* fold-const.c (fold_unary): Convert (T1)(X op Y) into ((T1)X op (T1)Y),

	for pointer type in more cases than before.

	* gimplify.c (gimplify_expr): Fold (void *)&a + 4.

	* tree-object-size.c (plus_expr_object_size): When operand size is
	unknown, return unknown.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@124403 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index eb93c4b..1add00f 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,13 @@
+2007-05-03  Jan Hubicka  <jh@suse.cz>
+
+       * fold-const.c (fold_unary): Convert (T1)(X op Y) into ((T1)X op (T1)Y),
+       for pointer type in more cases than before.
+
+       * gimplify.c (gimplify_expr): Fold (void *)&a + 4.
+
+       * tree-object-size.c (plus_expr_object_size): When operand size is
+       unknown, return unknown.
+
 2007-05-03  Dirk Mueller  <dmueller@suse.de>
 
        * doc/invoke.texi (-m386,-m486,-mpentium,-mpentiumpro): Remove.

diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index 2d9f752..ba17d46 100644 (file)
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -7814,24 +7814,20 @@ fold_unary (enum tree_code code, tree type, tree op0)
            }
        }
 
-      /* Convert (T1)((T2)X op Y) into (T1)X op Y, for pointer types T1 and
-        T2 being pointers to types of the same size.  */
-      if (POINTER_TYPE_P (type)
+      /* Convert (T1)(X op Y) into ((T1)X op (T1)Y), for pointer type,
+         when one of the new casts will fold away. Conservatively we assume
+        that this happens when X or Y is NOP_EXPR or Y is INTEGER_CST.  */
+      if (POINTER_TYPE_P (type) && POINTER_TYPE_P (TREE_TYPE (arg0))
          && BINARY_CLASS_P (arg0)
-         && TREE_CODE (TREE_OPERAND (arg0, 0)) == NOP_EXPR
-         && POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 0))))
+         && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
+             || TREE_CODE (TREE_OPERAND (arg0, 0)) == NOP_EXPR
+             || TREE_CODE (TREE_OPERAND (arg0, 1)) == NOP_EXPR))
        {
          tree arg00 = TREE_OPERAND (arg0, 0);
-         tree t0 = type;
-         tree t1 = TREE_TYPE (arg00);
-         tree tt0 = TREE_TYPE (t0);
-         tree tt1 = TREE_TYPE (t1);
-         tree s0 = TYPE_SIZE (tt0);
-         tree s1 = TYPE_SIZE (tt1);
-
-         if (s0 && s1 && operand_equal_p (s0, s1, OEP_ONLY_CONST))
-           return build2 (TREE_CODE (arg0), t0, fold_convert (t0, arg00),
-                          TREE_OPERAND (arg0, 1));
+         tree arg01 = TREE_OPERAND (arg0, 1);
+
+         return fold_build2 (TREE_CODE (arg0), type, fold_convert (type, arg00),
+                             fold_convert (type, arg01));
        }
 
       /* Convert (T1)(~(T2)X) into ~(T1)X if T1 and T2 are integral types

diff --git a/gcc/gimplify.c b/gcc/gimplify.c
index 805c302..3efb2b8 100644 (file)
--- a/gcc/gimplify.c
+++ b/gcc/gimplify.c
@@ -5881,7 +5881,22 @@ gimplify_expr (tree *expr_p, tree *pre_p, tree *post_p,
             {
                *expr_p = build_fold_addr_expr_with_type (tmp,
                                                         TREE_TYPE (*expr_p));
-               break;
+              break;
+            }
+         /* Convert (void *)&a + 4 into (void *)&a[1].  */
+         if (POINTER_TYPE_P (TREE_TYPE (*expr_p))
+             && TREE_CODE (TREE_OPERAND (*expr_p, 0)) == NOP_EXPR
+             && TREE_CODE (TREE_OPERAND (*expr_p, 1)) == INTEGER_CST
+             && (tmp = maybe_fold_offset_to_reference
+                        (TREE_OPERAND (TREE_OPERAND (*expr_p, 0), 0),
+                         TREE_OPERAND (*expr_p, 1),
+                         TREE_TYPE (TREE_TYPE
+                                 (TREE_OPERAND (TREE_OPERAND (*expr_p, 0),
+                                                0))))))
+            {
+               tmp = build_fold_addr_expr (tmp);
+               *expr_p = fold_convert (TREE_TYPE (*expr_p), tmp);
+              break;
             }
           /* FALLTHRU */
        default:

diff --git a/gcc/tree-object-size.c b/gcc/tree-object-size.c
index f1852ca..1eb09cb 100644 (file)
--- a/gcc/tree-object-size.c
+++ b/gcc/tree-object-size.c
@@ -588,7 +588,9 @@ plus_expr_object_size (struct object_size_info *osi, tree var, tree value)
          unsigned HOST_WIDE_INT off = tree_low_cst (op1, 1);
 
          bytes = compute_builtin_object_size (op0, object_size_type);
-         if (off > offset_limit)
+         if (bytes == unknown[object_size_type])
+           ;
+         else if (off > offset_limit)
            bytes = unknown[object_size_type];
          else if (off > bytes)
            bytes = 0;