diff options
| -rw-r--r-- | include/bitutils.h | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/include/bitutils.h b/include/bitutils.h index 7e5b6eb..baa752b 100644 --- a/include/bitutils.h +++ b/include/bitutils.h @@ -36,15 +36,16 @@ * PPC bitmask field manipulation */ +/* Find left shift from first set bit in mask */ +#define MASK_TO_LSH(m) (__builtin_ffsl(m) - 1) + /* Extract field fname from val */ -#define GETFIELD(fname, val) \ - (((val) & fname##_MASK) >> fname##_LSH) +#define GETFIELD(m, v) (((v) & (m)) >> MASK_TO_LSH(m)) /* Set field fname of oval to fval * NOTE: oval isn't modified, the combined result is returned */ -#define SETFIELD(fname, oval, fval) \ - (((oval) & ~fname##_MASK) | \ - ((((typeof(oval))(fval)) << fname##_LSH) & fname##_MASK)) +#define SETFIELD(m, v, val) \ + (((v) & ~(m)) | ((((typeof(v))(val)) << MASK_TO_LSH(m)) & (m))) #endif /* __BITUTILS_H */ |