/* * arch/alpha/lib/strncat.S * Contributed by Richard Henderson (rth@tamu.edu) * * Append no more than COUNT characters from the null-terminated string SRC * to the null-terminated string DST.  Always null-terminate the new DST. * * This differs slightly from the semantics in libc in that we never write * past count, whereas libc may write to count+1.  This follows the generic * implementation in lib/string.c and is, IMHO, more sensible. */	.text	.align 3	.globl strncat	.ent strncatstrncat:	.frame $30, 0, $26	.prologue 0	mov	$16, $0		# set up return value	beq	$18, $zerocount	/* Find the end of the string.  */	ldq_u   $1, 0($16)	# load first quadword ($16 may be misaligned)	lda     $2, -1($31)	insqh   $2, $16, $2	andnot  $16, 7, $16	or      $2, $1, $1	cmpbge  $31, $1, $2	# bits set iff byte == 0	bne     $2, $found$loop:	ldq     $1, 8($16)	addq    $16, 8, $16	cmpbge  $31, $1, $2	beq     $2, $loop$found:	negq    $2, $3		# clear all but least set bit	and     $2, $3, $2	and     $2, 0xf0, $3	# binary search for that set bit	and	$2, 0xcc, $4	and	$2, 0xaa, $5	cmovne	$3, 4, $3	cmovne	$4, 2, $4	cmovne	$5, 1, $5	addq	$3, $4, $3	addq	$16, $5, $16	addq	$16, $3, $16	/* Now do the append.  */	bsr	$23, __stxncpy	/* Worry about the null termination.  */	zapnot	$1, $27, $2	# was last byte a null?	bne	$2, 0f	ret0:	cmplt	$27, $24, $2	# did we fill the buffer completely?	or	$2, $18, $2	bne	$2, 2f	and	$24, 0x80, $2	# no zero next byte	bne	$2, 1f	/* Here there are bytes left in the current word.  Clear one.  */	addq	$24, $24, $24	# end-of-count bit <<= 12:	zap	$1, $24, $1	stq_u	$1, 0($16)	ret1:	/* Here we must read the next DST word and clear the first byte.  */	ldq_u	$1, 8($16)	zap	$1, 1, $1	stq_u	$1, 8($16)$zerocount:	ret	.end strncat