is there some known regression with gcc on armel?

[Luca Olivetti <luca@ventoso.org>]

Hello,

I upgraded a test machine (buffalo linkstation pro/Marvell Orion5x) from 
buster to bullseye, then I rebuilt the dspam[*] deb (since it's been 
dropped by debian since buster, I did the same there).
The newly built binary doesn't start, complaining of a configuration 
error, the binary built with buster still works.
I traced the execution with gdb and it doesn't make sense: a function is 
called with a pointer to the configuration struct but inside the 
function it is null.
I then recompiled it with -O0 instead of the default -O2 and this time 
it works (will try later with -O1).
I'm not very familiar with gcc, so do you know of any regression  with 
gcc optimizations on armel (maybe with some other package needing 
special optimization options)?
Note that I had to add the "-z muldefs" option to the linker, but I 
don't think that's the problem (the null I saw wasn't a global variable 
but a parameter).

[*] I know it's a dead project, but it still works and it is 
surprisingly effective and lightweight on such an under powered machine.

Bye
--
Luca