Hi Will,
On Thu, Aug 16, 2018 at 10:50:45AM -0500, Will Schmidt wrote:
> 2018-08-16 Will Schmidt <will_schm...@vnet.ibm.com>
>
> * config/rs6000/rs6000.c (rs6000_gimple_fold_builtin): Add support for
> early gimple folding of vec_splat().
Continuation lines should be indented to the *, not to the text after it.
> + /* Only fold the vec_splat_*() if arg1 is a constant
> + 5-bit unsigned literal. */
> + if (TREE_CODE (arg1) != INTEGER_CST || TREE_INT_CST_LOW (arg1) > 0x1f)
> + return false;
Does this need to check for negative as well? So something with IN_RANGE
then.
> + /* force arg1 into range. */
> + tree new_arg1 = build_int_cst (arg1_type,
> + TREE_INT_CST_LOW (arg1) % n_elts);
Or is the range check unnecessary completely, since you have this?
> + tree splat;
> + if (TREE_CODE (arg0) == VECTOR_CST)
> + splat = VECTOR_CST_ELT (arg0, TREE_INT_CST_LOW (new_arg1));
> + else
> + {
> + /* Determine (in bits) the length and start location of the
> + splat value for a call to the tree_vec_extract helper. */
> + int tree_size_in_bits = TREE_INT_CST_LOW (size_in_bytes (arg0_type))
> + * BITS_PER_UNIT;
> + int splat_elem_size = tree_size_in_bits / n_elts;
> + int splat_start_bit = TREE_INT_CST_LOW (new_arg1) * splat_elem_size;
> + /* Do not attempt to early-fold if the size + specified offset into
> + the vector would touch outside of the source vector. */
> + tree len = build_int_cst (bitsizetype, splat_elem_size);
> + tree start = build_int_cst (bitsizetype, splat_start_bit);
> + splat = tree_vec_extract (gsi, TREE_TYPE (lhs_type), arg0,
> + len, start);
> + }
This closing brace should be indented two spaces more.
> -static inline tree
> +tree
> tree_vec_extract (gimple_stmt_iterator *gsi, tree type,
> tree t, tree bitsize, tree bitpos)
It could use a comment, too (what the args are, etc.)
Other than those nits, looks fine to me. Maybe Richard or Bill have
more comments?
Segher
