fix memory accounting for copying nodes

tree.c can gather optionally statistics--counts and total bytes
allocated--when tree nodes are created.  Due to an oversight, however,
this accounting is not performed when nodes are copied.  The patch below
corrects this oversight and moves things around so the accounting is
done in (almost) only one place.  (The "almost" is due to special
decrementing when we reuse types, which is arguably bogus, since we've
created a node already, so we shouldn't be playing games to pretend we
didn't touch memory.)

Tested on x86_64-unknown-linux-gnu, with and without
--enable-gather-detailed-mem-stats.  OK to commit?

-Nathan

	* tree.c (record_node_allocation_statistics): New function.
	(make_node_stat, copy_node_stat, build_string): Call it.
	(make_tree_binfo_stat, make_tree_vec_stat, tree_cons_stat): Likewise.
	(build1_stat, build_omp_clause): Likewise.

On Thu, Mar 24, 2011 at 3:46 PM, Nathan Froyd <froydnj@codesourcery.com> wrote:
> tree.c can gather optionally statistics--counts and total bytes
> allocated--when tree nodes are created.  Due to an oversight, however,
> this accounting is not performed when nodes are copied.  The patch below
> corrects this oversight and moves things around so the accounting is
> done in (almost) only one place.  (The "almost" is due to special
> decrementing when we reuse types, which is arguably bogus, since we've
> created a node already, so we shouldn't be playing games to pretend we
> didn't touch memory.)
>
> Tested on x86_64-unknown-linux-gnu, with and without
> --enable-gather-detailed-mem-stats.  OK to commit?

Ok.

Thanks,
Richard.

> -Nathan
>
>        * tree.c (record_node_allocation_statistics): New function.
>        (make_node_stat, copy_node_stat, build_string): Call it.
>        (make_tree_binfo_stat, make_tree_vec_stat, tree_cons_stat): Likewise.
>        (build1_stat, build_omp_clause): Likewise.
>
> diff --git a/gcc/tree.c b/gcc/tree.c
> index efa51bd..2066c84 100644
> --- a/gcc/tree.c
> +++ b/gcc/tree.c
> @@ -769,20 +769,15 @@ tree_size (const_tree node)
>     }
>  }
>
> -/* Return a newly allocated node of code CODE.  For decl and type
> -   nodes, some other fields are initialized.  The rest of the node is
> -   initialized to zero.  This function cannot be used for TREE_VEC or
> -   OMP_CLAUSE nodes, which is enforced by asserts in tree_code_size.
> +/* Record interesting allocation statistics for a tree node with CODE
> +   and LENGTH.  */
>
> -   Achoo!  I got a code in the node.  */
> -
> -tree
> -make_node_stat (enum tree_code code MEM_STAT_DECL)
> +static void
> +record_node_allocation_statistics (enum tree_code code ATTRIBUTE_UNUSED,
> +                                  size_t length ATTRIBUTE_UNUSED)
>  {
> -  tree t;
> -  enum tree_code_class type = TREE_CODE_CLASS (code);
> -  size_t length = tree_code_size (code);
>  #ifdef GATHER_STATISTICS
> +  enum tree_code_class type = TREE_CODE_CLASS (code);
>   tree_node_kind kind;
>
>   switch (type)
> @@ -841,12 +836,20 @@ make_node_stat (enum tree_code code MEM_STAT_DECL)
>          kind = constr_kind;
>          break;
>
> +       case OMP_CLAUSE:
> +         kind = omp_clause_kind;
> +         break;
> +
>        default:
>          kind = x_kind;
>          break;
>        }
>       break;
>
> +    case tcc_vl_exp:
> +      kind = e_kind;
> +      break;
> +
>     default:
>       gcc_unreachable ();
>     }
> @@ -854,6 +857,23 @@ make_node_stat (enum tree_code code MEM_STAT_DECL)
>   tree_node_counts[(int) kind]++;
>   tree_node_sizes[(int) kind] += length;
>  #endif
> +}
> +
> +/* Return a newly allocated node of code CODE.  For decl and type
> +   nodes, some other fields are initialized.  The rest of the node is
> +   initialized to zero.  This function cannot be used for TREE_VEC or
> +   OMP_CLAUSE nodes, which is enforced by asserts in tree_code_size.
> +
> +   Achoo!  I got a code in the node.  */
> +
> +tree
> +make_node_stat (enum tree_code code MEM_STAT_DECL)
> +{
> +  tree t;
> +  enum tree_code_class type = TREE_CODE_CLASS (code);
> +  size_t length = tree_code_size (code);
> +
> +  record_node_allocation_statistics (code, length);
>
>   t = ggc_alloc_zone_cleared_tree_node_stat (
>                (code == IDENTIFIER_NODE) ? &tree_id_zone : &tree_zone,
> @@ -950,6 +970,7 @@ copy_node_stat (tree node MEM_STAT_DECL)
>   gcc_assert (code != STATEMENT_LIST);
>
>   length = tree_size (node);
> +  record_node_allocation_statistics (code, length);
>   t = ggc_alloc_zone_tree_node_stat (&tree_zone, length PASS_MEM_STAT);
>   memcpy (t, node, length);
>
> @@ -1540,10 +1561,7 @@ build_string (int len, const char *str)
>   /* Do not waste bytes provided by padding of struct tree_string.  */
>   length = len + offsetof (struct tree_string, str) + 1;
>
> -#ifdef GATHER_STATISTICS
> -  tree_node_counts[(int) c_kind]++;
> -  tree_node_sizes[(int) c_kind] += length;
> -#endif
> +  record_node_allocation_statistics (STRING_CST, length);
>
>   s = ggc_alloc_tree_node (length);
>
> @@ -1663,10 +1681,7 @@ make_tree_binfo_stat (unsigned base_binfos MEM_STAT_DECL)
>   size_t length = (offsetof (struct tree_binfo, base_binfos)
>                   + VEC_embedded_size (tree, base_binfos));
>
> -#ifdef GATHER_STATISTICS
> -  tree_node_counts[(int) binfo_kind]++;
> -  tree_node_sizes[(int) binfo_kind] += length;
> -#endif
> +  record_node_allocation_statistics (TREE_BINFO, length);
>
>   t = ggc_alloc_zone_tree_node_stat (&tree_zone, length PASS_MEM_STAT);
>
> @@ -1688,10 +1703,7 @@ make_tree_vec_stat (int len MEM_STAT_DECL)
>   tree t;
>   int length = (len - 1) * sizeof (tree) + sizeof (struct tree_vec);
>
> -#ifdef GATHER_STATISTICS
> -  tree_node_counts[(int) vec_kind]++;
> -  tree_node_sizes[(int) vec_kind] += length;
> -#endif
> +  record_node_allocation_statistics (TREE_VEC, length);
>
>   t = ggc_alloc_zone_cleared_tree_node_stat (&tree_zone, length PASS_MEM_STAT);
>
> @@ -2229,10 +2241,7 @@ tree_cons_stat (tree purpose, tree value, tree chain MEM_STAT_DECL)
>                                         PASS_MEM_STAT);
>   memset (node, 0, sizeof (struct tree_common));
>
> -#ifdef GATHER_STATISTICS
> -  tree_node_counts[(int) x_kind]++;
> -  tree_node_sizes[(int) x_kind] += sizeof (struct tree_list);
> -#endif
> +  record_node_allocation_statistics (TREE_LIST, sizeof (struct tree_list));
>
>   TREE_SET_CODE (node, TREE_LIST);
>   TREE_CHAIN (node) = chain;
> @@ -3689,28 +3698,9 @@ tree
>  build1_stat (enum tree_code code, tree type, tree node MEM_STAT_DECL)
>  {
>   int length = sizeof (struct tree_exp);
> -#ifdef GATHER_STATISTICS
> -  tree_node_kind kind;
> -#endif
>   tree t;
>
> -#ifdef GATHER_STATISTICS
> -  switch (TREE_CODE_CLASS (code))
> -    {
> -    case tcc_statement:  /* an expression with side effects */
> -      kind = s_kind;
> -      break;
> -    case tcc_reference:  /* a reference */
> -      kind = r_kind;
> -      break;
> -    default:
> -      kind = e_kind;
> -      break;
> -    }
> -
> -  tree_node_counts[(int) kind]++;
> -  tree_node_sizes[(int) kind] += length;
> -#endif
> +  record_node_allocation_statistics (code, length);
>
>   gcc_assert (TREE_CODE_LENGTH (code) == 1);
>
> @@ -9650,17 +9640,14 @@ build_omp_clause (location_t loc, enum omp_clause_code code)
>   length = omp_clause_num_ops[code];
>   size = (sizeof (struct tree_omp_clause) + (length - 1) * sizeof (tree));
>
> +  record_node_allocation_statistics (OMP_CLAUSE, size);
> +
>   t = ggc_alloc_tree_node (size);
>   memset (t, 0, size);
>   TREE_SET_CODE (t, OMP_CLAUSE);
>   OMP_CLAUSE_SET_CODE (t, code);
>   OMP_CLAUSE_LOCATION (t) = loc;
>
> -#ifdef GATHER_STATISTICS
> -  tree_node_counts[(int) omp_clause_kind]++;
> -  tree_node_sizes[(int) omp_clause_kind] += size;
> -#endif
> -
>   return t;
>  }
>
> @@ -9678,10 +9665,7 @@ build_vl_exp_stat (enum tree_code code, int len MEM_STAT_DECL)
>   gcc_assert (TREE_CODE_CLASS (code) == tcc_vl_exp);
>   gcc_assert (len >= 1);
>
> -#ifdef GATHER_STATISTICS
> -  tree_node_counts[(int) e_kind]++;
> -  tree_node_sizes[(int) e_kind] += length;
> -#endif
> +  record_node_allocation_statistics (code, length);
>
>   t = ggc_alloc_zone_cleared_tree_node_stat (&tree_zone, length PASS_MEM_STAT);
>
>