Re: Cost of XLogInsert CRC calculations

From: Kris Jurka <books(at)ejurka(dot)com>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: Mark Cave-Ayland <m(dot)cave-ayland(at)webbased(dot)co(dot)uk>, pgsql-hackers(at)postgresql(dot)org
Subject: Re: Cost of XLogInsert CRC calculations
Date: 2005-05-17 17:15:25
Message-ID: Pine.BSO.4.56.0505171159480.20628@leary.csoft.net
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On Mon, 16 May 2005, Tom Lane wrote:

> I did some experimentation and concluded that gcc is screwing up
> big-time on optimizing the CRC64 code for 32-bit Intel. It does much
> better on every other architecture though.
>
> Anyone want to try it with non-gcc compilers?

Solaris 9 x86 - Sun Workshop 6 update 2 C 5.3, gcc 3.2.3

gcc -O1 crctest.c .251422
gcc -O3 crctest.c .240223
gcc -O1 crctest64.c .281369
gcc -O3 crctest64.c .631290

cc -O crctest.c .268905
cc -fast crctest.c .242429
cc -O crctest64.c .283278
cc -fast crctest64.c .255560

Kris Jurka

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