From 52a0f83980082c9995f2d8ec9b88548520fb8a5f Mon Sep 17 00:00:00 2001 From: Richard Biener Date: Mon, 18 May 2020 09:17:24 +0200 Subject: tree-optimization/95172 - avoid mixing conditionalized and ordered SM The following testcase shows a missed optimization that then leads to wrong-code when issueing SMed stores on exits. When we were able to compute an ordered sequence of stores for an exit we need to emit that in the correct order and we can emit it disregarding to any conditional for whether a store actually happened (we know it did). We can also improve detection as of whether we need conditional processing at all. Both parts fix the testcase. 2020-05-18 Richard Biener PR tree-optimization/95172 * tree-ssa-loop-im.c (execute_sm): Get flag whether we eventually need the conditional processing. (execute_sm_exit): When processing an orderd sequence avoid doing any conditional processing. (hoist_memory_references): Pass down whether all edges have ordered processing for a ref to execute_sm. * gcc.dg/torture/pr95172.c: New testcase. --- gcc/tree-ssa-loop-im.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) (limited to 'gcc/tree-ssa-loop-im.c') diff --git a/gcc/tree-ssa-loop-im.c b/gcc/tree-ssa-loop-im.c index 0d77aaa..63f4ef8 100644 --- a/gcc/tree-ssa-loop-im.c +++ b/gcc/tree-ssa-loop-im.c @@ -2130,7 +2130,7 @@ struct sm_aux static void execute_sm (class loop *loop, im_mem_ref *ref, - hash_map &aux_map) + hash_map &aux_map, bool maybe_mt) { gassign *load; struct fmt_data fmt_data; @@ -2154,8 +2154,9 @@ execute_sm (class loop *loop, im_mem_ref *ref, for_each_index (&ref->mem.ref, force_move_till, &fmt_data); bool always_stored = ref_always_accessed_p (loop, ref, true); - if (bb_in_transaction (loop_preheader_edge (loop)->src) - || (! flag_store_data_races && ! always_stored)) + if (maybe_mt + && (bb_in_transaction (loop_preheader_edge (loop)->src) + || (! flag_store_data_races && ! always_stored))) multi_threaded_model_p = true; if (multi_threaded_model_p) @@ -2244,7 +2245,7 @@ execute_sm_exit (class loop *loop, edge ex, vec &seq, else { sm_aux *aux = *aux_map.get (ref); - if (!aux->store_flag) + if (!aux->store_flag || kind == sm_ord) { gassign *store; store = gimple_build_assign (unshare_expr (ref->mem.ref), @@ -2630,7 +2631,7 @@ hoist_memory_references (class loop *loop, bitmap mem_refs, EXECUTE_IF_SET_IN_BITMAP (mem_refs, 0, i, bi) { ref = memory_accesses.refs_list[i]; - execute_sm (loop, ref, aux_map); + execute_sm (loop, ref, aux_map, bitmap_bit_p (refs_not_supported, i)); } /* Materialize ordered store sequences on exits. */ -- cgit v1.1