identifying c++ aliasing violations

[Jack Howarth]

    In compiling xplor-nih under gcc 4.1 (it is a mix of c, c++ and fortran)
I discovered one of its c++ source files causes segfaults at optimization
levels higher than -O1 unless I add -fno-strict-aliasing to the compile
flags. In that case, there program passes all of its testsuite without
any segfaults. Unfortunately, the offending source file, dint-node.cc,
doesn't result in any warnings with  -Wstrict-aliasing.
     Is there any documentation on how to debug aliasing rule violations
in such cases where g++ is unable to produce any warnings? Are there any
tutorials or documentation on how to debug such situations? Thanks in
advance for any advice.
              Jack