PERFORCE change 29883 for review

[Marcel Moolenaar]

http://perforce.freebsd.org/chv.cgi?CH=29883

Change 29883 by marcel at marcel_nfs on 2003/04/27 11:30:56

	Prefer ar.bsp over ar.bspstore. The value of ar.bspstore is
	supposed to be equal to the value of ar.bsp due to flushing
	the register stack, but a PAL bug existed where a PMI could
	cause RSE spills or fills to fail to complete. This makes
	me wonder: why use a register that has a more dynamic nature
	than one that is invariant over the course of this function
	and has the value we're interested in?
	
	This change doesn't fix a problem (alas, because it means I
	still have to fix the problem I hoped this would fix :-) and
	is probably gratuitous for all practical purposes but it has
	higher quality this way. For example: ar.bsp may have faster
	access times because it's invariant. The RSE has to synchronize
	access to ar.bspstore with RSE operation...

Affected files ...

.. //depot/projects/ia64_epc/sys/ia64/ia64/context.s#13 edit

Differences ...

==== //depot/projects/ia64_epc/sys/ia64/ia64/context.s#13 (text+ko) ====

@@ -197,7 +197,7 @@
 }
 {	.mmi
 	st8		[r31]=r16,16		// pr
-	mov		r17=ar.bspstore
+	mov		r17=ar.bsp
 	mov		r16=ar.pfs
 	;;
 }