Robin Dapp <rdapp....@gmail.com> writes:
>> Actually, as Richard mentioned in the PR, it would probably be better
>> to use prepare_vec_mask instead. It should work in this context too
>> and would avoid redundant double masking.
>
> Attached is v2 that uses prepare_vec_mask.
>
> Regtested on riscv64 and armv8.8-a+sve via qemu.
> Bootstrap and regtest running on x86 and aarch64.
>
> Regards
> Robin
>
>
> Currently we discard the cond-op mask when the loop is fully masked
> which causes wrong code in
> gcc.dg/vect/vect-cond-reduc-in-order-2-signed-zero.c
> when compiled with
> -O3 -march=cascadelake --param vect-partial-vector-usage=2.
>
> This patch ANDs both masks.
>
> gcc/ChangeLog:
>
> PR tree-optimization/115382
>
> * tree-vect-loop.cc (vectorize_fold_left_reduction): Merge loop
> mask and cond-op mask.
> ---
> gcc/tree-vect-loop.cc | 10 +++++++++-
> gcc/tree-vect-stmts.cc | 2 +-
> gcc/tree-vectorizer.h | 2 ++
> 3 files changed, 12 insertions(+), 2 deletions(-)
>
> diff --git a/gcc/tree-vect-loop.cc b/gcc/tree-vect-loop.cc
> index 028692614bb..c9b037b8daf 100644
> --- a/gcc/tree-vect-loop.cc
> +++ b/gcc/tree-vect-loop.cc
> @@ -7215,7 +7215,15 @@ vectorize_fold_left_reduction (loop_vec_info
> loop_vinfo,
> tree len = NULL_TREE;
> tree bias = NULL_TREE;
> if (LOOP_VINFO_FULLY_MASKED_P (loop_vinfo))
> - mask = vect_get_loop_mask (loop_vinfo, gsi, masks, vec_num, vectype_in,
> i);
> + {
> + tree loop_mask = vect_get_loop_mask (loop_vinfo, gsi, masks,
> + vec_num, vectype_in, i);
> + if (is_cond_op)
> + mask = prepare_vec_mask (loop_vinfo, TREE_TYPE (loop_mask),
> + loop_mask, vec_opmask[i], gsi);
> + else
> + mask = loop_mask;
> + }
> else if (is_cond_op)
> mask = vec_opmask[i];
> if (LOOP_VINFO_FULLY_WITH_LENGTH_P (loop_vinfo))
> diff --git a/gcc/tree-vect-stmts.cc b/gcc/tree-vect-stmts.cc
> index 5098b7fab6a..124a3462753 100644
> --- a/gcc/tree-vect-stmts.cc
> +++ b/gcc/tree-vect-stmts.cc
> @@ -1643,7 +1643,7 @@ check_load_store_for_partial_vectors (loop_vec_info
> loop_vinfo, tree vectype,
> MASK_TYPE is the type of both masks. If new statements are needed,
> insert them before GSI. */
>
> -static tree
> +tree
> prepare_vec_mask (loop_vec_info loop_vinfo, tree mask_type, tree loop_mask,
> tree vec_mask, gimple_stmt_iterator *gsi)
> {
> diff --git a/gcc/tree-vectorizer.h b/gcc/tree-vectorizer.h
> index 97ec9c341e7..1f87c6c8ca2 100644
> --- a/gcc/tree-vectorizer.h
> +++ b/gcc/tree-vectorizer.h
> @@ -2508,6 +2508,8 @@ extern void vect_free_slp_tree (slp_tree);
> extern bool compatible_calls_p (gcall *, gcall *);
> extern int vect_slp_child_index_for_operand (const gimple *, int op, bool);
>
> +extern tree prepare_vec_mask (loop_vec_info, tree, tree, tree,
> gimple_stmt_iterator *);
Nit: long line.
OK with that fixed, thanks.
Richard
> +
> /* In tree-vect-patterns.cc. */
> extern void
> vect_mark_pattern_stmts (vec_info *, stmt_vec_info, gimple *, tree);
