X-Git-Url: https://codewiz.org/gitweb?a=blobdiff_plain;f=bertos%2Fcfg%2Fmacros.h;h=6c9b63ef0001b0877a0086a162f83b312cc7f10d;hb=84d7581d4e99d656db0064086ecee8d9f30aeba3;hp=17f9c6768d92db83972074b7ed26ba479f1c5451;hpb=620a5af8d34e5e7e9fc902eb46537faa479411f4;p=bertos.git

diff --git a/bertos/cfg/macros.h b/bertos/cfg/macros.h
index 17f9c676..6c9b63ef 100644
--- a/bertos/cfg/macros.h
+++ b/bertos/cfg/macros.h
@@ -196,6 +196,42 @@
  */
 #define DIV_ROUNDUP(dividend, divisor)  (((dividend) + (divisor) - 1) / (divisor))
 
+
+/**
+ * Perform a multiply between the integer \a a and the float constant \a f.
+ *
+ * This macro can be used in order to avoid floating point arithmetics
+ * in expressions like this:
+ * \code
+ * int a, b;
+ * a = b * 0.5579652750;
+ * \endcode
+ *
+ * This macro rounds the floating point constant to a fraction,
+ * usign (2 ^ prec) as the denominator.
+ * For instance, with prec = 8, the constant 0.5579652750 will be rounded to:
+ * (143 / 256) = 0.55859375
+ * So, the former code will be transformed to:
+ * \code
+ * a = b * 143 / 256;
+ * \endcode
+ *
+ * Since the denominator is a power of 2, we rely on the compiler to optimize
+ * this to a right shift.
+ * So, when you have to multiply an integer by a float constant, this macro
+ * will not use the floating point arithmentics.
+ * The operation will be converted to a mul + shift, with a huge performance boost.
+ *
+ * \note \a f MUST be a constant in order gain performance benefits.
+ *
+ * \param a integer you want to multiply
+ * \param f floating point constant which you want to multply with \a a
+ * \param prec conversion precision, ranges from 1 to the number of bits in a long.
+ *             The higher, the better the approximation of the float constant will be.
+ */
+#define INT_MULT(a, f, prec) (((a) * (long)((f) * (1 << (prec)) + 0.5)) >> (prec))
+
+
 /** 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))
 
@@ -370,6 +406,41 @@ INLINE bool is_aligned(const void *addr, size_t size)
 	return ((size_t)addr & (size - 1)) == 0;
 }
 
+/**
+ * Convert one 32bit bcd numbert to int.
+ */
+#define BCD_TO_INT_32BIT(bcd)  \
+	((uint32_t )((bcd) & 0xf) * 1 +  \
+	(((bcd) >> 4) & 0xf)  * 10 +      \
+	(((bcd) >> 8) & 0xf)  * 100 +     \
+	(((bcd) >> 12) & 0xf) * 1000 +   \
+	(((bcd) >> 16) & 0xf) * 10000 +   \
+	(((bcd) >> 20) & 0xf) * 100000 +  \
+	(((bcd) >> 24) & 0xf) * 1000000 + \
+	(((bcd) >> 28) & 0xf) * 10000000) \
+
+/**
+ * Extract chunk of bit from gived array (uint32_t type).
+ * \param resp array of bit 32bit aligned
+ * \param start bit position in array
+ * \param size of bit chuck from start
+ * \return uint32_t chunk value.
+ */
+#define UNSTUFF_BITS(resp, start, size)                   \
+    ({                              \
+        const uint32_t __size = size;                \
+        const uint32_t __mask = (__size < 32 ? 1 << __size : 0) - 1; \
+        const uint32_t __off = 3 - ((start) / 32);           \
+        const uint32_t __shft = (start) & 31;            \
+        uint32_t __res;                      \
+                                    \
+        __res = resp[__off] >> __shft;              \
+        if (__size + __shft > 32)               \
+            __res |= resp[__off-1] << ((32 - __shft) % 32); \
+        __res & __mask;                     \
+    })
+
+
 /** \} */ //defgroup macros
 
 #endif /* MACROS_H */