fold-const.c (fold_convert_const): Fold changing cv-quals on VECTOR_CST.

	* fold-const.c (fold_convert_const): Fold changing cv-quals on
	VECTOR_CST.

From-SVN: r230358

gcc/ChangeLog

 2015-11-13  Jason Merrill  <jason@redhat.com>
 
+	* fold-const.c (fold_convert_const): Fold changing cv-quals on
+	VECTOR_CST.
+
 	* hash-map.h (hash_map::empty): New.
 
 2015-11-13  Nathan Sidwell  <nathan@codesourcery.com>

gcc/fold-const.c

@@ -2095,6 +2095,25 @@ fold_convert_const (enum tree_code code, tree type, tree arg1)
       else if (TREE_CODE (arg1) == REAL_CST)
 	return fold_convert_const_fixed_from_real (type, arg1);
     }
+  else if (TREE_CODE (type) == VECTOR_TYPE)
+    {
+      if (TREE_CODE (arg1) == VECTOR_CST
+	  && TYPE_VECTOR_SUBPARTS (type) == VECTOR_CST_NELTS (arg1))
+	{
+	  int len = TYPE_VECTOR_SUBPARTS (type);
+	  tree elttype = TREE_TYPE (type);
+	  tree *v = XALLOCAVEC (tree, len);
+	  for (int i = 0; i < len; ++i)
+	    {
+	      tree elt = VECTOR_CST_ELT (arg1, i);
+	      tree cvt = fold_convert_const (code, elttype, elt);
+	      if (cvt == NULL_TREE)
+		return NULL_TREE;
+	      v[i] = cvt;
+	    }
+	  return build_vector (type, v);
+	}
+    }
   return NULL_TREE;
 }
 

gcc/tree.def

@@ -303,7 +303,7 @@ DEFTREECODE (FIXED_CST, "fixed_cst", tcc_constant, 0)
    whose contents are other constant nodes.  */
 DEFTREECODE (COMPLEX_CST, "complex_cst", tcc_constant, 0)
 
-/* Contents are in TREE_VECTOR_CST_ELTS field.  */
+/* Contents are in VECTOR_CST_ELTS field.  */
 DEFTREECODE (VECTOR_CST, "vector_cst", tcc_constant, 0)
 
 /* Contents are TREE_STRING_LENGTH and the actual contents of the string.  */