defaults for -march and -mtune

[Jay Foad <jay.foad@xxxxxxxxx>]

If I don't specify any -march= or -mtune= options, what are the
default architectures to generate code for and to tune for? Can I get
the compiler to tell me this information?

The documentation here doesn't seem to say anything about it:

http://gcc.gnu.org/onlinedocs/gcc/i386-and-x86_002d64-Options.html

I'm using "gcc (Ubuntu/Linaro 4.6.1-9ubuntu3) 4.6.1" targetting x86_64.

Thanks,
Jay.