fixed some build file flaws

lib/utl-rnd.c

@@ -0,0 +1,47 @@
+/*
+    Copyright (c) 2006-2020 Chung, Hyung-Hwan. All rights reserved.
+
+    Redistribution and use in source and binary forms, with or without
+    modification, are permitted provided that the following conditions
+    are met:
+    1. Redistributions of source code must retain the above copyright
+       notice, this list of conditions and the following disclaimer.
+    2. Redistributions in binary form must reproduce the above copyright
+       notice, this list of conditions and the following disclaimer in the
+       documentation and/or other materials provided with the distribution.
+
+    THIS SOFTWARE IS PROVIDED BY THE AUTHOR "AS IS" AND ANY EXPRESS OR
+    IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+    OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+    IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+    INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+    NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+    THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <hawk-utl.h>
+
+/* Park-Miller "minimal standard" 31 bit 
+ * pseudo-random number generator, implemented
+ * with David G. Carta's optimisation: with
+ * 32 bit math and without division.
+ */
+hawk_uint32_t hawk_rand31 (hawk_uint32_t seed)
+{
+	hawk_uint32_t hi, lo;
+
+	if (seed == 0) seed++;
+
+	lo = 16807 * (seed & 0xFFFF);
+	hi = 16807 * (seed >> 16);
+
+	lo += (hi & 0x7FFF) << 16;
+	lo += hi >> 15;
+
+	if (lo > 0x7FFFFFFFul) lo -= 0x7FFFFFFFul;
+
+	return lo;
+}