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gerrit-public.fairphone.software / platform / external / arm-optimized-routines / fcad5b82714f408d1c83bfdeb50578c6ca1ab20b / . / string / arm / strcpy.c
blob: 2d8834bf5c8b9e570257181cf27e2d799c84899d [file] [log] [blame]
Adhemerval Zanella80c535b2019-08-06 14:14:22 -0300[diff] [blame]1/*
Szabolcs Nagy558699c2019-08-27 15:57:58 +0100[diff] [blame]2 * strcpy
Adhemerval Zanella80c535b2019-08-06 14:14:22 -0300[diff] [blame]3 *
Szabolcs Nagy558699c2019-08-27 15:57:58 +0100[diff] [blame]4 * Copyright (c) 2008-2019, Arm Limited.
5 * SPDX-License-Identifier: MIT
Adhemerval Zanella80c535b2019-08-06 14:14:22 -0300[diff] [blame]6 */
7
Szabolcs Nagy1dfd7b82020-02-12 15:10:29 +0000[diff] [blame]8#if defined (__thumb2__) && !defined (__thumb__)
9
Adhemerval Zanella80c535b2019-08-06 14:14:22 -0300[diff] [blame]10/* For GLIBC:
11#include <string.h>
12#include <memcopy.h>
13
14#undef strcmp
15*/
16
17#ifdef __thumb2__
18#define magic1(REG) "#0x01010101"
19#define magic2(REG) "#0x80808080"
20#else
21#define magic1(REG) #REG
22#define magic2(REG) #REG ", lsl #7"
23#endif
24
25char* __attribute__((naked))
26__strcpy_arm (char* dst, const char* src)
27{
28 __asm__ (
29 "pld [r1, #0]\n\t"
30 "eor r2, r0, r1\n\t"
31 "mov ip, r0\n\t"
32 "tst r2, #3\n\t"
33 "bne 4f\n\t"
34 "tst r1, #3\n\t"
35 "bne 3f\n"
36 "5:\n\t"
37# ifndef __thumb2__
38 "str r5, [sp, #-4]!\n\t"
39 "mov r5, #0x01\n\t"
40 "orr r5, r5, r5, lsl #8\n\t"
41 "orr r5, r5, r5, lsl #16\n\t"
42# endif
43
44 "str r4, [sp, #-4]!\n\t"
45 "tst r1, #4\n\t"
46 "ldr r3, [r1], #4\n\t"
47 "beq 2f\n\t"
48 "sub r2, r3, "magic1(r5)"\n\t"
49 "bics r2, r2, r3\n\t"
50 "tst r2, "magic2(r5)"\n\t"
51 "itt eq\n\t"
52 "streq r3, [ip], #4\n\t"
53 "ldreq r3, [r1], #4\n"
54 "bne 1f\n\t"
55 /* Inner loop. We now know that r1 is 64-bit aligned, so we
56 can safely fetch up to two words. This allows us to avoid
57 load stalls. */
58 ".p2align 2\n"
59 "2:\n\t"
60 "pld [r1, #8]\n\t"
61 "ldr r4, [r1], #4\n\t"
62 "sub r2, r3, "magic1(r5)"\n\t"
63 "bics r2, r2, r3\n\t"
64 "tst r2, "magic2(r5)"\n\t"
65 "sub r2, r4, "magic1(r5)"\n\t"
66 "bne 1f\n\t"
67 "str r3, [ip], #4\n\t"
68 "bics r2, r2, r4\n\t"
69 "tst r2, "magic2(r5)"\n\t"
70 "itt eq\n\t"
71 "ldreq r3, [r1], #4\n\t"
72 "streq r4, [ip], #4\n\t"
73 "beq 2b\n\t"
74 "mov r3, r4\n"
75 "1:\n\t"
76# ifdef __ARMEB__
77 "rors r3, r3, #24\n\t"
78# endif
79 "strb r3, [ip], #1\n\t"
80 "tst r3, #0xff\n\t"
81# ifdef __ARMEL__
82 "ror r3, r3, #8\n\t"
83# endif
84 "bne 1b\n\t"
85 "ldr r4, [sp], #4\n\t"
86# ifndef __thumb2__
87 "ldr r5, [sp], #4\n\t"
88# endif
89 "BX LR\n"
90
91 /* Strings have the same offset from word alignment, but it's
92 not zero. */
93 "3:\n\t"
94 "tst r1, #1\n\t"
95 "beq 1f\n\t"
96 "ldrb r2, [r1], #1\n\t"
97 "strb r2, [ip], #1\n\t"
98 "cmp r2, #0\n\t"
99 "it eq\n"
100 "BXEQ LR\n"
101 "1:\n\t"
102 "tst r1, #2\n\t"
103 "beq 5b\n\t"
104 "ldrh r2, [r1], #2\n\t"
105# ifdef __ARMEB__
106 "tst r2, #0xff00\n\t"
107 "iteet ne\n\t"
108 "strneh r2, [ip], #2\n\t"
109 "lsreq r2, r2, #8\n\t"
110 "streqb r2, [ip]\n\t"
111 "tstne r2, #0xff\n\t"
112# else
113 "tst r2, #0xff\n\t"
114 "itet ne\n\t"
115 "strneh r2, [ip], #2\n\t"
116 "streqb r2, [ip]\n\t"
117 "tstne r2, #0xff00\n\t"
118# endif
119 "bne 5b\n\t"
120 "BX LR\n"
121
122 /* src and dst do not have a common word-alignement. Fall back to
123 byte copying. */
124 "4:\n\t"
125 "ldrb r2, [r1], #1\n\t"
126 "strb r2, [ip], #1\n\t"
127 "cmp r2, #0\n\t"
128 "bne 4b\n\t"
129 "BX LR");
130}
131/* For GLIBC: libc_hidden_builtin_def (strcpy) */
Szabolcs Nagy1dfd7b82020-02-12 15:10:29 +0000[diff] [blame]132
133#endif /* defined (__thumb2__) && !defined (__thumb__) */