aboutsummaryrefslogtreecommitdiff
path: root/sysdeps/mips/mips64/memcpy.S
blob: eab9463f864710477f2cf588501af6b6cf81c358 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
/* 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.
   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, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

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


/* void *memcpy(void *s1, const void *s2, size_t n);
	
   This could probably be optimized further.  */

#if __BYTE_ORDER == __BIG_ENDIAN
#  define LDHI	ldl		/* high part is left in big-endian	*/
#  define SDHI	sdl		/* high part is left in big-endian	*/
#  define LDLO	ldr		/* low part is right in big-endian	*/
#  define SDLO	sdr		/* low part is right in big-endian	*/
#else
#  define LDHI	ldr		/* high part is right in little-endian	*/
#  define SDHI	sdr		/* high part is right in little-endian	*/
#  define LDLO	ldl		/* low part is left in little-endian	*/
#  define SDLO	sdl		/* low part is left in little-endian	*/
#endif

ENTRY (memcpy)
	.set	noreorder

	slti	t0, a2, 16		# Less than 16?
	bne	t0, zero, L(last16)
	move	v0, a0			# Setup exit value before too late

	xor	t0, a1, a0		# Find a0/a1 displacement
	andi	t0, 0x7
	bne	t0, zero, L(shift)	# Go handle the unaligned case
	PTR_SUBU t1, zero, a1
	andi	t1, 0x7			# a0/a1 are aligned, but are we
	beq	t1, zero, L(chk8w)	#  starting in the middle of a word?
	PTR_SUBU a2, t1
	LDHI	t0, 0(a1)		# Yes we are... take care of that
	PTR_ADDU a1, t1
	SDHI	t0, 0(a0)
	PTR_ADDU a0, t1

L(chk8w):
	andi	t0, a2, 0x3f		# 64 or more bytes left?
	beq	t0, a2, L(chk1w)
	PTR_SUBU a3, a2, t0		# Yes
	PTR_ADDU a3, a1			# a3 = end address of loop
	move	a2, t0			# a2 = what will be left after loop
L(lop8w):	
	ld	t0,  0(a1)		# Loop taking 8 words at a time
	ld	t1,  8(a1)
	ld	t2, 16(a1)
	ld	t3, 24(a1)
	ld	ta0, 32(a1)
	ld	ta1, 40(a1)
	ld	ta2, 48(a1)
	ld	ta3, 56(a1)
	PTR_ADDIU a0, 64
	PTR_ADDIU a1, 64
	sd	t0, -64(a0)
	sd	t1, -56(a0)
	sd	t2, -48(a0)
	sd	t3, -40(a0)
	sd	ta0, -32(a0)
	sd	ta1, -24(a0)
	sd	ta2, -16(a0)
	bne	a1, a3, L(lop8w)
	sd	ta3,  -8(a0)

L(chk1w):
	andi	t0, a2, 0x7		# 8 or more bytes left?
	beq	t0, a2, L(last16)
	PTR_SUBU a3, a2, t0		# Yes, handle them one dword at a time
	PTR_ADDU a3, a1			# a3 again end address
	move	a2, t0
L(lop1w):
	ld	t0, 0(a1)
	PTR_ADDIU a0, 8
	PTR_ADDIU a1, 8
	bne	a1, a3, L(lop1w)
	sd	t0, -8(a0)

L(last16):
	blez	a2, L(lst16e)		# Handle last 16 bytes, one at a time
	PTR_ADDU a3, a2, a1
L(lst16l):
	lb	t0, 0(a1)
	PTR_ADDIU a0, 1
	PTR_ADDIU a1, 1
	bne	a1, a3, L(lst16l)
	sb	t0, -1(a0)
L(lst16e):
	jr	ra			# Bye, bye
	nop

L(shift):
	PTR_SUBU a3, zero, a0		# Src and Dest unaligned 
	andi	a3, 0x7			#  (unoptimized case...)
	beq	a3, zero, L(shft1)
	PTR_SUBU a2, a3			# a2 = bytes left
	LDHI	t0, 0(a1)		# Take care of first odd part
	LDLO	t0, 7(a1)
	PTR_ADDU a1, a3
	SDHI	t0, 0(a0)
	PTR_ADDU a0, a3
L(shft1):
	andi	t0, a2, 0x7
	PTR_SUBU a3, a2, t0
	PTR_ADDU a3, a1
L(shfth):
	LDHI	t1, 0(a1)		# Limp through, dword by dword
	LDLO	t1, 7(a1)
	PTR_ADDIU a0, 8
	PTR_ADDIU a1, 8
	bne	a1, a3, L(shfth)
	sd	t1, -8(a0)
	b	L(last16)		# Handle anything which may be left
	move	a2, t0

	.set	reorder
END (memcpy)
libc_hidden_builtin_def (memcpy)