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| author | mjacob <mjacob@FreeBSD.org> | 2001-07-04 05:16:56 +0000 |
|---|---|---|
| committer | mjacob <mjacob@FreeBSD.org> | 2001-07-04 05:16:56 +0000 |
| commit | d506b2b2f1707872a011c76f0e6b0786f8c1c3be (patch) | |
| tree | 257b5a0157e2802e22856227886a7c12cfcfd5c0 /sys/alpha/include | |
| parent | fcd999f3208dbbbd35a679be613f90244a28dbba (diff) | |
| download | FreeBSD-src-d506b2b2f1707872a011c76f0e6b0786f8c1c3be.zip FreeBSD-src-d506b2b2f1707872a011c76f0e6b0786f8c1c3be.tar.gz | |
Follow Bruce's suggestions. They're probably wrong, but better than before.
Diffstat (limited to 'sys/alpha/include')
| -rw-r--r-- | sys/alpha/include/param.h | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/sys/alpha/include/param.h b/sys/alpha/include/param.h index 7c0f1af..0a0206e 100644 --- a/sys/alpha/include/param.h +++ b/sys/alpha/include/param.h @@ -157,9 +157,16 @@ #define ctob(x) ((x) << PAGE_SHIFT) #define btoc(x) (((x) + PAGE_MASK) >> PAGE_SHIFT) -/* bytes to disk blocks */ -#define btodb(x) ((x) >> DEV_BSHIFT) -#define dbtob(x) ((x) << DEV_BSHIFT) +/* + * btodb() is messy and perhaps slow because `bytes' may be an off_t. We + * want to shift an unsigned type to avoid sign extension and we don't + * want to widen `bytes' unnecessarily. Assume that the result fits in + * a daddr_t. + */ +#define btodb(bytes) /* calculates (bytes / DEV_BSIZE) */ \ + (daddr_t)((unsigned long)(bytes) >> DEV_BSHIFT) +#define dbtob(db) /* calculates (db * DEV_BSIZE) */ \ + ((off_t)(db) << DEV_BSHIFT) /* * Mach derived conversion macros |
