diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index a325a19a993..51f92bcf0b0 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+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
diff --git a/gcc/cfgexpand.c b/gcc/cfgexpand.c
index 72fd8fd5a76..2ee6fbac2e3 100644
--- a/gcc/cfgexpand.c
+++ b/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))
 	      {