xref: /OK3568_Linux_fs/kernel/arch/csky/abiv2/memcmp.S (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun/* SPDX-License-Identifier: GPL-2.0 */
2*4882a593Smuzhiyun// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
3*4882a593Smuzhiyun
4*4882a593Smuzhiyun#include <linux/linkage.h>
5*4882a593Smuzhiyun#include "sysdep.h"
6*4882a593Smuzhiyun
7*4882a593SmuzhiyunENTRY(memcmp)
8*4882a593Smuzhiyun	/* Test if len less than 4 bytes.  */
9*4882a593Smuzhiyun	mov	r3, r0
10*4882a593Smuzhiyun	movi	r0, 0
11*4882a593Smuzhiyun	mov	r12, r4
12*4882a593Smuzhiyun	cmplti	r2, 4
13*4882a593Smuzhiyun	bt	.L_compare_by_byte
14*4882a593Smuzhiyun
15*4882a593Smuzhiyun	andi	r13, r0, 3
16*4882a593Smuzhiyun	movi	r19, 4
17*4882a593Smuzhiyun
18*4882a593Smuzhiyun	/* Test if s1 is not 4 bytes aligned.  */
19*4882a593Smuzhiyun	bnez	r13, .L_s1_not_aligned
20*4882a593Smuzhiyun
21*4882a593Smuzhiyun	LABLE_ALIGN
22*4882a593Smuzhiyun.L_s1_aligned:
23*4882a593Smuzhiyun	/* If dest is aligned, then copy.  */
24*4882a593Smuzhiyun	zext	r18, r2, 31, 4
25*4882a593Smuzhiyun	/* Test if len less than 16 bytes.  */
26*4882a593Smuzhiyun	bez	r18, .L_compare_by_word
27*4882a593Smuzhiyun
28*4882a593Smuzhiyun.L_compare_by_4word:
29*4882a593Smuzhiyun	/* If aligned, load word each time.  */
30*4882a593Smuzhiyun	ldw	r20, (r3, 0)
31*4882a593Smuzhiyun	ldw	r21, (r1, 0)
32*4882a593Smuzhiyun	/* If s1[i] != s2[i], goto .L_byte_check.  */
33*4882a593Smuzhiyun	cmpne	r20, r21
34*4882a593Smuzhiyun	bt	.L_byte_check
35*4882a593Smuzhiyun
36*4882a593Smuzhiyun	ldw	r20, (r3, 4)
37*4882a593Smuzhiyun	ldw	r21, (r1, 4)
38*4882a593Smuzhiyun	cmpne	r20, r21
39*4882a593Smuzhiyun	bt	.L_byte_check
40*4882a593Smuzhiyun
41*4882a593Smuzhiyun	ldw	r20, (r3, 8)
42*4882a593Smuzhiyun	ldw	r21, (r1, 8)
43*4882a593Smuzhiyun	cmpne	r20, r21
44*4882a593Smuzhiyun	bt	.L_byte_check
45*4882a593Smuzhiyun
46*4882a593Smuzhiyun	ldw	r20, (r3, 12)
47*4882a593Smuzhiyun	ldw	r21, (r1, 12)
48*4882a593Smuzhiyun	cmpne	r20, r21
49*4882a593Smuzhiyun	bt	.L_byte_check
50*4882a593Smuzhiyun
51*4882a593Smuzhiyun	PRE_BNEZAD (r18)
52*4882a593Smuzhiyun	addi	a3, 16
53*4882a593Smuzhiyun	addi	a1, 16
54*4882a593Smuzhiyun
55*4882a593Smuzhiyun	BNEZAD (r18, .L_compare_by_4word)
56*4882a593Smuzhiyun
57*4882a593Smuzhiyun.L_compare_by_word:
58*4882a593Smuzhiyun	zext	r18, r2, 3, 2
59*4882a593Smuzhiyun	bez	r18, .L_compare_by_byte
60*4882a593Smuzhiyun.L_compare_by_word_loop:
61*4882a593Smuzhiyun	ldw	r20, (r3, 0)
62*4882a593Smuzhiyun	ldw	r21, (r1, 0)
63*4882a593Smuzhiyun	addi	r3, 4
64*4882a593Smuzhiyun	PRE_BNEZAD (r18)
65*4882a593Smuzhiyun	cmpne	r20, r21
66*4882a593Smuzhiyun	addi    r1, 4
67*4882a593Smuzhiyun	bt	.L_byte_check
68*4882a593Smuzhiyun	BNEZAD (r18, .L_compare_by_word_loop)
69*4882a593Smuzhiyun
70*4882a593Smuzhiyun.L_compare_by_byte:
71*4882a593Smuzhiyun        zext    r18, r2, 1, 0
72*4882a593Smuzhiyun        bez     r18, .L_return
73*4882a593Smuzhiyun.L_compare_by_byte_loop:
74*4882a593Smuzhiyun        ldb     r0, (r3, 0)
75*4882a593Smuzhiyun        ldb     r4, (r1, 0)
76*4882a593Smuzhiyun        addi    r3, 1
77*4882a593Smuzhiyun        subu    r0, r4
78*4882a593Smuzhiyun        PRE_BNEZAD (r18)
79*4882a593Smuzhiyun        addi    r1, 1
80*4882a593Smuzhiyun        bnez    r0, .L_return
81*4882a593Smuzhiyun        BNEZAD (r18, .L_compare_by_byte_loop)
82*4882a593Smuzhiyun
83*4882a593Smuzhiyun.L_return:
84*4882a593Smuzhiyun        mov     r4, r12
85*4882a593Smuzhiyun        rts
86*4882a593Smuzhiyun
87*4882a593Smuzhiyun# ifdef __CSKYBE__
88*4882a593Smuzhiyun/* d[i] != s[i] in word, so we check byte 0.  */
89*4882a593Smuzhiyun.L_byte_check:
90*4882a593Smuzhiyun        xtrb0   r0, r20
91*4882a593Smuzhiyun        xtrb0   r2, r21
92*4882a593Smuzhiyun        subu    r0, r2
93*4882a593Smuzhiyun        bnez    r0, .L_return
94*4882a593Smuzhiyun
95*4882a593Smuzhiyun        /* check byte 1 */
96*4882a593Smuzhiyun        xtrb1   r0, r20
97*4882a593Smuzhiyun        xtrb1   r2, r21
98*4882a593Smuzhiyun        subu    r0, r2
99*4882a593Smuzhiyun        bnez    r0, .L_return
100*4882a593Smuzhiyun
101*4882a593Smuzhiyun        /* check byte 2 */
102*4882a593Smuzhiyun        xtrb2   r0, r20
103*4882a593Smuzhiyun        xtrb2   r2, r21
104*4882a593Smuzhiyun        subu    r0, r2
105*4882a593Smuzhiyun        bnez    r0, .L_return
106*4882a593Smuzhiyun
107*4882a593Smuzhiyun        /* check byte 3 */
108*4882a593Smuzhiyun        xtrb3   r0, r20
109*4882a593Smuzhiyun        xtrb3   r2, r21
110*4882a593Smuzhiyun        subu    r0, r2
111*4882a593Smuzhiyun# else
112*4882a593Smuzhiyun/* s1[i] != s2[i] in word, so we check byte 3.  */
113*4882a593Smuzhiyun.L_byte_check:
114*4882a593Smuzhiyun	xtrb3	r0, r20
115*4882a593Smuzhiyun	xtrb3	r2, r21
116*4882a593Smuzhiyun        subu    r0, r2
117*4882a593Smuzhiyun        bnez    r0, .L_return
118*4882a593Smuzhiyun
119*4882a593Smuzhiyun	/* check byte 2 */
120*4882a593Smuzhiyun	xtrb2	r0, r20
121*4882a593Smuzhiyun	xtrb2	r2, r21
122*4882a593Smuzhiyun        subu    r0, r2
123*4882a593Smuzhiyun        bnez    r0, .L_return
124*4882a593Smuzhiyun
125*4882a593Smuzhiyun	/* check byte 1 */
126*4882a593Smuzhiyun	xtrb1	r0, r20
127*4882a593Smuzhiyun	xtrb1	r2, r21
128*4882a593Smuzhiyun	subu	r0, r2
129*4882a593Smuzhiyun	bnez    r0, .L_return
130*4882a593Smuzhiyun
131*4882a593Smuzhiyun	/* check byte 0 */
132*4882a593Smuzhiyun	xtrb0	r0, r20
133*4882a593Smuzhiyun	xtrb0	r2, r21
134*4882a593Smuzhiyun	subu	r0, r2
135*4882a593Smuzhiyun	br	.L_return
136*4882a593Smuzhiyun# endif /* !__CSKYBE__ */
137*4882a593Smuzhiyun
138*4882a593Smuzhiyun/* Compare when s1 is not aligned.  */
139*4882a593Smuzhiyun.L_s1_not_aligned:
140*4882a593Smuzhiyun	sub	r13, r19, r13
141*4882a593Smuzhiyun	sub	r2, r13
142*4882a593Smuzhiyun.L_s1_not_aligned_loop:
143*4882a593Smuzhiyun	ldb	r0, (r3, 0)
144*4882a593Smuzhiyun	ldb	r4, (r1, 0)
145*4882a593Smuzhiyun	addi	r3, 1
146*4882a593Smuzhiyun	subu	r0, r4
147*4882a593Smuzhiyun	PRE_BNEZAD (r13)
148*4882a593Smuzhiyun	addi	r1, 1
149*4882a593Smuzhiyun	bnez	r0, .L_return
150*4882a593Smuzhiyun	BNEZAD (r13, .L_s1_not_aligned_loop)
151*4882a593Smuzhiyun	br	.L_s1_aligned
152*4882a593SmuzhiyunENDPROC(memcmp)
153