From c30bbd4d169c98b7535a30384c6a971ee875fa44 Mon Sep 17 00:00:00 2001 From: Richard Biener Date: Tue, 2 Aug 2022 08:37:16 +0200 Subject: [PATCH] tree-optimization/106498 - reduce SSA updates in autopar The following reduces the number of SSA updates done during autopar OMP expansion, specifically avoiding the cases that just add virtual operands (where maybe none have been before) in dead regions of the CFG. Instead virtual SSA update is delayed until after the pass. There's much more TLC needed here, but test coverage makes it really difficult. PR tree-optimization/106498 * omp-expand.cc (expand_omp_taskreg): Do not perform virtual SSA update here. (expand_omp_for): Or here. (execute_expand_omp): Instead schedule it here together with CFG cleanup via TODO. --- gcc/omp-expand.cc | 12 ++---------- 1 file changed, 2 insertions(+), 10 deletions(-) diff --git a/gcc/omp-expand.cc b/gcc/omp-expand.cc index 936adff7f45f..64e6308fc7b8 100644 --- a/gcc/omp-expand.cc +++ b/gcc/omp-expand.cc @@ -1530,8 +1530,6 @@ expand_omp_taskreg (struct omp_region *region) expand_teams_call (new_bb, as_a (entry_stmt)); else expand_task_call (region, new_bb, as_a (entry_stmt)); - if (gimple_in_ssa_p (cfun)) - update_ssa (TODO_update_ssa_only_virtuals); } /* Information about members of an OpenACC collapsed loop nest. */ @@ -8191,9 +8189,6 @@ expand_omp_for (struct omp_region *region, gimple *inner_stmt) (enum built_in_function) next_ix, sched_arg, inner_stmt); } - - if (gimple_in_ssa_p (cfun)) - update_ssa (TODO_update_ssa_only_virtuals); } /* Expand code for an OpenMP sections directive. In pseudo code, we generate @@ -10591,13 +10586,10 @@ execute_expand_omp (void) expand_omp (root_omp_region); - if (flag_checking && !loops_state_satisfies_p (LOOPS_NEED_FIXUP)) - verify_loop_structure (); - cleanup_tree_cfg (); - omp_free_regions (); - return 0; + return (TODO_cleanup_cfg + | (gimple_in_ssa_p (cfun) ? TODO_update_ssa_only_virtuals : 0)); } /* OMP expansion -- the default pass, run before creation of SSA form. */ -- 2.43.0