-#define container_of(ptr, type, member) \
- ((type *) ((char *) (ptr) - offset_of(type, member)))
+#define firm_container_of(ptr, type, member) \
+ ((type *) ((char *) (ptr) - offsetof(type, member)))
+
+/**
+ * Returns size of a static array. Warning: This returns invalid values for
+ * dynamically allocated arrays.
+ *
+ * @param a static array
+ */
+#define ARRAY_SIZE(a) (sizeof(a)/sizeof((a)[0]))
+
+#undef MIN
+#undef MAX
+#define MAX(x, y) ((x) > (y) ? (x) : (y))
+#define MIN(x, y) ((x) < (y) ? (x) : (y))
+
+/**
+ * Three valued compare as demanded by e.g. qsort(3)
+ * @param c A number.
+ * @param d Another number.
+ * @return 0 if c == d, -1 if c < d, 1 if c > d.
+ */
+#define QSORT_CMP(c, d) (((c) > (d)) - ((c) < (d)))
+
+/**
+ * convert an integer into pointer
+ */
+#define INT_TO_PTR(v) ((void *)((char *)0 + (v)))