Wireshark-dev: Re: [Wireshark-dev] Wireshark 3.0.0rc1 on macOS Mojave 10.14.3
From: Guy Harris <guy@xxxxxxxxxxxx>
Date: Mon, 25 Feb 2019 14:29:27 -0800
On Feb 25, 2019, at 2:02 PM, Gerald Combs <gerald@xxxxxxxxxxxxx> wrote:

> It looks like we need to build GMP for older CPUs. 
> 
> According to your last crash report, you're running a Core i7-3720QM and crashed in mpn_submul_1. GMP's "Build Options" documentation at https://gmplib.org/manual/Build-Options.html says that it can be optimized for a number of CPUs, and that its configure script defaults to "this CPU here, right here in my office". For the macOS builder that's a Core i7-8700B

...and for the old builder it was probably something less shiny and new.

> The "Notes for Package Builds" section of the documentation recommends "--enable-fat" when shipping binary packages, which builds a range of optimized code and chooses the fastest at run time: https://gmplib.org/manual/Notes-for-Package-Builds.html

If that works, I'd go for that.

> Homebrew defines an "oldest supported CPU", which appears to be "core2" and builds for that:

I think that's older than it needs to be for 10.12, which either requires SSE4 or SSE4.1 support.

> https://github.com/Homebrew/homebrew-core/blob/master/Formula/gmp.rb
> https://github.com/Homebrew/brew/blob/master/Library/Homebrew/hardware.rb
> 
> ...so, should be build GMP for everything or a single, older CPU?

I'd vote for "everything" to start with, as they support it, and, if that doesn't work, fall back on whatever CPU type is appropriate for "macOS 10.12 or later".