[Bug c/60821] New: gcc 4.8 on MacOS fails depending on -arch order

["a.h.jaffe at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60821

            Bug ID: 60821
           Summary: gcc 4.8 on MacOS fails depending on -arch order
           Product: gcc
           Version: 4.8.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: a.h.jaffe at gmail dot com

I am trying to get a recent version of gcc 4.8.2 up on my machine (OSX 10.9.2).
I have tried installs that come from MacPorts as well as the one that gets
installed alongside a binary install of gfortran. 

For a minimal source file, I get errors depending on the order of the -arch
flags.

Specifically,  `-arch x86_64 -arch i386` (or either of them alone) works:

    % /opt/local/bin/gcc-mp-4.8 -arch x86_64 -arch i386 conftest.c
    % /opt/local/bin/gcc-mp-4.8 -arch x86_64 -arch i386 -O3 conftest.c

But `-arch i386 -arch x86_64` fails:

    % /opt/local/bin/gcc-mp-4.8 -arch i386 -arch x86_64 conftest.c
    /var/folders/6l/7gzvw1zs42sbhj7_hlrpykfm0000gv/T//cc6JCBdP.s:5:bad register
name `%rbp'
    /var/folders/6l/7gzvw1zs42sbhj7_hlrpykfm0000gv/T//cc6JCBdP.s:7:bad register
name `%rsp'
    /var/folders/6l/7gzvw1zs42sbhj7_hlrpykfm0000gv/T//cc6JCBdP.s:10:bad
register name `%rbp'

    % /opt/local/bin/gcc-mp-4.8 -arch i386 -arch x86_64 -O3 conftest.c
    /var/folders/6l/7gzvw1zs42sbhj7_hlrpykfm0000gv/T//ccs67E0q.s:34:FATAL:Bad
fx_size (0x8) in fix_to_relocation_info()

Help!

The minimal source:

     int main ()
     {
      return 0;
     }

For info:

    % /opt/local/bin/gcc-mp-4.8 --version
    gcc-mp-4.8 (MacPorts gcc48 4.8.2_0+universal) 4.8.2
    Copyright (C) 2013 Free Software Foundation, Inc.
    This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.