Subject: Re: Architecture extenstions printed at attach
To: None <port-alpha@netbsd.org>
From: Jason R Thorpe <thorpej@zembu.com>
List: port-alpha
Date: 04/03/2000 08:08:29
On Mon, Apr 03, 2000 at 02:48:14PM +0200, Manuel Bouyer wrote:

 > cpu0: Architecture extensions: 303<PAT,MVI,FIX,BWX>

[ . . . ]

 > So, no 'CIX' it seems ...

Right, so it looks like it's incorrect for GCC to emit the Counting
instructions if -mcpu=21264.  Interestingly enough, GCC does the
following:

	-mcpu={ev4,21064}: explicitly disable BWX, CIX, MVI

	-mcpu={ev5,21164}: explicitly disable BWX, CIX, MVI

	-mcpu={ev56,21164a}: explicitly enable BWX, explicitly disable
	CIX, MVI

	-mcpu={pca56,21164pc}: explicitly enable BWX, MVI, explicitly
	disable CIX

	-mcpu={ev6,21264}: explicitly enable BWX, CIX, MVI

Try building with: -mcpu=21264 -mno-cix

We should probably disable CIX in the compiler unless it is explicitly
enabled with -mcix.

I'll check in EGCS-current soon (hopefully today) and if it is still
a problem, I'll discuss it with the GCC people.  It could be that
at one point they thought the 21264 always had it; at least one version
of the Alpha Architecture Reference Manual listed the wrong AMASK bit
for CIX (it was in the place where the FIX [floating point conversion]
bit actually is).

-- 
        -- Jason R. Thorpe <thorpej@zembu.com>