tree-object-size: Replace magic numbers with enums

A simple cleanup to allow inserting dynamic size code more easily.

gcc/ChangeLog:

	* tree-object-size.c: New enum.
	(object_sizes, computed, addr_object_size,
	compute_builtin_object_size, expr_object_size, call_object_size,
	merge_object_sizes, plus_stmt_object_size,
	collect_object_sizes_for, init_object_sizes, fini_object_sizes,
	object_sizes_execute): Replace magic numbers with enums.

Signed-off-by: Siddhesh Poyarekar <siddhesh@gotplt.org>

diff --git a/gcc/tree-object-size.c b/gcc/tree-object-size.c
index 4334e05ef70b77112f38dd0e75be56beab8e4154..5e93bb74f926b9071ba96bc60e97b8a75162b3e5 100644 (file)
--- a/gcc/tree-object-size.c
+++ b/gcc/tree-object-size.c
@@ -45,6 +45,13 @@ struct object_size_info
   unsigned int *stack, *tos;
 };
 
+enum
+{
+  OST_SUBOBJECT = 1,
+  OST_MINIMUM = 2,
+  OST_END = 4,
+};
+
 static tree compute_object_offset (const_tree, const_tree);
 static bool addr_object_size (struct object_size_info *,
                              const_tree, int, unsigned HOST_WIDE_INT *);
@@ -67,10 +74,10 @@ static void check_for_plus_in_loops_1 (struct object_size_info *, tree,
    the subobject (innermost array or field with address taken).
    object_sizes[2] is lower bound for number of bytes till the end of
    the object and object_sizes[3] lower bound for subobject.  */
-static vec<unsigned HOST_WIDE_INT> object_sizes[4];
+static vec<unsigned HOST_WIDE_INT> object_sizes[OST_END];
 
 /* Bitmaps what object sizes have been computed already.  */
-static bitmap computed[4];
+static bitmap computed[OST_END];
 
 /* Maximum value of offset we consider to be addition.  */
 static unsigned HOST_WIDE_INT offset_limit;
@@ -227,11 +234,11 @@ addr_object_size (struct object_size_info *osi, const_tree ptr,
     {
       unsigned HOST_WIDE_INT sz;
 
-      if (!osi || (object_size_type & 1) != 0
+      if (!osi || (object_size_type & OST_SUBOBJECT) != 0
          || TREE_CODE (TREE_OPERAND (pt_var, 0)) != SSA_NAME)
        {
          compute_builtin_object_size (TREE_OPERAND (pt_var, 0),
-                                      object_size_type & ~1, &sz);
+                                      object_size_type & ~OST_SUBOBJECT, &sz);
        }
       else
        {
@@ -266,7 +273,7 @@ addr_object_size (struct object_size_info *osi, const_tree ptr,
     }
   else if (DECL_P (pt_var))
     {
-      pt_var_size = decl_init_size (pt_var, object_size_type & 2);
+      pt_var_size = decl_init_size (pt_var, object_size_type & OST_MINIMUM);
       if (!pt_var_size)
        return false;
     }
@@ -287,7 +294,7 @@ addr_object_size (struct object_size_info *osi, const_tree ptr,
     {
       tree var;
 
-      if (object_size_type & 1)
+      if (object_size_type & OST_SUBOBJECT)
        {
          var = TREE_OPERAND (ptr, 0);
 
@@ -528,7 +535,7 @@ bool
 compute_builtin_object_size (tree ptr, int object_size_type,
                             unsigned HOST_WIDE_INT *psize)
 {
-  gcc_assert (object_size_type >= 0 && object_size_type <= 3);
+  gcc_assert (object_size_type >= 0 && object_size_type < OST_END);
 
   /* Set to unknown and overwrite just before returning if the size
      could be determined.  */
@@ -546,7 +553,7 @@ compute_builtin_object_size (tree ptr, int object_size_type,
 
   if (computed[object_size_type] == NULL)
     {
-      if (optimize || object_size_type & 1)
+      if (optimize || object_size_type & OST_SUBOBJECT)
        return false;
 
       /* When not optimizing, rather than failing, make a small effort
@@ -586,8 +593,8 @@ compute_builtin_object_size (tree ptr, int object_size_type,
       if (dump_file)
        {
          fprintf (dump_file, "Computing %s %sobject size for ",
-                  (object_size_type & 2) ? "minimum" : "maximum",
-                  (object_size_type & 1) ? "sub" : "");
+                  (object_size_type & OST_MINIMUM) ? "minimum" : "maximum",
+                  (object_size_type & OST_SUBOBJECT) ? "sub" : "");
          print_generic_expr (dump_file, ptr, dump_flags);
          fprintf (dump_file, ":\n");
        }
@@ -620,7 +627,7 @@ compute_builtin_object_size (tree ptr, int object_size_type,
             terminate, it could take a long time.  If a pointer is
             increasing this way, we need to assume 0 object size.
             E.g. p = &buf[0]; while (cond) p = p + 4;  */
-         if (object_size_type & 2)
+         if (object_size_type & OST_MINIMUM)
            {
              osi.depths = XCNEWVEC (unsigned int, num_ssa_names);
              osi.stack = XNEWVEC (unsigned int, num_ssa_names);
@@ -679,8 +686,9 @@ compute_builtin_object_size (tree ptr, int object_size_type,
                fprintf (dump_file,
                         ": %s %sobject size "
                         HOST_WIDE_INT_PRINT_UNSIGNED "\n",
-                        (object_size_type & 2) ? "minimum" : "maximum",
-                        (object_size_type & 1) ? "sub" : "",
+                        ((object_size_type & OST_MINIMUM) ? "minimum"
+                         : "maximum"),
+                        (object_size_type & OST_SUBOBJECT) ? "sub" : "",
                         object_sizes[object_size_type][i]);
              }
        }
@@ -718,7 +726,7 @@ expr_object_size (struct object_size_info *osi, tree ptr, tree value)
   else
     bytes = unknown (object_size_type);
 
-  if ((object_size_type & 2) == 0)
+  if ((object_size_type & OST_MINIMUM) == 0)
     {
       if (object_sizes[object_size_type][varno] < bytes)
        object_sizes[object_size_type][varno] = bytes;
@@ -748,7 +756,7 @@ call_object_size (struct object_size_info *osi, tree ptr, gcall *call)
 
   bytes = alloc_object_size (call, object_size_type);
 
-  if ((object_size_type & 2) == 0)
+  if ((object_size_type & OST_MINIMUM) == 0)
     {
       if (object_sizes[object_size_type][varno] < bytes)
        object_sizes[object_size_type][varno] = bytes;
@@ -804,7 +812,7 @@ merge_object_sizes (struct object_size_info *osi, tree dest, tree orig,
     orig_bytes = (offset > orig_bytes)
                 ? HOST_WIDE_INT_0U : orig_bytes - offset;
 
-  if ((object_size_type & 2) == 0)
+  if ((object_size_type & OST_MINIMUM) == 0)
     {
       if (object_sizes[object_size_type][varno] < orig_bytes)
        {
@@ -882,7 +890,7 @@ plus_stmt_object_size (struct object_size_info *osi, tree var, gimple *stmt)
   else
     bytes = unknown (object_size_type);
 
-  if ((object_size_type & 2) == 0)
+  if ((object_size_type & OST_MINIMUM) == 0)
     {
       if (object_sizes[object_size_type][varno] < bytes)
        object_sizes[object_size_type][varno] = bytes;
@@ -968,7 +976,7 @@ collect_object_sizes_for (struct object_size_info *osi, tree var)
       if (bitmap_set_bit (osi->visited, varno))
        {
          object_sizes[object_size_type][varno]
-           = (object_size_type & 2) ? -1 : 0;
+           = (object_size_type & OST_MINIMUM) ? -1 : 0;
        }
       else
        {
@@ -1238,7 +1246,7 @@ init_object_sizes (void)
   if (computed[0])
     return;
 
-  for (object_size_type = 0; object_size_type <= 3; object_size_type++)
+  for (object_size_type = 0; object_size_type < OST_END; object_size_type++)
     {
       object_sizes[object_size_type].safe_grow (num_ssa_names, true);
       computed[object_size_type] = BITMAP_ALLOC (NULL);
@@ -1255,7 +1263,7 @@ fini_object_sizes (void)
 {
   int object_size_type;
 
-  for (object_size_type = 0; object_size_type <= 3; object_size_type++)
+  for (object_size_type = 0; object_size_type < OST_END; object_size_type++)
     {
       object_sizes[object_size_type].release ();
       BITMAP_FREE (computed[object_size_type]);
@@ -1302,7 +1310,7 @@ object_sizes_execute (function *fun, bool insert_min_max_p)
                {
                  unsigned HOST_WIDE_INT object_size_type = tree_to_uhwi (ost);
                  tree ptr = gimple_call_arg (call, 0);
-                 if ((object_size_type == 1 || object_size_type == 3)
+                 if ((object_size_type & OST_SUBOBJECT)
                      && (TREE_CODE (ptr) == ADDR_EXPR
                          || TREE_CODE (ptr) == SSA_NAME))
                    {
@@ -1315,7 +1323,8 @@ object_sizes_execute (function *fun, bool insert_min_max_p)
                          tree tem = make_ssa_name (type);
                          gimple_call_set_lhs (call, tem);
                          enum tree_code code
-                           = object_size_type == 1 ? MIN_EXPR : MAX_EXPR;
+                           = (object_size_type & OST_MINIMUM
+                              ? MAX_EXPR : MIN_EXPR);
                          tree cst = build_int_cstu (type, bytes);
                          gimple *g
                            = gimple_build_assign (lhs, code, tem, cst);
@@ -1336,11 +1345,11 @@ object_sizes_execute (function *fun, bool insert_min_max_p)
                {
                  unsigned HOST_WIDE_INT object_size_type = tree_to_uhwi (ost);
 
-                 if (object_size_type < 2)
+                 if (object_size_type & OST_MINIMUM)
+                   result = build_zero_cst (size_type_node);
+                 else if (object_size_type < OST_END)
                    result = fold_convert (size_type_node,
                                           integer_minus_one_node);
-                 else if (object_size_type < 4)
-                   result = build_zero_cst (size_type_node);
                }
 
              if (!result)