[thirdparty/glibc.git] / ports / sysdeps / mips / mips64 / memset.S

/* Copyright (C) 2002-2012 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Hartvig Ekner <hartvige@mips.com>, 2002.
   Ported to mips3 n32/n64 by Alexandre Oliva <aoliva@redhat.com>

   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/>.  */

#include <sysdep.h>
#include <sys/asm.h>


/* void *memset(void *s, int c, size_t n);
	
   This could probably be optimized further.  */

#if __MIPSEB
# define SDHI	sdl		/* high part is left in big-endian	*/
#else
# define SDHI	sdr		/* high part is right in little-endian	*/
#endif

ENTRY (memset)
	.set	noreorder

	slti	ta1, a2, 16		# Less than 16?
	bne	ta1, zero, L(last16)
	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
	dsll	ta0, a1, 8
	or	a1, ta0
	dsll	ta0, a1, 16
	or	a1, ta0			# a1 is now pattern in full word
	dsll	ta0, a1, 32
	or	a1, ta0			# a1 is now pattern in double word

L(ueven):
	PTR_SUBU ta0, zero, a0		# Unaligned address?
	andi	ta0, 0x7
	beq	ta0, zero, L(chkw)
	PTR_SUBU a2, ta0
	SDHI	a1, 0(a0)		# Yes, handle first unaligned part
	PTR_ADDU a0, ta0		# Now both a0 and a2 are updated

L(chkw):
	andi	ta0, a2, 0xf		# Enough left for one loop iteration?
	beq	ta0, a2, L(chkl)
	PTR_SUBU a3, a2, ta0
	PTR_ADDU a3, a0			# a3 is last loop address +1
	move	a2, ta0			# a2 is now # of bytes left after loop
L(loopw):
	PTR_ADDIU a0, 16		# Handle 2 dwords pr. iteration
	sd	a1, -16(a0)
	bne	a0, a3, L(loopw)
	sd	a1,  -8(a0)

L(chkl):
	andi	ta0, a2, 0x8		# Check if there is at least a double
	beq	ta0, zero, L(last16)	#  word remaining after the loop
	PTR_SUBU a2, ta0
	sd	a1, 0(a0)		# Yes...
	PTR_ADDIU a0, 8

L(last16):
	blez	a2, L(exit)		# Handle last 16 bytes (if cnt>0)
	PTR_ADDU a3, a2, a0		# a3 is last address +1
L(lst16l):
	PTR_ADDIU a0, 1
	bne	a0, a3, L(lst16l)
	sb	a1, -1(a0)
L(exit):
	j	ra			# Bye, bye
	nop

	.set	reorder
END (memset)
libc_hidden_builtin_def (memset)
Commit	Line	Data
896216ff	1	/* Copyright (C) 2002-2012 Free Software Foundation, Inc.
500308e1 AO	2	This file is part of the GNU C Library.
	3	Contributed by Hartvig Ekner <hartvige@mips.com>, 2002.
	4	Ported to mips3 n32/n64 by Alexandre Oliva <aoliva@redhat.com>
	5
	6	The GNU C Library is free software; you can redistribute it and/or
	7	modify it under the terms of the GNU Lesser General Public
	8	License as published by the Free Software Foundation; either
	9	version 2.1 of the License, or (at your option) any later version.
	10
	11	The GNU C Library is distributed in the hope that it will be useful,
	12	but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	14	Lesser General Public License for more details.
	15
	16	You should have received a copy of the GNU Lesser General Public
ab84e3ff PE	17	License along with the GNU C Library. If not, see
ab84e3ff PE	18	<http://www.gnu.org/licenses/>. */
500308e1 AO	19
500308e1 AO	20	#include <sysdep.h>
500308e1 AO	21	#include <sys/asm.h>
	22
	23
	24	/* void memset(void s, int c, size_t n);
	25
	26	This could probably be optimized further. */
	27
896216ff	28	#if __MIPSEB
500308e1 AO	29	# define SDHI sdl /* high part is left in big-endian */
	30	#else
	31	# define SDHI sdr /* high part is right in little-endian */
	32	#endif
	33
	34	ENTRY (memset)
	35	.set noreorder
	36
96c095cf AO	37	slti ta1, a2, 16 # Less than 16?
96c095cf AO	38	bne ta1, zero, L(last16)
500308e1 AO	39	move v0, a0 # Setup exit value before too late
	40
	41	beq a1, zero, L(ueven) # If zero pattern, no need to extend
	42	andi a1, 0xff # Avoid problems with bogus arguments
96c095cf AO	43	dsll ta0, a1, 8
	44	or a1, ta0
	45	dsll ta0, a1, 16
	46	or a1, ta0 # a1 is now pattern in full word
	47	dsll ta0, a1, 32
	48	or a1, ta0 # a1 is now pattern in double word
500308e1 AO	49
500308e1 AO	50	L(ueven):
96c095cf AO	51	PTR_SUBU ta0, zero, a0 # Unaligned address?
	52	andi ta0, 0x7
	53	beq ta0, zero, L(chkw)
	54	PTR_SUBU a2, ta0
500308e1	55	SDHI a1, 0(a0) # Yes, handle first unaligned part
96c095cf	56	PTR_ADDU a0, ta0 # Now both a0 and a2 are updated
500308e1 AO	57
500308e1 AO	58	L(chkw):
96c095cf AO	59	andi ta0, a2, 0xf # Enough left for one loop iteration?
	60	beq ta0, a2, L(chkl)
	61	PTR_SUBU a3, a2, ta0
500308e1	62	PTR_ADDU a3, a0 # a3 is last loop address +1
96c095cf	63	move a2, ta0 # a2 is now # of bytes left after loop
500308e1	64	L(loopw):
2b15a211	65	PTR_ADDIU a0, 16 # Handle 2 dwords pr. iteration
500308e1 AO	66	sd a1, -16(a0)
	67	bne a0, a3, L(loopw)
	68	sd a1, -8(a0)
	69
	70	L(chkl):
96c095cf AO	71	andi ta0, a2, 0x8 # Check if there is at least a double
	72	beq ta0, zero, L(last16) # word remaining after the loop
	73	PTR_SUBU a2, ta0
500308e1 AO	74	sd a1, 0(a0) # Yes...
	75	PTR_ADDIU a0, 8
	76
2b15a211 AO	77	L(last16):
2b15a211 AO	78	blez a2, L(exit) # Handle last 16 bytes (if cnt>0)
500308e1	79	PTR_ADDU a3, a2, a0 # a3 is last address +1
2b15a211	80	L(lst16l):
500308e1	81	PTR_ADDIU a0, 1
2b15a211	82	bne a0, a3, L(lst16l)
500308e1 AO	83	sb a1, -1(a0)
	84	L(exit):
	85	j ra # Bye, bye
	86	nop
	87
	88	.set reorder
	89	END (memset)
79b7c863	90	libc_hidden_builtin_def (memset)