Re: Performance improvements for src/port/snprintf.c

Andres Freund <andres@anarazel.de>

From: Andres Freund <andres@anarazel.de>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Alexander Kuzmenkov <a.kuzmenkov@postgrespro.ru>, pgsql-hackers@lists.postgresql.org
Date: 2018-09-27T01:46:45Z
Lists: pgsql-hackers
Hi,

On 2018-09-26 21:30:25 -0400, Tom Lane wrote:
> Here's a rebased version of <15785.1536776055@sss.pgh.pa.us>.
> 
> I think we should try to get this reviewed and committed before
> we worry more about the float business.  It would be silly to
> not be benchmarking any bigger changes against the low-hanging
> fruit here.

Yea, no arguments there.

I'll try to have a look tomorrow.

Greetings,

Andres Freund


Commits

  1. Improve snprintf.c's handling of NaN, Infinity, and minus zero.

  2. Rationalize snprintf.c's handling of "ll" formats.

  3. Provide fast path in snprintf.c for conversion specs that are just "%s".

  4. Make assorted performance improvements in snprintf.c.

  5. Set snprintf.c's maximum number of NL arguments to be 31.

  6. Always use our own versions of *printf().