Re: Σχετ: Re: Σχετ: Re: Σχετ: Re: x86_64-solaris

[Rainer Orth]

Hi Apostolos,

[Again: *Please* leave config-patches on the Cc:  It is hard to discuss
how best to proceed with your patch if you exclude everyone else from
the discussion.  Thanks.]

> Yes there is. Try to run a 64bit binary on
>
> a 32bit machine. Also just because

No doubt about that.  But how is this relevant to the discussion at hand?

> SOLARIS contains both 32 and 64bit binaries
> and libraries it does not mean this is correct.

What do you mean by `correct'?  It's perfectly correct to run 32-bit
binaries on a machine that is also capable of running 64-bit ones.  In
fact, you'd be surprised that even in unexpected cases the 32-bit
ones may perform better than the 64-bit binaries.

As you certainly know, there are primarily two possible reasons for
wanting to run 64-bit code:

* Address space.  I seriously doubt that you'll often (if ever) run into
  a case where TeX comes even close to exceeding the 4 GB address space,
  even in the case of multiple-hundred-pages documents.

* Performance.  While there are certainly cases where 64-bit x86 code
  performs better than 32-bit code, among others due to the larger set
  of registers available, the opposite may be true just as well.  Case
  in point: a full bootstrap and test cycle of gcc mainline on Solaris
  11.4/x86 takes 1h 30m with a 32-bit-default build, but 1h 44m in a
  64-bit-default build, in both cases testing 32 and 64-bit
  compilations.  This is on a Dell PowerEdge R740 with two Xeon Gold
  6132 CPUs, not some historical hardware.

> The reason for doing is TeXLive. "We" 
> provide both 32 and 64bit binaries. But
> when you try to install the binaries, the
> script always guesses that the system is
> 32bit and never installs the 64bit binaries.

As I've said, you can control this (or could before Karl imported your
config.guess patch) either by setting CC='gcc -m64' in the environment,
or in the case of TeX Live's install-tl script, by passing
-force-platform if you don't like the default.

> On my 64bit system I want to run 64bit
> binaries. 

Unless you have really tried if 64-bit TeX performs better than 32-bit
TeX you may even do yourself a disfavor by insisting on 64-bit binaries.

You can certainly achieve your goal by always having CC='gcc -m64' in
your environment.  This way, you always get your preferred 64-bit
binaries irrespective of the version of config.guess the project is
currently using.  It often takes months or even years until a project
updates their copies of config.guess and config.sub.

I think I've now clearly made my point: your patch to config.guess
causes massive problems especially but not only for the compiler
etc. toolchain and is just your personal preference, nothing more.

It has since been reverted in the config repo, and I'd like to ask Karl
to do the same in TeX Live.

        Rainer

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Rainer Orth, Center for Biotechnology, Bielefeld University