macros: add mask() as a macro to calculate the bit mask

8 years ago · a22b59b2a8
parent fa49f634e4
commit a22b59b2a8
1 changed files with 1 additions and 0 deletions
--- a/include/macros.h
+++ b/include/macros.h
@ -21,6 +21,7 @@
 #define ROUND_DOWN(x, k) ((x) & ~((k) - 1))
 #define ROUND_UP(x, k) (((x) + (k) - 1) & ~((k) - 1))

+#define mask(x, k) ((x) & ((1 << (k)) - 1))
 #define align(x, k) ((x) & ~((1 << (k)) - 1))
 #define align_up(x, k) align(x + ((1 << (k)) - 1), k)
 #define is_aligned(x, k) (!((x) & ((1 << (k)) - 1)))