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

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 6767537e9c960809265a966854238394ad8eae37..6ad6ddc5b907557279290cd0de78d394bbbc82e5 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,11 @@
+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

diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index 0efa9d5b0b1dd338a324c5a75ddc5b7a8545a013..0b7ea82c03422bf3b1d59e764d43748e8787bfcb 100644 (file)
--- a/gcc/fold-const.c
+++ b/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

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index b40b6c015f9a9332164da02d526fec26bd0a5a51..d8b668cfaabda6e692999ad924be6fe4b0ab09c2 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+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

diff --git a/gcc/testsuite/g++.dg/torture/pr71448.C b/gcc/testsuite/g++.dg/torture/pr71448.C
new file mode 100644 (file)
index 0000000..ca00ca8
--- /dev/null
+++ b/gcc/testsuite/g++.dg/torture/pr71448.C
@@ -0,0 +1,27 @@
+// 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");