Feedback-ID: id4a34324:Fastmail
Date: Thu, 12 Oct 2023 16:31:20 -0700
From: Andres Freund <andres@anarazel.de>
To: Thomas Munro <thomas.munro@gmail.com>
Cc: Devrim =?utf-8?B?R8O8bmTDvHo=?= <devrim@gunduz.org>,
	PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>,
	Fabien COELHO <coelho@cri.ensmp.fr>,
	Ronan Dunklau <ronan.dunklau@aiven.io>,
	Dmitry Dolgov <9erthalion6@gmail.com>
Subject: Re: LLVM 16 (opaque pointers)
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Hi,

On 2023-10-11 21:59:50 +1300, Thomas Munro wrote:
> +#else
> +	LLVMPassBuilderOptionsRef options;
> +	LLVMErrorRef err;
> +	int			compile_optlevel;
> +	char	   *passes;
> +
> +	if (context->base.flags & PGJIT_OPT3)
> +		compile_optlevel = 3;
> +	else
> +		compile_optlevel = 0;
> +
> +	passes = psprintf("default<O%d>,mem2reg,function(no-op-function),no-op-module",
> +					  compile_optlevel);

I don't think the "function(no-op-function),no-op-module" bit does something
particularly useful?

I also don't think we should add the mem2reg pass outside of -O0 - running it
after a real optimization pipeline doesn't seem useful and might even make the
code worse? mem2reg is included in default<O1> (and obviously also in O3).


Thanks for working on this stuff!


I'm working on setting up buildfarm animals for 16, 17, each once with
a normal and an assertion enabled LLVM build.

Greetings,

Andres Freund