PERFORCE change 31046 for review

[Marcel Moolenaar]

http://perforce.freebsd.org/chv.cgi?CH=31046

Change 31046 by marcel at marcel_nfs on 2003/05/12 20:19:31

	I don't know what I've been drinking or smoking, but using
	a stacked register while switching the register stack can
	only be bad news. So, use r14/r15 instead of r31/r32. We
	could continue to use r31 of course, but r15 pairs better
	with r14 than r31 does. This significantly improves the
	stability under high load.
	
	While here, define savectx(x) as swapctx(x,NULL) instead of
	as savectx__(x).  The latter was implemented as swapctx()
	anyway.

Affected files ...

.. //depot/projects/ia64_epc/sys/ia64/ia64/context.s#17 edit
.. //depot/projects/ia64_epc/sys/ia64/include/pcb.h#9 edit

Differences ...

==== //depot/projects/ia64_epc/sys/ia64/ia64/context.s#17 (text+ko) ====

@@ -50,7 +50,7 @@
 {	.mmi
 	ld8		r17=[r30],16		// rp
 	ld8		r18=[r31],16		// pr
-	add		r32=SIZEOF_SPECIAL,r32
+	add		r14=SIZEOF_SPECIAL,r32
 	;;
 }
 {	.mmi
@@ -66,7 +66,7 @@
 	;;
 }
 {	.mmi
-	ld8		r17=[r32],8		// unat (after)
+	ld8		r17=[r14],8		// unat (after)
 	mov		ar.bspstore=r20
 	mov		ar.pfs=r19
 	;;
@@ -74,18 +74,18 @@
 {	.mmi
 	mov		ar.unat=r17
 	mov		ar.rnat=r21
-	add		r31=8,r32
+	add		r15=8,r14
 	;;
 }
 {	.mmi
-	ld8.fill	r4=[r32],16		// r4
-	ld8.fill	r5=[r31],16		// r5
+	ld8.fill	r4=[r14],16		// r4
+	ld8.fill	r5=[r15],16		// r5
 	nop		0
 	;;
 }
 {	.mmi
-	ld8.fill	r6=[r32],16		// r6
-	ld8.fill	r7=[r31],16		// r7
+	ld8.fill	r6=[r14],16		// r6
+	ld8.fill	r7=[r15],16		// r7
 	nop		1
 	;;
 }
@@ -95,86 +95,76 @@
 	nop		2
 }
 {	.mmi
-	ld8		r17=[r32],16		// b1
-	ld8		r18=[r31],16		// b2
+	ld8		r17=[r14],16		// b1
+	ld8		r18=[r15],16		// b2
 	nop		3
 	;;
 }
 {	.mmi
-	ld8		r19=[r32],16		// b3
-	ld8		r20=[r31],16		// b4
+	ld8		r19=[r14],16		// b3
+	ld8		r20=[r15],16		// b4
 	mov		b1=r17
 	;;
 }
 {	.mmi
-	ld8		r16=[r32],24		// b5
-	ld8		r17=[r31],32		// lc
+	ld8		r16=[r14],24		// b5
+	ld8		r17=[r15],32		// lc
 	mov		b2=r18
 	;;
 }
 {	.mmi
-	ldf.fill	f2=[r32],32
-	ldf.fill	f3=[r31],32
+	ldf.fill	f2=[r14],32
+	ldf.fill	f3=[r15],32
 	mov		b3=r19
 	;;
 }
 {	.mmi
-	ldf.fill	f4=[r32],32
-	ldf.fill	f5=[r31],32
+	ldf.fill	f4=[r14],32
+	ldf.fill	f5=[r15],32
 	mov		b4=r20
 	;;
 }
 {	.mmi
-	ldf.fill	f16=[r32],32
-	ldf.fill	f17=[r31],32
+	ldf.fill	f16=[r14],32
+	ldf.fill	f17=[r15],32
 	mov		b5=r16
 	;;
 }
 {	.mmi
-	ldf.fill	f18=[r32],32
-	ldf.fill	f19=[r31],32
+	ldf.fill	f18=[r14],32
+	ldf.fill	f19=[r15],32
 	mov		ar.lc=r17
 	;;
 }
-	ldf.fill	f20=[r32],32
-	ldf.fill	f21=[r31],32
+	ldf.fill	f20=[r14],32
+	ldf.fill	f21=[r15],32
 	;;
-	ldf.fill	f22=[r32],32
-	ldf.fill	f23=[r31],32
+	ldf.fill	f22=[r14],32
+	ldf.fill	f23=[r15],32
 	;;
-	ldf.fill	f24=[r32],32
-	ldf.fill	f25=[r31],32
+	ldf.fill	f24=[r14],32
+	ldf.fill	f25=[r15],32
 	;;
-	ldf.fill	f26=[r32],32
-	ldf.fill	f27=[r31],32
+	ldf.fill	f26=[r14],32
+	ldf.fill	f27=[r15],32
 	;;
 {	.mmi
-	ldf.fill	f28=[r32],32
-	ldf.fill	f29=[r31],32
+	ldf.fill	f28=[r14],32
+	ldf.fill	f29=[r15],32
 	add		r8=1,r0
 	;;
 }
 {	.mmb
-	ldf.fill	f30=[r32]
-	ldf.fill	f31=[r31]
+	ldf.fill	f30=[r14]
+	ldf.fill	f31=[r15]
 	br.ret.sptk	rp
 	;;
 }
 END(restorectx)
 
 /*
- * void savectx__(struct pcb *)
  * void swapctx(struct pcb *old, struct pcb *new)
  */
-	
-ENTRY(savectx__,1)
-{	.mib
-	alloc		r16=ar.pfs,1,1,0,0
-	add		r33=0,r0
-	nop		0
-	;;
-}
-	/* FALLTHROUGH */
 
 ENTRY(swapctx, 2)
 {	.mmi

==== //depot/projects/ia64_epc/sys/ia64/include/pcb.h#9 (text+ko) ====

@@ -59,10 +59,9 @@
 
 #ifdef _KERNEL
 
-#define	savectx	savectx__
+#define	savectx(p)	swapctx(p, NULL)
 void restorectx(struct pcb *) __dead2;
-int savectx(struct pcb *);
-void swapctx(struct pcb *old, struct pcb *new);
+int swapctx(struct pcb *old, struct pcb *new);
 
 #if IA32
 void ia32_restorectx(struct pcb *);