Code:
$ dmesg | grep cpu
cpu0: <ACPI CPU> on acpi0
est0: <Enhanced SpeedStep Frequency Control> on cpu0
p4tcc0: <CPU Frequency Thermal Control> on cpu0
I have also looked at the man page for gcc and found generic, native, i686, c3 and c3-2 under the -mtune=cpu-type section. Are any of those right?