re PR middle-end/41360 (Revision 151696 breaks gcc.c-torture/compile/builtin_unreachable-1.c)

        PR middle-end/41360
        * cfgbuild.c (find_bb_boundaries): Re-instate 2009-09-02 barrier fix.

From-SVN: r151759

gcc/ChangeLog

+2009-09-16  Richard Henderson  <rth@redhat.com>
+
+	PR middle-end/41360
+	* cfgbuild.c (find_bb_boundaries): Re-instate 2009-09-02 barrier fix.
+
 2009-09-16  Jakub Jelinek  <jakub@redhat.com>
 
 	* integrate.c (set_block_abstract_flags): Call

gcc/cfgbuild.c

@@ -477,9 +477,17 @@ find_bb_boundaries (basic_block bb)
 	  if (code == CODE_LABEL && LABEL_ALT_ENTRY_P (insn))
 	    make_edge (ENTRY_BLOCK_PTR, bb, 0);
 	}
-
-      if (control_flow_insn_p (insn))
+      else if (code == BARRIER)
+	{
+	  /* __builtin_unreachable () may cause a barrier to be emitted in
+	     the middle of a BB.  We need to split it in the same manner as
+	     if the barrier were preceded by a control_flow_insn_p insn.  */
+	  if (!flow_transfer_insn)
+	    flow_transfer_insn = prev_nonnote_insn_bb (insn);
+	}
+      else if (control_flow_insn_p (insn))
 	flow_transfer_insn = insn;
+
       if (insn == end)
 	break;
       insn = NEXT_INSN (insn);