tree.h (categorize_ctor_elements): Adjust prototype and add descriptive comment...

	* tree.h (categorize_ctor_elements): Adjust prototype and add
	descriptive comment, both in accordance with the interface change
	described below.
	* varasm.c (constructor_static_from_elts_p): New function.
	Whether a constructor node is a valid static constant initializer
	if all its elements are.
	(initializer_constant_valid_p) <CONSTRUCTOR value>: Use it.
	* output.h: Declare it.	
	* expr.c (categorize_ctor_elements_1): Return whether the constructor
	is a valid constant initializer instead of computing the number of
	non-constant elements.  Use constructor_static_from_elts_p for this
	purpose.  Replace the head comment with an indication that this is a
	helper for categorize_ctor_elements.
	(categorize_ctor_elements): Same interface change as for the _1
	helper.  Former head comment from this helper moved here, adjusted to
	account for the interface changes.
	(mostly_zeros_p): Adjust call to categorize_ctor_elements.
	(all_zeros_p): Likewise.	
	* gimplify.c (gimplify_init_constructor): Decide whether we can make
	static versions of the constructor from the categorize_ctor_elements
	return value instead of the formerly computed number of non-constant
	elements.

	* gnat.dg/outer_agg_bitfield_constructor.adb: New test.
	* gnat.dg/nested_agg_bitfield_constructor.adb: New test.

From-SVN: r115553

1 files changed, 15 insertions, 4 deletions

diff --git a/gcc/varasm.c b/gcc/varasm.c
index 9dcc3b4..1f5f43a 100644
--- a/gcc/varasm.c
+++ b/gcc/varasm.c
@@ -3699,6 +3699,20 @@ output_addressed_constants (tree exp)
     }
 }
 
+/* Whether a constructor CTOR is a valid static constant initializer if all
+   its elements are.  This used to be internal to initializer_constant_valid_p
+   and has been exposed to let other functions like categorize_ctor_elements
+   evaluate the property while walking a constructor for other purposes.  */
+
+bool
+constructor_static_from_elts_p (tree ctor)
+{
+  return (TREE_CONSTANT (ctor)
+	  && (TREE_CODE (TREE_TYPE (ctor)) == UNION_TYPE
+	      || TREE_CODE (TREE_TYPE (ctor)) == RECORD_TYPE)
+	  && !VEC_empty (constructor_elt, CONSTRUCTOR_ELTS (ctor)));
+}
+
 /* Return nonzero if VALUE is a valid constant-valued expression
    for use in initializing a static variable; one that can be an
    element of a "constant" initializer.
@@ -3719,10 +3733,7 @@ initializer_constant_valid_p (tree value, tree endtype)
   switch (TREE_CODE (value))
     {
     case CONSTRUCTOR:
-      if ((TREE_CODE (TREE_TYPE (value)) == UNION_TYPE
-	   || TREE_CODE (TREE_TYPE (value)) == RECORD_TYPE)
-	  && TREE_CONSTANT (value)
-	  && !VEC_empty (constructor_elt, CONSTRUCTOR_ELTS (value)))
+      if (constructor_static_from_elts_p (value))
 	{
 	  unsigned HOST_WIDE_INT idx;
 	  tree elt;