Fix for ia64 abort

[Bernd Schmidt <bernds at cambridge dot redhat dot com>]

This fixes the problem recently discovered by Richard Henderson.  The
motto for the ia64 scheduling code is "rotate early, rotate often" :-)

This also fixes the placement of nops around asm statements.

Bootstrapped on ia64-linux (libjava didn't build due to an apparently
unrelated problem).


Bernd

	* config/ia64/ia64.c (maybe_rotate): New function, broken out of
	ia64_sched_reorder.
	(ia64_sched_reorder): Call maybe_rotate; also rotate after
	scheduling a stop bit.
	(ia64_emit_nops): Correctly handle ASMs.

Index: gcc/config/ia64/ia64.c
===================================================================
RCS file: /cvs/gcc/egcs/gcc/config/ia64/ia64.c,v
retrieving revision 1.78
diff -u -p -r1.78 ia64.c
--- gcc/config/ia64/ia64.c	2001/03/01 14:25:30	1.78
+++ gcc/config/ia64/ia64.c	2001/03/15 10:47:04
@@ -5643,6 +5643,20 @@ schedule_stop (dump)
     dump_current_packet (dump);
 }

+/* If necessary, perform one or two rotations on the scheduling state.
+   This should only be called if we are starting a new cycle.  */
+
+static void
+maybe_rotate (dump)
+     FILE *dump;
+{
+  if (sched_data.cur == 6)
+    rotate_two_bundles (dump);
+  else if (sched_data.cur >= 3)
+    rotate_one_bundle (dump);
+  sched_data.first_slot = sched_data.cur;
+}
+
 /* We are about to being issuing insns for this clock cycle.
    Override the default sort algorithm to better slot instructions.  */

@@ -5666,13 +5680,7 @@ ia64_sched_reorder (dump, sched_verbose,
     }

   if (reorder_type == 0)
-    {
-      if (sched_data.cur == 6)
-	rotate_two_bundles (sched_verbose ? dump : NULL);
-      else if (sched_data.cur >= 3)
-	rotate_one_bundle (sched_verbose ? dump : NULL);
-      sched_data.first_slot = sched_data.cur;
-    }
+    maybe_rotate (sched_verbose ? dump : NULL);

   /* First, move all USEs, CLOBBERs and other crud out of the way.  */
   highest = ready[n_ready - 1];
@@ -5690,12 +5698,17 @@ ia64_sched_reorder (dump, sched_verbose,
 	      {
 		schedule_stop (sched_verbose ? dump : NULL);
 		sched_data.last_was_stop = 1;
+		maybe_rotate (sched_verbose ? dump : NULL);
+		if (dump)
+		  fprintf (dump, "// UNKNOWN insn; group barrier needed.\n");
 	      }
 	    else if (GET_CODE (PATTERN (insn)) == ASM_INPUT
 		     || asm_noperands (PATTERN (insn)) >= 0)
 	      {
 		/* It must be an asm of some kind.  */
 		cycle_end_fill_slots (sched_verbose ? dump : NULL);
+		if (dump)
+		  fprintf (dump, "// UNKNOWN (asm).\n");
 	      }
 	    return 1;
 	  }
@@ -5721,6 +5734,7 @@ ia64_sched_reorder (dump, sched_verbose,
 	{
 	  schedule_stop (sched_verbose ? dump : NULL);
 	  sched_data.last_was_stop = 1;
+	  maybe_rotate (sched_verbose ? dump : NULL);
 	  if (reorder_type == 1)
 	    return 0;
 	}
@@ -6075,6 +6089,17 @@ ia64_emit_nops ()
       if (b && INSN_P (insn))
 	{
 	  t = ia64_safe_type (insn);
+	  if (asm_noperands (PATTERN (insn)) >= 0
+	      || GET_CODE (PATTERN (insn)) == ASM_INPUT)
+	    {
+	      while (bundle_pos < 3)
+		{
+		  emit_insn_before (gen_nop_type (b->t[bundle_pos]), insn);
+		  bundle_pos++;
+		}
+	      continue;
+	    }
+
 	  if (t == TYPE_UNKNOWN)
 	    continue;
 	  while (bundle_pos < 3)