From 7ac7e2868d450dfb9080166ddc4abcc21b86fab3 Mon Sep 17 00:00:00 2001 From: Richard Sandiford Date: Tue, 2 Jan 2018 18:26:06 +0000 Subject: Split can_vec_perm_p into can_vec_perm_{var,const}_p This patch splits can_vec_perm_p into two functions: can_vec_perm_var_p for testing permute operations with variable selection vectors, and can_vec_perm_const_p for testing permute operations with specific constant selection vectors. This means that we can pass the constant selection vector by reference. Constant permutes can still use a variable permute as a fallback. A later patch adds a check to makre sure that we don't truncate the vector indices when doing this. However, have_whole_vector_shift checked: if (direct_optab_handler (vec_perm_const_optab, mode) == CODE_FOR_nothing) return false; which had the effect of disallowing the fallback to variable permutes. I'm not sure whether that was the intention or whether it was just supposed to short-cut the loop on targets that don't support permutes. (But then why bother? The first check in the loop would fail and we'd bail out straightaway.) The patch adds a parameter for disallowing the fallback. I think it makes sense to do this for the following code in the VEC_PERM_EXPR folder: /* Some targets are deficient and fail to expand a single argument permutation while still allowing an equivalent 2-argument version. */ if (need_mask_canon && arg2 == op2 && !can_vec_perm_p (TYPE_MODE (type), false, &sel) && can_vec_perm_p (TYPE_MODE (type), false, &sel2)) since it's really testing whether the expand_vec_perm_const code expects a particular form. 2018-01-02 Richard Sandiford gcc/ * optabs-query.h (can_vec_perm_p): Delete. (can_vec_perm_var_p, can_vec_perm_const_p): Declare. * optabs-query.c (can_vec_perm_p): Split into... (can_vec_perm_var_p, can_vec_perm_const_p): ...these two functions. (can_mult_highpart_p): Use can_vec_perm_const_p to test whether a particular selector is valid. * tree-ssa-forwprop.c (simplify_vector_constructor): Likewise. * tree-vect-data-refs.c (vect_grouped_store_supported): Likewise. (vect_grouped_load_supported): Likewise. (vect_shift_permute_load_chain): Likewise. * tree-vect-slp.c (vect_build_slp_tree_1): Likewise. (vect_transform_slp_perm_load): Likewise. * tree-vect-stmts.c (perm_mask_for_reverse): Likewise. (vectorizable_bswap): Likewise. (vect_gen_perm_mask_checked): Likewise. * fold-const.c (fold_ternary_loc): Likewise. Don't take implementations of variable permutation vectors into account when deciding which selector to use. * tree-vect-loop.c (have_whole_vector_shift): Don't check whether vec_perm_const_optab is supported; instead use can_vec_perm_const_p with a false third argument. * tree-vect-generic.c (lower_vec_perm): Use can_vec_perm_const_p to test whether the constant selector is valid and can_vec_perm_var_p to test whether a variable selector is valid. From-SVN: r256091 --- gcc/tree-ssa-forwprop.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'gcc/tree-ssa-forwprop.c') diff --git a/gcc/tree-ssa-forwprop.c b/gcc/tree-ssa-forwprop.c index 41ee409..783ceb6 100644 --- a/gcc/tree-ssa-forwprop.c +++ b/gcc/tree-ssa-forwprop.c @@ -2108,7 +2108,7 @@ simplify_vector_constructor (gimple_stmt_iterator *gsi) { tree mask_type; - if (!can_vec_perm_p (TYPE_MODE (type), false, &sel)) + if (!can_vec_perm_const_p (TYPE_MODE (type), sel)) return false; mask_type = build_vector_type (build_nonstandard_integer_type (elem_size, 1), -- cgit v1.1