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d2912cb1 | 1 | /* SPDX-License-Identifier: GPL-2.0-only */ |
5210d1e6 VG |
2 | /* |
3 | * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) | |
5210d1e6 VG |
4 | */ |
5 | ||
6 | /* ARC700 has a relatively long pipeline and branch prediction, so we want | |
7 | to avoid branches that are hard to predict. On the other hand, the | |
8 | presence of the norm instruction makes it easier to operate on whole | |
9 | words branch-free. */ | |
10 | ||
ec7ac6af | 11 | #include <linux/linkage.h> |
5210d1e6 | 12 | |
86effd0d | 13 | ENTRY_CFI(strchr) |
5210d1e6 VG |
14 | extb_s r1,r1 |
15 | asl r5,r1,8 | |
16 | bmsk r2,r0,1 | |
17 | or r5,r5,r1 | |
18 | mov_s r3,0x01010101 | |
19 | breq.d r2,r0,.Laligned | |
20 | asl r4,r5,16 | |
21 | sub_s r0,r0,r2 | |
22 | asl r7,r2,3 | |
23 | ld_s r2,[r0] | |
24 | #ifdef __LITTLE_ENDIAN__ | |
25 | asl r7,r3,r7 | |
26 | #else | |
27 | lsr r7,r3,r7 | |
28 | #endif | |
29 | or r5,r5,r4 | |
30 | ror r4,r3 | |
31 | sub r12,r2,r7 | |
32 | bic_s r12,r12,r2 | |
33 | and r12,r12,r4 | |
34 | brne.d r12,0,.Lfound0_ua | |
35 | xor r6,r2,r5 | |
36 | ld.a r2,[r0,4] | |
37 | sub r12,r6,r7 | |
38 | bic r12,r12,r6 | |
b0f55f2a | 39 | #ifdef __LITTLE_ENDIAN__ |
5210d1e6 VG |
40 | and r7,r12,r4 |
41 | breq r7,0,.Loop ; For speed, we want this branch to be unaligned. | |
42 | b .Lfound_char ; Likewise this one. | |
b0f55f2a JR |
43 | #else |
44 | and r12,r12,r4 | |
45 | breq r12,0,.Loop ; For speed, we want this branch to be unaligned. | |
46 | lsr_s r12,r12,7 | |
47 | bic r2,r7,r6 | |
48 | b.d .Lfound_char_b | |
49 | and_s r2,r2,r12 | |
50 | #endif | |
5210d1e6 VG |
51 | ; /* We require this code address to be unaligned for speed... */ |
52 | .Laligned: | |
53 | ld_s r2,[r0] | |
54 | or r5,r5,r4 | |
55 | ror r4,r3 | |
56 | ; /* ... so that this code address is aligned, for itself and ... */ | |
57 | .Loop: | |
58 | sub r12,r2,r3 | |
59 | bic_s r12,r12,r2 | |
60 | and r12,r12,r4 | |
61 | brne.d r12,0,.Lfound0 | |
62 | xor r6,r2,r5 | |
63 | ld.a r2,[r0,4] | |
64 | sub r12,r6,r3 | |
65 | bic r12,r12,r6 | |
66 | and r7,r12,r4 | |
67 | breq r7,0,.Loop /* ... so that this branch is unaligned. */ | |
68 | ; Found searched-for character. r0 has already advanced to next word. | |
69 | #ifdef __LITTLE_ENDIAN__ | |
70 | /* We only need the information about the first matching byte | |
71 | (i.e. the least significant matching byte) to be exact, | |
72 | hence there is no problem with carry effects. */ | |
73 | .Lfound_char: | |
74 | sub r3,r7,1 | |
75 | bic r3,r3,r7 | |
76 | norm r2,r3 | |
77 | sub_s r0,r0,1 | |
78 | asr_s r2,r2,3 | |
79 | j.d [blink] | |
80 | sub_s r0,r0,r2 | |
81 | ||
82 | .balign 4 | |
83 | .Lfound0_ua: | |
84 | mov r3,r7 | |
85 | .Lfound0: | |
86 | sub r3,r6,r3 | |
87 | bic r3,r3,r6 | |
88 | and r2,r3,r4 | |
89 | or_s r12,r12,r2 | |
90 | sub_s r3,r12,1 | |
91 | bic_s r3,r3,r12 | |
92 | norm r3,r3 | |
93 | add_s r0,r0,3 | |
94 | asr_s r12,r3,3 | |
95 | asl.f 0,r2,r3 | |
96 | sub_s r0,r0,r12 | |
97 | j_s.d [blink] | |
98 | mov.pl r0,0 | |
99 | #else /* BIG ENDIAN */ | |
100 | .Lfound_char: | |
101 | lsr r7,r7,7 | |
102 | ||
103 | bic r2,r7,r6 | |
b0f55f2a | 104 | .Lfound_char_b: |
5210d1e6 VG |
105 | norm r2,r2 |
106 | sub_s r0,r0,4 | |
107 | asr_s r2,r2,3 | |
108 | j.d [blink] | |
109 | add_s r0,r0,r2 | |
110 | ||
111 | .Lfound0_ua: | |
112 | mov_s r3,r7 | |
113 | .Lfound0: | |
114 | asl_s r2,r2,7 | |
115 | or r7,r6,r4 | |
116 | bic_s r12,r12,r2 | |
117 | sub r2,r7,r3 | |
118 | or r2,r2,r6 | |
119 | bic r12,r2,r12 | |
120 | bic.f r3,r4,r12 | |
121 | norm r3,r3 | |
122 | ||
123 | add.pl r3,r3,1 | |
124 | asr_s r12,r3,3 | |
125 | asl.f 0,r2,r3 | |
126 | add_s r0,r0,r12 | |
127 | j_s.d [blink] | |
128 | mov.mi r0,0 | |
129 | #endif /* ENDIAN */ | |
86effd0d | 130 | END_CFI(strchr) |