This removes the code that makes us walk DECL_INITIAL (recursively)
on add_referenced_var - one source of compile-time hogs in the past
and not strictly necessary. Fallout is fixed by guarding used flag
setting in unused-var-removal as all reads of that flag are already.
This is a first patch in a series to make referenced vars tracking
cheaper and more robust.
Bootstrapped on x86_64-unknown-linux-gnu, testing in progress.
Richard.
2012-05-21 Richard Guenther <rguent...@suse.de>
* tree-dfa.c (add_referenced_var): Do not walk DECL_INITIAL for
more referenced vars.
* tree-ssa-live.c (mark_all_vars_used_1): Only set the used
flag on variables that have a var-annotation.
Index: gcc/tree-dfa.c
===================================================================
--- gcc/tree-dfa.c (revision 187708)
+++ gcc/tree-dfa.c (working copy)
@@ -577,24 +577,16 @@ set_default_def (tree var, tree def)
bool
add_referenced_var (tree var)
{
- gcc_assert (DECL_P (var));
+ gcc_checking_assert (TREE_CODE (var) == VAR_DECL
+ || TREE_CODE (var) == PARM_DECL
+ || TREE_CODE (var) == RESULT_DECL);
+
if (!*DECL_VAR_ANN_PTR (var))
create_var_ann (var);
/* Insert VAR into the referenced_vars hash table if it isn't present. */
if (referenced_var_check_and_insert (var))
- {
- /* Scan DECL_INITIAL for pointer variables as they may contain
- address arithmetic referencing the address of other
- variables. As we are only interested in directly referenced
- globals or referenced locals restrict this to initializers
- than can refer to local variables. */
- if (DECL_INITIAL (var)
- && DECL_CONTEXT (var) == current_function_decl)
- walk_tree (&DECL_INITIAL (var), find_vars_r, NULL, 0);
-
- return true;
- }
+ return true;
return false;
}
Index: gcc/tree-ssa-live.c
===================================================================
--- gcc/tree-ssa-live.c (revision 187708)
+++ gcc/tree-ssa-live.c (working copy)
@@ -377,7 +377,8 @@ mark_all_vars_used_1 (tree *tp, int *wal
if (data != NULL && bitmap_clear_bit ((bitmap) data, DECL_UID (t))
&& DECL_CONTEXT (t) == current_function_decl)
mark_all_vars_used (&DECL_INITIAL (t), data);
- set_is_used (t);
+ if (var_ann (t) != NULL)
+ set_is_used (t);
}
/* remove_unused_scope_block_p requires information about labels
which are not DECL_IGNORED_P to tell if they might be used in the IL. */
