Robin Dapp <rdapp....@gmail.com> writes:
> Hi,
>
> 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 instead.
>
> Bootstrapped and regtested on x86, aarch64 and power10.
> Regtested on riscv64 and armv8.8-a+sve via qemu.
>
> Regards
> Robin
>
> gcc/ChangeLog:
>
> * tree-vect-loop.cc (vectorize_fold_left_reduction): Merge loop
> mask and cond-op mask.
OK, thanks.
Richard
> ---
> gcc/tree-vect-loop.cc | 16 +++++++++++++++-
> 1 file changed, 15 insertions(+), 1 deletion(-)
>
> diff --git a/gcc/tree-vect-loop.cc b/gcc/tree-vect-loop.cc
> index 028692614bb..f9bf6a45611 100644
> --- a/gcc/tree-vect-loop.cc
> +++ b/gcc/tree-vect-loop.cc
> @@ -7215,7 +7215,21 @@ 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 mask_loop = vect_get_loop_mask (loop_vinfo, gsi, masks,
> + vec_num, vectype_in, i);
> + if (is_cond_op)
> + {
> + /* Merge the loop mask and the cond_op mask. */
> + mask = make_ssa_name (TREE_TYPE (mask_loop));
> + gassign *and_stmt = gimple_build_assign (mask, BIT_AND_EXPR,
> + mask_loop,
> + vec_opmask[i]);
> + gsi_insert_before (gsi, and_stmt, GSI_SAME_STMT);
> + }
> + else
> + mask = mask_loop;
> + }
> else if (is_cond_op)
> mask = vec_opmask[i];
> if (LOOP_VINFO_FULLY_WITH_LENGTH_P (loop_vinfo))
