the difference between -mtune and -march

[Ian Lance Taylor]

kevin diggs <diggskevin38@gmail.com> writes:

> In a similar vein, what is the deal with -march and -mcpu? x86 uses
> -march and powerpc uses -mcpu???

All -m options are target dependent.

Yes, it would probably be better if all targets used -march, -mtune, and
-mcpu consistently.  However, the details are complex.  For the PowerPC,
the actual instruction mnemonics change based on the CPU.  It's not
clear that it's useful to provide -march which only changes the
architecture.

Ian