From e80f7c13f64e10c6a3354c5d6b42da60b21ed0b8 Mon Sep 17 00:00:00 2001 From: Richard Biener Date: Thu, 24 Aug 2023 10:30:12 +0200 Subject: [PATCH] tree-optimization/111125 - properly cost BB reduction remain stmt handling We assume that all root stmts which compose the total reduction chain are vectorized but fail to account for the cost of adding back the scalar defs we are not vectorizing. The following rectifies this, fixing the gcc.dg/tree-ssa/slsr-11.c FAIL on aarch64. PR tree-optimization/111125 * tree-vect-slp.cc (vectorizable_bb_reduc_epilogue): Account for the remain_defs processing. --- gcc/tree-vect-slp.cc | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/gcc/tree-vect-slp.cc b/gcc/tree-vect-slp.cc index b5f9333fc22e..0bcc53013178 100644 --- a/gcc/tree-vect-slp.cc +++ b/gcc/tree-vect-slp.cc @@ -6406,6 +6406,11 @@ vectorizable_bb_reduc_epilogue (slp_instance instance, vectype, 0, vect_body); record_stmt_cost (cost_vec, 1, vec_to_scalar, instance->root_stmts[0], vectype, 0, vect_body); + + /* Since we replace all stmts of a possibly longer scalar reduction + chain account for the extra scalar stmts for that. */ + record_stmt_cost (cost_vec, instance->remain_defs.length (), scalar_stmt, + instance->root_stmts[0], 0, vect_body); return true; } -- 2.47.2