I just tried building my 2.4.29 kernel with gcc-4.0.0.  The attached 
patch is needed.

It seems to run fine but I have not extensively tested it.

The changes to include/asm/uaccess.h and include/linux/byteorder/swab.h 
are mostly back ports from CVS HEAD.  The rest is just random things 
that I had to change to make it work.

In addition to these changes you need the changes that are floating 
around on the list to asm-mips/ptrace.h, arch/mips/kernel/signal.c and 
arch/mips/kernel/syscall.c so that it will run when compiled with gcc-3.4

The diffs are from my internal CVS so version numbers will not match 
those on linux-mips' CVS.

David Daney.