[thirdparty/glibc.git] / sysdeps / mips / memset.S

/* Copyright (C) 2002, 2003 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Hartvig Ekner <hartvige@mips.com>, 2002.

   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, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#include <sysdep.h>
#include <endian.h>


/* void *memset(void *s, int c, size_t n).  */

#if __BYTE_ORDER == __BIG_ENDIAN
# define SWHI	swl		/* high part is left in big-endian	*/
#else
# define SWHI	swr		/* high part is right in little-endian	*/
#endif

ENTRY (memset)
	.set	noreorder

	slti	t1, a2, 8		# Less than 8?
	bne	t1, zero, L(last8)
	move	v0, a0			# Setup exit value before too late

	beq	a1, zero, L(ueven)	# If zero pattern, no need to extend
	andi	a1, 0xff		# Avoid problems with bogus arguments
	sll	t0, a1, 8
	or	a1, t0
	sll	t0, a1, 16
	or	a1, t0			# a1 is now pattern in full word

L(ueven):	
	subu	t0, zero, a0		# Unaligned address?
	andi	t0, 0x3
	beq	t0, zero, L(chkw)
	subu	a2, t0
	SWHI	a1, 0(a0)		# Yes, handle first unaligned part
	addu	a0, t0			# Now both a0 and a2 are updated

L(chkw):	
	andi	t0, a2, 0x7		# Enough left for one loop iteration?
	beq	t0, a2, L(chkl)
	subu	a3, a2, t0
	addu	a3, a0			# a3 is last loop address +1
	move	a2, t0			# a2 is now # of bytes left after loop
L(loopw):	
	addiu	a0, 8			# Handle 2 words pr. iteration
	sw	a1, -8(a0)
	bne	a0, a3, L(loopw)
	sw	a1, -4(a0)

L(chkl):	
	andi	t0, a2, 0x4		# Check if there is at least a full
	beq	t0, zero, L(last8)	#  word remaining after the loop
	subu	a2, t0
	sw	a1, 0(a0)		# Yes...
	addiu	a0, 4

L(last8):	
	blez	a2, L(exit)		# Handle last 8 bytes (if cnt>0)
	addu	a3, a2, a0		# a3 is last address +1
L(lst8l):	
	addiu	a0, 1
	bne	a0, a3, L(lst8l)
	sb	a1, -1(a0)
L(exit):	
	j	ra			# Bye, bye
	nop

	.set	reorder
END (memset)
libc_hidden_builtin_def (memset)
Commit	Line	Data
d8a5edc2	1	/* Copyright (C) 2002, 2003 Free Software Foundation, Inc.
9f70d804 AJ	2	This file is part of the GNU C Library.
	3	Contributed by Hartvig Ekner <hartvige@mips.com>, 2002.
	4
	5	The GNU C Library is free software; you can redistribute it and/or
	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.
	9
	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
	13	Lesser General Public License for more details.
	14
	15	You should have received a copy of the GNU Lesser General Public
	16	License along with the GNU C Library; if not, write to the Free
	17	Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
	18	02111-1307 USA. */
	19
	20	#include <sysdep.h>
	21	#include <endian.h>
	22
	23
ee7b7036	24	/* void memset(void s, int c, size_t n). */
9f70d804 AJ	25
	26	#if __BYTE_ORDER == __BIG_ENDIAN
	27	# define SWHI swl /* high part is left in big-endian */
	28	#else
	29	# define SWHI swr /* high part is right in little-endian */
	30	#endif
	31
	32	ENTRY (memset)
	33	.set noreorder
	34
	35	slti t1, a2, 8 # Less than 8?
d8a5edc2	36	bne t1, zero, L(last8)
9f70d804 AJ	37	move v0, a0 # Setup exit value before too late
9f70d804 AJ	38
d8a5edc2	39	beq a1, zero, L(ueven) # If zero pattern, no need to extend
9f70d804 AJ	40	andi a1, 0xff # Avoid problems with bogus arguments
	41	sll t0, a1, 8
	42	or a1, t0
	43	sll t0, a1, 16
	44	or a1, t0 # a1 is now pattern in full word
	45
8f9fb000 AO	46	L(ueven):
8f9fb000 AO	47	subu t0, zero, a0 # Unaligned address?
9f70d804	48	andi t0, 0x3
d8a5edc2	49	beq t0, zero, L(chkw)
9f70d804 AJ	50	subu a2, t0
	51	SWHI a1, 0(a0) # Yes, handle first unaligned part
	52	addu a0, t0 # Now both a0 and a2 are updated
	53
8f9fb000 AO	54	L(chkw):
8f9fb000 AO	55	andi t0, a2, 0x7 # Enough left for one loop iteration?
d8a5edc2	56	beq t0, a2, L(chkl)
9f70d804 AJ	57	subu a3, a2, t0
	58	addu a3, a0 # a3 is last loop address +1
	59	move a2, t0 # a2 is now # of bytes left after loop
8f9fb000 AO	60	L(loopw):
8f9fb000 AO	61	addiu a0, 8 # Handle 2 words pr. iteration
9f70d804	62	sw a1, -8(a0)
d8a5edc2	63	bne a0, a3, L(loopw)
9f70d804 AJ	64	sw a1, -4(a0)
9f70d804 AJ	65
8f9fb000 AO	66	L(chkl):
8f9fb000 AO	67	andi t0, a2, 0x4 # Check if there is at least a full
d8a5edc2	68	beq t0, zero, L(last8) # word remaining after the loop
9f70d804 AJ	69	subu a2, t0
	70	sw a1, 0(a0) # Yes...
	71	addiu a0, 4
	72
8f9fb000 AO	73	L(last8):
8f9fb000 AO	74	blez a2, L(exit) # Handle last 8 bytes (if cnt>0)
9f70d804	75	addu a3, a2, a0 # a3 is last address +1
8f9fb000 AO	76	L(lst8l):
8f9fb000 AO	77	addiu a0, 1
d8a5edc2	78	bne a0, a3, L(lst8l)
9f70d804	79	sb a1, -1(a0)
8f9fb000 AO	80	L(exit):
8f9fb000 AO	81	j ra # Bye, bye
9f70d804 AJ	82	nop
	83
	84	.set reorder
	85	END (memset)
85dd1003	86	libc_hidden_builtin_def (memset)