Re: pgsql: Improve performance of SendRowDescriptionMessage.

On Thu, Oct 12, 2017 at 04:08:44PM -0700, Andres Freund wrote:
> So we've two animals (hornet, sungazer) that are:
> #define SIZEOF_SIZE_T 8
> #define WORDS_BIGENDIAN 1
> #define restrict __restrict
>
> one compiled with xlc that fails and one with gcc that succeeds. I'm
> hesitant to reach for that, but I wonder if there's a compiler
> bug. Alternatively there could be some undefined behaviour here that
> only triggers on xlc 64bit, but I'm not quite seeing it.
>
> Noah, any chance you could force restrict to off on that animal?

I can confirm it allows "make check" to pass. Specifically, I did this
against commit 91d5f1a:

--- src/include/pg_config.h~ 2017-10-12 18:11:33.000000000 -0700
+++ src/include/pg_config.h 2017-10-12 18:22:34.000000000 -0700
@@ -929 +929 @@
- #define pg_restrict __restrict
+ #define pg_restrict
@@ -934 +934 @@
- #define restrict __restrict
+ #define restrict

I have no reason to believe this is specific to hornet's installation, so I
recommend against altering hornet's configuration. It's too likely that the
next xlc user will need to do the same thing. I don't see the problem with
xlc 13.1.3, though.

> Otherwise I can push a platform fix that disables it.

This sounds reasonable.

nm