--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libgcc/floatunsisf.c	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,18 @@
+/* Public domain.  */
+typedef int SItype __attribute__ ((mode (SI)));
+typedef unsigned int USItype __attribute__ ((mode (SI)));
+typedef float SFtype __attribute__ ((mode (SF)));
+
+SFtype
+__floatunsisf (USItype u)
+{
+  SItype s = (SItype) u;
+  if (s < 0)
+    {
+      /* As in expand_float, compute (u & 1) | (u >> 1) to ensure
+	 correct rounding if a nonzero bit is shifted out.  */
+      return (SFtype) 2.0 * (SFtype) (SItype) ((u & 1) | (u >> 1));
+    }
+  else
+    return (SFtype) s;
+}