diff --git a/gcc/config/i386/i386-expand.cc b/gcc/config/i386/i386-expand.cc
index 39ee9b8662ad763384998c36274f36cba53c5fb0..a9f83a299e3a569b282759639d3ae07e8cc41b30 100644
--- a/gcc/config/i386/i386-expand.cc
+++ b/gcc/config/i386/i386-expand.cc
@@ -3095,6 +3095,8 @@ ix86_expand_int_compare (enum rtx_code code, rtx op0, rtx op1)
       && GET_MODE_SIZE (GET_MODE (SUBREG_REG (op0))) == 16)
     {
       tmp = SUBREG_REG (op0);
+      if (GET_MODE (tmp) == V8HFmode || GET_MODE (tmp) == V8BFmode)
+	tmp = gen_lowpart (V8HImode, tmp);
       tmp = gen_rtx_UNSPEC (CCZmode, gen_rtvec (2, tmp, tmp), UNSPEC_PTEST);
     }
   else
diff --git a/gcc/testsuite/gcc.target/i386/pr116921.c b/gcc/testsuite/gcc.target/i386/pr116921.c
new file mode 100644
index 0000000000000000000000000000000000000000..8cd4cf93b76d04ea0649e6f6870f77fda082280f
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr116921.c
@@ -0,0 +1,12 @@
+/* PR target/116921 */
+/* { dg-do compile { target int128 } } */
+/* { dg-options "-O2 -msse4" } */
+
+long x;
+_Float16 __attribute__((__vector_size__ (16))) f;
+
+void
+foo (void)
+{
+  x -= !(__int128) (f / 2);
+}