From 7002a33d1ba81e4577d965fb9daaee146b31faa8 Mon Sep 17 00:00:00 2001 From: Richard Biener Date: Thu, 4 Feb 2021 12:08:47 +0100 Subject: tree-optimization/98855 - fix some vectorizer cost issues This fixes us not costing vectorized bswap for SLP as well as avoiding biasing to the vectorized side when costing single-argument PHIs. Instead we assume coalescing here and cost them with zero cost for both the scalar and vectorized code. This doesn't fix the PR on its own. 2021-02-04 Richard Biener PR tree-optimization/98855 * tree-vect-loop.c (vectorizable_phi): Do not cost single-argument PHIs. * tree-vect-slp.c (vect_bb_slp_scalar_cost): Likewise. * tree-vect-stmts.c (vectorizable_bswap): Also perform costing for SLP operation. --- gcc/tree-vect-loop.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'gcc/tree-vect-loop.c') diff --git a/gcc/tree-vect-loop.c b/gcc/tree-vect-loop.c index 200ed27..f1f16e3 100644 --- a/gcc/tree-vect-loop.c +++ b/gcc/tree-vect-loop.c @@ -7777,8 +7777,12 @@ vectorizable_phi (vec_info *, "incompatible vector types for invariants\n"); return false; } - record_stmt_cost (cost_vec, SLP_TREE_NUMBER_OF_VEC_STMTS (slp_node), - vector_stmt, stmt_info, vectype, 0, vect_body); + /* For single-argument PHIs assume coalescing which means zero cost + for the scalar and the vector PHIs. This avoids artificially + favoring the vector path (but may pessimize it in some cases). */ + if (gimple_phi_num_args (as_a (stmt_info->stmt)) > 1) + record_stmt_cost (cost_vec, SLP_TREE_NUMBER_OF_VEC_STMTS (slp_node), + vector_stmt, stmt_info, vectype, 0, vect_body); STMT_VINFO_TYPE (stmt_info) = phi_info_type; return true; } -- cgit v1.1