Fix misscheduling of epilogue predicate register restore.

	* config/ia64/ia64.c (rtx_needs_barrier, case UNSPEC): Move case 6...
	(rtx_needs_barrier, case UNSPEC_VOLATILE): to here.
	* config/ia64/ia64.md (pr_restore): Change UNSPEC to UNSPEC_VOLATILE.

From-SVN: r32714

gcc/ChangeLog

+Thu Mar 23 11:34:39 2000  Jim Wilson  <wilson@cygnus.com>
+
+	* config/ia64/ia64.c (rtx_needs_barrier, case UNSPEC): Move case 6...
+	(rtx_needs_barrier, case UNSPEC_VOLATILE): to here.
+	* config/ia64/ia64.md (pr_restore): Change UNSPEC to UNSPEC_VOLATILE.
+
 Thu Mar 23 16:04:40 2000  Andrew Haley  <aph@cygnus.com>
 
         * config/mips/mips.md (movdf_internal1a): Delete (set 'f', 'F')

gcc/config/ia64/ia64.c

@@ -2421,16 +2421,7 @@ rtx_needs_barrier (x, flags, pred)
 	    need_barrier |= rws_access_reg (i, flags, pred);
 	  break;
 
-	case 6: /* mov pr= */
-	  /* This writes all predicate registers.  */
-	  new_flags.is_write = 1;
-	  /* We need to skip by two, because rws_access_reg always writes
-	     to two predicate registers at a time.  */
-	  /* ??? Strictly speaking, we shouldn't be counting writes to pr0.  */
-	  for (i = PR_REG (0); i < PR_REG (64); i += 2)
-	    need_barrier |= rws_access_reg (i, new_flags, pred);
-	  break;
-
+	case 6:
 	case 7:
 	  abort ();
 
@@ -2486,6 +2477,16 @@ rtx_needs_barrier (x, flags, pred)
 	  need_barrier = rws_access_reg (REG_AR_PFS, new_flags, pred);
 	  break;
 
+	case 6: /* mov pr= */
+	  /* This writes all predicate registers.  */
+	  new_flags.is_write = 1;
+	  /* We need to skip by two, because rws_access_reg always writes
+	     to two predicate registers at a time.  */
+	  /* ??? Strictly speaking, we shouldn't be counting writes to pr0.  */
+	  for (i = PR_REG (0); i < PR_REG (64); i += 2)
+	    need_barrier |= rws_access_reg (i, new_flags, pred);
+	  break;
+
 	default:
 	  abort ();
 	}

gcc/config/ia64/ia64.md

@@ -3049,8 +3049,11 @@
   "mov %0 = pr"
   [(set_attr "type" "I")])
 
+;; ??? This is volatile to prevent it from being moved before a conditional
+;; expression that calculates the return value.
+
 (define_insn "pr_restore"
-  [(unspec [(const_int 0)] 6)
+  [(unspec_volatile [(const_int 0)] 6)
    (use (match_operand:DI 0 "register_operand" "r"))]
   ""
   "mov pr = %0, -1"