[thirdparty/glibc.git] / ports / sysdeps / alpha / stpncpy.S

/* Copyright (C) 1996-2013 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Richard Henderson (rth@tamu.edu)

   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/>.  */

/* Copy no more than COUNT bytes of the null-terminated string from
   SRC to DST.  If SRC does not cover all of COUNT, the balance is
   zeroed.  Return the address of the terminating null in DEST, if
   any, else DEST + COUNT.  */

#include <sysdep.h>

	.set noat
	.set noreorder

	.text

ENTRY(__stpncpy)
	ldgp	gp, 0(pv)
#ifdef PROF
	lda	AT, _mcount
	jsr	AT, (AT), _mcount
#endif
	.prologue 1

	beq	a2, $zerocount
	jsr	t9, __stxncpy	# do the work of the copy

	and	t8, 0xf0, t3	# binary search for byte offset of the
	and	t8, 0xcc, t2	# last byte written.
	and	t8, 0xaa, t1
	andnot	a0, 7, v0
	cmovne	t3, 4, t3
	cmovne	t2, 2, t2
	cmovne	t1, 1, t1
	addq	v0, t3, v0
	addq	t1, t2, t1
	addq	v0, t1, v0

	bne	a2, $multiword	# do we have full words left?

	.align 3
	zapnot	t0, t8, t4	# e0    : was last byte a null?
	subq	t8, 1, t2	# .. e1 :
	addq	v0, 1, t5	# e0    :
	subq	t10, 1, t3	# .. e1 :
	or	t2, t8, t2	# e0    : clear the bits between the last
	or	t3, t10, t3	# .. e1 : written byte and the last byte in
	andnot	t3, t2, t3	# e0    : COUNT
	cmovne	t4, t5, v0	# .. e1 : if last written wasnt null, inc v0
	zap	t0, t3, t0	# e0    :
	stq_u	t0, 0(a0)	# e1    :
	ret			# .. e1 :

	.align 3
$multiword:
	subq	t8, 1, t7	# e0    : clear the final bits in the prev
	or	t7, t8, t7	# e1    : word
	zapnot	t0, t7, t0	# e0    :
	subq	a2, 1, a2	# .. e1 :
	stq_u	t0, 0(a0)	# e0    :
	addq	a0, 8, a0	# .. e1 :

	beq	a2, 1f		# e1    :
	blbc	a2, 0f		# e1    :

	stq_u	zero, 0(a0)	# e0    : zero one word
	subq	a2, 1, a2	# .. e1 :
	addq	a0, 8, a0	# e0    :
	beq	a2, 1f		# .. e1 :

0:	stq_u	zero, 0(a0)	# e0    : zero two words
	subq	a2, 2, a2	# .. e1 :
	stq_u	zero, 8(a0)	# e0    :
	addq	a0, 16, a0	# .. e1 :
	bne	a2, 0b		# e1    :
	unop

1:	ldq_u	t0, 0(a0)	# e0    : clear the leading bits in the final
	subq	t10, 1, t7	# .. e1 : word
	or	t7, t10, t7	# e0    :
	zap	t0, t7, t0	# e1 (stall)
	stq_u	t0, 0(a0)	# e0    :
	ret			# .. e1 :

$zerocount:
	mov	a0, v0
	ret

	END(__stpncpy)

libc_hidden_def (__stpncpy)
weak_alias (__stpncpy, stpncpy)
Commit	Line	Data
568035b7	1	/* Copyright (C) 1996-2013 Free Software Foundation, Inc.
60c74cf0	2	This file is part of the GNU C Library.
cf182b58 UD	3	Contributed by Richard Henderson (rth@tamu.edu)
cf182b58 UD	4
60c74cf0	5	The GNU C Library is free software; you can redistribute it and/or
3214b89b AJ	6	modify it under the terms of the GNU Lesser General Public
	7	License as published by the Free Software Foundation; either
	8	version 2.1 of the License, or (at your option) any later version.
cf182b58	9
60c74cf0 UD	10	The GNU C Library is distributed in the hope that it will be useful,
	11	but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
3214b89b	13	Lesser General Public License for more details.
cf182b58	14
3214b89b	15	You should have received a copy of the GNU Lesser General Public
ab84e3ff PE	16	License along with the GNU C Library. If not, see
ab84e3ff PE	17	<http://www.gnu.org/licenses/>. */
cf182b58	18
60c74cf0	19	/* Copy no more than COUNT bytes of the null-terminated string from
cf182b58 UD	20	SRC to DST. If SRC does not cover all of COUNT, the balance is
	21	zeroed. Return the address of the terminating null in DEST, if
	22	any, else DEST + COUNT. */
	23
	24	#include <sysdep.h>
	25
	26	.set noat
	27	.set noreorder
	28
	29	.text
	30
	31	ENTRY(__stpncpy)
	32	ldgp gp, 0(pv)
60c74cf0 UD	33	#ifdef PROF
	34	lda AT, _mcount
	35	jsr AT, (AT), _mcount
	36	#endif
cf182b58	37	.prologue 1
60c74cf0	38
cf182b58 UD	39	beq a2, $zerocount
	40	jsr t9, __stxncpy # do the work of the copy
	41
	42	and t8, 0xf0, t3 # binary search for byte offset of the
	43	and t8, 0xcc, t2 # last byte written.
	44	and t8, 0xaa, t1
	45	andnot a0, 7, v0
	46	cmovne t3, 4, t3
	47	cmovne t2, 2, t2
	48	cmovne t1, 1, t1
	49	addq v0, t3, v0
	50	addq t1, t2, t1
	51	addq v0, t1, v0
	52
	53	bne a2, $multiword # do we have full words left?
	54
	55	.align 3
	56	zapnot t0, t8, t4 # e0 : was last byte a null?
	57	subq t8, 1, t2 # .. e1 :
	58	addq v0, 1, t5 # e0 :
	59	subq t10, 1, t3 # .. e1 :
	60	or t2, t8, t2 # e0 : clear the bits between the last
	61	or t3, t10, t3 # .. e1 : written byte and the last byte in
	62	andnot t3, t2, t3 # e0 : COUNT
	63	cmovne t4, t5, v0 # .. e1 : if last written wasnt null, inc v0
	64	zap t0, t3, t0 # e0 :
	65	stq_u t0, 0(a0) # e1 :
	66	ret # .. e1 :
	67
	68	.align 3
	69	$multiword:
	70	subq t8, 1, t7 # e0 : clear the final bits in the prev
	71	or t7, t8, t7 # e1 : word
	72	zapnot t0, t7, t0 # e0 :
	73	subq a2, 1, a2 # .. e1 :
	74	stq_u t0, 0(a0) # e0 :
	75	addq a0, 8, a0 # .. e1 :
	76
	77	beq a2, 1f # e1 :
	78	blbc a2, 0f # e1 :
	79
	80	stq_u zero, 0(a0) # e0 : zero one word
	81	subq a2, 1, a2 # .. e1 :
	82	addq a0, 8, a0 # e0 :
	83	beq a2, 1f # .. e1 :
	84
	85	0: stq_u zero, 0(a0) # e0 : zero two words
	86	subq a2, 2, a2 # .. e1 :
	87	stq_u zero, 8(a0) # e0 :
	88	addq a0, 16, a0 # .. e1 :
	89	bne a2, 0b # e1 :
	90	unop
	91
	92	1: ldq_u t0, 0(a0) # e0 : clear the leading bits in the final
	93	subq t10, 1, t7 # .. e1 : word
	94	or t7, t10, t7 # e0 :
	95	zap t0, t7, t0 # e1 (stall)
	96	stq_u t0, 0(a0) # e0 :
	97	ret # .. e1 :
	98
	99	$zerocount:
	100	mov a0, v0
	101	ret
	102
103	END(__stpncpy)
104
d8c656ce	105	libc_hidden_def (__stpncpy)
cf182b58	106	weak_alias (__stpncpy, stpncpy)