please pull powerpc.git 'merge' branch

Segher Boessenkool segher at kernel.crashing.org
Sun Apr 30 13:12:57 EST 2006


>> Previously we've said implementation instead of specification
>> ("PPC_FEATURE_POWER5_PLUS" etc). That's better than saying base
>> architecture version, since there are parts of the arch that might or
>> might not be implemented (i.e. optional features, etc).
>
> We now have the AT_PLATFORM string, which we didn't have when we added
> the POWER5_PLUS etc. features.  That specifies which particular
> implementation we are on quite precisely.  We don't want to have a bit
> for every single implementation or we'll run out of bits.
>
> The ARCH_2_05 bit means all the non-optional bits of the 2.05
> architecture.  If there are optional features in the architecture, we
> have separate bits for them.  For example, we don't have separate
> bits for POWER4 and for 970; instead we have a HAS_ALTIVEC bit, and
> for 970 we set both POWER4 and HAS_ALTIVEC.  So the POWER4 bit is
> really a "2.00 architecture version" bit.

Except that the 970 at least is actually version 2.01.  Sounds
like names are better than bare numbers -- you showed yourself that
numbers like this are confusing, but you also say that a cpu name
really means an arch version (which isn't so bad -- there generally
is only one "main" CPU per arch version anyway, and people generally
know what is compatible to what).

So please rename ARCH_2_05 to the name of the first CPU that implements
architecture 2.05?


Segher




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