[3/4] Factor out removal of write only stores from execute_fixup_cfg
Commit Message
From: Andrew Pinski <apinski@marvell.com>
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(-)
Comments
On 10/18/2021 10:54 PM, apinski--- via Gcc-patches wrote:
> From: Andrew Pinski <apinski@marvell.com>
>
> 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.
OK
jeff
@@ -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)