[pgpool-hackers: 4600] Re: Porting likely/unlikely

[Tatsuo Ishii]

> Long time ago PostgreSQL has started to use likely/unlikely macros,
> that give a hint to GNU C compiler.
> 
>     commit aa3ca5e3dd60bf0b992b74f955378f28e601292a
>     Author: Andres Freund <andres at anarazel.de>
>     Date:   Fri Oct 14 16:05:30 2016 -0700
> 
>     Add likely/unlikely() branch hint macros.
>     
>     These are useful for very hot code paths. Because it's easy to guess
>     wrongly about likelihood, and because such likelihoods change over time,
>     they should be used sparingly.
>     
>     Past tests have shown it'd be a good idea to use them in some places,
>     e.g. in error checks around ereports that ERROR out, but that's work for
>     later.
>     
>     Discussion: <20160727004333.r3e2k2y6fvk2ntup at alap3.anarazel.de>
> 
> I think these macros are not only useful to enhance performance (if
> correctly used) but make porting codes from PostgreSQL to pgpool
> easier since the macros occasionally used in the code. Attached is the
> patch to implement likely/unlikely in pgpool.

Patch pushed to master branch.

Best regards,
--
Tatsuo Ishii
SRA OSS K.K.
English: http://www.sraoss.co.jp/index_en/
Japanese:http://www.sraoss.co.jp