If you read this file _as_is_, just ignore the funny characters you
see.  It is written in the POD format (see pod/perlpod.pod) which is
specifically designed to be readable as is.

=head1 NAME

README.irix - Perl version 5 on Irix systems

=head1 DESCRIPTION

This document describes various features of Irix that will affect how Perl
version 5 (hereafter just Perl) is compiled and/or runs.

=head2 Building 32-bit Perl in Irix

Use

	sh Configure -Dcc='cc -n32'

to compile Perl 32-bit.  Don't bother with -n32 unless you have 7.1
or later compilers (use cc -version to check).

(Building 'cc -n32' is the default.)

=head2 Building 64-bit Perl in Irix

Use

	sh Configure -Dcc='cc -64' -Duse64bitint

This requires require a 64-bit MIPS CPU (R8000, R10000, ...)

You can also use

	sh Configure -Dcc='cc -64' -Duse64bitall

but that makes no difference compared with the -Duse64bitint because
of the C<cc -64>.

You can also do

	sh Configure -Dcc='cc -n32' -Duse64bitint

to use long longs for the 64-bit integer type, in case you don't
have a 64-bit CPU.

If you are using gcc, just

	sh Configure -Dcc=gcc -Duse64bitint

should be enough, the Configure should automatically probe for the
correct 64-bit settings.

=head2 About Compiler Versions of Irix

Some Irix cc versions, e.g. 7.3.1.1m (try cc -version) have been known
to have issues (coredumps) when compiling perl.c.  If you've used
-OPT:fast_io=ON and this happens, try removing it.  If that fails, or
you didn't use that, then try adjusting other optimization options
(-LNO, -INLINE, -O3 to -O2, etcetera).  The compiler bug has been
reported to SGI.  (Allen Smith <easmith@beatrice.rutgers.edu>)

=head2 Linker Problems in Irix

If you get complaints about so_locations then search in the file
hints/irix_6.sh for "lddflags" and do the suggested adjustments.
(David Billinghurst <David.Billinghurst@riotinto.com.au>)

=head2 Malloc in Irix

Do not try to use Perl's malloc, this will lead into very mysterious
errors (especially with -Duse64bitall).

=head2 Building with threads in Irix

Run Configure with -Duseithreads which will configure Perl with
the new Perl 5.8.0 "interpreter threads", see L<threads>.

The old Perl 5.005 threads is obsolete, unmaintained, and its use is
discouraged.  If you really want it, run Configure with the
-Dusethreads -Duse5005threads options as described in INSTALL.

For either thread model and for Irix 6.2, you have to have the
following patches installed:

        1404 Irix 6.2 Posix 1003.1b man pages
        1645 Irix 6.2 & 6.3 POSIX header file updates
        2000 Irix 6.2 Posix 1003.1b support modules
        2254 Pthread library fixes
        2401 6.2 all platform kernel rollup

B<IMPORTANT>: Without patch 2401, a kernel bug in Irix 6.2 will cause
your machine to panic and crash when running threaded perl.  Irix 6.3
and later are okay.

    Thanks to Hannu Napari <Hannu.Napari@hut.fi> for the IRIX
    pthreads patches information.

=head2 Irix 5.3

While running Configure and when building, you are likely to get
quite a few of these warnings:

  ld:
  The shared object /usr/lib/libm.so did not resolve any symbols.
        You may want to remove it from your link line.

Ignore them: in IRIX 5.3 there is no way to quieten ld about this.

During compilation you will see this warning from toke.c:

  uopt: Warning: Perl_yylex: this procedure not optimized because it
        exceeds size threshold; to optimize this procedure, use -Olimit option
        with value >= 4252.

Ignore the warning.

In IRIX 5.3 and with Perl 5.8.1 (Perl 5.8.0 didn't compile in IRIX 5.3)
the following failures are known.

 Failed Test                  Stat Wstat Total Fail  Failed  List of Failed
 --------------------------------------------------------------------------
 ../ext/List/Util/t/shuffle.t    0   139    ??   ??       %  ??
 ../lib/Math/Trig.t            255 65280    29   12  41.38%  24-29
 ../lib/sort.t                   0   138   119   72  60.50%  48-119
 56 tests and 474 subtests skipped.
 Failed 3/811 test scripts, 99.63% okay. 78/75813 subtests failed, 99.90% okay.

They are suspected to be compiler errors (at least the shuffle.t
failure is known from some IRIX 6 setups) and math library errors
(the Trig.t failure), but since IRIX 5 is long since end-of-lifed,
further fixes for the IRIX are unlikely.  If you can get gcc for 5.3,
you could try that, too, since gcc in IRIX 6 is a known workaround for
at least the shuffle.t and sort.t failures.

=head1 AUTHOR

Jarkko Hietaniemi <jhi@iki.fi>

Please report any errors, updates, or suggestions to F<perlbug@perl.org>.

