Reorder AO_double_t union elements for AO_DOUBLE_T_INITIALIZER portability

* src/atomic_ops/sysdeps/standard_ao_double_t.h (AO_double_t):
Make "AO_parts" element to be the first one in the enum so that
AO_DOUBLE_T_INITIALIZER could be defined both strictly complying with
ANSI C standard (thus preventing "missing braces around initializer"
64-bit compiler warning) and independently of __m128 type definition;
add comment.
* src/atomic_ops/sysdeps/standard_ao_double_t.h
(AO_DOUBLE_T_INITIALIZER): Update to reflect the change in AO_double_t.

diff --git a/src/atomic_ops/sysdeps/standard_ao_double_t.h b/src/atomic_ops/sysdeps/standard_ao_double_t.h
index d73af92eb879ecb60e002349916cd0c3df611db3..1ed32b82e72710385ca5f5e6346a7b9e79a25db4 100644 (file)
--- a/src/atomic_ops/sysdeps/standard_ao_double_t.h
+++ b/src/atomic_ops/sysdeps/standard_ao_double_t.h
@@ -38,14 +38,18 @@
 # define AO_HAVE_DOUBLE_PTR_STORAGE
 
 typedef union {
-    double_ptr_storage AO_whole;
     struct { AO_t AO_v1; AO_t AO_v2; } AO_parts;
         /* Note that AO_v1 corresponds to the low or the high part of   */
         /* AO_whole depending on the machine endianness.                */
+    double_ptr_storage AO_whole;
+        /* AO_whole is now (starting from v7.3alpha3) the 2nd element   */
+        /* of this union to make AO_DOUBLE_T_INITIALIZER portable       */
+        /* (because __m128 definition could vary from a primitive type  */
+        /* to a structure or array/vector).                             */
 } AO_double_t;
 #define AO_HAVE_double_t
 
-#define AO_DOUBLE_T_INITIALIZER { 0 }
+#define AO_DOUBLE_T_INITIALIZER { { (AO_t)0, (AO_t)0 } }
 
 #define AO_val1 AO_parts.AO_v1
 #define AO_val2 AO_parts.AO_v2