attribs.c (decl_attributes): Avoid emitting a warning if ATTR_FLAG_BUILT_IN.

	* attribs.c (decl_attributes): Avoid emitting a warning if
	ATTR_FLAG_BUILT_IN.
	* doc/rtl.texi (CALL_INSN_FUNCTION_USAGE): Use lowercase for rtx
	codes.  Document meaning of sets inside CALL_INSN_FUNCTION_USAGE.
	* c-family/c-common.c (DEF_ATTR_STRING): Define and undefine as
	necessary.
	* builtin-attrs.def (DEF_ATTR_FOR_STRING): Define.  Use it to
	define a string "1".
	(ATTR_RET1_NOTHROW_NONNULL_LEAF): New attr definition.
	* builtins.def (BUILT_IN_MEMCPY, BUILT_IN_MEMMOVE, BUILT_IN_MEMSET,
	BUILT_IN_STRCPY): Use it for these functions.
	* postreload.c (reload_combine): Deal with SETs inside
	CALL_INSN_FUNCTION_USAGE.
	* caller-save.c (setup_save_areas, save_call_clobbered_regs):
	Look for REG_RETURNED notes and use a cheap restore if possible.
	* ira-int.h (struct ira_allocno): New member cheap_calls_crossed_num.
	(ALLOCNO_CHEAP_CALLS_CROSSED_NUM): New macro.
	* ira-build.c (ira_create_allocno, create_cap_allocno,
	propagate_allocno_info, propagate_some_info_from_allocno,
	copy_info_to_removed_store_destination, ira_flattening): Handle it.
	* ira-lives.c (pseudo_regno_single_word_and_live_p,
	find_call_crossed_cheap_reg): New static functions.
	(process_bb_node_lives): Look for SETs in CALL_INSN_FUNCTION_USAGE,
	and set ALLOCNO_CHEAP_CALLS_CROSSED_NUM if possible.  Also make
	a REG_RETURNED note in that case.
	* ira.c (setup_reg_renumber): Change assert to allow cases where
	allocnos only cross calls for which they are cheap to restore.
	* ira-costs.c (ira_tune_allocno_costs): Compare
	ALLOCNO_CALLS_CROSSED_NUM to ALLOCNO_CHEAP_CALLS_CROSSED_NUM rather
	than 0.
	* reg-notes.def (REG_RETURNED): New note.
	* cse.c (cse_insn): Likewise.
	* sched-deps.c (sched_analyze_insn): Likewise.
	* expr.c (init_block_move_fn): Set a "fn spec" attribute.
	* calls.c (decl_return_flags): New static function.
	(expand_call): Generate a SET in CALL_INSN_FUNCTION_USAGE for
	functions that return one of their arguments.
	* lto/lto-lang.c (handle_fnspec_attribute): New static function.
	(lto_attribute_table): Add "fn spec".
	(DEF_ATTR_STRING): Define and undefine along with the other macros.
	* regcprop.c (struct kill_set_value_data): New.
	(kill_set_value): Interpret data as a pointer to such a struct.
	Do nothing if the caller wants the register to be ignored.
	(copyprop_hardreg_forward_1): Handle SETs in CALL_INSN_FUNCTION_USAGE.

testsuite/
	* gcc.target/i386/retarg.c: New test.

From-SVN: r187459

1 files changed, 7 insertions, 5 deletions

diff --git a/gcc/expr.c b/gcc/expr.c
index 3edb4a2..0d52725 100644
--- a/gcc/expr.c
+++ b/gcc/expr.c
@@ -1386,7 +1386,7 @@ init_block_move_fn (const char *asmspec)
 {
   if (!block_move_fn)
     {
-      tree args, fn;
+      tree args, fn, attrs, attr_args;
 
       fn = get_identifier ("memcpy");
       args = build_function_type_list (ptr_type_node, ptr_type_node,
@@ -1401,6 +1401,11 @@ init_block_move_fn (const char *asmspec)
       DECL_VISIBILITY (fn) = VISIBILITY_DEFAULT;
       DECL_VISIBILITY_SPECIFIED (fn) = 1;
 
+      attr_args = build_tree_list (NULL_TREE, build_string (1, "1"));
+      attrs = tree_cons (get_identifier ("fn spec"), attr_args, NULL);
+
+      decl_attributes (&fn, attrs, ATTR_FLAG_BUILT_IN);
+
       block_move_fn = fn;
     }
 
@@ -8190,10 +8195,7 @@ expand_expr_real_2 (sepops ops, rtx target, enum machine_mode tmode,
 	      || DECL_RTL (treeop1) == stack_pointer_rtx
 	      || DECL_RTL (treeop1) == arg_pointer_rtx))
 	{
-	  tree t = treeop1;
-
-	  treeop1 = TREE_OPERAND (treeop0, 0);
-	  TREE_OPERAND (treeop0, 0) = t;
+	  gcc_unreachable ();
 	}
 
       /* If the result is to be ptr_mode and we are adding an integer to