Add a few or handy macros

include/ucore/utils.h

@@ -50,13 +50,60 @@
 typeof( ((type *)0)->member ) *__mptr = (ptr);    \
     (type *)( (void *)__mptr - offsetof(type, member) ); })
 
+/** Align a value.
+ * @param val value to align
+ * @param align alignment, must be power of 2
+ * @return the aligned val
+ */
 #define UC_ALIGN(val,align) (((val)+(align)-1UL)&~((align)-1UL))
 
+/**
+ * Test if x is a power of 2
+ * 
+ * @param x value
+ * @return 1 if x is a power of 20, 0 if it is not
+ */
+#define UC_IS_POW2(x) ((x) && !((x) & (x) - 1))
+
 /**
  *  * Expands @x and turns it into a string.
  *   */
 #define UC_STRINGIFY(x) UC_STRINGIFY_HLP(x)
 #define UC_STRINGIFY_HLP(x) #x
 
+/** 
+ * Macro for asserting code that should not be reached, 
+ * terminates the program if executed
+ */
+#define UC_NOT_REACED() abort()
+
+/**
+ * Round up X / y
+ * 
+ * @param x numerator, must be positive
+ * @param y denominator
+ * @return x/y rounded up 
+ */
+#define UC_DIV_ROUND_UP(x, y) (((x) + ((y) - 1))/(y))
+
+/**
+ * Round x down to nearest multiple of y
+ *
+ * @param x numerator, must be positive
+ * @param y denominator
+ * @return x rounded to nearest multiple of y
+ */
+#define UC_ROUND_UP(x, y) (((x) / (y)) * (y))
+
+/**
+ * Round x up to nearest multiple of y
+ *
+ * @param x numerator, must be positive
+ * @param y denominator
+ * @return x rounded to nearest multiple of y
+ */
+#define UC_ROUND_UP(x, y) (UC_DIV_ROUND_UP((x),(y)) * (y))
+
+
 #endif