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gerrit-public.fairphone.software / kernel / msm-4.9 / a29d64a45eed1ee0d4ac90335da79ad1a9a0990d / . / arch / arc / lib / strchr-700.S
blob: b725d586210709d9020ec4cf4969d2187a3df24d [file] [log] [blame]
Vineet Gupta5210d1e2013-01-18 15:12:18 +0530[diff] [blame]1/*
2 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 */
8
9/* ARC700 has a relatively long pipeline and branch prediction, so we want
10 to avoid branches that are hard to predict. On the other hand, the
11 presence of the norm instruction makes it easier to operate on whole
12 words branch-free. */
13
Vineet Guptaec7ac6a2014-02-07 13:47:43 +0530[diff] [blame]14#include <linux/linkage.h>
Vineet Gupta5210d1e2013-01-18 15:12:18 +0530[diff] [blame]15
Vineet Guptaec7ac6a2014-02-07 13:47:43 +0530[diff] [blame]16ENTRY(strchr)
Vineet Gupta5210d1e2013-01-18 15:12:18 +0530[diff] [blame]17 extb_s r1,r1
18 asl r5,r1,8
19 bmsk r2,r0,1
20 or r5,r5,r1
21 mov_s r3,0x01010101
22 breq.d r2,r0,.Laligned
23 asl r4,r5,16
24 sub_s r0,r0,r2
25 asl r7,r2,3
26 ld_s r2,[r0]
27#ifdef __LITTLE_ENDIAN__
28 asl r7,r3,r7
29#else
30 lsr r7,r3,r7
31#endif
32 or r5,r5,r4
33 ror r4,r3
34 sub r12,r2,r7
35 bic_s r12,r12,r2
36 and r12,r12,r4
37 brne.d r12,0,.Lfound0_ua
38 xor r6,r2,r5
39 ld.a r2,[r0,4]
40 sub r12,r6,r7
41 bic r12,r12,r6
Joern Renneckeb0f55f22013-08-24 12:03:06 +0530[diff] [blame]42#ifdef __LITTLE_ENDIAN__
Vineet Gupta5210d1e2013-01-18 15:12:18 +0530[diff] [blame]43 and r7,r12,r4
44 breq r7,0,.Loop ; For speed, we want this branch to be unaligned.
45 b .Lfound_char ; Likewise this one.
Joern Renneckeb0f55f22013-08-24 12:03:06 +0530[diff] [blame]46#else
47 and r12,r12,r4
48 breq r12,0,.Loop ; For speed, we want this branch to be unaligned.
49 lsr_s r12,r12,7
50 bic r2,r7,r6
51 b.d .Lfound_char_b
52 and_s r2,r2,r12
53#endif
Vineet Gupta5210d1e2013-01-18 15:12:18 +0530[diff] [blame]54; /* We require this code address to be unaligned for speed... */
55.Laligned:
56 ld_s r2,[r0]
57 or r5,r5,r4
58 ror r4,r3
59; /* ... so that this code address is aligned, for itself and ... */
60.Loop:
61 sub r12,r2,r3
62 bic_s r12,r12,r2
63 and r12,r12,r4
64 brne.d r12,0,.Lfound0
65 xor r6,r2,r5
66 ld.a r2,[r0,4]
67 sub r12,r6,r3
68 bic r12,r12,r6
69 and r7,r12,r4
70 breq r7,0,.Loop /* ... so that this branch is unaligned. */
71 ; Found searched-for character. r0 has already advanced to next word.
72#ifdef __LITTLE_ENDIAN__
73/* We only need the information about the first matching byte
74 (i.e. the least significant matching byte) to be exact,
75 hence there is no problem with carry effects. */
76.Lfound_char:
77 sub r3,r7,1
78 bic r3,r3,r7
79 norm r2,r3
80 sub_s r0,r0,1
81 asr_s r2,r2,3
82 j.d [blink]
83 sub_s r0,r0,r2
84
85 .balign 4
86.Lfound0_ua:
87 mov r3,r7
88.Lfound0:
89 sub r3,r6,r3
90 bic r3,r3,r6
91 and r2,r3,r4
92 or_s r12,r12,r2
93 sub_s r3,r12,1
94 bic_s r3,r3,r12
95 norm r3,r3
96 add_s r0,r0,3
97 asr_s r12,r3,3
98 asl.f 0,r2,r3
99 sub_s r0,r0,r12
100 j_s.d [blink]
101 mov.pl r0,0
102#else /* BIG ENDIAN */
103.Lfound_char:
104 lsr r7,r7,7
105
106 bic r2,r7,r6
Joern Renneckeb0f55f22013-08-24 12:03:06 +0530[diff] [blame]107.Lfound_char_b:
Vineet Gupta5210d1e2013-01-18 15:12:18 +0530[diff] [blame]108 norm r2,r2
109 sub_s r0,r0,4
110 asr_s r2,r2,3
111 j.d [blink]
112 add_s r0,r0,r2
113
114.Lfound0_ua:
115 mov_s r3,r7
116.Lfound0:
117 asl_s r2,r2,7
118 or r7,r6,r4
119 bic_s r12,r12,r2
120 sub r2,r7,r3
121 or r2,r2,r6
122 bic r12,r2,r12
123 bic.f r3,r4,r12
124 norm r3,r3
125
126 add.pl r3,r3,1
127 asr_s r12,r3,3
128 asl.f 0,r2,r3
129 add_s r0,r0,r12
130 j_s.d [blink]
131 mov.mi r0,0
132#endif /* ENDIAN */
Vineet Guptaec7ac6a2014-02-07 13:47:43 +0530[diff] [blame]133END(strchr)