Merge branch 'upstream' into dfsg-orig

[debian/gnuradio] / gr-pager / lib / pageri_util.cc

diff --git a/gr-pager/lib/pageri_util.cc b/gr-pager/lib/pageri_util.cc
new file mode 100644 (file)
index 0000000..bdd0957
--- /dev/null
+++ b/gr-pager/lib/pageri_util.cc
@@ -0,0 +1,46 @@
+/*
+ * Copyright 2006 Free Software Foundation, Inc.
+ * 
+ * This file is part of GNU Radio
+ * 
+ * GNU Radio is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3, or (at your option)
+ * any later version.
+ * 
+ * GNU Radio 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 General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with GNU Radio; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <pageri_util.h>
+
+unsigned char pageri_reverse_bits8(unsigned char val)
+{
+    // This method was attributed to Rich Schroeppel in the Programming 
+    // Hacks section of Beeler, M., Gosper, R. W., and Schroeppel, R. 
+    // HAKMEM. MIT AI Memo 239, Feb. 29, 1972.
+    //
+    // Reverses 8 bits in 5 machine operations with 64 bit arch
+    return (val * 0x0202020202ULL & 0x010884422010ULL) % 1023;
+}
+
+gr_int32 pageri_reverse_bits32(gr_int32 val)
+{
+    gr_int32 out = 0x00000000;
+    out |= (pageri_reverse_bits8((val >> 24) & 0x000000FF)      );
+    out |= (pageri_reverse_bits8((val >> 16) & 0x000000FF) <<  8);
+    out |= (pageri_reverse_bits8((val >>  8) & 0x000000FF) << 16);
+    out |= (pageri_reverse_bits8((val      ) & 0x000000FF) << 24);
+    return out;
+}