From: Tom Lane <tgl@sss.pgh.pa.us>
To: YunQiang Su <wzssyqa@gmail.com>
Cc: pgsql-bugs@lists.postgresql.org
Subject: Re: BUG #15844: MIPS: remove .set mips2 in s_lock.h to fix r6 build
Date: Sun, 16 Jun 2019 12:16:53 -0400
Message-ID: <22615.1560701813@sss.pgh.pa.us> (raw)
In-Reply-To: <CAKcpw6XYkD9Ku-0Fw6VZ6=wR030c5xCBOnTGsjLzFqdffkM8dw@mail.gmail.com>
References: <15844-8f62fe7e163939b3@postgresql.org>
<15052.1560455595@sss.pgh.pa.us>
<CAKcpw6W2WBdTVnJSeV845V78bwOPDjhROfteX7D2o0TTU2_opA@mail.gmail.com>
<23287.1560655935@sss.pgh.pa.us>
<CAKcpw6W8Y56cxKJna6EsA+j2ZQ1p6DeXwMJFOOjb=baPigbV+Q@mail.gmail.com>
<25321.1560659282@sss.pgh.pa.us>
<CAKcpw6XYkD9Ku-0Fw6VZ6=wR030c5xCBOnTGsjLzFqdffkM8dw@mail.gmail.com>
YunQiang Su <wzssyqa@gmail.com> writes:
> Tom Lane <tgl@sss.pgh.pa.us> 于2019年6月16日周日 下午12:28写道：
>> I found that specifying -march=mips2 gets it to accept the s_lock.h
>> code without ".set mips2". Given that we don't make any pretense of
>> actually running on MIPS-I hardware, I wonder if some hack involving
>> forcing -march would be sane? You'd get better code quality across
>> the board, presumably.
> -march is not a good idea, since r6 cannot compatible with the previous version.
> If you use -march=mips2 or something else, it will failed to build for r6.
> Which -march to use should be determined by finial user or distribution vendor.
Sure, the trick would be to not override a (default or specified)
architecture setting that's higher than mips2. I was imagining
using AC_EGREP_CPP() to see if __mips expands to exactly 1. But
on reflection, probably a better idea is to just see if asm with
ll/sc/sync compiles, and add -march=mips2 if not.
(We should not do anything if --disable-spinlocks has been specified,
btw, since then we don't need those asm commands to work. This is
and would remain the workaround for building PG for MIPS-I, if some
benighted soul insists on doing that.)
>> (BTW, have you got any recommendations for booting recent Debian/MIPS
>> under qemu? I can't get anything newer than wheezy to work.)
> I have an r6 one:
> http://mips64el.bfsu.edu.cn/debian-new/tarball/qemu/
> It is buster.
Thanks for the pointer.
regards, tom lane
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-bugs@postgresql.org
Cc: tgl@sss.pgh.pa.us, wzssyqa@gmail.com, pgsql-bugs@lists.postgresql.org
Subject: Re: BUG #15844: MIPS: remove .set mips2 in s_lock.h to fix r6 build
In-Reply-To: <22615.1560701813@sss.pgh.pa.us>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox