diff options
Diffstat (limited to 'support/timespec-sub.c')
| -rw-r--r-- | support/timespec-sub.c | 20 |
1 files changed, 7 insertions, 13 deletions
diff --git a/support/timespec-sub.c b/support/timespec-sub.c index 0fe6517109..cf16ed7832 100644 --- a/support/timespec-sub.c +++ b/support/timespec-sub.c @@ -33,36 +33,30 @@ timespec_sub (struct timespec a, struct timespec b) time_t bs = b.tv_sec; int ns = a.tv_nsec - b.tv_nsec; int rns = ns; - time_t tmin = TYPE_MINIMUM (time_t); - time_t tmax = TYPE_MAXIMUM (time_t); if (ns < 0) { rns = ns + TIMESPEC_HZ; - if (bs < tmax) - bs++; + time_t bs1; + if (!INT_ADD_WRAPV (bs, 1, &bs1)) + bs = bs1; else if (- TYPE_SIGNED (time_t) < rs) rs--; else goto low_overflow; } - /* INT_SUBTRACT_WRAPV is not appropriate since time_t might be unsigned. - In theory time_t might be narrower than int, so plain - INT_SUBTRACT_OVERFLOW does not suffice. */ - if (! INT_SUBTRACT_OVERFLOW (rs, bs) && tmin <= rs - bs && rs - bs <= tmax) - rs -= bs; - else + if (INT_SUBTRACT_WRAPV (rs, bs, &rs)) { - if (rs < 0) + if (0 < bs) { low_overflow: - rs = tmin; + rs = TYPE_MINIMUM (time_t); rns = 0; } else { - rs = tmax; + rs = TYPE_MAXIMUM (time_t); rns = TIMESPEC_HZ - 1; } } |