diff --git a/libf2c/libU77/system_clock_.c b/libf2c/libU77/system_clock_.c
new file mode 100644
index 0000000..d5cbaac
--- /dev/null
+++ b/libf2c/libU77/system_clock_.c
@@ -0,0 +1,64 @@
+/* Copyright (C) 1996 Free Software Foundation, Inc.
+This file is part of GNU Fortran libU77 library.
+
+This library is free software; you can redistribute it and/or modify it
+under the terms of the GNU Library General Public License as published
+by the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+GNU Fortran is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+Library General Public License for more details.
+
+You should have received a copy of the GNU Library General Public
+License along with GNU Fortran; see the file COPYING.LIB.  If
+not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+Boston, MA 02111-1307, USA.  */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+#if TIME_WITH_SYS_TIME
+# include <sys/time.h>
+# include <time.h>
+#else
+# if HAVE_SYS_TIME_H
+#  include <sys/time.h>
+# else
+#  include <time.h>
+# endif
+#endif
+#include <sys/times.h>
+#include <limits.h>
+#if HAVE_UNISTD_H
+#  include <unistd.h>
+#endif
+#include "f2c.h"
+
+#ifdef KR_headers
+int G77_system_clock_0 (count, count_rate, count_max)
+     integer *count, *count_rate, *count_max;
+#else
+int G77_system_clock_0 (integer *count, integer *count_rate, integer *count_max)
+#endif
+{
+  struct tms buffer;
+  unsigned long cnt;
+#ifdef _SC_CLK_TCK
+  *count_rate = sysconf(_SC_CLK_TCK);
+#elif defined CLOCKS_PER_SECOND
+  *count_rate = CLOCKS_PER_SECOND;
+#elif defined CLK_TCK
+  *count_rate = CLK_TCK;
+#else
+  #error Dont know clock tick length
+#endif
+  *count_max = INT_MAX;		/* dubious */
+  cnt = times (&buffer);
+  if (cnt > (unsigned long) (*count_max))
+    *count = *count_max;	/* also dubious */
+  else
+    *count = cnt;
+  return 0;
+}