On Fri, Jul 11, 2025 at 11:03 AM Robin Dapp <rdapp....@gmail.com> wrote:
>
> This patch adds access helpers for the gather/scatter offset and scale
> parameters.
OK.
> gcc/ChangeLog:
>
> * internal-fn.cc (expand_scatter_store_optab_fn): Use new
> function.
> (expand_gather_load_optab_fn): Ditto.
> (internal_fn_offset_index): Ditto.
> (internal_fn_scale_index): Ditto.
> * internal-fn.h (internal_fn_offset_index): New function.
> (internal_fn_scale_index): Ditto.
> * optabs-query.cc (supports_vec_gather_load_p): Adjust index.
> * tree-vect-data-refs.cc (vect_describe_gather_scatter_call):
> Use new function.
> ---
> gcc/internal-fn.cc | 57 ++++++++++++++++++++++++++++++++++----
> gcc/internal-fn.h | 2 ++
> gcc/tree-vect-data-refs.cc | 6 ++--
> 3 files changed, 58 insertions(+), 7 deletions(-)
>
> diff --git a/gcc/internal-fn.cc b/gcc/internal-fn.cc
> index 044bdc22481..4a9dc26e836 100644
> --- a/gcc/internal-fn.cc
> +++ b/gcc/internal-fn.cc
> @@ -3652,8 +3652,8 @@ expand_scatter_store_optab_fn (internal_fn, gcall
> *stmt, direct_optab optab)
> internal_fn ifn = gimple_call_internal_fn (stmt);
> int rhs_index = internal_fn_stored_value_index (ifn);
> tree base = gimple_call_arg (stmt, 0);
> - tree offset = gimple_call_arg (stmt, 1);
> - tree scale = gimple_call_arg (stmt, 2);
> + tree offset = gimple_call_arg (stmt, internal_fn_offset_index (ifn));
> + tree scale = gimple_call_arg (stmt, internal_fn_scale_index (ifn));
> tree rhs = gimple_call_arg (stmt, rhs_index);
>
> rtx base_rtx = expand_normal (base);
> @@ -3678,12 +3678,12 @@ expand_scatter_store_optab_fn (internal_fn, gcall
> *stmt, direct_optab optab)
> /* Expand {MASK_,}GATHER_LOAD call CALL using optab OPTAB. */
>
> static void
> -expand_gather_load_optab_fn (internal_fn, gcall *stmt, direct_optab optab)
> +expand_gather_load_optab_fn (internal_fn ifn, gcall *stmt, direct_optab
> optab)
> {
> tree lhs = gimple_call_lhs (stmt);
> tree base = gimple_call_arg (stmt, 0);
> - tree offset = gimple_call_arg (stmt, 1);
> - tree scale = gimple_call_arg (stmt, 2);
> + tree offset = gimple_call_arg (stmt, internal_fn_offset_index (ifn));
> + tree scale = gimple_call_arg (stmt, internal_fn_scale_index (ifn));
>
> rtx lhs_rtx = expand_expr (lhs, NULL_RTX, VOIDmode, EXPAND_WRITE);
> rtx base_rtx = expand_normal (base);
> @@ -5125,6 +5125,53 @@ internal_fn_stored_value_index (internal_fn fn)
> }
> }
>
> +/* If FN is a gather/scatter return the index of its offset argument,
> + otherwise return -1. */
> +
> +int
> +internal_fn_offset_index (internal_fn fn)
> +{
> + if (!internal_gather_scatter_fn_p (fn))
> + return -1;
> +
> + switch (fn)
> + {
> + case IFN_GATHER_LOAD:
> + case IFN_MASK_GATHER_LOAD:
> + case IFN_MASK_LEN_GATHER_LOAD:
> + case IFN_SCATTER_STORE:
> + case IFN_MASK_SCATTER_STORE:
> + case IFN_MASK_LEN_SCATTER_STORE:
> + return 1;
> +
> + default:
> + return -1;
> + }
> +}
> +
> +/* If FN is a gather/scatter return the index of its scale argument,
> + otherwise return -1. */
> +
> +int
> +internal_fn_scale_index (internal_fn fn)
> +{
> + if (!internal_gather_scatter_fn_p (fn))
> + return -1;
> +
> + switch (fn)
> + {
> + case IFN_GATHER_LOAD:
> + case IFN_MASK_GATHER_LOAD:
> + case IFN_MASK_LEN_GATHER_LOAD:
> + case IFN_SCATTER_STORE:
> + case IFN_MASK_SCATTER_STORE:
> + case IFN_MASK_LEN_SCATTER_STORE:
> + return 2;
> +
> + default:
> + return -1;
> + }
> +}
>
> /* Store all supported else values for the optab referred to by ICODE
> in ELSE_VALS. The index of the else operand must be specified in
> diff --git a/gcc/internal-fn.h b/gcc/internal-fn.h
> index afd4f8e64c7..c5b533c0abd 100644
> --- a/gcc/internal-fn.h
> +++ b/gcc/internal-fn.h
> @@ -239,6 +239,8 @@ extern int internal_fn_mask_index (internal_fn);
> extern int internal_fn_len_index (internal_fn);
> extern int internal_fn_else_index (internal_fn);
> extern int internal_fn_stored_value_index (internal_fn);
> +extern int internal_fn_offset_index (internal_fn fn);
> +extern int internal_fn_scale_index (internal_fn fn);
> extern bool internal_gather_scatter_fn_supported_p (internal_fn, tree,
> tree, tree, int,
> vec<int> * = nullptr);
> diff --git a/gcc/tree-vect-data-refs.cc b/gcc/tree-vect-data-refs.cc
> index c84cd29116e..5b2cb537438 100644
> --- a/gcc/tree-vect-data-refs.cc
> +++ b/gcc/tree-vect-data-refs.cc
> @@ -4539,10 +4539,12 @@ vect_describe_gather_scatter_call (stmt_vec_info
> stmt_info,
> info->ifn = gimple_call_internal_fn (call);
> info->decl = NULL_TREE;
> info->base = gimple_call_arg (call, 0);
> - info->offset = gimple_call_arg (call, 1);
> + info->offset = gimple_call_arg
> + (call, internal_fn_offset_index (info->ifn));
> info->offset_dt = vect_unknown_def_type;
> info->offset_vectype = NULL_TREE;
> - info->scale = TREE_INT_CST_LOW (gimple_call_arg (call, 2));
> + info->scale = TREE_INT_CST_LOW (gimple_call_arg
> + (call, internal_fn_scale_index
> (info->ifn)));
> info->element_type = TREE_TYPE (vectype);
> info->memory_type = TREE_TYPE (DR_REF (dr));
> }
> --
> 2.50.0
>
