x

From-SVN: r13974

gcc/calls.c

@@ -1025,14 +1025,19 @@ expand_call (exp, target, ignore)
 #endif
 	  )
 	{
+	  /* If we're compiling a thunk, pass through invisible
+             references instead of making a copy.  */
+	  if (current_function_is_thunk
 #ifdef FUNCTION_ARG_CALLEE_COPIES
-	  if (FUNCTION_ARG_CALLEE_COPIES (args_so_far, TYPE_MODE (type), type,
-					  argpos < n_named_args)
-	      /* If it's in a register, we must make a copy of it too.  */
-	      /* ??? Is this a sufficient test?  Is there a better one? */
-	      && !(TREE_CODE (args[i].tree_value) == VAR_DECL
-		   && REG_P (DECL_RTL (args[i].tree_value)))
-	      && ! TREE_ADDRESSABLE (type))
+	      || (FUNCTION_ARG_CALLEE_COPIES (args_so_far, TYPE_MODE (type),
+					     type, argpos < n_named_args)
+		  /* If it's in a register, we must make a copy of it too.  */
+		  /* ??? Is this a sufficient test?  Is there a better one? */
+		  && !(TREE_CODE (args[i].tree_value) == VAR_DECL
+		       && REG_P (DECL_RTL (args[i].tree_value)))
+		  && ! TREE_ADDRESSABLE (type))
+#endif
+	      )
 	    {
 	      args[i].tree_value = build1 (ADDR_EXPR,
 					   build_pointer_type (type),
@@ -1040,7 +1045,6 @@ expand_call (exp, target, ignore)
 	      type = build_pointer_type (type);
 	    }
 	  else
-#endif
 	    {
 	      /* We make a copy of the object and pass the address to the
 		 function being called.  */

gcc/flags.h

@@ -392,3 +392,7 @@ extern int current_function_has_nonlocal_label;
    function.  */
 
 extern int current_function_has_nonlocal_goto;
+
+/* Nonzero if the current function is a thunk, so we should try to cut
+   corners where we can.  */
+int current_function_is_thunk;

gcc/function.c

@@ -132,6 +132,11 @@ int current_function_has_nonlocal_goto;
 
 int current_function_contains_functions;
 
+/* Nonzero if the current function is a thunk (a lightweight function that
+   just adjusts one of its arguments and forwards to another function), so
+   we should try to cut corners where we can.  */
+int current_function_is_thunk;
+
 /* Nonzero if function being compiled can call alloca,
    either as a subroutine or builtin.  */
 
@@ -489,6 +494,7 @@ push_function_context_to (context)
   p->has_nonlocal_label = current_function_has_nonlocal_label;
   p->has_nonlocal_goto = current_function_has_nonlocal_goto;
   p->contains_functions = current_function_contains_functions;
+  p->is_thunk = current_function_is_thunk;
   p->args_size = current_function_args_size;
   p->pretend_args_size = current_function_pretend_args_size;
   p->arg_offset_rtx = current_function_arg_offset_rtx;
@@ -568,6 +574,7 @@ pop_function_context_from (context)
   current_function_calls_alloca = p->calls_alloca;
   current_function_has_nonlocal_label = p->has_nonlocal_label;
   current_function_has_nonlocal_goto = p->has_nonlocal_goto;
+  current_function_is_thunk = p->is_thunk;
   current_function_args_size = p->args_size;
   current_function_pretend_args_size = p->pretend_args_size;
   current_function_arg_offset_rtx = p->arg_offset_rtx;
@@ -4971,6 +4978,7 @@ init_function_start (subr, filename, line)
   current_function_has_nonlocal_label = 0;
   current_function_has_nonlocal_goto = 0;
   current_function_contains_functions = 0;
+  current_function_is_thunk = 0;
 
   current_function_returns_pcc_struct = 0;
   current_function_returns_struct = 0;

gcc/function.h

@@ -78,6 +78,7 @@ struct function
   int has_nonlocal_label;
   int has_nonlocal_goto;
   int contains_functions;
+  int is_thunk;
   rtx nonlocal_goto_handler_slot;
   rtx nonlocal_goto_stack_level;
   tree nonlocal_labels;