combine.c (distribute_notes): Don't delete sets to global register variables.

2004-06-24  Eric Christopher  <echristo@redhat.com>

	* combine.c (distribute_notes): Don't delete sets to
	global register variables.

From-SVN: r83606

gcc/ChangeLog

+2004-06-24  Eric Christopher  <echristo@redhat.com>
+
+	* combine.c (distribute_notes): Don't delete sets to
+	global register variables.
+
 2004-06-24  Jakub Jelinek  <jakub@redhat.com>
 
 	* config/i386/i386.md (ffsdi2, clzdi2): New expanders.

gcc/combine.c

@@ -11821,8 +11821,10 @@ distribute_notes (rtx notes, rtx from_insn, rtx i3, rtx i2)
 
 		  /* If the register is being set at TEM, see if that is all
 		     TEM is doing.  If so, delete TEM.  Otherwise, make this
-		     into a REG_UNUSED note instead.  */
-		  if (reg_set_p (XEXP (note, 0), PATTERN (tem)))
+		     into a REG_UNUSED note instead. Don't delete sets to
+		     global register vars.  */
+		  if (reg_set_p (XEXP (note, 0), PATTERN (tem))
+		      && !global_regs [REGNO(XEXP (note, 0))])
 		    {
 		      rtx set = single_set (tem);
 		      rtx inner_dest = 0;