compiling CP2K at -O1 I get the following ICE:

> gfortran -c -O1 -cpp bug.f90
bug.f90: In function ‘qs_ks_build_kohn_sham_matrix’:
bug.f90:1392: internal compiler error: Segmentation fault

with a trace
Program received signal SIGSEGV, Segmentation fault.
find_decomposable_subregs (px=<value optimized out>, data=0x7fff4c98757c)
    at /data03/vondele/gcc_trunk/gcc/gcc/lower-subreg.c:250
250       if (GET_CODE (x) == SUBREG)
(gdb) bt
#0  find_decomposable_subregs (px=<value optimized out>, data=0x7fff4c98757c)
    at /data03/vondele/gcc_trunk/gcc/gcc/lower-subreg.c:250
#1  0x00000000006eceb1 in for_each_rtx (x=0x20110060, f=0xb60cf0
<find_decomposable_subregs>, data=0x7fff4c98757c)
    at /data03/vondele/gcc_trunk/gcc/gcc/rtlanal.c:2827
#2  0x0000000000b61120 in decompose_multiword_subregs () at
/data03/vondele/gcc_trunk/gcc/gcc/lower-subreg.c:1119
#3  0x0000000000b61ff9 in rest_of_handle_lower_subreg2 () at
/data03/vondele/gcc_trunk/gcc/gcc/lower-subreg.c:1320
#4  0x000000000069c2ad in execute_one_pass (pass=0x10e4d40) at
/data03/vondele/gcc_trunk/gcc/gcc/passes.c:1279
#5  0x000000000069c4f5 in execute_pass_list (pass=0x10e4d40) at
/data03/vondele/gcc_trunk/gcc/gcc/passes.c:1328
#6  0x000000000069c50d in execute_pass_list (pass=0x10dfc00) at
/data03/vondele/gcc_trunk/gcc/gcc/passes.c:1329
#7  0x0000000000792ccc in tree_rest_of_compilation (fndecl=0x7f14440fce00)
    at /data03/vondele/gcc_trunk/gcc/gcc/tree-optimize.c:419
#8  0x00000000009124c4 in cgraph_expand_function (node=0x7f1443c11f00)
    at /data03/vondele/gcc_trunk/gcc/gcc/cgraphunit.c:1047
#9  0x0000000000914225 in cgraph_optimize () at
/data03/vondele/gcc_trunk/gcc/gcc/cgraphunit.c:1106
#10 0x000000000048db65 in gfc_be_parse_file (set_yydebug=<value optimized out>)
    at /data03/vondele/gcc_trunk/gcc/gcc/fortran/f95-lang.c:240
#11 0x000000000074357d in toplev_main (argc=<value optimized out>, argv=<value
optimized out>)
    at /data03/vondele/gcc_trunk/gcc/gcc/toplev.c:970
#12 0x00007f1444431436 in __libc_start_main () from /lib64/libc.so.6
#13 0x0000000000402bf9 in _start ()

I'll be working on a testcase


-- 
           Summary: [4.4 Regression] ICE in find_decomposable_subregs
           Product: gcc
           Version: 4.4.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: middle-end
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: jv244 at cam dot ac dot uk


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38722