[PATCH] improve C++ code by changing fold-const.c

[Andrew Pinski]

Oh here are the three patches:

Patch 1 uses lang_hooks.types_compatible_p, patch 2
uses memory equality, patch 3 uses memory equality
on TYPE_MAIN_VARIANT.

Patch1:
Index: fold-const.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/fold-const.c,v
retrieving revision 1.376
diff -u -p -r1.376 fold-const.c
--- fold-const.c	15 May 2004 23:07:49 -0000	1.376
+++ fold-const.c	16 May 2004 23:09:54 -0000
@@ -5815,6 +5815,17 @@ fold (tree expr)
        if (TREE_TYPE (TREE_OPERAND (t, 0)) == type)
  	return TREE_OPERAND (t, 0);

+      if (TREE_CODE (TREE_OPERAND (t, 0)) == ADDR_EXPR)
+	{
+	  tree inside_tree = TREE_OPERAND (t, 0);
+	  tree inside_type = TREE_TYPE (inside_tree);
+	  if (POINTER_TYPE_P (inside_type)
+	      && POINTER_TYPE_P (type)
+	      && lang_hooks.types_compatible_p (TREE_TYPE (type),
+						TREE_TYPE (inside_type)))
+	    return build (ADDR_EXPR, type, TREE_OPERAND (inside_tree, 0));
+	}
+
        /* Handle cases of two conversions in a row.  */
        if (TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
  	  || TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR)

Patch2:
Index: fold-const.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/fold-const.c,v
retrieving revision 1.379
diff -u -p -r1.379 fold-const.c
--- fold-const.c	21 May 2004 00:54:35 -0000	1.379
+++ fold-const.c	21 May 2004 14:20:42 -0000
@@ -5672,6 +5672,19 @@ fold (tree expr)
        if (TREE_TYPE (TREE_OPERAND (t, 0)) == type)
  	return TREE_OPERAND (t, 0);

+     /* If this is an address casted to a compatible
+	pointer type then just create a new address expression.  */
+     if (TREE_CODE (TREE_OPERAND (t, 0)) == ADDR_EXPR)
+	{
+	  tree outer_type = TREE_TYPE (t);
+	  tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
+	  if (POINTER_TYPE_P (inner_type)
+	      && POINTER_TYPE_P (outer_type)
+	      && TREE_TYPE (inner_type) == TREE_TYPE (outer_type))
+	    return build1 (ADDR_EXPR, outer_type,
+			   TREE_OPERAND (TREE_OPERAND (t, 0), 0));
+	}
+
        /* Handle cases of two conversions in a row.  */
        if (TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
  	  || TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR)


Patch3:
Index: fold-const.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/fold-const.c,v
retrieving revision 1.379
diff -u -p -r1.379 fold-const.c
--- fold-const.c	21 May 2004 00:54:35 -0000	1.379
+++ fold-const.c	21 May 2004 15:24:48 -0000
@@ -5672,6 +5672,20 @@ fold (tree expr)
        if (TREE_TYPE (TREE_OPERAND (t, 0)) == type)
  	return TREE_OPERAND (t, 0);

+     /* If this is an address casted to a compatible
+	pointer type then just create a new address expression.  */
+     if (TREE_CODE (TREE_OPERAND (t, 0)) == ADDR_EXPR)
+	{
+	  tree outer_type = TREE_TYPE (t);
+	  tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
+	  if (POINTER_TYPE_P (inner_type)
+	      && POINTER_TYPE_P (outer_type)
+	      && TYPE_MAIN_VARIANT (TREE_TYPE (inner_type))
+	         == TYPE_MAIN_VARIANT (TREE_TYPE (outer_type)))
+	    return build1 (ADDR_EXPR, outer_type,
+			   TREE_OPERAND (TREE_OPERAND (t, 0), 0));
+	}
+
        /* Handle cases of two conversions in a row.  */
        if (TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
  	  || TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR)