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, 42 insertions, 7 deletions

diff --git a/gcc/regcprop.c b/gcc/regcprop.c
index ceb4635..4d6ea29 100644
--- a/gcc/regcprop.c
+++ b/gcc/regcprop.c
@@ -254,18 +254,27 @@ kill_clobbered_value (rtx x, const_rtx set, void *data)
     kill_value (x, vd);
 }
 
+/* A structure passed as data to kill_set_value through note_stores.  */
+struct kill_set_value_data
+{
+  struct value_data *vd;
+  rtx ignore_set_reg;
+};
+  
 /* Called through note_stores.  If X is set, not clobbered, kill its
    current value and install it as the root of its own value list.  */
 
 static void
 kill_set_value (rtx x, const_rtx set, void *data)
 {
-  struct value_data *const vd = (struct value_data *) data;
+  struct kill_set_value_data *ksvd = (struct kill_set_value_data *) data;
+  if (rtx_equal_p (x, ksvd->ignore_set_reg))
+    return;
   if (GET_CODE (set) != CLOBBER)
     {
-      kill_value (x, vd);
+      kill_value (x, ksvd->vd);
       if (REG_P (x))
-	set_value_regno (REGNO (x), GET_MODE (x), vd);
+	set_value_regno (REGNO (x), GET_MODE (x), ksvd->vd);
     }
 }
 
@@ -743,6 +752,7 @@ copyprop_hardreg_forward_1 (basic_block bb, struct value_data *vd)
       rtx set;
       bool replaced[MAX_RECOG_OPERANDS];
       bool changed = false;
+      struct kill_set_value_data ksvd;
 
       if (!NONDEBUG_INSN_P (insn))
 	{
@@ -976,14 +986,39 @@ copyprop_hardreg_forward_1 (basic_block bb, struct value_data *vd)
 	    note_uses (&PATTERN (insn), cprop_find_used_regs, vd);
 	}
 
+      ksvd.vd = vd;
+      ksvd.ignore_set_reg = NULL_RTX;
+
       /* Clobber call-clobbered registers.  */
       if (CALL_P (insn))
-	for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
-	  if (TEST_HARD_REG_BIT (regs_invalidated_by_call, i))
-	    kill_value_regno (i, 1, vd);
+	{
+	  int set_regno = INVALID_REGNUM;
+	  int set_nregs = 0;
+	  rtx exp;
+	  for (exp = CALL_INSN_FUNCTION_USAGE (insn); exp; exp = XEXP (exp, 1))
+	    {
+	      rtx x = XEXP (exp, 0);
+	      if (GET_CODE (x) == SET)
+		{
+		  rtx dest = SET_DEST (x);
+		  kill_value (dest, vd);
+		  set_value_regno (REGNO (dest), GET_MODE (dest), vd);
+		  copy_value (dest, SET_SRC (x), vd);
+		  ksvd.ignore_set_reg = dest;
+		  set_regno = REGNO (dest);
+		  set_nregs
+		    = hard_regno_nregs[set_regno][GET_MODE (dest)];
+		  break;
+		}
+	    }
+	  for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
+	    if (TEST_HARD_REG_BIT (regs_invalidated_by_call, i)
+		&& (i < set_regno || i >= set_regno + set_nregs))
+	      kill_value_regno (i, 1, vd);
+	}
 
       /* Notice stores.  */
-      note_stores (PATTERN (insn), kill_set_value, vd);
+      note_stores (PATTERN (insn), kill_set_value, &ksvd);
 
       /* Notice copies.  */
       if (set && REG_P (SET_DEST (set)) && REG_P (SET_SRC (set)))