re PR c++/53094 (constexpr vector subscripting)

2013-07-09  Marc Glisse  <marc.glisse@inria.fr>

	PR c++/53094
gcc/cp/
	* semantics.c (cxx_eval_bit_field_ref): Handle VECTOR_CST.

gcc/testsuite/
	* g++.dg/cpp0x/constexpr-53094-1.C: Adjust.
	* g++.dg/ext/vector24.C: New testcase.

From-SVN: r200822

gcc/cp/ChangeLog

 2013-07-09  Marc Glisse  <marc.glisse@inria.fr>
 
+	PR c++/53094
+	* semantics.c (cxx_eval_bit_field_ref): Handle VECTOR_CST.
+
+2013-07-09  Marc Glisse  <marc.glisse@inria.fr>
+
 	PR c++/53000
 	* call.c (build_conditional_expr_1): Preserve xvalues.
 

gcc/cp/semantics.c

@@ -7197,7 +7197,9 @@ cxx_eval_bit_field_ref (const constexpr_call *call, tree t,
     return t;
   /* Don't VERIFY_CONSTANT here; we only want to check that we got a
      CONSTRUCTOR.  */
-  if (!*non_constant_p && TREE_CODE (whole) != CONSTRUCTOR)
+  if (!*non_constant_p
+      && TREE_CODE (whole) != VECTOR_CST
+      && TREE_CODE (whole) != CONSTRUCTOR)
     {
       if (!allow_non_constant)
 	error ("%qE is not a constant expression", orig_whole);
@@ -7206,6 +7208,10 @@ cxx_eval_bit_field_ref (const constexpr_call *call, tree t,
   if (*non_constant_p)
     return t;
 
+  if (TREE_CODE (whole) == VECTOR_CST)
+    return fold_ternary (BIT_FIELD_REF, TREE_TYPE (t), whole,
+			 TREE_OPERAND (t, 1), TREE_OPERAND (t, 2));
+
   start = TREE_OPERAND (t, 2);
   istart = tree_low_cst (start, 0);
   isize = tree_low_cst (TREE_OPERAND (t, 1), 0);

gcc/testsuite/ChangeLog

 2013-07-09  Marc Glisse  <marc.glisse@inria.fr>
 
+	PR c++/53094
+	* g++.dg/cpp0x/constexpr-53094-1.C: Adjust.
+	* g++.dg/ext/vector24.C: New testcase.
+
+2013-07-09  Marc Glisse  <marc.glisse@inria.fr>
+
 	PR c++/53000
 	* g++.dg/cpp0x/decltype17.C: Adjust.
 

gcc/testsuite/g++.dg/cpp0x/constexpr-53094-1.C

@@ -3,4 +3,4 @@
 
 typedef float __attribute__ ((vector_size (4 * sizeof (float)))) V4;
 constexpr V4 v = { 1, 1, 1, 0 };
-constexpr V4 r = v[0] + v; // { dg-bogus "not a constant expression" "" { xfail *-*-* } }
+constexpr V4 r = v[0] + v;

gcc/testsuite/g++.dg/ext/vector24.C

+// { dg-do compile { target c++11 } }
+
+typedef long vec __attribute__((vector_size(2*sizeof(long))));
+constexpr vec v = { 33, 42 };
+constexpr auto l0 = v[0];
+constexpr auto l1 = v[1];
+static_assert(l0==33,"Fail");
+static_assert(l1==42,"Fail");