[patch][trunk] ipa-type-escape - add POINTER_PLUS_EXPR

[Olga Golovanevsky <OLGA at il dot ibm dot com>]

This patch was already submitted:

http://gcc.gnu.org/ml/gcc-patches/2007-08/msg00024.html

It got positive responses from Jan and Daniel,
but did not get formal approval.

Ok for mainline?

Olga

2007-10-23  Olga Golovanevsky  <olga@il.ibm.com>

      * ipa-type-escape.h: Expose function
      is_array_access_through_pointer_and_index.
      * ipa-type-escape.c
      (is_array_access_through_pointer_and_index):
      Add three new parameters. Add support of
      POINTER_PLUS_EXPR tree code.

Index: ipa-type-escape.c
===================================================================
--- ipa-type-escape.c   (revision 129551)
+++ ipa-type-escape.c   (working copy)
@@ -926,56 +926,89 @@

 */

-static bool
-is_array_access_through_pointer_and_index (tree op0, tree op1)
+bool
+is_array_access_through_pointer_and_index (enum tree_code code, tree op0,
+                                tree op1, tree *base, tree *offset,
+                                tree *offset_cast_stmt)
 {
-  tree base, offset, offset_cast_stmt;
   tree before_cast, before_cast_def_stmt;
   cast_t op0_cast, op1_cast;

+  *base = NULL;
+  *offset = NULL;
+  *offset_cast_stmt = NULL;
+
   /* Check 1.  */
+  if (code == POINTER_PLUS_EXPR)
+    {
+      tree op0type = TYPE_MAIN_VARIANT (TREE_TYPE (op0));
+      tree op1type = TYPE_MAIN_VARIANT (TREE_TYPE (op1));

-  /* Init data for walk_use_def_chains function.  */
-  op0_cast.type = op1_cast.type = 0;
-  op0_cast.stmt = op1_cast.stmt = NULL;
+      /* One of op0 and op1 is of pointer type and the other is numerical.
*/
+      if (POINTER_TYPE_P (op0type) && NUMERICAL_TYPE_CHECK (op1type))
+     {
+       *base = op0;
+       *offset = op1;
+     }
+      else if (POINTER_TYPE_P (op1type) && NUMERICAL_TYPE_CHECK (op0type))
+     {
+       *base = op1;
+       *offset = op0;
+     }
+      else
+     return false;
+    }
+  else
+    {
+      /* Init data for walk_use_def_chains function.  */
+      op0_cast.type = op1_cast.type = 0;
+      op0_cast.stmt = op1_cast.stmt = NULL;

-  visited_stmts = pointer_set_create ();
-  walk_use_def_chains (op0, is_cast_from_non_pointer,(void *)(&op0_cast),
false);
-  pointer_set_destroy (visited_stmts);
+      visited_stmts = pointer_set_create ();
+      walk_use_def_chains (op0, is_cast_from_non_pointer,(void
*)(&op0_cast),
+                    false);
+      pointer_set_destroy (visited_stmts);

-  visited_stmts = pointer_set_create ();
-  walk_use_def_chains (op1, is_cast_from_non_pointer,(void *)(&op1_cast),
false);
-  pointer_set_destroy (visited_stmts);
+      visited_stmts = pointer_set_create ();
+      walk_use_def_chains (op1, is_cast_from_non_pointer,(void
*)(&op1_cast),
+                    false);
+      pointer_set_destroy (visited_stmts);

-  if (op0_cast.type == 1 && op1_cast.type == 0)
-    {
-      base = op1;
-      offset = op0;
-      offset_cast_stmt = op0_cast.stmt;
+      if (op0_cast.type == 1 && op1_cast.type == 0)
+     {
+       *base = op1;
+       *offset = op0;
+       *offset_cast_stmt = op0_cast.stmt;
+     }
+      else if (op0_cast.type == 0 && op1_cast.type == 1)
+     {
+       *base = op0;
+       *offset = op1;
+       *offset_cast_stmt = op1_cast.stmt;
+     }
+      else
+     return false;
     }
-  else if (op0_cast.type == 0 && op1_cast.type == 1)
-    {
-      base = op0;
-      offset = op1;
-      offset_cast_stmt = op1_cast.stmt;
-    }
-  else
-    return false;
-
+
   /* Check 2.
      offset_cast_stmt is of the form:
      D.1606_7 = (struct str_t *) D.1605_6;  */

-  before_cast = SINGLE_SSA_TREE_OPERAND (offset_cast_stmt, SSA_OP_USE);
-  if (!before_cast)
-    return false;
+  if (*offset_cast_stmt)
+    {
+      before_cast = SINGLE_SSA_TREE_OPERAND (*offset_cast_stmt,
SSA_OP_USE);
+      if (!before_cast)
+     return false;

-  if (SSA_NAME_IS_DEFAULT_DEF(before_cast))
-    return false;
+      if (SSA_NAME_IS_DEFAULT_DEF(before_cast))
+     return false;

-  before_cast_def_stmt = SSA_NAME_DEF_STMT (before_cast);
-  if (!before_cast_def_stmt)
-    return false;
+      before_cast_def_stmt = SSA_NAME_DEF_STMT (before_cast);
+      if (!before_cast_def_stmt)
+     return false;
+    }
+  else
+    before_cast_def_stmt = SSA_NAME_DEF_STMT (*offset);

   /* before_cast_def_stmt should be of the form:
      D.1605_6 = i.1_5 * 16; */
@@ -1449,7 +1482,6 @@
 okay_pointer_operation (enum tree_code code, tree op0, tree op1)
 {
   tree op0type = TYPE_MAIN_VARIANT (TREE_TYPE (op0));
-  tree op1type = TYPE_MAIN_VARIANT (TREE_TYPE (op1));

   switch (code)
     {
@@ -1459,11 +1491,17 @@
       break;
     case MINUS_EXPR:
     case PLUS_EXPR:
+    case POINTER_PLUS_EXPR:
       {
-     if (POINTER_TYPE_P (op1type)
+     tree base, offset, offset_cast_stmt;
+
+     if (POINTER_TYPE_P (op0type)
          && TREE_CODE (op0) == SSA_NAME
          && TREE_CODE (op1) == SSA_NAME
-         && is_array_access_through_pointer_and_index (op0, op1))
+         && is_array_access_through_pointer_and_index (code, op0, op1,
+                                           &base,
+                                           &offset,
+                                           &offset_cast_stmt))
        return true;
      else
        {
Index: ipa-type-escape.h
===================================================================
--- ipa-type-escape.h   (revision 129551)
+++ ipa-type-escape.h   (working copy)
@@ -26,6 +26,8 @@
 bool   ipa_type_escape_field_does_not_clobber_p (tree record_type, tree
field_type);
 int    ipa_type_escape_star_count_of_interesting_type (tree type);
 int    ipa_type_escape_star_count_of_interesting_or_array_type (tree
type);
+bool   is_array_access_through_pointer_and_index (enum tree_code, tree,
tree,
+                                     tree *, tree *, tree *);


 #endif  /* GCC_IPA_TYPE_ESCAPE_H  */