From: Paul Eggert Date: Fri, 25 Oct 2019 00:30:44 +0000 (-0700) Subject: timespec-add, timespec-sub: simplify X-Git-Tag: v1.0~4618 X-Git-Url: https://gitweb.git.savannah.gnu.org/gitweb/?a=commitdiff_plain;h=06011ed74e978613422aca43c0bd92dc44213933;p=gnulib.git timespec-add, timespec-sub: simplify * lib/timespec-add.c (timespec_add): * lib/timespec-sub.c (timespec_sub): Simplify, now that INT_ADD_WRAPV and INT_SUBTRACT_WRAPV work on unsigned integers. --- diff --git a/ChangeLog b/ChangeLog index 804294150c..2469945b4a 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,11 @@ +2019-10-24 Paul Eggert + + timespec-add, timespec-sub: simplify + * lib/timespec-add.c (timespec_add): + * lib/timespec-sub.c (timespec_sub): + Simplify, now that INT_ADD_WRAPV and INT_SUBTRACT_WRAPV + work on unsigned integers. + 2019-10-23 Paul Eggert nstrftime: speed up integer overflow checking diff --git a/lib/timespec-add.c b/lib/timespec-add.c index e0a9f12e14..abee154820 100644 --- a/lib/timespec-add.c +++ b/lib/timespec-add.c @@ -33,36 +33,30 @@ timespec_add (struct timespec a, struct timespec b) int ns = a.tv_nsec + b.tv_nsec; int nsd = ns - TIMESPEC_HZ; int rns = ns; - time_t tmin = TYPE_MINIMUM (time_t); - time_t tmax = TYPE_MAXIMUM (time_t); if (0 <= nsd) { rns = nsd; - if (bs < tmax) - bs++; + time_t bs1; + if (!INT_ADD_WRAPV (bs, 1, &bs1)) + bs = bs1; else if (rs < 0) rs++; else goto high_overflow; } - /* INT_ADD_WRAPV is not appropriate since time_t might be unsigned. - In theory time_t might be narrower than int, so plain - INT_ADD_OVERFLOW does not suffice. */ - if (! INT_ADD_OVERFLOW (rs, bs) && tmin <= rs + bs && rs + bs <= tmax) - rs += bs; - else + if (INT_ADD_WRAPV (rs, bs, &rs)) { - if (rs < 0) + if (bs < 0) { - rs = tmin; + rs = TYPE_MINIMUM (time_t); rns = 0; } else { high_overflow: - rs = tmax; + rs = TYPE_MAXIMUM (time_t); rns = TIMESPEC_HZ - 1; } } diff --git a/lib/timespec-sub.c b/lib/timespec-sub.c index 48434e8150..77b9353df1 100644 --- a/lib/timespec-sub.c +++ b/lib/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; } }