diff options
Diffstat (limited to 'lib/timespec-sub.c')
| -rw-r--r-- | lib/timespec-sub.c | 30 |
1 files changed, 12 insertions, 18 deletions
diff --git a/lib/timespec-sub.c b/lib/timespec-sub.c index 3872f1bc2db..36747833e39 100644 --- a/lib/timespec-sub.c +++ b/lib/timespec-sub.c @@ -1,10 +1,10 @@ /* Subtract two struct timespec values. - Copyright (C) 2011-2017 Free Software Foundation, Inc. + Copyright (C) 2011-2022 Free Software Foundation, Inc. This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by - the Free Software Foundation; either version 3 of the License, or + the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, @@ -19,7 +19,7 @@ /* Return the difference between two timespec values A and B. On overflow, return an extremal value. This assumes 0 <= tv_nsec < - TIMESPEC_RESOLUTION. */ + TIMESPEC_HZ. */ #include <config.h> #include "timespec.h" @@ -33,37 +33,31 @@ 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_RESOLUTION; - if (bs < tmax) - bs++; + rns = ns + TIMESPEC_HZ; + 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; - rns = TIMESPEC_RESOLUTION - 1; + rs = TYPE_MAXIMUM (time_t); + rns = TIMESPEC_HZ - 1; } } |