[Bug optimization/12861] New: internal compiler error: in flow_loops_find at cfgloop.c:830

["peter at emailross dot com" <gcc-bugzilla at gcc dot gnu dot org>]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12861

           Summary: internal compiler error: in flow_loops_find at
                    cfgloop.c:830
           Product: gcc
           Version: 3.3.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: peter at emailross dot com
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: i686-pc-cygwin
  GCC host triplet: i686-pc-cygwin
GCC target triplet: i686-pc-cygwin

I get the error 
  internal compiler error: in flow_loops_find, at cfgloop.c:830
when compiled at -O2 -fno-strict-aliasing.  If you use -O0 the error disappears.

To reproduce
  gcc -O2 -fno-strict-aliasing -c tree234.i

Here is the output with --save-temps -v

$ gcc -v --save-temps -O2 -DMR_USE_ASM_LABELS -DMR_USE_GCC_NONLOCAL_GOTOS
-DMR_USE_GCC_GLOBAL_REGISTERS -DMR_CONSERVATIVE_GC -DMR_BOEHM_GC -DNO_SIGNALS
-I../boehm_gc -I../boehm_gc/include -I../mps_gc/code -I../runtime -I../trace
-fno-strict-aliasing -c tree234.c -o tree234.o

Reading specs from /usr/lib/gcc-lib/i686-pc-cygwin/3.3.1/specs
Configured with: /netrel/src/gcc-3.3.1-2/configure --enable-languages=c,c++,f77,
java --enable-libgcj --enable-threads=posix --with-system-zlib --enable-nls --wi
thout-included-gettext --enable-interpreter --enable-sjlj-exceptions --disable-v
ersion-specific-runtime-libs --enable-shared --build=i686-pc-linux --host=i686-p
c-cygwin --target=i686-pc-cygwin --prefix=/usr --exec-prefix=/usr --sysconfdir=/
etc --libdir=/usr/lib --includedir=/nonexistent/include --libexecdir=/usr/sbin
Thread model: posix
gcc version 3.3.1 (cygming special)
 /usr/lib/gcc-lib/i686-pc-cygwin/3.3.1/cc1.exe -E -quiet -v -I../boehm_gc -I../b
oehm_gc/include -I../mps_gc/code -I../runtime -I../trace -D__GNUC__=3 -D__GNUC_M
INOR__=3 -D__GNUC_PATCHLEVEL__=1 -D__CYGWIN32__ -D__CYGWIN__ -Dunix -D__unix__ -
D__unix -idirafter /usr/lib/gcc-lib/i686-pc-cygwin/3.3.1/../../../../include/w32
api -idirafter /usr/lib/gcc-lib/i686-pc-cygwin/3.3.1/../../../../i686-pc-cygwin/
lib/../../include/w32api -DMR_USE_ASM_LABELS -DMR_USE_GCC_NONLOCAL_GOTOS -DMR_US
E_GCC_GLOBAL_REGISTERS -DMR_CONSERVATIVE_GC -DMR_BOEHM_GC -DNO_SIGNALS tree234.c
 -fno-strict-aliasing -O2 tree234.i
ignoring nonexistent directory "../mps_gc/code"
ignoring nonexistent directory "/usr/local/include"
ignoring nonexistent directory "/usr/i686-pc-cygwin/include"
ignoring duplicate directory "/usr/i686-pc-cygwin/lib/../../include/w32api"
#include "..." search starts here:
#include <...> search starts here:
 ../boehm_gc
 ../boehm_gc/include
 ../runtime
 ../trace
 /usr/lib/gcc-lib/i686-pc-cygwin/3.3.1/include
 /usr/include
 /usr/include/w32api
End of search list.
 /usr/lib/gcc-lib/i686-pc-cygwin/3.3.1/cc1.exe -fpreprocessed tree234.i -quiet -
dumpbase tree234.c -auxbase-strip tree234.o -O2 -version -fno-strict-aliasing -o
 tree234.s
GNU C version 3.3.1 (cygming special) (i686-pc-cygwin)
        compiled by GNU C version 3.3.1 (cygming special).
GGC heuristics: --param ggc-min-expand=47 --param ggc-min-heapsize=32702
tree234.c: In function `tree234_module64':
tree234.c:307: internal compiler error: in flow_loops_find, at cfgloop.c:830
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://gcc.gnu.org/bugs.html> for instructions.