Make return in memory explicit.

        * function.c (aggregate_value_p): Check DECL_BY_REFERENCE.
        (assign_parm_find_data_types): Remove code for old front end
        invisible reference handling.
        (assign_parms): Handle DECL_BY_REFERENCE on the RESULT_DECL.
        (expand_function_end): Likewise.
        * gimplify.c (gimplify_return_expr): Handle a dereferenced
        RESULT_DECL.
        * tree-inline.c (copy_body_r): Don't bother looking for &* anymore.
        (declare_return_variable): Handle DECL_BY_REFERENCE.
        * cp/cp-gimplify.c (is_invisiref_parm): Also handle RESULT_DECL.
        (cp_genericize_r): Use convert_from_reference.
        Don't dereference a RESULT_DECL directly inside a RETURN_EXPR.
        (cp_genericize): Handle the RESULT_DECL.  Unset TREE_ADDRESSABLE.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@85675 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 26 insertions, 20 deletions

diff --git a/gcc/function.c b/gcc/function.c
index 699a009ee03..4de748aceb8 100644
--- a/gcc/function.c
+++ b/gcc/function.c
@@ -1883,6 +1883,11 @@ aggregate_value_p (tree exp, tree fntype)
 
   if (TREE_CODE (type) == VOID_TYPE)
     return 0;
+  /* If the front end has decided that this needs to be passed by
+     reference, do so.  */
+  if ((TREE_CODE (exp) == PARM_DECL || TREE_CODE (exp) == RESULT_DECL)
+      && DECL_BY_REFERENCE (exp))
+    return 1;
   if (targetm.calls.return_in_memory (type, fntype))
     return 1;
   /* Types that are TREE_ADDRESSABLE must be constructed in memory,
@@ -2187,15 +2192,6 @@ assign_parm_find_data_types (struct assign_parm_data_all *all, tree parm,
       data->passed_pointer = true;
       passed_mode = nominal_mode = Pmode;
     }
-  /* See if the frontend wants to pass this by invisible reference.  */
-  else if (passed_type != nominal_type
-	   && POINTER_TYPE_P (passed_type)
-	   && TREE_TYPE (passed_type) == nominal_type)
-    {
-      nominal_type = passed_type;
-      data->passed_pointer = 1;
-      passed_mode = nominal_mode = Pmode;
-    }
 
   /* Find mode as it is passed by the ABI.  */
   promoted_mode = passed_mode;
@@ -3095,9 +3091,14 @@ assign_parms (tree fndecl)
       rtx addr = DECL_RTL (all.function_result_decl);
       rtx x;
 
-      addr = convert_memory_address (Pmode, addr);
-      x = gen_rtx_MEM (DECL_MODE (result), addr);
-      set_mem_attributes (x, result, 1);
+      if (DECL_BY_REFERENCE (result))
+	x = addr;
+      else
+	{
+	  addr = convert_memory_address (Pmode, addr);
+	  x = gen_rtx_MEM (DECL_MODE (result), addr);
+	  set_mem_attributes (x, result, 1);
+	}
       SET_DECL_RTL (result, x);
     }
 
@@ -4385,17 +4386,22 @@ expand_function_end (void)
   if (current_function_returns_struct
       || current_function_returns_pcc_struct)
     {
-      rtx value_address
-	= XEXP (DECL_RTL (DECL_RESULT (current_function_decl)), 0);
+      rtx value_address = DECL_RTL (DECL_RESULT (current_function_decl));
       tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
+      rtx outgoing;
+
+      if (DECL_BY_REFERENCE (DECL_RESULT (current_function_decl)))
+	type = TREE_TYPE (type);
+      else
+	value_address = XEXP (value_address, 0);
+
 #ifdef FUNCTION_OUTGOING_VALUE
-      rtx outgoing
-	= FUNCTION_OUTGOING_VALUE (build_pointer_type (type),
-				   current_function_decl);
+      outgoing = FUNCTION_OUTGOING_VALUE (build_pointer_type (type),
+					  current_function_decl);
 #else
-      rtx outgoing
-	= FUNCTION_VALUE (build_pointer_type (type), current_function_decl);
-#endif
+      outgoing = FUNCTION_VALUE (build_pointer_type (type),
+				 current_function_decl);
+#endif 
 
       /* Mark this as a function return value so integrate will delete the
 	 assignment and USE below when inlining this function.  */