Miscompilation of glibc with CVS mainline

[Andreas Jaeger <aj@suse.de>]

GCC CVS mainline miscompiles glibc on i686-linux-gnu.  The actual
error I noticed is:
CPP='/opt/gcc/3.3-devel/bin/gcc -E -x c-header'  /builds/glibc/test-libc/elf/ld-linux.so.2 --library-path /builds/glibc/test-libc:/builds/glibc/test-libc/math:/builds/glibc/test-libc/elf:/builds/glibc/test-libc/dlfcn:/builds/glibc/test-libc/nss:/builds/glibc/test-libc/nis:/builds/glibc/test-libc/rt:/builds/glibc/test-libc/resolv:/builds/glibc/test-libc/crypt:/builds/glibc/test-libc/linuxthreads /builds/glibc/test-libc/sunrpc/rpcgen -Y ../scripts -c rpcsvc/bootparam_prot.x -o /builds/glibc/test-libc/sunrpc/xbootparam_prot.T
make[2]: *** [/builds/glibc/test-libc/sunrpc/xbootparam_prot.stmp] Segmentation fault
make[2]: Leaving directory `/cvs/libc/sunrpc'

To track down the failure, I used Janis' script and noticed that it
fails since the merge from the 3_4-basic-improvement branch.
Searching that branch I found this patch as beeing the problem:

+2002-10-07  Richard Henderson  <rth@redhat.com>
+
+       * cse.c (fixed_base_plus_p): Turn FIXED_BASE_PLUS_P into a
+       function; cleanup PLUS case by using recursion.  Update all users.
+       (NONZERO_BASE_PLUS_P): Remove.
+       (find_comparison_args): Use rtx_addr_can_trap_p instead.
+       (fold_rtx): Use nonzero_address_p.
+       * rtl.h (nonzero_address_p): Declare.
+       * rtlanal.c (rtx_varies_p): Handle ADDRESSOF.
+       (rtx_addr_can_trap_p): Likewise.
+       (nonzero_address_p): New.
+       * simplify-rtx.c (NONZERO_BASE_PLUS_P): Remove.
+       (simplify_relational_operation): Use nonzero_address_p.


I haven't been able to figure out which file in glibc is miscompiled
and therefore like to ask for an additional review of that patch
again.

Andreas
-- 
 Andreas Jaeger
  SuSE Labs aj@suse.de
   private aj@arthur.inka.de
    http://www.suse.de/~aj