Re: Failure to build go on some 32bit port-i386 machines

[Benny Siegert <bsiegert%gmail.com@localhost>]

Hey Alexander,

I suspect you will find better answers to this question on the golang-dev mailing list.

-- 
Benny

> Am 05.05.2024 um 00:45 schrieb Alexander Schreiber <als%thangorodrim.ch@localhost>:
> 
> On Mon, Apr 29, 2024 at 05:21:36PM -0400, Greg Troxel wrote:
>> "Jonathan A. Kollasch" <jakllsch%kollasch.net@localhost> writes:
>> 
>>> https://github.com/prometheus/node_exporter/issues/1568
>> 
>> I guess we should be doing some flavor of that.  I'm fuzzy because my
>> oldest machine is now not so old (only about 20 years), but I think
>> NetBSD/i386 supports 486 and up.  If so, pkgsrc should be fixing the
>> upstream bug of having a newer default and targeting 486.
> 
> Grabbed the node_exporter binary package via pkgin and ran it on the
> Alix (AMD Geode LX). Died with SIGILL. So I ran it under gdb until it
> died (during early startup) and looked at the disassembly. It dies
> on:
> 0x08098c9b <+27>:    xorps  %xmm0,%xmm0
> 
> Now xorps is Bitwise Logical XOR for Single-FP Values and was apparently
> introduced with the Pentium3, which is much newer than the i586 (OG
> Pentium) baseline that the Geode was built to provide.
> 
> Which would explain this exploding on qemu with -cpu=pentium, but being
> happy with -cpu=n270.
> 
> Testing with qemu 9.0.0 and -cpu=pentium3, NetBSD 10.0 and current
> pkgsrc results in the go118 build exploding with SIGILL, specifically
> lang/go118/work/go/pkg/tool/netbsd_386/go_bootstrap. Running under
> gdb and disassembling yields:
> 
> => 0x080a5a95 <+21>:    mfence
> 
> and the mfence instruction was introduced with the Pentium4, so of
> course it causes SIGILL on Pentium3.
> 
> So, it looks like golang on port-i386 class machines (aka 32bit Intel
> and friends, which apparently goes down all the way to the i486) is
> basically no-can-do except for the very latest 32bit Intel CPUs.
> 
> Short of flagging golang as "forget it on port-i386", does anybody
> have any better ideas of making the golang toolchain actually work
> on some of the more, *cough* ancient 32bit Intel CPUs?
> 
> Kind regards,
>           Alex.
> --
> "Opportunity is missed by most people because it is dressed in overalls and
> looks like work."                                      -- Thomas A. Edison