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Aubrey.Li3f0606a2007-03-09 13:38:44 +08001/*
Aubrey Li155fd762007-04-05 18:31:18 +08002 * File: memcpy.S
Aubrey.Li3f0606a2007-03-09 13:38:44 +08003 *
Aubrey Li155fd762007-04-05 18:31:18 +08004 * Copyright 2004-2007 Analog Devices Inc.
5 * Enter bugs at http://blackfin.uclinux.org/
Aubrey.Li3f0606a2007-03-09 13:38:44 +08006 *
Wolfgang Denk1a459662013-07-08 09:37:19 +02007 * SPDX-License-Identifier: GPL-2.0+
Aubrey.Li3f0606a2007-03-09 13:38:44 +08008 */
Aubrey Li155fd762007-04-05 18:31:18 +08009
Aubrey.Li3f0606a2007-03-09 13:38:44 +080010.align 2
11
12.globl _memcpy_ASM;
Mike Frysinger5b221632008-02-19 00:36:14 -050013.type _memcpy_ASM, STT_FUNC;
Aubrey.Li3f0606a2007-03-09 13:38:44 +080014_memcpy_ASM:
15 CC = R2 <= 0; /* length not positive?*/
16 IF CC JUMP .L_P1L2147483647; /* Nothing to do */
17
18 P0 = R0 ; /* dst*/
19 P1 = R1 ; /* src*/
20 P2 = R2 ; /* length */
21
22 /* check for overlapping data */
23 CC = R1 < R0; /* src < dst */
24 IF !CC JUMP .Lno_overlap;
25 R3 = R1 + R2;
26 CC = R0 < R3; /* and dst < src+len */
27 IF CC JUMP .Lhas_overlap;
28
29.Lno_overlap:
30 /* Check for aligned data.*/
31
32 R3 = R1 | R0;
33 R0 = 0x3;
34 R3 = R3 & R0;
35 CC = R3; /* low bits set on either address? */
36 IF CC JUMP .Lnot_aligned;
37
38 /* Both addresses are word-aligned, so we can copy
39 at least part of the data using word copies.*/
40 P2 = P2 >> 2;
41 CC = P2 <= 2;
42 IF !CC JUMP .Lmore_than_seven;
43 /* less than eight bytes... */
44 P2 = R2;
45 LSETUP(.Lthree_start, .Lthree_end) LC0=P2;
46 R0 = R1; /* setup src address for return */
47.Lthree_start:
48 R3 = B[P1++] (X);
49.Lthree_end:
50 B[P0++] = R3;
51
52 RTS;
53
54.Lmore_than_seven:
55 /* There's at least eight bytes to copy. */
56 P2 += -1; /* because we unroll one iteration */
57 LSETUP(.Lword_loop, .Lword_loop) LC0=P2;
58 R0 = R1;
59 I1 = P1;
60 R3 = [I1++];
61.Lword_loop:
62 MNOP || [P0++] = R3 || R3 = [I1++];
63
64 [P0++] = R3;
65 /* Any remaining bytes to copy? */
66 R3 = 0x3;
67 R3 = R2 & R3;
68 CC = R3 == 0;
69 P1 = I1; /* in case there's something left, */
70 IF !CC JUMP .Lbytes_left;
71 RTS;
72.Lbytes_left: P2 = R3;
73.Lnot_aligned:
74 /* From here, we're copying byte-by-byte. */
75 LSETUP (.Lbyte_start , .Lbyte_end) LC0=P2;
76 R0 = R1; /* Save src address for return */
77.Lbyte_start:
78 R1 = B[P1++] (X);
79.Lbyte_end:
80 B[P0++] = R1;
81
82.L_P1L2147483647:
83 RTS;
84
85.Lhas_overlap:
86/* Need to reverse the copying, because the
87 * dst would clobber the src.
88 * Don't bother to work out alignment for
89 * the reverse case.
90 */
91 R0 = R1; /* save src for later. */
92 P0 = P0 + P2;
93 P0 += -1;
94 P1 = P1 + P2;
95 P1 += -1;
96 LSETUP(.Lover_start, .Lover_end) LC0=P2;
97.Lover_start:
98 R1 = B[P1--] (X);
99.Lover_end:
100 B[P0--] = R1;
101
102 RTS;
Mike Frysinger5b221632008-02-19 00:36:14 -0500103
104.size _memcpy_ASM, .-_memcpy_ASM