Bug#677606: gcc-4.7: ICE compiling ByteToDir() from ioquake3 on any-i386

[Simon McVittie <smcv@debian.org>]

> I have been able to reduce the failing file to a self-contained file
> with no #include directives, mini_q_math.c (also attached), and the
> failing command-line to:
>
> /usr/lib/gcc/i486-linux-gnu/4.7/cc1 mini_q_math.c \
> -g -fPIC -O -fvisibility=hidden -funroll-loops -fschedule-insns2 -o -

This also fails with gcc-snapshot 20120601-1:

% /usr/lib/gcc-snapshot/bin/gcc mini_q_math.c -g -fPIC -O
-fvisibility=hidden -funroll-loops -fschedule-insns2 -o tmp.o
mini_q_math.c: In function 'ByteToDir':
mini_q_math.c:124:1: internal compiler error: Segmentation fault
 }
 ^

Here is reportbug's system information for the i386 schroot where I've
been testing this.

-- System Information:
Debian Release: wheezy/sid
  APT prefers unstable
  APT policy: (500, 'unstable')
Architecture: i386 (i686)
Foreign Architectures: amd64

Kernel: Linux 3.2.0-2-amd64 (SMP w/4 CPU cores)
Locale: LANG=C, LC_CTYPE=C (charmap=ANSI_X3.4-1968)
Shell: /bin/sh linked to /bin/dash

Versions of packages gcc-4.7 depends on:
ii  binutils      2.22-6.1
ii  cpp-4.7       4.7.0-13
ii  gcc-4.7-base  4.7.0-13
ii  libc6         2.13-33
ii  libgcc1       1:4.7.0-13
ii  libgmp10      2:5.0.5+dfsg-2
ii  libgomp1      4.7.0-13
ii  libitm1       4.7.0-13
ii  libmpc2       0.9-4
ii  libmpfr4      3.1.0-5
ii  libquadmath0  4.7.0-13
ii  zlib1g        1:1.2.7.dfsg-11

Versions of packages gcc-4.7 recommends:
ii  libc6-dev  2.13-33

Versions of packages gcc-4.7 suggests:
pn  binutils-gold        <none>
pn  gcc-4.7-doc          <none>
pn  gcc-4.7-locales      <none>
ii  gcc-4.7-multilib     4.7.0-13
pn  libgcc1-dbg          <none>
pn  libgomp1-dbg         <none>
pn  libitm1-dbg          <none>
pn  libmudflap0-4.7-dev  <none>
pn  libmudflap0-dbg      <none>
pn  libquadmath0-dbg     <none>

-- no debconf information