[xtensa-cvscommit] linux/arch/xtensa/lib checksum.S,1.3,1.4

[<joe...@us...>]

Update of /cvsroot/xtensa/linux/arch/xtensa/lib
In directory usw-pr-cvs1:/tmp/cvs-serv31798/arch/xtensa/lib

Modified Files:
	checksum.S 
Log Message:

csum_partial() now handles odd addresses properly, just to be safe.


Index: checksum.S
===================================================================
RCS file: /cvsroot/xtensa/linux/arch/xtensa/lib/checksum.S,v
retrieving revision 1.3
retrieving revision 1.4
diff -C2 -d -r1.3 -r1.4
*** checksum.S	8 Nov 2002 01:44:00 -0000	1.3
--- checksum.S	8 Nov 2002 23:17:41 -0000	1.4
***************
*** 117,125 ****
  	beqz	a3, 7b		/* branch if len == 0 */
  	beqi	a3, 1, 6b	/* branch if len == 1 */
! 	l16ui	a6, a2, 0	/* common case, len == 2 */
  	ONES_ADD(a4, a6)
  	addi	a2, a2, 2	/* adjust buf */
  	addi	a3, a3, -2	/* adjust len */
  	j	1b		/* now buf is 4-byte aligned */
  
  
--- 117,174 ----
  	beqz	a3, 7b		/* branch if len == 0 */
  	beqi	a3, 1, 6b	/* branch if len == 1 */
! 
! 	extui	a5, a2, 0, 1
! 	bnez	a5, 8f		/* branch if 1-byte aligned */
! 
! 	l16ui	a6, a2, 0	/* common case, len >= 2 */
  	ONES_ADD(a4, a6)
  	addi	a2, a2, 2	/* adjust buf */
  	addi	a3, a3, -2	/* adjust len */
  	j	1b		/* now buf is 4-byte aligned */
+ 
+ 	/* case: odd-byte aligned, len > 1
+ 	 * This case is dog slow, so don't give us an odd address.
+ 	 * (I don't think this ever happens, but just in case.)
+ 	 */
+ 8:
+ 	srli	a5, a3, 2	/* 4-byte chunks */
+ #if XCHAL_HAVE_LOOPS
+ 	loopgtz	a5, 2f
+ #else
+ 	beqz	a5, 2f
+ 	slli	a5, a5, 2
+ 	add	a5, a5, a2	/* a5 = end of last 4-byte chunk */
+ .Loop3:
+ #endif
+ 	l8ui	a6, a2, 0	/* bits 24..31 */
+ 	l16ui	a7, a2, 1	/* bits  8..23 */
+ 	l8ui	a8, a2, 3	/* bits  0.. 8 */
+ #ifdef	__XTENSA_EB__
+ 	slli	a6, a6, 24
+ #else
+ 	slli	a8, a8, 24
+ #endif
+ 	slli	a7, a7, 8
+ 	or	a7, a7, a6
+ 	or	a7, a7, a8
+ 	ONES_ADD(a4, a7)
+ 	addi	a2, a2, 4
+ #if !XCHAL_HAVE_LOOPS
+ 	blt	a2, a5, .Loop3
+ #endif
+ 2:
+ 	_bbci.l	a3, 1, 3f	/* remaining 2-byte chunk, still odd addr */
+ 	l8ui	a6, a2, 0
+ 	l8ui	a7, a2, 1
+ #ifdef	__XTENSA_EB__
+ 	slli	a6, a6, 8
+ #else
+ 	slli	a7, a7, 8
+ #endif
+ 	or	a7, a7, a6
+ 	ONES_ADD(a4, a7)
+ 	addi	a2, a2, 2
+ 3:
+ 	j	5b		/* branch to handle the remaining byte */