Re: strncpy (maybe others) broken on Alpha

[Ivan Kokshaysky <ink@jurassic.park.msu.ru>]

On Fri, Apr 21, 2006 at 01:55:56PM +0200, Mathieu Chouquet-Stringer wrote:
> I've attached to this email a tarball of what I use to test the
> compiler/binutils.  It's faster than recompiling the whole kernel on
> these slow machines!

Oops. I was using a wrong copy of strncpy.S (remained from previous
__stxncpy() debugging). What's why I wasn't able to reproduce that...

It seems that the registers $24 and $27 are mixed up in strncpy().
This fixes your test case, please check if it fixes kernel problem
as well.

Ivan.

--- strncpy_debug/strncpy.S	Thu Apr 20 14:18:05 2006
+++ strncpy.S	Fri Apr 21 17:52:04 2006
@@ -43,8 +43,8 @@
 
 	.align	4
 $multiword:
-	subq	$24, 1, $2	# clear the final bits in the prev word
-	or	$2, $24, $2
+	subq	$27, 1, $2	# clear the final bits in the prev word
+	or	$2, $27, $2
 	zapnot	$1, $2, $1
 	subq	$18, 1, $18
 
@@ -70,8 +70,8 @@
 	bne	$18, 0b
 
 1:	ldq_u	$1, 0($16)	# clear the leading bits in the final word
-	subq	$27, 1, $2
-	or	$2, $27, $2
+	subq	$24, 1, $2
+	or	$2, $24, $2
 
 	zap	$1, $2, $1
 	stq_u	$1, 0($16)