> -----Original Message----- > From: Tom Lane [mailto:[EMAIL PROTECTED] > Sent: 16 May 2005 17:36 > To: Mark Cave-Ayland (External) > Cc: pgsql-hackers@postgresql.org > Subject: Re: [HACKERS] Cost of XLogInsert CRC calculations
(cut) > 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. Hi Tom, Thanks very much for showing that the unint64 slowdown was caused by the optimisation done by gcc - I've had a go at filing a bug with the gcc people at http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21617 so it would be interesting see if they can solve this. Perhaps like you suggest, the short term solution is to use the uint32 CRC64 code everywhere at the moment. I hope to find some time later this week to write and test some CRC32 routines, and will post the results back to the list. Many thanks, Mark. ------------------------ WebBased Ltd 17 Research Way Plymouth PL6 8BT T: +44 (0)1752 797131 F: +44 (0)1752 791023 W: http://www.webbased.co.uk ---------------------------(end of broadcast)--------------------------- TIP 7: don't forget to increase your free space map settings
