re PR debug/83694 (New test case gcc.dg/pr83666.c from r256232 ICEs)

	PR middle-end/83694
	* cfgexpand.c (expand_debug_expr): Punt if mode1 is VOIDmode
	and bitsize might be greater than MAX_BITSIZE_MODE_ANY_INT.

From-SVN: r256307

gcc/ChangeLog

+2018-01-06  Jakub Jelinek  <jakub@redhat.com>
+
+	PR middle-end/83694
+	* cfgexpand.c (expand_debug_expr): Punt if mode1 is VOIDmode
+	and bitsize might be greater than MAX_BITSIZE_MODE_ANY_INT.
+
 2018-01-05  Jakub Jelinek  <jakub@redhat.com>
 
 	PR target/83604

gcc/cfgexpand.c

@@ -4534,8 +4534,12 @@ expand_debug_expr (tree exp)
 	if (MEM_P (op0))
 	  {
 	    if (mode1 == VOIDmode)
-	      /* Bitfield.  */
-	      mode1 = smallest_int_mode_for_size (bitsize);
+	      {
+		if (maybe_gt (bitsize, MAX_BITSIZE_MODE_ANY_INT))
+		  return NULL;
+		/* Bitfield.  */
+		mode1 = smallest_int_mode_for_size (bitsize);
+	      }
 	    poly_int64 bytepos = bits_to_bytes_round_down (bitpos);
 	    if (maybe_ne (bytepos, 0))
 	      {