diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 980573ff3c6..9c59870638d 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2018-01-15  Richard Biener  <rguenther@suse.de>
+
+	PR middle-end/83850
+	* expmed.c (extract_bit_field_1): Fix typo.
+
 2018-01-15  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
 
 	PR target/83687
diff --git a/gcc/expmed.c b/gcc/expmed.c
index 35ce82bbb29..4c74e7dc2ea 100644
--- a/gcc/expmed.c
+++ b/gcc/expmed.c
@@ -1631,7 +1631,7 @@ extract_bit_field_1 (rtx str_rtx, poly_uint64 bitsize, poly_uint64 bitnum,
   if (VECTOR_MODE_P (GET_MODE (op0))
       && !MEM_P (op0)
       && VECTOR_MODE_P (tmode)
-      && known_eq (bitsize, GET_MODE_SIZE (tmode))
+      && known_eq (bitsize, GET_MODE_BITSIZE (tmode))
       && maybe_gt (GET_MODE_SIZE (GET_MODE (op0)), GET_MODE_SIZE (tmode)))
     {
       machine_mode new_mode = GET_MODE (op0);