macros: add proper BIT_MASK() macro

7 years ago · 538b3150a5
parent 736d7d74a0
commit 538b3150a5
1 changed files with 1 additions and 0 deletions
--- a/include/macros.h
+++ b/include/macros.h
@ -35,3 +35,4 @@
 #define BIT_SIZE(t) (CHAR_BIT * sizeof(t))
 #define BIT(n) (1 << (n))
 #define BITS(_start, _end) ((BIT(_end) - BIT(_start)) + BIT(_end))
+#define BIT_MASK(x, k) ((x) & ((1 << (k)) - 1))