1///////////////////////////////////////////////////////////////////////////////
2//
3/// \file       crc32_tablegen.c
4/// \brief      Generate crc32_table_le.h and crc32_table_be.h
5///
6/// Compiling: gcc -std=c99 -o crc32_tablegen crc32_tablegen.c
7/// Add -DWORDS_BIGENDIAN to generate big endian table.
8/// Add -DLZ_HASH_TABLE to generate lz_encoder_hash_table.h (little endian).
9//
10//  Author:     Lasse Collin
11//
12//  This file has been put into the public domain.
13//  You can do whatever you want with this file.
14//
15///////////////////////////////////////////////////////////////////////////////
16
17#include <stdio.h>
18#include "../../common/tuklib_integer.h"
19
20
21static uint32_t crc32_table[8][256];
22
23
24static void
25init_crc32_table(void)
26{
27	static const uint32_t poly32 = UINT32_C(0xEDB88320);
28
29	for (size_t s = 0; s < 8; ++s) {
30		for (size_t b = 0; b < 256; ++b) {
31			uint32_t r = s == 0 ? b : crc32_table[s - 1][b];
32
33			for (size_t i = 0; i < 8; ++i) {
34				if (r & 1)
35					r = (r >> 1) ^ poly32;
36				else
37					r >>= 1;
38			}
39
40			crc32_table[s][b] = r;
41		}
42	}
43
44#ifdef WORDS_BIGENDIAN
45	for (size_t s = 0; s < 8; ++s)
46		for (size_t b = 0; b < 256; ++b)
47			crc32_table[s][b] = bswap32(crc32_table[s][b]);
48#endif
49
50	return;
51}
52
53
54static void
55print_crc32_table(void)
56{
57	printf("/* This file has been automatically generated by "
58			"crc32_tablegen.c. */\n\n"
59			"const uint32_t lzma_crc32_table[8][256] = {\n\t{");
60
61	for (size_t s = 0; s < 8; ++s) {
62		for (size_t b = 0; b < 256; ++b) {
63			if ((b % 4) == 0)
64				printf("\n\t\t");
65
66			printf("0x%08" PRIX32, crc32_table[s][b]);
67
68			if (b != 255)
69				printf(",%s", (b+1) % 4 == 0 ? "" : " ");
70		}
71
72		if (s == 7)
73			printf("\n\t}\n};\n");
74		else
75			printf("\n\t}, {");
76	}
77
78	return;
79}
80
81
82static void
83print_lz_table(void)
84{
85	printf("/* This file has been automatically generated by "
86			"crc32_tablegen.c. */\n\n"
87			"const uint32_t lzma_lz_hash_table[256] = {");
88
89	for (size_t b = 0; b < 256; ++b) {
90		if ((b % 4) == 0)
91			printf("\n\t");
92
93		printf("0x%08" PRIX32, crc32_table[0][b]);
94
95		if (b != 255)
96			printf(",%s", (b+1) % 4 == 0 ? "" : " ");
97	}
98
99	printf("\n};\n");
100
101	return;
102}
103
104
105int
106main(void)
107{
108	init_crc32_table();
109
110#ifdef LZ_HASH_TABLE
111	print_lz_table();
112#else
113	print_crc32_table();
114#endif
115
116	return 0;
117}
118