Re: Pentium M config option for 2.6

[Amit Gurdasani <amitg@alumni.cmu.edu>]

:On Date: Sun, 4 Jan 2004 13:33:58 +0100, Tomas Szepe wrote:
:> > IOW, don't lie to the compiler and pretend P-M == P4
:> > with that -march=pentium4.
:>
:> What do you recommend to use as march then?  There is
:> no pentiumm subarch support in gcc yet;  I was convinced
:> p4 was the closest match.
:
:march=pentium3 is the closest safe choice, at least
:until gcc implements P-M specific support.
:
:/Mikael

Perhaps -mcpu=pentium3 -march=pentium4 would be a good compromise? From the
GCC 3.3 info pages:

`-mcpu=CPU-TYPE'
     Tune to CPU-TYPE everything applicable about the generated code,
     except for the ABI and the set of available instructions. [...]

     While picking a specific CPU-TYPE will schedule things
     appropriately for that particular chip, the compiler will not
     generate any code that does not run on the i386 without the
     `-march=CPU-TYPE' option being used. [...]

`-march=CPU-TYPE'
     Generate instructions for the machine type CPU-TYPE.  The choices
     for CPU-TYPE are the same as for `-mcpu'.  Moreover, specifying
     `-march=CPU-TYPE' implies `-mcpu=CPU-TYPE'.

Amit