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+/* Copyright (C) 1996-2014 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Richard Henderson <rth@tamu.edu>, 1996.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library.  If not, see
+   <http://www.gnu.org/licenses/>.  */
+
+/* Append no more than COUNT characters from the null-terminated string SRC
+   to the null-terminated string DST.  Always null-terminate the new DST.  */
+
+#include <sysdep.h>
+
+	.text
+
+ENTRY(strncat)
+	ldgp	gp, 0(pv)
+#ifdef PROF
+	.set noat
+	lda	AT, _mcount
+	jsr	AT, (AT), _mcount
+	.set at
+#endif
+	.prologue 1
+
+	mov	a0, v0		# set up return value
+	beq	a2, $zerocount
+
+	/* Find the end of the string.  */
+
+	ldq_u   t0, 0(a0)	# load first quadword (a0 may be misaligned)
+	lda     t1, -1(zero)
+	insqh   t1, a0, t1
+	andnot  a0, 7, a0
+	or      t1, t0, t0
+	cmpbge  zero, t0, t1	# t1 <- bitmask: bit i == 1 <==> i-th byte == 0
+	bne     t1, $found
+
+$loop:	ldq     t0, 8(a0)
+	addq    a0, 8, a0	# addr += 8
+	cmpbge  zero, t0, t1
+	beq     t1, $loop
+
+$found:	negq    t1, t2		# clear all but least set bit
+	and     t1, t2, t1
+
+	and     t1, 0xf0, t2	# binary search for that set bit
+	and	t1, 0xcc, t3
+	and	t1, 0xaa, t4
+	cmovne	t2, 4, t2
+	cmovne	t3, 2, t3
+	cmovne	t4, 1, t4
+	addq	t2, t3, t2
+	addq	a0, t4, a0
+	addq	a0, t2, a0
+
+	/* Now do the append.  */
+
+	jsr	t9, __stxncpy
+
+	/* Worry about the null termination.  */
+
+	zapnot	t0, t8, t1	# was last byte a null?
+	bne	t1, 0f
+	ret
+
+0:	and	t10, 0x80, t1
+	bne	t1, 1f
+
+	/* Here there are bytes left in the current word.  Clear one.  */
+	addq	t10, t10, t10	# end-of-count bit <<= 1
+	zap	t0, t10, t0
+	stq_u	t0, 0(a0)
+	ret
+
+1:	/* Here we must read the next DST word and clear the first byte.  */
+	ldq_u	t0, 8(a0)
+	zap	t0, 1, t0
+	stq_u	t0, 8(a0)
+
+$zerocount:
+	ret
+
+	END(strncat)