Add REVERSE macro and its test unit.

git-svn-id: https://src.develer.com/svnoss/bertos/trunk@3042 38d2e660-2303-0410-9eaa-f027e97ec537

diff --git a/bertos/algo/reverse_test.c b/bertos/algo/reverse_test.c
new file mode 100644 (file)
index 0000000..5377e1d
--- /dev/null
+++ b/bertos/algo/reverse_test.c
@@ -0,0 +1,82 @@
+/**
+ * \file
+ * <!--
+ * This file is part of BeRTOS.
+ *
+ * Bertos 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 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * As a special exception, you may use this file as part of a free software
+ * library without restriction.  Specifically, if other files instantiate
+ * templates or use macros or inline functions from this file, or you compile
+ * this file and link it with other files to produce an executable, this
+ * file does not by itself cause the resulting executable to be covered by
+ * the GNU General Public License.  This exception does not however
+ * invalidate any other reasons why the executable file might be covered by
+ * the GNU General Public License.
+ *
+ * Copyright 2003,2004 Develer S.r.l. (http://www.develer.com/)
+ * Copyright 1999 Bernie Innocenti <bernie@codewiz.org>
+ *
+ * -->
+ *
+ * \brief REVERSE macro test.
+ *
+ * \version $Id$
+ * \author Francesco Sacchi <batt@develer.com>
+ */
+
+#include <cfg/macros.h>
+#include <cfg/debug.h>
+#include <cfg/test.h>
+
+
+int reverse_testSetup(void)
+{
+       kdbg_init();
+       return 0;
+}
+
+int reverse_testTearDown(void)
+{
+       return 0;
+}
+
+/**
+ * Naice reverse implementation.
+ */
+static uint8_t reverse(uint8_t b)
+{
+       uint8_t r = 0;
+
+       for (int i = 0; i < 8; i++)
+       {
+               r <<= 1;
+               r |= (b & BV(i)) ? 1 : 0;
+       }
+
+       return r;
+}
+
+int reverse_testRun(void)
+{
+       for (int i = 0; i < 256; i++)
+       {
+               kprintf("i [%02X], REVERSE(i) [%02X], reverse(i) [%02X]\n", i, REVERSE(i), reverse(i));
+               ASSERT(reverse(i) == REVERSE(i));
+       }
+       return  0;
+}
+
+TEST_MAIN(reverse);

diff --git a/bertos/cfg/macros.h b/bertos/cfg/macros.h
index 9e8139688402d4e64d51c6e5e6dacb8b96149235..0dad9d393effcb3f44abfa7aa85264c342a27206 100644 (file)
--- a/bertos/cfg/macros.h
+++ b/bertos/cfg/macros.h
@@ -154,6 +154,12 @@
                (b) = tmp; \
        } while (0)
 
+/**
+ * Reverse the bits contained in b (LSB becomes the MSB and so on).
+ * \note \a b is evaluated twice
+ */
+#define REVERSE(b) \
+       ((uint8_t)((((b) * 0x0802UL & 0x22110UL) | ((b) * 0x8020UL & 0x88440UL)) * 0x10101UL >> 16))
 
 #ifndef BV
        /** Convert a bit value to a binary flag. */