diff --git a/gcc/simplify-rtx.cc b/gcc/simplify-rtx.cc
index c7215cfad2a..36dd5227917 100644
--- a/gcc/simplify-rtx.cc
+++ b/gcc/simplify-rtx.cc
@@ -1305,7 +1305,7 @@ simplify_context::simplify_unary_operation_1 (rtx_code code, machine_mode mode,
 	  			   > GET_MODE_UNIT_SIZE (mode)
 	  			   ? FLOAT_TRUNCATE : FLOAT_EXTEND,
 				   mode,
-				   XEXP (op, 0), mode);
+				   XEXP (op, 0), GET_MODE (XEXP (op, 0)));
 
       /*  (float_truncate (float x)) is (float x)  */
       if ((GET_CODE (op) == FLOAT || GET_CODE (op) == UNSIGNED_FLOAT)
diff --git a/gcc/testsuite/gcc.target/i386/pr113656.c b/gcc/testsuite/gcc.target/i386/pr113656.c
new file mode 100644
index 00000000000..fa57a56bfc8
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr113656.c
@@ -0,0 +1,12 @@
+/* PR rtl-optimization/113656 */
+/* { dg-do compile } */
+/* { dg-options "-O3 -frounding-math -funsafe-math-optimizations -mavx512fp16 -mavx512vl" } */
+
+_Float16 a[8];
+
+void
+foo ()
+{
+  for (int i = 0; i < 8; i++)
+    a[i] = i - 8.4;
+}