[PATCH 0/3] Split off powerpcspe from rs6000 port

[Segher Boessenkool <segher at kernel dot crashing dot org>]

Hi!

As discussed before, here is a series to split powerpcspe from the
rs6000 port.  This series does not yet make any real changes to either
port: it is a copy of rs6000/ to powerpcspe/, with some renames and
some necessary changes to the port file, and slightly more involved
changes to config.gcc .

This was tested on powerpc64-linux {-m32,-m64}, and it was build-tested
on powerpc-linux-gnuspe (and the resulting compiler was tested to be
functional: it can build various Linux defconfigs for SPE systems).

I have tried to see how much the powerpcspe port can be simplified
after this, and found it can lose 80% of the code without big problems.
You may however not want all that, for example, I removed all 64-bit
support in that test.  Getting rid of all VMX/VSX support is a big part
of it already, as is removing "classic" floating point (and paired
single, and xilinx fpu, and all newer ISA features, etc.)

For the rs6000 port the low-hanging fruits are much more modest, only
5% or a bit more; but in pretty gnarly code.  For example, some current
pain points are the SPE ABI (for separate shrink-wrapping), and how
isel is handled.

This won't be the final series...  I have a few questions:

-- This uses powerpc-*-rtems*spe*; do we want powerpcspe-*-rtems*
   instead?  Or both?
-- This uses powerpc-wrs-vxworksspe; do we want powerpcspe-wrs-vxworks
   instead?  Both?  What about the ae and mils variants?
-- Does powerpc*-*-freebsd*spe* exist?
-- Does powerpc-*-netbsd*spe* exist?
-- Does powerpc-*-eabisim*spe* exist?
-- Does powerpcle-*-*spe* exist?

Also, testing is needed :-)  You can get better testing by removing
the rs6000/ directories completely, btw.; otherwise files from rs6000/
can accidentally be picked up instead of the corresponfing file from
powerpcspe/, which will currently work because there are no big
differences yet, but things will diverge later (and then break).


Segher