re PR c++/71448 (pointer relational comparison fails inside constant expression)

	PR c++/71448
	* fold-const.c (fold_comparison): Handle CONSTANT_CLASS_P (base0)
	the same as DECL_P (base0) for indirect_base0.  Use equality_code
	in one further place.

	* g++.dg/torture/pr71448.C: New test.

Co-Authored-By: Richard Biener <rguenther@suse.de>

From-SVN: r237212

gcc/ChangeLog

+2016-06-08  Jakub Jelinek  <jakub@redhat.com>
+	    Richard Biener  <rguenther@suse.de>
+
+	PR c++/71448
+	* fold-const.c (fold_comparison): Handle CONSTANT_CLASS_P (base0)
+	the same as DECL_P (base0) for indirect_base0.  Use equality_code
+	in one further place.
+
 2016-06-08  Richard Sandiford  <richard.sandiford@arm.com>
 
 	* expmed.c (store_bit_field_1): Do not restrict a multiword op0

gcc/fold-const.c

@@ -8527,9 +8527,9 @@ fold_comparison (location_t loc, enum tree_code code, tree type,
 	  if ((offset0 == offset1
 	       || (offset0 && offset1
 		   && operand_equal_p (offset0, offset1, 0)))
-	      && (code == EQ_EXPR
-		  || code == NE_EXPR
-		  || (indirect_base0 && DECL_P (base0))
+	      && (equality_code
+		  || (indirect_base0
+		      && (DECL_P (base0) || CONSTANT_CLASS_P (base0)))
 		  || POINTER_TYPE_OVERFLOW_UNDEFINED))
 
 	    {
@@ -8568,7 +8568,8 @@ fold_comparison (location_t loc, enum tree_code code, tree type,
 	     6.5.6/8 and /9 with respect to the signed ptrdiff_t.  */
 	  else if (bitpos0 == bitpos1
 		   && (equality_code
-		       || (indirect_base0 && DECL_P (base0))
+		       || (indirect_base0
+			   && (DECL_P (base0) || CONSTANT_CLASS_P (base0)))
 		       || POINTER_TYPE_OVERFLOW_UNDEFINED))
 	    {
 	      /* By converting to signed sizetype we cover middle-end pointer

gcc/testsuite/ChangeLog

+2016-06-08  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/71448
+	* g++.dg/torture/pr71448.C: New test.
+
 2016-06-08  Bernd Schmidt  <bschmidt@redhat.com>
 
 	PR debug/71432

gcc/testsuite/g++.dg/torture/pr71448.C

+// PR c++/71448
+// { dg-do compile }
+// { dg-additional-options "-std=c++11" }
+
+static constexpr const char foo[] = "foo";
+static constexpr const char *bar = "bar";
+
+static_assert ((foo + 3 - foo) == 3, "check");
+static_assert (foo + 2 != foo, "check");
+static_assert (foo + 2 >= foo, "check");
+static_assert (3 + foo >= foo, "check");
+static_assert (foo <= foo + 2, "check");
+static_assert (foo <= 3 + foo, "check");
+static_assert (foo + 2 > foo, "check");
+static_assert (3 + foo > foo, "check");
+static_assert (foo < 2 + foo, "check");
+static_assert (foo < foo + 3, "check");
+static_assert ((bar + 3 - bar) == 3, "check");
+static_assert (bar + 2 != bar, "check");
+static_assert (2 + bar >= bar, "check");
+static_assert (bar + 3 >= bar, "check");
+static_assert (bar <= bar + 2, "check");
+static_assert (bar <= 3 + bar, "check");
+static_assert (bar + 2 > bar, "check");
+static_assert (3 + bar > bar, "check");
+static_assert (bar < 2 + bar, "check");
+static_assert (bar < bar + 3, "check");