GCC 4.6 is now the default compiler in wheezy. This is what gcc --version says:
% gcc --version
gcc (Debian 4.6.0-6) 4.6.1 20110428 (prerelease)
To celebrate the occasion, I did a quick (non-scientific!) benchmark, comparing old 4.5.2 and new 4.6.0 when compiling 2.6.38 kernel. Test compiles were run on a dual core CPU (make -j2). The old compiler took 1:58.48 to finish (real time), where the new one needed 2:02.47. So, the new one is only a bit (3.4%) slower. I also compared the resulting kernel size (vmlinux.bin) and it was almost the same 2122360 vs 2119448, meaning the new kernel produces a whopping 0.14% more tight code! I'm just kidding, of course. This was just a quick check. To learn more about the new compiler and where it's improvements are, you'd need to browse it's Changelog.
I also noticed that the new kernel is slightly more picky, producing some amount of noise like this during kernel compilation:
net/sched/sch_generic.c: In function ‘dev_graft_qdisc’:
net/sched/sch_generic.c:671:2: warning: the comparison will always evaluate as ‘true’ for the address of ‘noop_qdisc’ will never be NULL [-Waddress]
net/unix/af_unix.c: In function ‘unix_stream_sendmsg’:
net/unix/af_unix.c:1564:22: warning: variable ‘sunaddr’ set but not used [-Wunused-but-set-variable]
I suppose this stuff will be fixed, or appropriate command line switches used for compilation to silence the unwanted warnings.
Short entry today. I still miss properly labeled new packages in my package manager. :(