diff options
| -rw-r--r-- | newlib/libc/include/sys/time.h | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/newlib/libc/include/sys/time.h b/newlib/libc/include/sys/time.h index e5023ae64..5182dc14e 100644 --- a/newlib/libc/include/sys/time.h +++ b/newlib/libc/include/sys/time.h @@ -171,6 +171,10 @@ sbttobt(sbintime_t _sbt) * Decimal<->sbt conversions. Multiplying or dividing by SBT_1NS results in * large roundoff errors which sbttons() and nstosbt() avoid. Millisecond and * microsecond functions are also provided for completeness. + * + * These functions return the smallest sbt larger or equal to the number of + * seconds requested so that sbttoX(Xtosbt(y)) == y. The 1 << 32 - 1 term added + * transforms the >> 32 from floor() to ceil(). */ static __inline int64_t sbttons(sbintime_t _sbt) @@ -183,7 +187,7 @@ static __inline sbintime_t nstosbt(int64_t _ns) { - return ((_ns * (((uint64_t)1 << 63) / 500000000)) >> 32); + return ((_ns * (((uint64_t)1 << 63) / 500000000) + (1ull << 32) - 1) >> 32); } static __inline int64_t @@ -197,7 +201,7 @@ static __inline sbintime_t ustosbt(int64_t _us) { - return ((_us * (((uint64_t)1 << 63) / 500000)) >> 32); + return ((_us * (((uint64_t)1 << 63) / 500000) + (1ull << 32) - 1) >> 32); } static __inline int64_t @@ -211,7 +215,7 @@ static __inline sbintime_t mstosbt(int64_t _ms) { - return ((_ms * (((uint64_t)1 << 63) / 500)) >> 32); + return ((_ms * (((uint64_t)1 << 63) / 500) + (1ull << 32) - 1) >> 32); } /*- |