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, 13 insertions, 0 deletions

diff --git a/gcc/builtin-attrs.def b/gcc/builtin-attrs.def
index c3132cc..9eb5e71 100644
--- a/gcc/builtin-attrs.def
+++ b/gcc/builtin-attrs.def
@@ -59,6 +59,14 @@ DEF_ATTR_FOR_INT (5)
 DEF_ATTR_FOR_INT (6)
 #undef DEF_ATTR_FOR_INT
 
+/* Construct a tree for a given string and a list containing it.  */
+#define DEF_ATTR_FOR_STRING(ENUM, VALUE)					\
+  DEF_ATTR_STRING (ATTR_##ENUM, VALUE)			\
+  DEF_ATTR_TREE_LIST (ATTR_LIST_##ENUM, ATTR_NULL,	\
+		      ATTR_##ENUM, ATTR_NULL)
+DEF_ATTR_FOR_STRING (STR1, "1")
+#undef DEF_ATTR_FOR_STRING
+
 /* Construct a tree for a list of two integers.  */
 #define DEF_LIST_INT_INT(VALUE1, VALUE2)				 \
   DEF_ATTR_TREE_LIST (ATTR_LIST_##VALUE1##_##VALUE2, ATTR_NULL,		 \
@@ -84,6 +92,7 @@ DEF_ATTR_IDENT (ATTR_NONNULL, "nonnull")
 DEF_ATTR_IDENT (ATTR_NORETURN, "noreturn")
 DEF_ATTR_IDENT (ATTR_NOTHROW, "nothrow")
 DEF_ATTR_IDENT (ATTR_LEAF, "leaf")
+DEF_ATTR_IDENT (ATTR_FNSPEC, "fn spec")
 DEF_ATTR_IDENT (ATTR_PRINTF, "printf")
 DEF_ATTR_IDENT (ATTR_ASM_FPRINTF, "asm_fprintf")
 DEF_ATTR_IDENT (ATTR_GCC_DIAG, "gcc_diag")
@@ -170,6 +179,10 @@ DEF_ATTR_TREE_LIST (ATTR_NOTHROW_NONNULL_5, ATTR_NONNULL, ATTR_LIST_5, \
 /* Nothrow const functions whose pointer parameter(s) are all nonnull.  */
 DEF_ATTR_TREE_LIST (ATTR_CONST_NOTHROW_NONNULL, ATTR_CONST, ATTR_NULL, \
 			ATTR_NOTHROW_NONNULL)
+/* Nothrow leaf functions whose pointer parameter(s) are all nonnull,
+   and which return their first argument.  */
+DEF_ATTR_TREE_LIST (ATTR_RET1_NOTHROW_NONNULL_LEAF, ATTR_FNSPEC, ATTR_LIST_STR1, \
+			ATTR_NOTHROW_NONNULL_LEAF)
 /* Nothrow const leaf functions whose pointer parameter(s) are all nonnull.  */
 DEF_ATTR_TREE_LIST (ATTR_CONST_NOTHROW_NONNULL_LEAF, ATTR_CONST, ATTR_NULL, \
 			ATTR_NOTHROW_NONNULL_LEAF)