* gimple.c (walk_gimple_op) <GIMPLE_ASSIGN>: Do not request a pure

	rvalue on the RHS if the LHS is of a non-renamable type.
	* tree-ssa-ccp.c (maybe_fold_offset_to_component_ref): Fold result.
ada/
	* gcc-interface/ada-tree.h (TYPE_BY_REFERENCE_P): Delete.
	(DECL_CONST_ADDRESS_P): New macro.
	(SET_DECL_ORIGINAL_FIELD_TO_FIELD): Likewise.
	(SAME_FIELD_P): Likewise.
	* gcc-interface/decl.c (constructor_address_p): New static function.
	(gnat_to_gnu_entity) <object>: Set DECL_CONST_ADDRESS_P according to
	the return value of above function.
	(gnat_to_gnu_entity) <E_Record_Type>: Force BLKmode for all types
	passed by reference.
	<E_Record_Subtype>: Likewise.
	Set TREE_ADDRESSABLE on the type if it passed by reference.
	(make_packable_type): Use SET_DECL_ORIGINAL_FIELD_TO_FIELD.
	(create_field_decl_from): Likewise.
	(substitute_in_type): Likewise.
	(purpose_member_field): Use SAME_FIELD_P.
	* gcc-interface/misc.c (must_pass_by_ref): Test TREE_ADDRESSABLE.
	* gcc-interface/trans.c (lvalue_required_p): Add ADDRESS_OF_CONSTANT
	parameter and adjust recursive calls.
	<N_Explicit_Dereference>: New case.
	<N_Object_Declaration>: Return 1 if the object is of a class-wide type.
	Adjust calls to lvalue_required_p.  Do not return the initializer of a
	DECL_CONST_ADDRESS_P constant if an lvalue is required for it.
	(call_to_gnu): Delay issuing error message for a misaligned actual and
	avoid the associated back-end assertion.  Test TREE_ADDRESSABLE.
	(gnat_gimplify_expr) <ADDR_EXPR>: Handle non-static constructors.
	* gcc-interface/utils.c (make_dummy_type): Set TREE_ADDRESSABLE if the
	type is passed by reference.
	(convert) <CONSTRUCTOR>: Convert in-place in more cases.
	* gcc-interface/utils2.c (build_cond_expr): Drop TYPE_BY_REFERENCE_P.
	(build_simple_component_ref): Use SAME_FIELD_P.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@158254 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 8 insertions, 4 deletions

diff --git a/gcc/gimple.c b/gcc/gimple.c
index ce1f75a884e..aab6ef25f34 100644
--- a/gcc/gimple.c
+++ b/gcc/gimple.c
@@ -1324,11 +1324,15 @@ walk_gimple_op (gimple stmt, walk_tree_fn callback_op,
   switch (gimple_code (stmt))
     {
     case GIMPLE_ASSIGN:
-      /* Walk the RHS operands.  A formal temporary LHS may use a
-	 COMPONENT_REF RHS.  */
+      /* Walk the RHS operands.  If the LHS is of a non-renamable type or
+         is a register variable, we may use a COMPONENT_REF on the RHS.  */
       if (wi)
-	wi->val_only = !is_gimple_reg (gimple_assign_lhs (stmt))
-                       || !gimple_assign_single_p (stmt);
+	{
+	  tree lhs = gimple_assign_lhs (stmt);
+	  wi->val_only
+	    = (is_gimple_reg_type (TREE_TYPE (lhs)) && !is_gimple_reg (lhs))
+	      || !gimple_assign_single_p (stmt);
+	}
 
       for (i = 1; i < gimple_num_ops (stmt); i++)
 	{