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| author | Jan Hubicka <hubicka@ucw.cz> | 2014-05-16 19:49:06 +0200 |
|---|---|---|
| committer | Jan Hubicka <hubicka@gcc.gnu.org> | 2014-05-16 17:49:06 +0000 |
| commit | 6de88c6a1c7fb017720cf79a6f93e52221afdfb8 (patch) | |
| tree | 95128482337699b940df1c3ea7402e38fb4ecb88 /gcc/tree-cfg.c | |
| parent | 54674a35bd0a8d231ad314064d5f7bb8a60ef5df (diff) | |
| download | gcc-6de88c6a1c7fb017720cf79a6f93e52221afdfb8.zip gcc-6de88c6a1c7fb017720cf79a6f93e52221afdfb8.tar.gz gcc-6de88c6a1c7fb017720cf79a6f93e52221afdfb8.tar.bz2 | |
varpool.c (dump_varpool_node): Dump write-only flag.
* varpool.c (dump_varpool_node): Dump write-only flag.
* lto-cgraph.c (lto_output_varpool_node, input_varpool_node): Stream
write-only flag.
* tree-cfg.c (execute_fixup_cfg): Remove statements setting write-only variables.
* gcc.c-torture/execute/20101011-1.c: Update testcase.
* gcc.dg/ira-shrinkwrap-prep-1.c: Update testcase.
* gcc.dg/tree-ssa/writeonly.c: New testcase.
* gcc.dg/tree-ssa/ssa-dse-6.c: Update testcase.
* gcc.dg/tree-ssa/pr21559.c: Update testcase.
* gcc.dg/debug/pr35154.c: Update testcase.
* gcc.target/i386/vectorize1.c: Update testcase.
* ipa.c (process_references): New function.
(set_readonly_bit): New function.
(set_writeonly_bit): New function.
(clear_addressable_bit): New function.
(ipa_discover_readonly_nonaddressable_var): Mark write only variables; fix
handling of aliases.
* cgraph.h (struct varpool_node): Add writeonly flag.
From-SVN: r210522
Diffstat (limited to 'gcc/tree-cfg.c')
| -rw-r--r-- | gcc/tree-cfg.c | 39 |
1 files changed, 38 insertions, 1 deletions
diff --git a/gcc/tree-cfg.c b/gcc/tree-cfg.c index fee1ede8..9228d41 100644 --- a/gcc/tree-cfg.c +++ b/gcc/tree-cfg.c @@ -8431,7 +8431,7 @@ execute_fixup_cfg (void) FOR_EACH_BB_FN (bb, cfun) { bb->count = apply_scale (bb->count, count_scale); - for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) + for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi);) { gimple stmt = gsi_stmt (gsi); tree decl = is_gimple_call (stmt) @@ -8457,9 +8457,46 @@ 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)) + { + tree lhs = get_base_address (gimple_get_lhs (stmt)); + + if (TREE_CODE (lhs) == VAR_DECL + && (TREE_STATIC (lhs) || DECL_EXTERNAL (lhs)) + && varpool_get_node (lhs)->writeonly) + { + unlink_stmt_vdef (stmt); + gsi_remove (&gsi, true); + release_defs (stmt); + 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) + && gimple_get_lhs (stmt)) + { + tree lhs = get_base_address (gimple_get_lhs (stmt)); + + if (TREE_CODE (lhs) == VAR_DECL + && (TREE_STATIC (lhs) || DECL_EXTERNAL (lhs)) + && varpool_get_node (lhs)->writeonly) + { + gimple_call_set_lhs (stmt, NULL); + update_stmt (stmt); + todo |= TODO_update_ssa | TODO_cleanup_cfg; + } + } + if (maybe_clean_eh_stmt (stmt) && gimple_purge_dead_eh_edges (bb)) todo |= TODO_cleanup_cfg; + gsi_next (&gsi); } FOR_EACH_EDGE (e, ei, bb->succs) |