if (!uniform_val
> + && !can_duplicate_and_interleave_p (vinfo,
> + oprnd_info->ops.length (),
> + TREE_TYPE (op0)))
> + {
> + matches[j] = false;
> + if (dump_enabled_p ())
> + dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
> + "Build SLP failed: invalid type of def "
> + "for variable-length SLP %T\n", op0);
> + goto fail;
> + }
> + }
> slp_tree invnode = vect_create_new_slp_node (oprnd_info->ops);
> SLP_TREE_DEF_TYPE (invnode) = oprnd_info->first_dt;
> oprnd_info->ops = vNULL;
> @@ -8157,6 +8168,7 @@ vect_create_constant_vectors (vec_info *vinfo, slp_tree
> op_node)
>
> number_of_places_left_in_vector = nunits;
> constant_p = true;
> + tree uniform_elt = NULL_TREE;
> tree_vector_builder elts (vector_type, nunits, 1);
> elts.quick_grow (nunits);
> stmt_vec_info insert_after = NULL;
> @@ -8166,8 +8178,14 @@ vect_create_constant_vectors (vec_info *vinfo,
> slp_tree op_node)
> for (i = group_size - 1; op_node->ops.iterate (i, &op); i--)
> {
> /* Create 'vect_ = {op0,op1,...,opn}'. */
> - number_of_places_left_in_vector--;
> tree orig_op = op;
> + if (number_of_places_left_in_vector == nunits)
> + uniform_elt = op;
> + else if (uniform_elt && operand_equal_p (uniform_elt, op))
> + op = elts[number_of_places_left_in_vector];
> + else
> + uniform_elt = NULL_TREE;
> + number_of_places_left_in_vector--;
> if (!types_compatible_p (TREE_TYPE (vector_type), TREE_TYPE (op)))
> {
> if (CONSTANT_CLASS_P (op))
> @@ -8236,9 +8254,13 @@ vect_create_constant_vectors (vec_info *vinfo,
> slp_tree op_node)
>
> if (number_of_places_left_in_vector == 0)
> {
> - if (constant_p
> - ? multiple_p (TYPE_VECTOR_SUBPARTS (vector_type), nunits)
> - : known_eq (TYPE_VECTOR_SUBPARTS (vector_type), nunits))
> + auto type_nunits = TYPE_VECTOR_SUBPARTS (vector_type);
> + if (uniform_elt)
> + vec_cst = gimple_build_vector_from_val (&ctor_seq, vector_type,
> + elts[0]);
> + else if (constant_p
> + ? multiple_p (type_nunits, nunits)
> + : known_eq (type_nunits, nunits))
> vec_cst = gimple_build_vector (&ctor_seq, &elts);
> else
> {
>
--
Richard Biener <rguent...@suse.de>
SUSE Software Solutions Germany GmbH,
Frankenstrasse 146, 90461 Nuernberg, Germany;
GF: Ivo Totev, Andrew McDonald, Werner Knoblich; (HRB 36809, AG Nuernberg)
