rl78.c (rl78_note_reg_set): fixed dead reg check for non-QImode registers

2018-01-12  Sebastian Perta  <sebastian.perta@renesas.com>
	
	* config/rl78/rl78.c (rl78_note_reg_set): fixed dead reg check 
	for non-QImode registers

From-SVN: r256945

gcc/ChangeLog

+2018-01-22  Sebastian Perta  <sebastian.perta@renesas.com>
+	
+	* config/rl78/rl78.c (rl78_note_reg_set): fixed dead reg check 
+	for non-QImode registers
+
 2018-01-22  Richard Biener  <rguenther@suse.de>
 
 	PR tree-optimization/83963

gcc/config/rl78/rl78.c

@@ -3792,16 +3792,21 @@ static void
 rl78_note_reg_set (char *dead, rtx d, rtx insn)
 {
   int r, i;
-
+  bool is_dead;
   if (GET_CODE (d) == MEM)
     rl78_note_reg_uses (dead, XEXP (d, 0), insn);
 
   if (GET_CODE (d) != REG)
     return;
 
+  /* Do not mark the reg unused unless all QImode parts of it are dead.  */
   r = REGNO (d);
-  if (dead [r])
-    add_reg_note (insn, REG_UNUSED, gen_rtx_REG (GET_MODE (d), r));
+  is_dead = true;
+  for (i = 0; i < GET_MODE_SIZE (GET_MODE (d)); i ++)
+	  if (!dead [r + i])
+		  is_dead = false;
+  if(is_dead)
+	add_reg_note (insn, REG_UNUSED, gen_rtx_REG (GET_MODE (d), r));
   if (dump_file)
     fprintf (dump_file, "note set reg %d size %d\n", r, GET_MODE_SIZE (GET_MODE (d)));
   for (i = 0; i < GET_MODE_SIZE (GET_MODE (d)); i ++)