xref: /openbmc/linux/arch/arc/lib/memcmp.S (revision 0545810f)
1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
4 */
5
6#include <linux/linkage.h>
7
8#ifdef __LITTLE_ENDIAN__
9#define WORD2 r2
10#define SHIFT r3
11#else /* BIG ENDIAN */
12#define WORD2 r3
13#define SHIFT r2
14#endif
15
16ENTRY_CFI(memcmp)
17	or	r12,r0,r1
18	asl_s	r12,r12,30
19	sub	r3,r2,1
20	brls	r2,r12,.Lbytewise
21	ld	r4,[r0,0]
22	ld	r5,[r1,0]
23	lsr.f	lp_count,r3,3
24#ifdef CONFIG_ISA_ARCV2
25	/* In ARCv2 a branch can't be the last instruction in a zero overhead
26	 * loop.
27	 * So we move the branch to the start of the loop, duplicate it
28	 * after the end, and set up r12 so that the branch isn't taken
29	 *  initially.
30	 */
31	mov_s	r12,WORD2
32	lpne	.Loop_end
33	brne	WORD2,r12,.Lodd
34	ld	WORD2,[r0,4]
35#else
36	lpne	.Loop_end
37	ld_s	WORD2,[r0,4]
38#endif
39	ld_s	r12,[r1,4]
40	brne	r4,r5,.Leven
41	ld.a	r4,[r0,8]
42	ld.a	r5,[r1,8]
43#ifdef CONFIG_ISA_ARCV2
44.Loop_end:
45	brne	WORD2,r12,.Lodd
46#else
47	brne	WORD2,r12,.Lodd
48.Loop_end:
49#endif
50	asl_s	SHIFT,SHIFT,3
51	bhs_s	.Last_cmp
52	brne	r4,r5,.Leven
53	ld	r4,[r0,4]
54	ld	r5,[r1,4]
55#ifdef __LITTLE_ENDIAN__
56	nop_s
57	; one more load latency cycle
58.Last_cmp:
59	xor	r0,r4,r5
60	bset	r0,r0,SHIFT
61	sub_s	r1,r0,1
62	bic_s	r1,r1,r0
63	norm	r1,r1
64	b.d	.Leven_cmp
65	and	r1,r1,24
66.Leven:
67	xor	r0,r4,r5
68	sub_s	r1,r0,1
69	bic_s	r1,r1,r0
70	norm	r1,r1
71	; slow track insn
72	and	r1,r1,24
73.Leven_cmp:
74	asl	r2,r4,r1
75	asl	r12,r5,r1
76	lsr_s	r2,r2,1
77	lsr_s	r12,r12,1
78	j_s.d	[blink]
79	sub	r0,r2,r12
80	.balign	4
81.Lodd:
82	xor	r0,WORD2,r12
83	sub_s	r1,r0,1
84	bic_s	r1,r1,r0
85	norm	r1,r1
86	; slow track insn
87	and	r1,r1,24
88	asl_s	r2,r2,r1
89	asl_s	r12,r12,r1
90	lsr_s	r2,r2,1
91	lsr_s	r12,r12,1
92	j_s.d	[blink]
93	sub	r0,r2,r12
94#else /* BIG ENDIAN */
95.Last_cmp:
96	neg_s	SHIFT,SHIFT
97	lsr	r4,r4,SHIFT
98	lsr	r5,r5,SHIFT
99	; slow track insn
100.Leven:
101	sub.f	r0,r4,r5
102	mov.ne	r0,1
103	j_s.d	[blink]
104	bset.cs	r0,r0,31
105.Lodd:
106	cmp_s	WORD2,r12
107	mov_s	r0,1
108	j_s.d	[blink]
109	bset.cs	r0,r0,31
110#endif /* ENDIAN */
111	.balign	4
112.Lbytewise:
113	breq	r2,0,.Lnil
114	ldb	r4,[r0,0]
115	ldb	r5,[r1,0]
116	lsr.f	lp_count,r3
117#ifdef CONFIG_ISA_ARCV2
118	mov	r12,r3
119	lpne	.Lbyte_end
120	brne	r3,r12,.Lbyte_odd
121#else
122	lpne	.Lbyte_end
123#endif
124	ldb_s	r3,[r0,1]
125	ldb	r12,[r1,1]
126	brne	r4,r5,.Lbyte_even
127	ldb.a	r4,[r0,2]
128	ldb.a	r5,[r1,2]
129#ifdef CONFIG_ISA_ARCV2
130.Lbyte_end:
131	brne	r3,r12,.Lbyte_odd
132#else
133	brne	r3,r12,.Lbyte_odd
134.Lbyte_end:
135#endif
136	bcc	.Lbyte_even
137	brne	r4,r5,.Lbyte_even
138	ldb_s	r3,[r0,1]
139	ldb_s	r12,[r1,1]
140.Lbyte_odd:
141	j_s.d	[blink]
142	sub	r0,r3,r12
143.Lbyte_even:
144	j_s.d	[blink]
145	sub	r0,r4,r5
146.Lnil:
147	j_s.d	[blink]
148	mov	r0,0
149END_CFI(memcmp)
150