Add REVERSE macro and its test unit.

[bertos.git] / bertos / cfg / macros.h

diff --git a/bertos/cfg/macros.h b/bertos/cfg/macros.h
index dda5fe0e635a023bfc1c3cb338b9d65d0a09ff8d..0dad9d393effcb3f44abfa7aa85264c342a27206 100644 (file)
--- a/bertos/cfg/macros.h
+++ b/bertos/cfg/macros.h
@@ -33,7 +33,7 @@
  * \brief Common and handy function macros
  *
  * \version $Id$
- * \author Bernardo Innocenti <bernie@develer.com>
+ * \author Bernie Innocenti <bernie@codewiz.org>
  * \author Giovanni Bajo <rasky@develer.com>
  */
 #ifndef CFG_MACROS_H
@@ -126,6 +126,19 @@
 
 #endif /* COMPILER_TYPEOF */
 
+/**
+ * Shuffle the content of \a array that counts \a len elements.
+ */
+#define SHUFFLE(array, len) \
+       do { \
+               int i, j; \
+               for (i = (len) - 1; i > 0; i--) \
+               { \
+                       j = ((i + 1) * (rand() / (RAND_MAX + 1.0))); \
+                       SWAP((array)[i], (array)[j]); \
+               } \
+       } while (0)
+
 /**
  * Macro to swap \a a with \a b, with explicit type \a T for dumb C89 compilers.
  *
@@ -141,6 +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. */
@@ -166,9 +185,6 @@
 /** Round up \a x to an even multiple of the 2's power \a pad. */
 #define ROUND_UP2(x, pad) (((x) + ((pad) - 1)) & ~((pad) - 1))
 
-/* OBSOLETE */
-#define ROUND2 ROUND_UP2
-
 /**
  * \name Integer round macros.
  *
@@ -263,11 +279,11 @@
 
        #define BIT_MASK_SINGLE__(use_bv, index, max, arg) \
                ((index < max) ? (PP_CAT(BIT_EXTRACT_FLAG_, use_bv) arg) : 0) \
-               /**/
+               /* */
 
        #define BIT_MASK_IF_SINGLE__(use_bv, index, max, arg) \
                (((index < max) && (BIT_EXTRACT_VALUE__ arg)) ? (PP_CAT(BIT_EXTRACT_FLAG_, use_bv) arg) : 0) \
-               /**/
+               /* */
 
        #define BIT_ITER__2(macro, use_bv, max, a0,a1,a2,a3,a4,a5,a6,a7,a8,a9,a10,a11,a12,a13,a14,a15, ...) \
                (macro(use_bv, 0, max, a0) | \
@@ -286,23 +302,23 @@
                macro(use_bv, 13, max, a13) | \
                macro(use_bv, 14, max, a14) | \
                macro(use_bv, 15, max, a15)) \
-               /**/
+               /* */
 
        #define BIT_ITER__(macro, use_bv, ...) \
                BIT_ITER__2(macro, use_bv, PP_COUNT(__VA_ARGS__), __VA_ARGS__, (0,1),(0,1),(0,1),(0,1),(0,1),(0,1),(0,1),(0,1),(0,1),(0,1),(0,1),(0,1),(0,1),(0,1),(0,1),(0,1)) \
-               /**/
+               /* */
 
        #define BIT_MASKS__(use_bv, ...) \
                BIT_ITER__(BIT_MASK_SINGLE__, use_bv, __VA_ARGS__)
-               /**/
+               /* */
 
        #define BIT_MASKS_CONDITIONAL__(use_bv, ...) \
                BIT_ITER__(BIT_MASK_IF_SINGLE__, use_bv, __VA_ARGS__)
-               /**/
+               /* */
 
        #define BIT_CHANGE__(reg, use_bv, ...) \
                ((reg) = ((reg) & ~BIT_MASKS__(use_bv, __VA_ARGS__)) | BIT_MASKS_CONDITIONAL__(use_bv, __VA_ARGS__)) \
-               /**/
+               /* */
 
        #define BIT_CHANGE(reg, ...)        BIT_CHANGE__(reg, 0, __VA_ARGS__)
        #define BIT_CHANGE_BV(reg, ...)     BIT_CHANGE__(reg, 1, __VA_ARGS__)