tree-ssa-forwprop.c (forward_propagate_addr_expr_1): Also recurse on an…

tree-ssa-forwprop.c (forward_propagate_addr_expr_1): Also recurse on an invariant address if a conversion from a pointer type to a...

	* tree-ssa-forwprop.c (forward_propagate_addr_expr_1): Also
	recurse on an invariant address if a conversion from a pointer
	type to a wider integer type is involved.

testsuite:
	* gcc.c-torture/compile/ptr-conv-1.c: New test.

From-SVN: r147570

gcc/ChangeLog

+2009-05-15  Joseph Myers  <joseph@codesourcery.com>
+
+	* tree-ssa-forwprop.c (forward_propagate_addr_expr_1): Also
+	recurse on an invariant address if a conversion from a pointer
+	type to a wider integer type is involved.
+
 2009-05-15  Jan Hubicka  <jh@suse.cz>
 
 	* cgraph.c (dump_cgraph_node): Dump size/time/benefit.

gcc/testsuite/ChangeLog

+2009-05-15  Joseph Myers  <joseph@codesourcery.com>
+
+	* gcc.c-torture/compile/ptr-conv-1.c: New test.
+
 2009-05-14  Ian Lance Taylor  <iant@google.com>
 
 	* gcc.dg/Wcxx-compat-9.c: New testcase.

gcc/testsuite/gcc.c-torture/compile/ptr-conv-1.c

+/* The intermediate conversion to __PTRDIFF_TYPE__ could be lost,
+   resulting in an "invalid types in nop conversion" ICE.  */
+long long a;
+void
+f (void)
+{
+  int c = 1;
+  volatile int *p = &c;
+  a = (long long) (__PTRDIFF_TYPE__) p;
+  *p;
+}

gcc/tree-ssa-forwprop.c

@@ -739,7 +739,11 @@ forward_propagate_addr_expr_1 (tree name, tree def_rhs,
 	 address which we cannot do in a single statement.  */
       if (!single_use_p
 	  || (!useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (def_rhs))
-	      && !is_gimple_min_invariant (def_rhs)))
+	      && (!is_gimple_min_invariant (def_rhs)
+		  || (INTEGRAL_TYPE_P (TREE_TYPE (lhs))
+		      && POINTER_TYPE_P (TREE_TYPE (def_rhs))
+		      && (TYPE_PRECISION (TREE_TYPE (lhs))
+			  > TYPE_PRECISION (TREE_TYPE (def_rhs)))))))
 	return forward_propagate_addr_expr (lhs, def_rhs);
 
       gimple_assign_set_rhs1 (use_stmt, unshare_expr (def_rhs));