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ProgramRipperProgramRipper
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perf: compute last_index first
1 parent 5007e63 commit d9b09ab

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-60
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2 files changed

+68
-60
lines changed

‎main.c‎

Lines changed: 65 additions & 53 deletions
Original file line numberDiff line numberDiff line change
@@ -6,50 +6,70 @@
66

77
static const uint32_t
88
POLY = 0xEDB88320,
9-
table[256] = {
10-
0x00000000, 0x77073096, 0xEE0E612C, 0x990951BA, 0x076DC419, 0x706AF48F,
11-
0xE963A535, 0x9E6495A3, 0x0EDB8832, 0x79DCB8A4, 0xE0D5E91E, 0x97D2D988,
12-
0x09B64C2B, 0x7EB17CBD, 0xE7B82D07, 0x90BF1D91, 0x1DB71064, 0x6AB020F2,
13-
0xF3B97148, 0x84BE41DE, 0x1ADAD47D, 0x6DDDE4EB, 0xF4D4B551, 0x83D385C7,
14-
0x136C9856, 0x646BA8C0, 0xFD62F97A, 0x8A65C9EC, 0x14015C4F, 0x63066CD9,
15-
0xFA0F3D63, 0x8D080DF5, 0x3B6E20C8, 0x4C69105E, 0xD56041E4, 0xA2677172,
16-
0x3C03E4D1, 0x4B04D447, 0xD20D85FD, 0xA50AB56B, 0x35B5A8FA, 0x42B2986C,
17-
0xDBBBC9D6, 0xACBCF940, 0x32D86CE3, 0x45DF5C75, 0xDCD60DCF, 0xABD13D59,
18-
0x26D930AC, 0x51DE003A, 0xC8D75180, 0xBFD06116, 0x21B4F4B5, 0x56B3C423,
19-
0xCFBA9599, 0xB8BDA50F, 0x2802B89E, 0x5F058808, 0xC60CD9B2, 0xB10BE924,
20-
0x2F6F7C87, 0x58684C11, 0xC1611DAB, 0xB6662D3D, 0x76DC4190, 0x01DB7106,
21-
0x98D220BC, 0xEFD5102A, 0x71B18589, 0x06B6B51F, 0x9FBFE4A5, 0xE8B8D433,
22-
0x7807C9A2, 0x0F00F934, 0x9609A88E, 0xE10E9818, 0x7F6A0DBB, 0x086D3D2D,
23-
0x91646C97, 0xE6635C01, 0x6B6B51F4, 0x1C6C6162, 0x856530D8, 0xF262004E,
24-
0x6C0695ED, 0x1B01A57B, 0x8208F4C1, 0xF50FC457, 0x65B0D9C6, 0x12B7E950,
25-
0x8BBEB8EA, 0xFCB9887C, 0x62DD1DDF, 0x15DA2D49, 0x8CD37CF3, 0xFBD44C65,
26-
0x4DB26158, 0x3AB551CE, 0xA3BC0074, 0xD4BB30E2, 0x4ADFA541, 0x3DD895D7,
27-
0xA4D1C46D, 0xD3D6F4FB, 0x4369E96A, 0x346ED9FC, 0xAD678846, 0xDA60B8D0,
28-
0x44042D73, 0x33031DE5, 0xAA0A4C5F, 0xDD0D7CC9, 0x5005713C, 0x270241AA,
29-
0xBE0B1010, 0xC90C2086, 0x5768B525, 0x206F85B3, 0xB966D409, 0xCE61E49F,
30-
0x5EDEF90E, 0x29D9C998, 0xB0D09822, 0xC7D7A8B4, 0x59B33D17, 0x2EB40D81,
31-
0xB7BD5C3B, 0xC0BA6CAD, 0xEDB88320, 0x9ABFB3B6, 0x03B6E20C, 0x74B1D29A,
32-
0xEAD54739, 0x9DD277AF, 0x04DB2615, 0x73DC1683, 0xE3630B12, 0x94643B84,
33-
0x0D6D6A3E, 0x7A6A5AA8, 0xE40ECF0B, 0x9309FF9D, 0x0A00AE27, 0x7D079EB1,
34-
0xF00F9344, 0x8708A3D2, 0x1E01F268, 0x6906C2FE, 0xF762575D, 0x806567CB,
35-
0x196C3671, 0x6E6B06E7, 0xFED41B76, 0x89D32BE0, 0x10DA7A5A, 0x67DD4ACC,
36-
0xF9B9DF6F, 0x8EBEEFF9, 0x17B7BE43, 0x60B08ED5, 0xD6D6A3E8, 0xA1D1937E,
37-
0x38D8C2C4, 0x4FDFF252, 0xD1BB67F1, 0xA6BC5767, 0x3FB506DD, 0x48B2364B,
38-
0xD80D2BDA, 0xAF0A1B4C, 0x36034AF6, 0x41047A60, 0xDF60EFC3, 0xA867DF55,
39-
0x316E8EEF, 0x4669BE79, 0xCB61B38C, 0xBC66831A, 0x256FD2A0, 0x5268E236,
40-
0xCC0C7795, 0xBB0B4703, 0x220216B9, 0x5505262F, 0xC5BA3BBE, 0xB2BD0B28,
41-
0x2BB45A92, 0x5CB36A04, 0xC2D7FFA7, 0xB5D0CF31, 0x2CD99E8B, 0x5BDEAE1D,
42-
0x9B64C2B0, 0xEC63F226, 0x756AA39C, 0x026D930A, 0x9C0906A9, 0xEB0E363F,
43-
0x72076785, 0x05005713, 0x95BF4A82, 0xE2B87A14, 0x7BB12BAE, 0x0CB61B38,
44-
0x92D28E9B, 0xE5D5BE0D, 0x7CDCEFB7, 0x0BDBDF21, 0x86D3D2D4, 0xF1D4E242,
45-
0x68DDB3F8, 0x1FDA836E, 0x81BE16CD, 0xF6B9265B, 0x6FB077E1, 0x18B74777,
46-
0x88085AE6, 0xFF0F6A70, 0x66063BCA, 0x11010B5C, 0x8F659EFF, 0xF862AE69,
47-
0x616BFFD3, 0x166CCF45, 0xA00AE278, 0xD70DD2EE, 0x4E048354, 0x3903B3C2,
48-
0xA7672661, 0xD06016F7, 0x4969474D, 0x3E6E77DB, 0xAED16A4A, 0xD9D65ADC,
49-
0x40DF0B66, 0x37D83BF0, 0xA9BCAE53, 0xDEBB9EC5, 0x47B2CF7F, 0x30B5FFE9,
50-
0xBDBDF21C, 0xCABAC28A, 0x53B39330, 0x24B4A3A6, 0xBAD03605, 0xCDD70693,
51-
0x54DE5729, 0x23D967BF, 0xB3667A2E, 0xC4614AB8, 0x5D681B02, 0x2A6F2B94,
52-
0xB40BBE37, 0xC30C8EA1, 0x5A05DF1B, 0x2D02EF8D};
9+
table[256] =
10+
{0x00000000, 0x77073096, 0xEE0E612C, 0x990951BA, 0x076DC419, 0x706AF48F,
11+
0xE963A535, 0x9E6495A3, 0x0EDB8832, 0x79DCB8A4, 0xE0D5E91E, 0x97D2D988,
12+
0x09B64C2B, 0x7EB17CBD, 0xE7B82D07, 0x90BF1D91, 0x1DB71064, 0x6AB020F2,
13+
0xF3B97148, 0x84BE41DE, 0x1ADAD47D, 0x6DDDE4EB, 0xF4D4B551, 0x83D385C7,
14+
0x136C9856, 0x646BA8C0, 0xFD62F97A, 0x8A65C9EC, 0x14015C4F, 0x63066CD9,
15+
0xFA0F3D63, 0x8D080DF5, 0x3B6E20C8, 0x4C69105E, 0xD56041E4, 0xA2677172,
16+
0x3C03E4D1, 0x4B04D447, 0xD20D85FD, 0xA50AB56B, 0x35B5A8FA, 0x42B2986C,
17+
0xDBBBC9D6, 0xACBCF940, 0x32D86CE3, 0x45DF5C75, 0xDCD60DCF, 0xABD13D59,
18+
0x26D930AC, 0x51DE003A, 0xC8D75180, 0xBFD06116, 0x21B4F4B5, 0x56B3C423,
19+
0xCFBA9599, 0xB8BDA50F, 0x2802B89E, 0x5F058808, 0xC60CD9B2, 0xB10BE924,
20+
0x2F6F7C87, 0x58684C11, 0xC1611DAB, 0xB6662D3D, 0x76DC4190, 0x01DB7106,
21+
0x98D220BC, 0xEFD5102A, 0x71B18589, 0x06B6B51F, 0x9FBFE4A5, 0xE8B8D433,
22+
0x7807C9A2, 0x0F00F934, 0x9609A88E, 0xE10E9818, 0x7F6A0DBB, 0x086D3D2D,
23+
0x91646C97, 0xE6635C01, 0x6B6B51F4, 0x1C6C6162, 0x856530D8, 0xF262004E,
24+
0x6C0695ED, 0x1B01A57B, 0x8208F4C1, 0xF50FC457, 0x65B0D9C6, 0x12B7E950,
25+
0x8BBEB8EA, 0xFCB9887C, 0x62DD1DDF, 0x15DA2D49, 0x8CD37CF3, 0xFBD44C65,
26+
0x4DB26158, 0x3AB551CE, 0xA3BC0074, 0xD4BB30E2, 0x4ADFA541, 0x3DD895D7,
27+
0xA4D1C46D, 0xD3D6F4FB, 0x4369E96A, 0x346ED9FC, 0xAD678846, 0xDA60B8D0,
28+
0x44042D73, 0x33031DE5, 0xAA0A4C5F, 0xDD0D7CC9, 0x5005713C, 0x270241AA,
29+
0xBE0B1010, 0xC90C2086, 0x5768B525, 0x206F85B3, 0xB966D409, 0xCE61E49F,
30+
0x5EDEF90E, 0x29D9C998, 0xB0D09822, 0xC7D7A8B4, 0x59B33D17, 0x2EB40D81,
31+
0xB7BD5C3B, 0xC0BA6CAD, 0xEDB88320, 0x9ABFB3B6, 0x03B6E20C, 0x74B1D29A,
32+
0xEAD54739, 0x9DD277AF, 0x04DB2615, 0x73DC1683, 0xE3630B12, 0x94643B84,
33+
0x0D6D6A3E, 0x7A6A5AA8, 0xE40ECF0B, 0x9309FF9D, 0x0A00AE27, 0x7D079EB1,
34+
0xF00F9344, 0x8708A3D2, 0x1E01F268, 0x6906C2FE, 0xF762575D, 0x806567CB,
35+
0x196C3671, 0x6E6B06E7, 0xFED41B76, 0x89D32BE0, 0x10DA7A5A, 0x67DD4ACC,
36+
0xF9B9DF6F, 0x8EBEEFF9, 0x17B7BE43, 0x60B08ED5, 0xD6D6A3E8, 0xA1D1937E,
37+
0x38D8C2C4, 0x4FDFF252, 0xD1BB67F1, 0xA6BC5767, 0x3FB506DD, 0x48B2364B,
38+
0xD80D2BDA, 0xAF0A1B4C, 0x36034AF6, 0x41047A60, 0xDF60EFC3, 0xA867DF55,
39+
0x316E8EEF, 0x4669BE79, 0xCB61B38C, 0xBC66831A, 0x256FD2A0, 0x5268E236,
40+
0xCC0C7795, 0xBB0B4703, 0x220216B9, 0x5505262F, 0xC5BA3BBE, 0xB2BD0B28,
41+
0x2BB45A92, 0x5CB36A04, 0xC2D7FFA7, 0xB5D0CF31, 0x2CD99E8B, 0x5BDEAE1D,
42+
0x9B64C2B0, 0xEC63F226, 0x756AA39C, 0x026D930A, 0x9C0906A9, 0xEB0E363F,
43+
0x72076785, 0x05005713, 0x95BF4A82, 0xE2B87A14, 0x7BB12BAE, 0x0CB61B38,
44+
0x92D28E9B, 0xE5D5BE0D, 0x7CDCEFB7, 0x0BDBDF21, 0x86D3D2D4, 0xF1D4E242,
45+
0x68DDB3F8, 0x1FDA836E, 0x81BE16CD, 0xF6B9265B, 0x6FB077E1, 0x18B74777,
46+
0x88085AE6, 0xFF0F6A70, 0x66063BCA, 0x11010B5C, 0x8F659EFF, 0xF862AE69,
47+
0x616BFFD3, 0x166CCF45, 0xA00AE278, 0xD70DD2EE, 0x4E048354, 0x3903B3C2,
48+
0xA7672661, 0xD06016F7, 0x4969474D, 0x3E6E77DB, 0xAED16A4A, 0xD9D65ADC,
49+
0x40DF0B66, 0x37D83BF0, 0xA9BCAE53, 0xDEBB9EC5, 0x47B2CF7F, 0x30B5FFE9,
50+
0xBDBDF21C, 0xCABAC28A, 0x53B39330, 0x24B4A3A6, 0xBAD03605, 0xCDD70693,
51+
0x54DE5729, 0x23D967BF, 0xB3667A2E, 0xC4614AB8, 0x5D681B02, 0x2A6F2B94,
52+
0xB40BBE37, 0xC30C8EA1, 0x5A05DF1B, 0x2D02EF8D},
53+
last_index[256] = {
54+
0, 65, 195, 130, 134, 199, 69, 4, 77, 12, 142, 207, 203, 138,
55+
8, 73, 154, 219, 89, 24, 28, 93, 223, 158, 215, 150, 20, 85,
56+
81, 16, 146, 211, 117, 52, 182, 247, 243, 178, 48, 113, 56, 121,
57+
251, 186, 190, 255, 125, 60, 239, 174, 44, 109, 105, 40, 170, 235,
58+
162, 227, 97, 32, 36, 101, 231, 166, 234, 171, 41, 104, 108, 45,
59+
175, 238, 167, 230, 100, 37, 33, 96, 226, 163, 112, 49, 179, 242,
60+
246, 183, 53, 116, 61, 124, 254, 191, 187, 250, 120, 57, 159, 222,
61+
92, 29, 25, 88, 218, 155, 210, 147, 17, 80, 84, 21, 151, 214,
62+
5, 68, 198, 135, 131, 194, 64, 1, 72, 9, 139, 202, 206, 143,
63+
13, 76, 149, 212, 86, 23, 19, 82, 208, 145, 216, 153, 27, 90,
64+
94, 31, 157, 220, 15, 78, 204, 141, 137, 200, 74, 11, 66, 3,
65+
129, 192, 196, 133, 7, 70, 224, 161, 35, 98, 102, 39, 165, 228,
66+
173, 236, 110, 47, 43, 106, 232, 169, 122, 59, 185, 248, 252, 189,
67+
63, 126, 55, 118, 244, 181, 177, 240, 114, 51, 127, 62, 188, 253,
68+
249, 184, 58, 123, 50, 115, 241, 176, 180, 245, 119, 54, 229, 164,
69+
38, 103, 99, 34, 160, 225, 168, 233, 107, 42, 46, 111, 237, 172,
70+
10, 75, 201, 136, 140, 205, 79, 14, 71, 6, 132, 197, 193, 128,
71+
2, 67, 144, 209, 83, 18, 22, 87, 213, 148, 221, 156, 30, 95,
72+
91, 26, 152, 217};
5373

5474
typedef struct {
5575
uint32_t crc;
@@ -67,14 +87,6 @@ crc_t crc32(const unsigned char str[]) {
6787
return result;
6888
}
6989

70-
uint8_t last_index(const uint32_t crc) {
71-
for (uint8_t i = 0; i < sizeof(table); i++) {
72-
if (crc == table[i] >> 24) {
73-
return i;
74-
}
75-
}
76-
}
77-
7890
int16_t check(uintmax_t high, uint8_t indexes[4]) {
7991
unsigned char buf[17] = {0};
8092
sprintf(buf, "%ju", high);
@@ -114,7 +126,7 @@ uintmax_t crack(uint32_t crc) {
114126
}
115127

116128
for (int8_t i = 3; i > -1; i--) {
117-
indexes[3 - i] = last_index(crc >> (i << 3));
129+
indexes[3 - i] = last_index[crc >> (i << 3)];
118130
crc ^= table[indexes[3 - i]] >> ((3 - i) << 3);
119131
}
120132

‎main.py‎

Lines changed: 3 additions & 7 deletions
Original file line numberDiff line numberDiff line change
@@ -4,6 +4,7 @@
44
POLY: Literal[0xEDB88320] = 0xEDB88320
55

66
table: list[int] = []
7+
last_index: list[int] = [0] * 256
78

89
for i in range(256):
910
value = i
@@ -13,6 +14,7 @@
1314
else:
1415
value >>= 1
1516
table.append(value)
17+
last_index[value >> 24] = i
1618

1719

1820
def crc32(string: str) -> tuple[int, int]:
@@ -24,12 +26,6 @@ def crc32(string: str) -> tuple[int, int]:
2426
return crc, index
2527

2628

27-
def last_index(crc: int) -> int: # type: ignore
28-
for index, value in enumerate(table):
29-
if crc == value >> 24:
30-
return index
31-
32-
3329
def check(high: int, indexes: list) -> int | None:
3430
crc, index = crc32(str(high))
3531
if index != indexes[3]:
@@ -51,7 +47,7 @@ def main(crc: str | int) -> int: # type: ignore
5147
if crc == crc32(str(i))[0]:
5248
return i
5349
for i in range(3, -1, -1):
54-
index = indexes[3 - i] = last_index(crc >> (i << 3))
50+
index = indexes[3 - i] = last_index[crc >> (i << 3)]
5551
crc ^= table[index] >> ((3 - i) << 3)
5652
for i in count(1):
5753
if result := check(i, indexes):

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