Using a host system of Linux 2.6.8.1, binutils version 2.16 and the 
aforementioned GCC, I have observed the following gcc segmentation faults:

util-linux-2.12q: -pipe -O2 -mtune=i486 -fomit-frame-pointer (defaults)
fdiskbsdlabel.c: In function 'bselect' (void):
fdiskbsdlabel.c: 164: internal compiler error: Segmentation fault

sfdisk.c: In function 'do_fdisk (static void)':
sfdisk.c:3006: internal compiler error: Segmentation fault

I have also found that many variations of '-march=pentium4 -OX' segfault when 
compiling different instantiations of quotearg. For example:

patch-2.5.9:
quotearg.c: In function 'quotearg_char'
quotearg.c:619: internal compiler error: Segmentation fault

when -O3 was used, but worked fine with a -O2 optimization.

(I realize that optimizations greater than -O2 are risky but I didn't expect 
the compiler to choke with a segmentation fault).

I marked this as critical because it causes a seg fault and thought that 
someone might want to know.

Sean McLinden
Allegheny County Health Department