libgcc_s.so 3.4 vs 3.0 compatibility

[Peter FELECAN]

Currently the libgcc_s.so library has the same version in 3.4 and 4.0,
i.e libgcc_s.so.1 (SONAME = libgcc_s.so.1).

Is this as expected?

Are the 2 libraries compatible? Interchangeable? Looking in the map
file, I don't think so.

If not, how can I make the most correct separation for a 3.4 and 4.0
cohabitation? --- the 2 versions are installed in separate
directories, however, the run-path, used by the dynamic linker,
containing libgcc_s.so is shared.

If someone can give me a pointer toward the relevant documentation I
would be grateful.
-- 
Peter FELECAN