1/*
2 * internal version of memcpy(), issued by the compiler to copy blocks of
3 * data around. This is really memmove() - it has to be able to deal with
4 * possible overlaps, because that ambiguity is when the compiler gives up
5 * and calls a function. We have our own, internal version so that we get
6 * something we trust, even if the user has redefined the normal symbol.
7 *
8 * Copyright 2004-2009 Analog Devices Inc.
9 *
10 * Licensed under the Clear BSD license or the GPL-2 (or later)
11 */
12
13#include <linux/linkage.h>
14
15/* void *memcpy(void *dest, const void *src, size_t n);
16 * R0 = To Address (dest) (leave unchanged to form result)
17 * R1 = From Address (src)
18 * R2 = count
19 *
20 * Note: Favours word alignment
21 */
22
23#ifdef CONFIG_MEMCPY_L1
24.section .l1.text
25#else
26.text
27#endif
28
29.align 2
30
31ENTRY(_memcpy)
32	CC = R2 <=  0;	/* length not positive? */
33	IF CC JUMP .L_P1L2147483647;	/* Nothing to do */
34
35	P0 = R0 ;	/* dst*/
36	P1 = R1 ;	/* src*/
37	P2 = R2 ;	/* length */
38
39	/* check for overlapping data */
40	CC = R1 < R0;	/* src < dst */
41	IF !CC JUMP .Lno_overlap;
42	R3 = R1 + R2;
43	CC = R0 < R3;	/* and dst < src+len */
44	IF CC JUMP .Lhas_overlap;
45
46.Lno_overlap:
47	/* Check for aligned data.*/
48
49	R3 = R1 | R0;
50	R1 = 0x3;
51	R3 = R3 & R1;
52	CC = R3;	/* low bits set on either address? */
53	IF CC JUMP .Lnot_aligned;
54
55	/* Both addresses are word-aligned, so we can copy
56	at least part of the data using word copies.*/
57	P2 = P2 >> 2;
58	CC = P2 <= 2;
59	IF !CC JUMP .Lmore_than_seven;
60	/* less than eight bytes... */
61	P2 = R2;
62	LSETUP(.Lthree_start, .Lthree_end) LC0=P2;
63.Lthree_start:
64	R3 = B[P1++] (X);
65.Lthree_end:
66	B[P0++] = R3;
67
68	RTS;
69
70.Lmore_than_seven:
71	/* There's at least eight bytes to copy. */
72	P2 += -1;	/* because we unroll one iteration */
73	LSETUP(.Lword_loops, .Lword_loope) LC0=P2;
74	I1 = P1;
75	R3 = [I1++];
76#if ANOMALY_05000202
77.Lword_loops:
78	[P0++] = R3;
79.Lword_loope:
80	R3 = [I1++];
81#else
82.Lword_loops:
83.Lword_loope:
84	MNOP || [P0++] = R3 || R3 = [I1++];
85#endif
86	[P0++] = R3;
87	/* Any remaining bytes to copy? */
88	R3 = 0x3;
89	R3 = R2 & R3;
90	CC = R3 == 0;
91	P1 = I1;	/* in case there's something left, */
92	IF !CC JUMP .Lbytes_left;
93	RTS;
94.Lbytes_left:	P2 = R3;
95.Lnot_aligned:
96	/* From here, we're copying byte-by-byte. */
97	LSETUP (.Lbyte_start, .Lbyte_end) LC0=P2;
98.Lbyte_start:
99	R1 = B[P1++] (X);
100.Lbyte_end:
101	B[P0++] = R1;
102
103.L_P1L2147483647:
104	RTS;
105
106.Lhas_overlap:
107	/* Need to reverse the copying, because the
108	 * dst would clobber the src.
109	 * Don't bother to work out alignment for
110	 * the reverse case.
111	 */
112	P0 = P0 + P2;
113	P0 += -1;
114	P1 = P1 + P2;
115	P1 += -1;
116	LSETUP(.Lover_start, .Lover_end) LC0=P2;
117.Lover_start:
118	R1 = B[P1--] (X);
119.Lover_end:
120	B[P0--] = R1;
121
122	RTS;
123
124ENDPROC(_memcpy)
125