1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
|
/*
* Speed-optimized CRC64 using slicing-by-four algorithm
* Instruction set: i386
* Optimized for: i686
*
* This code has been put into the public domain by its authors:
* Igor Pavlov <http://7-zip.org/>
* Lasse Collin <lasse.collin@tukaani.org>
*
* This code needs lzma_crc64_table, which can be created using the
* following C code:
uint64_t lzma_crc64_table[4][256];
void
init_table(void)
{
static const uint64_t poly64 = UINT64_C(0xC96C5795D7870F42);
for (size_t s = 0; s < 4; ++s) {
for (size_t b = 0; b < 256; ++b) {
uint64_t r = s == 0 ? b : lzma_crc64_table[s - 1][b];
for (size_t i = 0; i < 8; ++i) {
if (r & 1)
r = (r >> 1) ^ poly64;
else
r >>= 1;
}
lzma_crc64_table[s][b] = r;
}
}
}
* The prototype of the CRC64 function:
* extern uint64_t lzma_crc64(const uint8_t *buf, size_t size, uint64_t crc);
*/
/*
* On some systems, the functions need to be prefixed. The prefix is
* usually an underscore.
*/
#ifndef __USER_LABEL_PREFIX__
# define __USER_LABEL_PREFIX__
#endif
#define MAKE_SYM_CAT(prefix, sym) prefix ## sym
#define MAKE_SYM(prefix, sym) MAKE_SYM_CAT(prefix, sym)
#define LZMA_CRC64 MAKE_SYM(__USER_LABEL_PREFIX__, lzma_crc64)
#define LZMA_CRC64_TABLE MAKE_SYM(__USER_LABEL_PREFIX__, lzma_crc64_table)
/*
* Solaris assembler doesn't have .p2align, and Darwin uses .align
* differently than GNU/Linux and Solaris.
*/
#if defined(__MACH__) || defined(__MSDOS__)
# define ALIGN(pow2, abs) .align pow2
#else
# define ALIGN(pow2, abs) .align abs
#endif
.text
.globl LZMA_CRC64
#if !defined(__MACH__) && !defined(_WIN32) && !defined(__MSDOS__)
.type LZMA_CRC64, @function
#endif
ALIGN(4, 16)
LZMA_CRC64:
/*
* Register usage:
* %eax crc LSB
* %edx crc MSB
* %esi buf
* %edi size or buf + size
* %ebx lzma_crc64_table
* %ebp Table index
* %ecx Temporary
*/
pushl %ebx
pushl %esi
pushl %edi
pushl %ebp
movl 0x14(%esp), %esi /* buf */
movl 0x18(%esp), %edi /* size */
movl 0x1C(%esp), %eax /* crc LSB */
movl 0x20(%esp), %edx /* crc MSB */
/*
* Store the address of lzma_crc64_table to %ebx. This is needed to
* get position-independent code (PIC).
*
* The PIC macro is defined by libtool, while __PIC__ is defined
* by GCC but only on some systems. Testing for both makes it simpler
* to test this code without libtool, and keeps the code working also
* when built with libtool but using something else than GCC.
*/
#if !defined(PIC) && !defined(__PIC__)
/* Not PIC */
movl $LZMA_CRC64_TABLE, %ebx
#elif defined(__MACH__)
/* Mach-O */
call .L_get_pc
.L_pic:
leal .L_lzma_crc64_table$non_lazy_ptr-.L_pic(%ebx), %ebx
movl (%ebx), %ebx
#else
/* ELF */
call .L_get_pc
addl $_GLOBAL_OFFSET_TABLE_, %ebx
movl LZMA_CRC64_TABLE@GOT(%ebx), %ebx
#endif
/* Complement the initial value. */
notl %eax
notl %edx
.L_align:
/*
* Check if there is enough input to use slicing-by-four.
* We need eight bytes, because the loop pre-reads four bytes.
*/
cmpl $8, %edi
jl .L_rest
/* Check if we have reached alignment of four bytes. */
testl $3, %esi
jz .L_slice
/* Calculate CRC of the next input byte. */
movzbl (%esi), %ebp
incl %esi
movzbl %al, %ecx
xorl %ecx, %ebp
shrdl $8, %edx, %eax
xorl (%ebx, %ebp, 8), %eax
shrl $8, %edx
xorl 4(%ebx, %ebp, 8), %edx
decl %edi
jmp .L_align
.L_slice:
/*
* If we get here, there's at least eight bytes of aligned input
* available. Make %edi multiple of four bytes. Store the possible
* remainder over the "size" variable in the argument stack.
*/
movl %edi, 0x18(%esp)
andl $-4, %edi
subl %edi, 0x18(%esp)
/*
* Let %edi be buf + size - 4 while running the main loop. This way
* we can compare for equality to determine when exit the loop.
*/
addl %esi, %edi
subl $4, %edi
/* Read in the first four aligned bytes. */
movl (%esi), %ecx
.L_loop:
xorl %eax, %ecx
movzbl %cl, %ebp
movl 0x1800(%ebx, %ebp, 8), %eax
xorl %edx, %eax
movl 0x1804(%ebx, %ebp, 8), %edx
movzbl %ch, %ebp
xorl 0x1000(%ebx, %ebp, 8), %eax
xorl 0x1004(%ebx, %ebp, 8), %edx
shrl $16, %ecx
movzbl %cl, %ebp
xorl 0x0800(%ebx, %ebp, 8), %eax
xorl 0x0804(%ebx, %ebp, 8), %edx
movzbl %ch, %ebp
addl $4, %esi
xorl (%ebx, %ebp, 8), %eax
xorl 4(%ebx, %ebp, 8), %edx
/* Check for end of aligned input. */
cmpl %edi, %esi
/*
* Copy the next input byte to %ecx. It is slightly faster to
* read it here than at the top of the loop.
*/
movl (%esi), %ecx
jl .L_loop
/*
* Process the remaining four bytes, which we have already
* copied to %ecx.
*/
xorl %eax, %ecx
movzbl %cl, %ebp
movl 0x1800(%ebx, %ebp, 8), %eax
xorl %edx, %eax
movl 0x1804(%ebx, %ebp, 8), %edx
movzbl %ch, %ebp
xorl 0x1000(%ebx, %ebp, 8), %eax
xorl 0x1004(%ebx, %ebp, 8), %edx
shrl $16, %ecx
movzbl %cl, %ebp
xorl 0x0800(%ebx, %ebp, 8), %eax
xorl 0x0804(%ebx, %ebp, 8), %edx
movzbl %ch, %ebp
addl $4, %esi
xorl (%ebx, %ebp, 8), %eax
xorl 4(%ebx, %ebp, 8), %edx
/* Copy the number of remaining bytes to %edi. */
movl 0x18(%esp), %edi
.L_rest:
/* Check for end of input. */
testl %edi, %edi
jz .L_return
/* Calculate CRC of the next input byte. */
movzbl (%esi), %ebp
incl %esi
movzbl %al, %ecx
xorl %ecx, %ebp
shrdl $8, %edx, %eax
xorl (%ebx, %ebp, 8), %eax
shrl $8, %edx
xorl 4(%ebx, %ebp, 8), %edx
decl %edi
jmp .L_rest
.L_return:
/* Complement the final value. */
notl %eax
notl %edx
popl %ebp
popl %edi
popl %esi
popl %ebx
ret
#if defined(PIC) || defined(__PIC__)
ALIGN(4, 16)
.L_get_pc:
movl (%esp), %ebx
ret
#endif
#if defined(__MACH__) && (defined(PIC) || defined(__PIC__))
/* Mach-O PIC */
.section __IMPORT,__pointers,non_lazy_symbol_pointers
.L_lzma_crc64_table$non_lazy_ptr:
.indirect_symbol LZMA_CRC64_TABLE
.long 0
#elif defined(_WIN32)
# ifndef LZMA_API_STATIC
/* This is equivalent of __declspec(dllexport). */
.section .drectve
.ascii " -export:lzma_crc64"
# endif
#elif !defined(__MSDOS__)
/* ELF */
.size LZMA_CRC64, .-LZMA_CRC64
#endif
/*
* This is needed to support non-executable stack. It's ugly to
* use __linux__ here, but I don't know a way to detect when
* we are using GNU assembler.
*/
#if defined(__ELF__) && defined(__linux__)
.section .note.GNU-stack,"",@progbits
#endif
|
