re PR rtl-optimization/57422 (ICE: SIGSEGV in dominated_by_p with custom flags)

        PR rtl-optimization/57422
        * sel-sched.c (fill_vec_av_set): Assert that the fence insn
        can always be scheduled in its current form.

From-SVN: r206174

gcc/ChangeLog

 2013-12-23  Andrey Belevantsev  <abel@ispras.ru>
 
 	PR rtl-optimization/57422
+	* sel-sched.c (fill_vec_av_set): Assert that the fence insn
+	can always be scheduled in its current form.
+
+2013-12-23  Andrey Belevantsev  <abel@ispras.ru>
+
+	PR rtl-optimization/57422
 	* sel-sched.c (mark_unavailable_hard_regs): Fix typo when calling
 	add_to_hard_reg_set.
 

gcc/sel-sched.c

@@ -3801,6 +3801,7 @@ fill_vec_av_set (av_set_t av, blist_t bnds, fence_t fence,
       signed char target_available;
       bool is_orig_reg_p = true;
       int need_cycles, new_prio;
+      bool fence_insn_p = INSN_UID (insn) == INSN_UID (FENCE_INSN (fence));
 
       /* Don't allow any insns other than from SCHED_GROUP if we have one.  */
       if (FENCE_SCHED_NEXT (fence) && insn != FENCE_SCHED_NEXT (fence))
@@ -3855,9 +3856,16 @@ fill_vec_av_set (av_set_t av, blist_t bnds, fence_t fence,
           if (sched_verbose >= 4)
             sel_print ("Expr %d has no suitable target register\n",
                        INSN_UID (insn));
-          continue;
+
+	  /* A fence insn should not get here.  */
+	  gcc_assert (!fence_insn_p);
+	  continue;
         }
 
+      /* At this point a fence insn should always be available.  */
+      gcc_assert (!fence_insn_p
+		  || INSN_UID (FENCE_INSN (fence)) == INSN_UID (EXPR_INSN_RTX (expr)));
+
       /* Filter expressions that need to be renamed or speculated when
 	 pipelining, because compensating register copies or speculation
 	 checks are likely to be placed near the beginning of the loop,