From: Florian Weimer via Libc-alpha <libc-alpha@sourceware.org>
To: "H.J. Lu" <hjl.tools@gmail.com>
Cc: "H.J. Lu via Libc-alpha" <libc-alpha@sourceware.org>
Subject: Re: [PATCH] Correct timespec implementation [BZ #26232]
Date: Tue, 14 Jul 2020 14:18:18 +0200 [thread overview]
Message-ID: <87sgdu8f3p.fsf@oldenburg2.str.redhat.com> (raw)
In-Reply-To: <CAMe9rOrv-k-2Y3BetUfNnM0Fu+2xoY4DUajtshPFAPB=sL0HVQ@mail.gmail.com> (H. J. Lu's message of "Tue, 14 Jul 2020 05:04:23 -0700")
* H. J. Lu:
> There are
>
> time_t
> support_timespec_ns (struct timespec time)
> {
> time_t time_ns;
> if (INT_MULTIPLY_WRAPV(time.tv_sec, TIMESPEC_HZ, &time_ns))
> return time.tv_sec < 0 ? TYPE_MINIMUM(time_t) : TYPE_MAXIMUM(time_t);
> if (INT_ADD_WRAPV(time_ns, time.tv_nsec, &time_ns))
> return time.tv_nsec < 0 ? TYPE_MINIMUM(time_t) : TYPE_MAXIMUM(time_t);
> return time_ns;
> }
>
> Even if support_timespec_ns is changed to return long long, we still
> may need to keep
>
> time_t time_ns;
>
> for
>
> if (INT_MULTIPLY_WRAPV(time.tv_sec, TIMESPEC_HZ, &time_ns))
>
> and
>
> if (INT_ADD_WRAPV(time_ns, time.tv_nsec, &time_ns))
>
> It looks odd to return long long here.
Why?
You can use the GCC built-ins for checked arithmetic, they support mixed
types.
Thanks,
Florian
next prev parent reply other threads:[~2020-07-14 12:18 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-06 14:48 [PATCH v2] Fix time/tst-cpuclock1 intermitent failures Lucas A. M. Magalhaes
2020-02-17 16:44 ` Lucas A. M. Magalhaes
2020-02-18 12:44 ` Adhemerval Zanella
2020-02-19 16:42 ` Lucas A. M. Magalhaes
2020-02-19 18:51 ` Adhemerval Zanella
2020-02-20 18:17 ` [PATCH v3] " Lucas A. M. Magalhaes
2020-03-04 19:24 ` Matheus Castanho
2020-03-06 17:31 ` Lucas A. M. Magalhaes
2020-03-10 16:20 ` [PATCH v4] " Lucas A. M. Magalhaes
2020-03-10 16:30 ` Andreas Schwab
2020-03-10 17:45 ` Carlos O'Donell via Libc-alpha
2020-03-23 17:20 ` [PATCH v5] " Lucas A. M. Magalhaes via Libc-alpha
2020-03-23 21:06 ` Carlos O'Donell via Libc-alpha
2020-03-24 19:42 ` Lucas A. M. Magalhaes via Libc-alpha
2020-03-31 18:55 ` Carlos O'Donell via Libc-alpha
2020-03-31 11:34 ` [PATCH v6] " Lucas A. M. Magalhaes via Libc-alpha
2020-03-31 19:02 ` Carlos O'Donell via Libc-alpha
2020-04-03 19:24 ` [PATCH v7] " Lucas A. M. Magalhaes via Libc-alpha
2020-04-03 20:48 ` Carlos O'Donell via Libc-alpha
2020-04-07 13:59 ` [PATCH v8] " Lucas A. M. Magalhaes via Libc-alpha
2020-04-21 17:44 ` [PATCH v9] " Lucas A. M. Magalhaes via Libc-alpha
2020-05-11 17:41 ` Lucas A. M. Magalhaes via Libc-alpha
2020-05-25 11:46 ` Lucas A. M. Magalhaes via Libc-alpha
2020-06-08 13:58 ` Lucas A. M. Magalhaes via Libc-alpha
2020-06-08 16:52 ` Carlos O'Donell via Libc-alpha
2020-06-12 15:28 ` [PATCH v10] " Lucas A. M. Magalhaes via Libc-alpha
2020-06-25 17:26 ` Lucas A. M. Magalhaes via Libc-alpha
2020-07-06 14:15 ` Lucas A. M. Magalhaes via Libc-alpha
2020-07-07 20:12 ` Carlos O'Donell via Libc-alpha
2020-07-10 23:07 ` Tulio Magno Quites Machado Filho
2020-07-11 14:45 ` H.J. Lu via Libc-alpha
2020-07-11 16:31 ` H.J. Lu via Libc-alpha
2020-07-13 23:30 ` [PATCH] Correct timespec implementation [BZ #26232] H.J. Lu via Libc-alpha
2020-07-14 2:35 ` Carlos O'Donell via Libc-alpha
2020-07-14 11:16 ` Florian Weimer via Libc-alpha
2020-07-14 11:42 ` H.J. Lu via Libc-alpha
2020-07-14 12:04 ` H.J. Lu via Libc-alpha
2020-07-14 12:18 ` Florian Weimer via Libc-alpha [this message]
2020-07-14 13:12 ` H.J. Lu via Libc-alpha
2020-07-14 13:14 ` Florian Weimer via Libc-alpha
2020-07-14 13:17 ` H.J. Lu via Libc-alpha
2020-07-15 19:38 ` Paul Eggert
2020-07-15 19:44 ` H.J. Lu via Libc-alpha
2020-07-14 13:08 ` Lucas A. M. Magalhaes via Libc-alpha
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