Re: JIT compiling with LLVM v12.2

Hi,

On 2018-03-21 12:07:59 +1300, Thomas Munro wrote:
> The documentation builds and the resulting HTML looks good, and I like
> what you've written for users and also for developers in the README
> file.

Cool.

> Perhaps it could use something about how to know it's working
> with EXPLAIN (or any other introspection there might be), but maybe
> you're still working on that?

I'd not yet seen that as a priority, but I think it'd make sense to show
an example of that. Perhaps showing a select query from a function,
once with that function's cost set to the default, and once with it set
to something high?

> I did a proof-reading pass and have some minor language and
> typesetting suggestions. See comments below and attached patch
> (against current HEAD of your jit branch) which implements all of
> these changes, which of course you can feel free to take individual
> hunks from or ignore if you disagree!

Yeha!

> + <varlistentry>
> + <term><acronym>JIT</acronym></term>
> + <listitem>
> + <para>
> + <ulink url="https://en.wikipedia.org/wiki/Just-in-time_compilation">Just
> in Time
> + Compilation</ulink>
> + </para>
> + </listitem>
> + </varlistentry>
>
> The usual typesetting seems to be "just-in-time" (with hyphens),
> including on Wikipedia, various literature and in dictionaries. Here
> "compilation" doesn't seem to need a capital letter (it's not part of
> the acronym, it's not otherwise in a title context where
> capitalisation is called for).

I wasn't sure about that one, thanks.

> + <varlistentry id="guc-jit-above-cost" xreflabel="guc-jit-above-cost">
>
> xreflabel should use underscores not hyphens, and shouldn't have the
> leading "guc" (this breaks the resulting HTML).

Oops, yea, that's definitely a mistake.

> + Sets the planner's cutoff after which JIT compilation is used as part
> ...
> + Sets the planner's cutoff after which JIT compiled programs (see <xref
>
> s/after which/above which/. I see there was some nearby text that
> used "after which", but that was talking about time.
>
> I think writers might do s/JIT compiled/JIT-compiled/ here and some
> similar places (JIT-generated, JIT-accelerated etc), though I'm not
> sure about that and I doubt anyone cares so I didn't change it.

I was wondering about that...

Thanks a lot for going through this!

Greetings,

Andres Freund