From 3a7ba8fd0cda387809e4902328af2473662b6a4a Mon Sep 17 00:00:00 2001 From: Richard Biener Date: Thu, 17 Mar 2022 08:10:59 +0100 Subject: [PATCH] tree-optimization/104960 - unsplit edges after late sinking Something went wrong when testing the earlier patch to move the late sinking to before the late phiopt for PR102008. The following makes sure to unsplit edges after the late sinking since the split edges confuse the following phiopt leading to missed optimizations. I've went for a new pass parameter for this to avoid changing the CFG after the early sinking pass at this point. 2022-03-17 Richard Biener PR tree-optimization/104960 * passes.def: Add pass parameter to pass_sink_code, mark last one to unsplit edges. * tree-ssa-sink.cc (pass_sink_code::set_pass_param): New. (pass_sink_code::execute): Always execute TODO_cleanup_cfg when we need to unsplit edges. * gcc.dg/gimplefe-37.c: Adjust to allow either the true or false edge to have a forwarder. --- gcc/passes.def | 4 ++-- gcc/testsuite/gcc.dg/gimplefe-37.c | 2 +- gcc/tree-ssa-sink.cc | 13 +++++++++++-- 3 files changed, 14 insertions(+), 5 deletions(-) diff --git a/gcc/passes.def b/gcc/passes.def index c8903b4ec16..3e44797b10f 100644 --- a/gcc/passes.def +++ b/gcc/passes.def @@ -259,7 +259,7 @@ along with GCC; see the file COPYING3. If not see NEXT_PASS (pass_lim); NEXT_PASS (pass_walloca, false); NEXT_PASS (pass_pre); - NEXT_PASS (pass_sink_code); + NEXT_PASS (pass_sink_code, false /* unsplit edges */); NEXT_PASS (pass_sancov); NEXT_PASS (pass_asan); NEXT_PASS (pass_tsan); @@ -349,7 +349,7 @@ along with GCC; see the file COPYING3. If not see /* After late CD DCE we rewrite no longer addressed locals into SSA form if possible. */ NEXT_PASS (pass_forwprop); - NEXT_PASS (pass_sink_code); + NEXT_PASS (pass_sink_code, true /* unsplit edges */); NEXT_PASS (pass_phiopt, false /* early_p */); NEXT_PASS (pass_fold_builtins); NEXT_PASS (pass_optimize_widening_mul); diff --git a/gcc/testsuite/gcc.dg/gimplefe-37.c b/gcc/testsuite/gcc.dg/gimplefe-37.c index d3ea186d7f9..12f6f64fc2c 100644 --- a/gcc/testsuite/gcc.dg/gimplefe-37.c +++ b/gcc/testsuite/gcc.dg/gimplefe-37.c @@ -22,6 +22,6 @@ main (int argc) /* { dg-final { scan-tree-dump-times " \\\[count: 3" 2 "optimized" } } */ -/* { dg-final { scan-tree-dump-times " \\\[count: 2" 1 "optimized" } } */ +/* { dg-final { scan-tree-dump-times " \\\[count: \[12\]" 1 "optimized" } } */ /* { dg-final { scan-tree-dump-times "goto ; \\\[33\\\.33%\\\]" 1 "optimized" } } */ /* { dg-final { scan-tree-dump-times "goto ; \\\[66\\\.67%\\\]" 1 "optimized" } } */ diff --git a/gcc/tree-ssa-sink.cc b/gcc/tree-ssa-sink.cc index 66d7ae89e90..1c226406feb 100644 --- a/gcc/tree-ssa-sink.cc +++ b/gcc/tree-ssa-sink.cc @@ -822,14 +822,21 @@ class pass_sink_code : public gimple_opt_pass { public: pass_sink_code (gcc::context *ctxt) - : gimple_opt_pass (pass_data_sink_code, ctxt) + : gimple_opt_pass (pass_data_sink_code, ctxt), unsplit_edges (false) {} /* opt_pass methods: */ virtual bool gate (function *) { return flag_tree_sink != 0; } virtual unsigned int execute (function *); opt_pass *clone (void) { return new pass_sink_code (m_ctxt); } + void set_pass_param (unsigned n, bool param) + { + gcc_assert (n == 0); + unsplit_edges = param; + } +private: + bool unsplit_edges; }; // class pass_sink_code unsigned int @@ -837,11 +844,13 @@ pass_sink_code::execute (function *fun) { loop_optimizer_init (LOOPS_NORMAL); split_edges_for_insertion (); + /* Arrange for the critical edge splitting to be undone if requested. */ + unsigned todo = unsplit_edges ? TODO_cleanup_cfg : 0; connect_infinite_loops_to_exit (); memset (&sink_stats, 0, sizeof (sink_stats)); calculate_dominance_info (CDI_DOMINATORS); calculate_dominance_info (CDI_POST_DOMINATORS); - unsigned todo = sink_code_in_bb (EXIT_BLOCK_PTR_FOR_FN (fun)); + todo |= sink_code_in_bb (EXIT_BLOCK_PTR_FOR_FN (fun)); statistics_counter_event (fun, "Sunk statements", sink_stats.sunk); statistics_counter_event (fun, "Commoned stores", sink_stats.commoned); free_dominance_info (CDI_POST_DOMINATORS);