Alpha ev67 strncat implementation.

sysdeps/alpha/alphaev67/strncat.S

@@ -0,0 +1,101 @@
+/* Copyright (C) 2000 Free Software Foundation, Inc.
+   Contributed by Richard Henderson <rth@tamu.edu>, 1996.
+   EV67 optimized by Rick Gorton <rick.gorton@alpha-processor.com>.
+
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 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
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+/* 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>
+
+	.arch ev6
+	.set noreorder
+	.text
+
+ENTRY(strncat)
+	ldgp	gp, 0(pv)
+#ifdef PROF
+	.set noat
+	lda	AT, _mcount
+	jsr	AT, (AT), _mcount
+	.set at
+#endif
+	.prologue 1
+
+	mov	$16, $0		# set up return value
+	beq	$18, $zerocount	# U :
+	/* Find the end of the string.  */
+	ldq_u   $1, 0($16)	# L : load first quadword ($16 may be misaligned)
+	lda     $2, -1($31)	# E :
+
+	insqh   $2, $0, $2	# U :
+	andnot  $16, 7, $16	# E :
+	nop			# E :
+	or      $2, $1, $1	# E :
+
+	nop			# E :
+	nop			# E :
+	cmpbge  $31, $1, $2	# E : bits set iff byte == 0
+	bne     $2, $found	# U :
+
+$loop:	ldq     $1, 8($16)	# L :
+	addq    $16, 8, $16	# E :
+	cmpbge  $31, $1, $2	# E :
+	beq     $2, $loop	# U :
+
+$found:	cttz	$2, $3		# U0 :
+	addq	$16, $3, $16	# E :
+	jsr	$23, __stxncpy	# L0 :/* Now do the append.  */
+
+	/* Worry about the null termination.  */
+
+	zapnot	$1, $27, $2	# U : was last byte a null?
+	cmplt	$27, $24, $5	# E : did we fill the buffer completely?
+	bne	$2, 0f		# U :
+	ret			# L0 :
+
+0:	or	$5, $18, $2	# E :
+	nop
+	bne	$2, 2f		# U :
+	and	$24, 0x80, $3	# E : no zero next byte
+
+	nop			# E :
+	bne	$3, 1f		# U :
+	/* Here there are bytes left in the current word.  Clear one.  */
+	addq	$24, $24, $24	# E : end-of-count bit <<= 1
+	nop			# E :
+
+2:	zap	$1, $24, $1	# U :
+	nop			# E :
+	stq_u	$1, 0($16)	# L :
+	ret			# L0 :
+
+1:	/* Here we must clear the first byte of the next DST word */
+	stb	$31, 8($16)	# L :
+	nop			# E :
+	nop			# E :
+	ret			# L0 :
+
+$zerocount:
+	nop			# E :
+	nop			# E :
+	nop			# E :
+	ret			# L0 :
+
+	END(strncat)