From 36ec4a3c927bd2cc212a7f331ad842cd90eb5283 Mon Sep 17 00:00:00 2001 From: Andrew Pinski Date: Sat, 16 Oct 2021 03:09:05 +0000 Subject: [PATCH] Factor out removal of write only stores from execute_fixup_cfg To make it easier to fix PR 102703, factoring this code out to its own function makes it easier to read and less indentions too. gcc/ChangeLog: * tree-cfg.c (maybe_remove_writeonly_store): New function factored out from ... (execute_fixup_cfg): Here. Call maybe_remove_writeonly_store. --- gcc/tree-cfg.c | 62 +++++++++++++++++++++++++++++++++++----------------------- 1 file changed, 37 insertions(+), 25 deletions(-) diff --git a/gcc/tree-cfg.c b/gcc/tree-cfg.c index c20fc49..dbbf6be 100644 --- a/gcc/tree-cfg.c +++ b/gcc/tree-cfg.c @@ -9666,6 +9666,38 @@ make_pass_warn_unused_result (gcc::context *ctxt) return new pass_warn_unused_result (ctxt); } +/* Maybe Remove stores to variables we marked write-only. + Return true if a store was removed. */ +static bool +maybe_remove_writeonly_store (gimple_stmt_iterator &gsi, gimple *stmt) +{ + /* Keep access when store has side effect, i.e. in case when source + is volatile. */ + if (!gimple_store_p (stmt) + || gimple_has_side_effects (stmt) + || optimize_debug) + return false; + + tree lhs = get_base_address (gimple_get_lhs (stmt)); + + if (!VAR_P (lhs) + || (!TREE_STATIC (lhs) && !DECL_EXTERNAL (lhs)) + || !varpool_node::get (lhs)->writeonly) + return false; + + if (dump_file && (dump_flags & TDF_DETAILS)) + { + fprintf (dump_file, "Removing statement, writes" + " to write only var:\n"); + print_gimple_stmt (dump_file, stmt, 0, + TDF_VOPS|TDF_MEMSYMS); + } + unlink_stmt_vdef (stmt); + gsi_remove (&gsi, true); + release_defs (stmt); + return true; +} + /* IPA passes, compilation of earlier functions or inlining might have changed some properties, such as marked functions nothrow, pure, const or noreturn. @@ -9721,33 +9753,13 @@ execute_fixup_cfg (void) todo |= TODO_cleanup_cfg; } - /* Remove stores to variables we marked write-only. - Keep access when store has side effect, i.e. in case when source - is volatile. */ - if (gimple_store_p (stmt) - && !gimple_has_side_effects (stmt) - && !optimize_debug) + /* Remove stores to variables we marked write-only. */ + if (maybe_remove_writeonly_store (gsi, stmt)) { - tree lhs = get_base_address (gimple_get_lhs (stmt)); - - if (VAR_P (lhs) - && (TREE_STATIC (lhs) || DECL_EXTERNAL (lhs)) - && varpool_node::get (lhs)->writeonly) - { - if (dump_file && (dump_flags & TDF_DETAILS)) - { - fprintf (dump_file, "Removing statement, writes" - " to write only var:\n"); - print_gimple_stmt (dump_file, stmt, 0, - TDF_VOPS|TDF_MEMSYMS); - } - unlink_stmt_vdef (stmt); - gsi_remove (&gsi, true); - release_defs (stmt); - todo |= TODO_update_ssa | TODO_cleanup_cfg; - continue; - } + todo |= TODO_update_ssa | TODO_cleanup_cfg; + continue; } + /* For calls we can simply remove LHS when it is known to be write-only. */ if (is_gimple_call (stmt) -- 2.7.4