blob: 9ab20770d0bc2611e661ce75035c8c96f5342b86 [file] [log] [blame]
Aubrey.Li3f0606a2007-03-09 13:38:44 +08001/*
Aubrey Li155fd762007-04-05 18:31:18 +08002 * File: memmove.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 */
9
10.align 2
11
12/*
13 * C Library function MEMMOVE
14 * R0 = To Address (leave unchanged to form result)
15 * R1 = From Address
16 * R2 = count
17 * Data may overlap
18 */
19
20.globl _memmove;
Mike Frysinger5b221632008-02-19 00:36:14 -050021.type _memmove, STT_FUNC;
Aubrey.Li3f0606a2007-03-09 13:38:44 +080022_memmove:
23 I1 = P3;
24 P0 = R0; /* P0 = To address */
25 P3 = R1; /* P3 = From Address */
26 P2 = R2 ; /* P2 = count */
27 CC = P2 == 0; /* Check zero count*/
28 IF CC JUMP .Lfinished; /* very unlikely */
29
30 CC = R1 < R0 (IU); /* From < To */
31 IF !CC JUMP .Lno_overlap;
32 R3 = R1 + R2;
33 CC = R0 <= R3 (IU); /* (From+len) >= To */
34 IF CC JUMP .Loverlap;
35.Lno_overlap:
36 R3 = 11;
37 CC = R2 <= R3;
38 IF CC JUMP .Lbytes;
39 R3 = R1 | R0; /* OR addresses together */
40 R3 <<= 30; /* check bottom two bits */
41 CC = AZ; /* AZ set if zero.*/
42 IF !CC JUMP .Lbytes ; /* Jump if addrs not aligned.*/
43
44 I0 = P3;
45 P1 = P2 >> 2; /* count = n/4 */
46 P1 += -1;
47 R3 = 3;
48 R2 = R2 & R3; /* remainder */
49 P2 = R2; /* set remainder */
50 R1 = [I0++];
51
52 LSETUP (.Lquad_loop , .Lquad_loop) LC0=P1;
53.Lquad_loop: MNOP || [P0++] = R1 || R1 = [I0++];
54 [P0++] = R1;
55
56 CC = P2 == 0; /* any remaining bytes? */
57 P3 = I0; /* Ammend P3 to updated ptr. */
58 IF !CC JUMP .Lbytes;
59 P3 = I1;
60 RTS;
61
62.Lbytes: LSETUP (.Lbyte2_s , .Lbyte2_e) LC0=P2;
63.Lbyte2_s: R1 = B[P3++](Z);
64.Lbyte2_e: B[P0++] = R1;
65
66.Lfinished: P3 = I1;
67 RTS;
68
69.Loverlap:
70 P2 += -1;
71 P0 = P0 + P2;
72 P3 = P3 + P2;
73 R1 = B[P3--] (Z);
74 CC = P2 == 0;
75 IF CC JUMP .Lno_loop;
76 LSETUP (.Lol_s, .Lol_e) LC0 = P2;
77.Lol_s: B[P0--] = R1;
78.Lol_e: R1 = B[P3--] (Z);
79.Lno_loop: B[P0] = R1;
80 P3 = I1;
81 RTS;
Mike Frysinger5b221632008-02-19 00:36:14 -050082
83.size _memmove, .-_memmove