combine.c (try_combine): Trying to check the missed case 3->2 combining…

combine.c (try_combine): Trying to check the missed case 3->2 combining (combining with splitting) in...

	* combine.c (try_combine) [HAVE_cc0]: Trying to check the missed
	case 3->2 combining (combining with splitting) in which 2 is CC0
	setter/user and 3 is user. The rest of cases 2->1 and 3->2 are
	checked at the begining of the function with the aid of calling
	function 'can_combine_p'.

From-SVN: r31727

gcc/ChangeLog

+2000-01-31  Chandra Chavva <cchavva@cygnus.com>
+
+	* combine.c (try_combine) [HAVE_cc0]: Trying to check the missed
+	case 3->2 combining (combining with splitting) in which 2 is CC0
+	setter/user and 3 is user. The rest of cases 2->1 and 3->2 are 
+	checked at the begining of the function with the aid of calling 
+	function 'can_combine_p'. 
+
 2000-01-31  Dave Brolley  <brolley@redhat.com>
 
 	* cccp.c (struct argdata): Redeclare 'newlines' field as 'int'.

gcc/combine.c

@@ -2391,6 +2391,18 @@ try_combine (i3, i2, i1)
       distribute_notes (new_other_notes, undobuf.other_insn,
 			undobuf.other_insn, NULL_RTX, NULL_RTX, NULL_RTX);
     }
+#ifdef HAVE_cc0
+  /* If I2 is the setter CC0 and I3 is the user CC0 then check whether 
+     they are adjacent to each other or not. */
+  {
+    rtx p = prev_nonnote_insn (i3);
+    if (p && p != i2 && GET_CODE (p) == INSN && newi2pat && sets_cc0_p (newi2pat))
+      {
+        undo_all ();
+        return 0;
+      }
+    }
+#endif 
 
   /* We now know that we can do this combination.  Merge the insns and 
      update the status of registers and LOG_LINKS.  */