[Qemu-devel] Overoptimization

[Alexander E. Patrakov]

The CFLAGS in Makefile.target are bad for gcc 3.3.2. This is not a my 
problem with my gcc, because it passes the "make check" testsuite except 
some known errors in libstdc++, which cannot affect qemu.

The victim is the tcp_input function in slirp. When compiling with the 
decault CFLAGS, for some reason all packets are dropped as having a 
wrong TCP checksum. I tried debugging this by placing some debug printfs 
in tcp_input.c file, but the problem disappeared after I inserted them. 
I concluded that it is very strange and compiled this tcp_input.c file 
without my debug statements, but with -O1 instead of -O2. The problem 
went away.

Will this workaround (use of -O1 instead of -O2 for tcp_input.c) enter 
the qemu CVS?

--
Alexander E. Patrakov