From: Jim Wilson <jimw@sifive.com>
To: "Maciej W. Rozycki" <macro@orcam.me.uk>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>,
GCC Development <gcc@gcc.gnu.org>,
syq@debian.org, "open list:MIPS" <linux-mips@vger.kernel.org>,
Matthew Fortune <mfortune@gmail.com>,
Binutils <binutils@sourceware.org>
Subject: Re: HELP: MIPS PC Relative Addressing
Date: Wed, 24 Feb 2021 13:46:28 -0800 [thread overview]
Message-ID: <CAFyWVaayq1ZVuwakdG6gAAKGf9hZTBFygVtgxnZGM39023t6TA@mail.gmail.com> (raw)
In-Reply-To: <alpine.DEB.2.21.2102241813420.1900@angie.orcam.me.uk>
On Wed, Feb 24, 2021 at 9:30 AM Maciej W. Rozycki <macro@orcam.me.uk> wrote:
> On Wed, 24 Feb 2021, Jiaxun Yang wrote:
>
> > For RISC-V, %pcrel_lo shall point to the label of corresponding
> %pcrel_hi,
> > like
> >
> > .LA0:
> > auipc a0, %pcrel_hi(sym)
> > addi a0, a0, %pcrel_lo(.LA0)
>
> I commented on it once, in the course of the FDPIC design project, and I
> find it broken by design. Sadly it has made it into the RISC-V psABI and
> it is hard to revert at this time, too many places have started relying on
> it.
>
It was already a production ABI before you asked for the change. And
changing a production ABI is extremely difficult. You were not the first
to complain about this, and you probably won't be the last.
Jim
next prev parent reply other threads:[~2021-02-24 21:46 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-24 14:18 Jiaxun Yang
2021-02-24 17:30 ` Maciej W. Rozycki
2021-02-24 21:46 ` Jim Wilson [this message]
2021-02-24 22:00 ` Maciej W. Rozycki
2021-02-25 0:55 ` Jiaxun Yang
2021-02-27 16:45 ` Maciej W. Rozycki
2021-02-24 21:40 ` Jim Wilson
2021-02-25 0:48 ` Jiaxun Yang
2021-02-25 2:57 ` Maciej W. Rozycki
2021-02-25 3:09 ` Jiaxun Yang
2021-02-25 22:30 ` Maciej W. Rozycki
2021-03-02 7:23 ` Jiaxun Yang
2021-03-02 15:30 ` Maciej W. Rozycki
2021-03-04 3:33 ` Jiaxun Yang
2021-03-04 16:54 ` Maciej W. Rozycki
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