[PATCH] fix memory accounting for copying nodes

Richard Guenther richard.guenther@gmail.com
Thu Mar 24 14:55:00 GMT 2011


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);
>
>



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