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

2012-12-11  Marc Glisse  <marc.glisse@inria.fr>

	PR c++/53094
cp/
	* tree.c (cp_tree_equal): Handle VECTOR_CST.
	* semantics.c (cxx_eval_bare_aggregate): Protect a dereference.
	Handle VECTOR_CST.
testsuite/
	* g++.dg/cpp0x/constexpr-53094-1.C: New testcase.
	* g++.dg/cpp0x/constexpr-53094-2.C: Likewise.
	* g++.dg/cpp0x/constexpr-53094-3.C: Likewise.

From-SVN: r194421

gcc/cp/ChangeLog

+2012-12-11  Marc Glisse  <marc.glisse@inria.fr>
+
+	PR c++/53094
+	* tree.c (cp_tree_equal): Handle VECTOR_CST.
+	* semantics.c (cxx_eval_bare_aggregate): Protect a dereference.
+	Handle VECTOR_CST.
+
 2012-12-11  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c++/55643

gcc/cp/semantics.c

@@ -7123,7 +7123,7 @@ cxx_eval_bare_aggregate (const constexpr_call *call, tree t,
 	goto fail;
       if (elt != ce->value)
 	changed = true;
-      if (TREE_CODE (ce->index) == COMPONENT_REF)
+      if (ce->index && TREE_CODE (ce->index) == COMPONENT_REF)
 	{
 	  /* This is an initialization of a vfield inside a base
 	     subaggregate that we already initialized; push this
@@ -7131,7 +7131,7 @@ cxx_eval_bare_aggregate (const constexpr_call *call, tree t,
 	  constructor_elt *inner = base_field_constructor_elt (n, ce->index);
 	  inner->value = elt;
 	}
-      else if (TREE_CODE (ce->index) == NOP_EXPR)
+      else if (ce->index && TREE_CODE (ce->index) == NOP_EXPR)
 	{
 	  /* This is an initializer for an empty base; now that we've
 	     checked that it's constant, we can ignore it.  */
@@ -7148,6 +7148,8 @@ cxx_eval_bare_aggregate (const constexpr_call *call, tree t,
     }
   t = build_constructor (TREE_TYPE (t), n);
   TREE_CONSTANT (t) = true;
+  if (TREE_CODE (TREE_TYPE (t)) == VECTOR_TYPE)
+    t = fold (t);
   return t;
 }
 

gcc/cp/tree.c

@@ -2468,6 +2468,9 @@ cp_tree_equal (tree t1, tree t2)
       return cp_tree_equal (TREE_REALPART (t1), TREE_REALPART (t2))
 	&& cp_tree_equal (TREE_IMAGPART (t1), TREE_IMAGPART (t2));
 
+    case VECTOR_CST:
+      return operand_equal_p (t1, t2, OEP_ONLY_CONST);
+
     case CONSTRUCTOR:
       /* We need to do this when determining whether or not two
 	 non-type pointer to member function template arguments

gcc/testsuite/ChangeLog

+2012-12-11  Marc Glisse  <marc.glisse@inria.fr>
+
+	PR c++/53094
+	* g++.dg/cpp0x/constexpr-53094-1.C: New testcase.
+	* g++.dg/cpp0x/constexpr-53094-2.C: Likewise.
+	* g++.dg/cpp0x/constexpr-53094-3.C: Likewise.
+
 2012-12-11  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c++/55643

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

+// { dg-do compile }
+// { dg-options "-std=gnu++11" }
+
+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 *-*-* } }

gcc/testsuite/g++.dg/cpp0x/constexpr-53094-2.C

+// { dg-do compile }
+// { dg-options "-std=gnu++11" }
+
+typedef float __attribute__ ((vector_size (4 * sizeof (float)))) V4;
+constexpr V4 build (float x, float y, float z) { return (V4){ x, y, z, 0 };}
+constexpr V4 x = build (1, 0, 0);

gcc/testsuite/g++.dg/cpp0x/constexpr-53094-3.C

+// { dg-do compile }
+// { dg-options "-std=gnu++11" }
+
+typedef float __attribute__ ((vector_size (4 * sizeof (float)))) V4;
+
+struct Rot3 {
+  typedef float T;
+  typedef V4 Vec;
+  Vec axis[3];
+  constexpr Rot3 (V4 ix, V4 iy, V4 iz) : axis {ix, iy, iz} {}
+
+  constexpr Rot3(T xx, T xy, T xz, T yx, T yy, T yz, T zx, T zy, T zz) :
+    Rot3((Vec) { xx, xy, xz, 0 },
+	 (Vec) { yx, yy, yz, 0 },
+	 (Vec) { zx, zy, zz, 0 }) {}
+
+};
+
+constexpr Rot3 r1( 0, 1 ,0, 0, 0, 1,  1, 0, 0);