[PATCH 04/18] remove TREE_CHAIN from SSA_NAME nodes
Richard Guenther
richard.guenther@gmail.com
Fri Mar 11 13:06:00 GMT 2011
On Fri, Mar 11, 2011 at 5:23 AM, Nathan Froyd <froydnj@codesourcery.com> wrote:
> This conversion is straightforward. The tricky part is converting
> FREE_SSANAMES into a VEC to eliminate the only use of TREE_CHAIN on
> SSA_NAMEs.
Ok for 4.7.
Thanks,
Richard.
> -Nathan
>
> gcc/
> * tree-flow.h (struct gimple_df): Make free_ssanames a VEC.
> * tree-ssanames.c (fini_ssanames): VEC_free it.
> (make_ssa_name_fn): Update for VECness of free_ssanames.
> (release_ssa_name, release_dead_ssa_names): Likewise.
> * tree.h (struct tree_ssa_name): Include typed_tree instead of
> tree_common.
> * tree.c (initialize_tree_contains_struct): Mark TS_SSA_NAME as
> TS_TYPED instead of TS_COMMON.
>
> diff --git a/gcc/tree-flow.h b/gcc/tree-flow.h
> index 14c8827..6b48697 100644
> --- a/gcc/tree-flow.h
> +++ b/gcc/tree-flow.h
> @@ -61,7 +61,7 @@ struct GTY(()) gimple_df {
> struct pointer_map_t * GTY((skip(""))) decls_to_pointers;
>
> /* Free list of SSA_NAMEs. */
> - tree free_ssanames;
> + VEC(tree,gc) *free_ssanames;
>
> /* Hashtable holding definition for symbol. If this field is not NULL, it
> means that the first reference to this variable in the function is a
> diff --git a/gcc/tree-ssanames.c b/gcc/tree-ssanames.c
> index c76dba5..06cdbee 100644
> --- a/gcc/tree-ssanames.c
> +++ b/gcc/tree-ssanames.c
> @@ -96,7 +96,7 @@ void
> fini_ssanames (void)
> {
> VEC_free (tree, gc, SSANAMES (cfun));
> - FREE_SSANAMES (cfun) = NULL;
> + VEC_free (tree, gc, FREE_SSANAMES (cfun));
> }
>
> /* Dump some simple statistics regarding the re-use of SSA_NAME nodes. */
> @@ -124,10 +124,9 @@ make_ssa_name_fn (struct function *fn, tree var, gimple stmt)
> gcc_assert (DECL_P (var));
>
> /* If our free list has an element, then use it. */
> - if (FREE_SSANAMES (fn))
> + if (!VEC_empty (tree, FREE_SSANAMES (fn)))
> {
> - t = FREE_SSANAMES (fn);
> - FREE_SSANAMES (fn) = TREE_CHAIN (FREE_SSANAMES (fn));
> + t = VEC_pop (tree, FREE_SSANAMES (fn));
> #ifdef GATHER_STATISTICS
> ssa_name_nodes_reused++;
> #endif
> @@ -234,9 +233,8 @@ release_ssa_name (tree var)
> /* Note this SSA_NAME is now in the first list. */
> SSA_NAME_IN_FREE_LIST (var) = 1;
>
> - /* And finally link it into the free list. */
> - TREE_CHAIN (var) = FREE_SSANAMES (cfun);
> - FREE_SSANAMES (cfun) = var;
> + /* And finally put it on the free list. */
> + VEC_safe_push (tree, gc, FREE_SSANAMES (cfun), var);
> }
> }
>
> @@ -334,8 +332,8 @@ replace_ssa_name_symbol (tree ssa_name, tree sym)
> static unsigned int
> release_dead_ssa_names (void)
> {
> - tree t, next;
> - int n = 0;
> + tree t;
> + int n = VEC_length (tree, FREE_SSANAMES (cfun));
> referenced_var_iterator rvi;
>
> /* Current defs point to various dead SSA names that in turn point to
> @@ -343,17 +341,7 @@ release_dead_ssa_names (void)
> FOR_EACH_REFERENCED_VAR (cfun, t, rvi)
> set_current_def (t, NULL);
> /* Now release the freelist. */
> - for (t = FREE_SSANAMES (cfun); t; t = next)
> - {
> - next = TREE_CHAIN (t);
> - /* Dangling pointers might make GGC to still see dead SSA names, so it is
> - important to unlink the list and avoid GGC from seeing all subsequent
> - SSA names. In longer run we want to have all dangling pointers here
> - removed (since they usually go through dead statements that consume
> - considerable amounts of memory). */
> - TREE_CHAIN (t) = NULL_TREE;
> - n++;
> - }
> + VEC_free (tree, gc, FREE_SSANAMES (cfun));
> FREE_SSANAMES (cfun) = NULL;
>
> statistics_counter_event (cfun, "SSA names released", n);
> diff --git a/gcc/tree.c b/gcc/tree.c
> index 7d73c74..072ff19 100644
> --- a/gcc/tree.c
> +++ b/gcc/tree.c
> @@ -376,6 +376,7 @@ initialize_tree_contains_struct (void)
> case TS_VECTOR:
> case TS_STRING:
> case TS_COMPLEX:
> + case TS_SSA_NAME:
> MARK_TS_TYPED (code);
> break;
>
> @@ -385,7 +386,6 @@ initialize_tree_contains_struct (void)
> case TS_LIST:
> case TS_VEC:
> case TS_EXP:
> - case TS_SSA_NAME:
> case TS_BLOCK:
> case TS_BINFO:
> case TS_STATEMENT_LIST:
> diff --git a/gcc/tree.h b/gcc/tree.h
> index 11c2f83..80888bc 100644
> --- a/gcc/tree.h
> +++ b/gcc/tree.h
> @@ -1970,7 +1970,7 @@ typedef struct GTY(()) ssa_use_operand_d {
> #define SSA_NAME_IMM_USE_NODE(NODE) SSA_NAME_CHECK (NODE)->ssa_name.imm_uses
>
> struct GTY(()) tree_ssa_name {
> - struct tree_common common;
> + struct typed_tree typed;
>
> /* _DECL wrapped by this SSA name. */
> tree var;
> --
> 1.7.0.4
>
>
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