https://gcc.gnu.org/g:a3a3e4fa672a5d925f303440345a62925fb5f5e8
commit r17-2683-ga3a3e4fa672a5d925f303440345a62925fb5f5e8 Author: Richard Biener <[email protected]> Date: Fri Jul 24 09:21:50 2026 +0200 Remove shift vectorization check from vect_build_slp_tree_1 The following removes the SLP discovery failure caused by not vectorizable shifts. This does not belong here. I have kept the heuristic that forces uniform shift operands when vector-vector shifts are not supported. * tree-vect-slp.cc (vect_build_slp_tree_1): Remove failure on unvectorizable shifts. Diff: --- gcc/tree-vect-slp.cc | 18 ++++-------------- 1 file changed, 4 insertions(+), 14 deletions(-) diff --git a/gcc/tree-vect-slp.cc b/gcc/tree-vect-slp.cc index dcd35da43a29..cc802f4f4cd9 100644 --- a/gcc/tree-vect-slp.cc +++ b/gcc/tree-vect-slp.cc @@ -1327,26 +1327,16 @@ vect_build_slp_tree_1 (vec_info *vinfo, unsigned char *swap, /* Shift arguments should be equal in all the packed stmts for a vector shift with scalar shift operand. */ - if (rhs_code == LSHIFT_EXPR || rhs_code == RSHIFT_EXPR + if (rhs_code == LSHIFT_EXPR + || rhs_code == RSHIFT_EXPR || rhs_code == LROTATE_EXPR || rhs_code == RROTATE_EXPR) { /* First see if we have a vector/vector shift. */ if (!directly_supported_p (rhs_code, vectype, optab_vector)) { - /* No vector/vector shift, try for a vector/scalar shift. */ - if (!directly_supported_p (rhs_code, vectype, optab_scalar)) - { - if (dump_enabled_p ()) - dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, - "Build SLP failed: " - "op not supported by target.\n"); - if (is_a <bb_vec_info> (vinfo) && i != 0) - continue; - /* Fatal mismatch. */ - matches[0] = false; - return false; - } + /* No vector/vector shift, arrange for a vector/scalar + SLP layout. */ need_same_oprnds = true; first_op1 = gimple_assign_rhs2 (stmt); }
