1/*
2 * Copyright 2004-2009 Analog Devices Inc.
3 *
4 * Licensed under the Clear BSD license or the GPL-2 (or later)
5 */
6
7#include <linux/linkage.h>
8
9/* int memcmp(const void *s1, const void *s2, size_t n);
10 * R0 = First Address (s1)
11 * R1 = Second Address (s2)
12 * R2 = count (n)
13 *
14 * Favours word aligned data.
15 */
16
17.text
18
19.align 2
20
21ENTRY(_memcmp)
22	I1 = P3;
23	P0 = R0;			/* P0 = s1 address */
24	P3 = R1;			/* P3 = s2 Address  */
25	P2 = R2 ;			/* P2 = count */
26	CC = R2 <= 7(IU);
27	IF CC JUMP .Ltoo_small;
28	I0 = R1;			/* s2 */
29	R1 = R1 | R0;		/* OR addresses together */
30	R1 <<= 30;		/* check bottom two bits */
31	CC =  AZ;			/* AZ set if zero. */
32	IF !CC JUMP .Lbytes ;	/* Jump if addrs not aligned. */
33
34	P1 = P2 >> 2;		/* count = n/4 */
35	R3 =  3;
36	R2 = R2 & R3;		/* remainder */
37	P2 = R2;			/* set remainder */
38
39	LSETUP (.Lquad_loop_s, .Lquad_loop_e) LC0=P1;
40.Lquad_loop_s:
41#if ANOMALY_05000202
42	R0 = [P0++];
43	R1 = [I0++];
44#else
45	MNOP || R0 = [P0++] || R1 = [I0++];
46#endif
47	CC = R0 == R1;
48	IF !CC JUMP .Lquad_different;
49.Lquad_loop_e:
50	NOP;
51
52	P3 = I0;			/* s2 */
53.Ltoo_small:
54	CC = P2 == 0;		/* Check zero count*/
55	IF CC JUMP .Lfinished;	/* very unlikely*/
56
57.Lbytes:
58	LSETUP (.Lbyte_loop_s, .Lbyte_loop_e) LC0=P2;
59.Lbyte_loop_s:
60	R1 = B[P3++](Z);	/* *s2 */
61	R0 = B[P0++](Z);	/* *s1 */
62	CC = R0 == R1;
63	IF !CC JUMP .Ldifferent;
64.Lbyte_loop_e:
65	NOP;
66
67.Ldifferent:
68	R0 = R0 - R1;
69	P3 = I1;
70	RTS;
71
72.Lquad_different:
73	/* We've read two quads which don't match.
74	 * Can't just compare them, because we're
75	 * a little-endian machine, so the MSBs of
76	 * the regs occur at later addresses in the
77	 * string.
78	 * Arrange to re-read those two quads again,
79	 * byte-by-byte.
80	 */
81	P0 += -4;		/* back up to the start of the */
82	P3 = I0;		/* quads, and increase the*/
83	P2 += 4;		/* remainder count*/
84	P3 += -4;
85	JUMP .Lbytes;
86
87.Lfinished:
88	R0 = 0;
89	P3 = I1;
90	RTS;
91
92ENDPROC(_memcmp)
93