Mercurial > repos > blastem
annotate zlib/crc32.c @ 1925:039553703c20
Don't apply address and cd register changes to the 'live' registers until pending flag is cleared, but do preserve the upper address bits in the latch. Fixes regression in Overdrive 2 while preserving fix to Mona in 344 bytes
author | Michael Pavone <pavone@retrodev.com> |
---|---|
date | Mon, 13 Apr 2020 20:43:25 -0700 |
parents | 00d788dac91a |
children |
rev | line source |
---|---|
1530
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
1 /* crc32.c -- compute the CRC-32 of a data stream |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
2 * Copyright (C) 1995-2006, 2010, 2011, 2012, 2016 Mark Adler |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
3 * For conditions of distribution and use, see copyright notice in zlib.h |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
4 * |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
5 * Thanks to Rodney Brown <rbrown64@csc.com.au> for his contribution of faster |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
6 * CRC methods: exclusive-oring 32 bits of data at a time, and pre-computing |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
7 * tables for updating the shift register in one step with three exclusive-ors |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
8 * instead of four steps with four exclusive-ors. This results in about a |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
9 * factor of two increase in speed on a Power PC G4 (PPC7455) using gcc -O3. |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
10 */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
11 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
12 /* @(#) $Id$ */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
13 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
14 /* |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
15 Note on the use of DYNAMIC_CRC_TABLE: there is no mutex or semaphore |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
16 protection on the static variables used to control the first-use generation |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
17 of the crc tables. Therefore, if you #define DYNAMIC_CRC_TABLE, you should |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
18 first call get_crc_table() to initialize the tables before allowing more than |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
19 one thread to use crc32(). |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
20 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
21 DYNAMIC_CRC_TABLE and MAKECRCH can be #defined to write out crc32.h. |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
22 */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
23 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
24 #ifdef MAKECRCH |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
25 # include <stdio.h> |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
26 # ifndef DYNAMIC_CRC_TABLE |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
27 # define DYNAMIC_CRC_TABLE |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
28 # endif /* !DYNAMIC_CRC_TABLE */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
29 #endif /* MAKECRCH */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
30 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
31 #include "zutil.h" /* for STDC and FAR definitions */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
32 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
33 /* Definitions for doing the crc four data bytes at a time. */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
34 #if !defined(NOBYFOUR) && defined(Z_U4) |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
35 # define BYFOUR |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
36 #endif |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
37 #ifdef BYFOUR |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
38 local unsigned long crc32_little OF((unsigned long, |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
39 const unsigned char FAR *, z_size_t)); |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
40 local unsigned long crc32_big OF((unsigned long, |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
41 const unsigned char FAR *, z_size_t)); |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
42 # define TBLS 8 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
43 #else |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
44 # define TBLS 1 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
45 #endif /* BYFOUR */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
46 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
47 /* Local functions for crc concatenation */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
48 local unsigned long gf2_matrix_times OF((unsigned long *mat, |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
49 unsigned long vec)); |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
50 local void gf2_matrix_square OF((unsigned long *square, unsigned long *mat)); |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
51 local uLong crc32_combine_ OF((uLong crc1, uLong crc2, z_off64_t len2)); |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
52 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
53 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
54 #ifdef DYNAMIC_CRC_TABLE |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
55 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
56 local volatile int crc_table_empty = 1; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
57 local z_crc_t FAR crc_table[TBLS][256]; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
58 local void make_crc_table OF((void)); |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
59 #ifdef MAKECRCH |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
60 local void write_table OF((FILE *, const z_crc_t FAR *)); |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
61 #endif /* MAKECRCH */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
62 /* |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
63 Generate tables for a byte-wise 32-bit CRC calculation on the polynomial: |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
64 x^32+x^26+x^23+x^22+x^16+x^12+x^11+x^10+x^8+x^7+x^5+x^4+x^2+x+1. |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
65 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
66 Polynomials over GF(2) are represented in binary, one bit per coefficient, |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
67 with the lowest powers in the most significant bit. Then adding polynomials |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
68 is just exclusive-or, and multiplying a polynomial by x is a right shift by |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
69 one. If we call the above polynomial p, and represent a byte as the |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
70 polynomial q, also with the lowest power in the most significant bit (so the |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
71 byte 0xb1 is the polynomial x^7+x^3+x+1), then the CRC is (q*x^32) mod p, |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
72 where a mod b means the remainder after dividing a by b. |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
73 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
74 This calculation is done using the shift-register method of multiplying and |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
75 taking the remainder. The register is initialized to zero, and for each |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
76 incoming bit, x^32 is added mod p to the register if the bit is a one (where |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
77 x^32 mod p is p+x^32 = x^26+...+1), and the register is multiplied mod p by |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
78 x (which is shifting right by one and adding x^32 mod p if the bit shifted |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
79 out is a one). We start with the highest power (least significant bit) of |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
80 q and repeat for all eight bits of q. |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
81 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
82 The first table is simply the CRC of all possible eight bit values. This is |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
83 all the information needed to generate CRCs on data a byte at a time for all |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
84 combinations of CRC register values and incoming bytes. The remaining tables |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
85 allow for word-at-a-time CRC calculation for both big-endian and little- |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
86 endian machines, where a word is four bytes. |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
87 */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
88 local void make_crc_table() |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
89 { |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
90 z_crc_t c; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
91 int n, k; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
92 z_crc_t poly; /* polynomial exclusive-or pattern */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
93 /* terms of polynomial defining this crc (except x^32): */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
94 static volatile int first = 1; /* flag to limit concurrent making */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
95 static const unsigned char p[] = {0,1,2,4,5,7,8,10,11,12,16,22,23,26}; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
96 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
97 /* See if another task is already doing this (not thread-safe, but better |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
98 than nothing -- significantly reduces duration of vulnerability in |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
99 case the advice about DYNAMIC_CRC_TABLE is ignored) */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
100 if (first) { |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
101 first = 0; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
102 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
103 /* make exclusive-or pattern from polynomial (0xedb88320UL) */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
104 poly = 0; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
105 for (n = 0; n < (int)(sizeof(p)/sizeof(unsigned char)); n++) |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
106 poly |= (z_crc_t)1 << (31 - p[n]); |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
107 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
108 /* generate a crc for every 8-bit value */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
109 for (n = 0; n < 256; n++) { |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
110 c = (z_crc_t)n; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
111 for (k = 0; k < 8; k++) |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
112 c = c & 1 ? poly ^ (c >> 1) : c >> 1; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
113 crc_table[0][n] = c; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
114 } |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
115 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
116 #ifdef BYFOUR |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
117 /* generate crc for each value followed by one, two, and three zeros, |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
118 and then the byte reversal of those as well as the first table */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
119 for (n = 0; n < 256; n++) { |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
120 c = crc_table[0][n]; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
121 crc_table[4][n] = ZSWAP32(c); |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
122 for (k = 1; k < 4; k++) { |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
123 c = crc_table[0][c & 0xff] ^ (c >> 8); |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
124 crc_table[k][n] = c; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
125 crc_table[k + 4][n] = ZSWAP32(c); |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
126 } |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
127 } |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
128 #endif /* BYFOUR */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
129 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
130 crc_table_empty = 0; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
131 } |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
132 else { /* not first */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
133 /* wait for the other guy to finish (not efficient, but rare) */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
134 while (crc_table_empty) |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
135 ; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
136 } |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
137 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
138 #ifdef MAKECRCH |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
139 /* write out CRC tables to crc32.h */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
140 { |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
141 FILE *out; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
142 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
143 out = fopen("crc32.h", "w"); |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
144 if (out == NULL) return; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
145 fprintf(out, "/* crc32.h -- tables for rapid CRC calculation\n"); |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
146 fprintf(out, " * Generated automatically by crc32.c\n */\n\n"); |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
147 fprintf(out, "local const z_crc_t FAR "); |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
148 fprintf(out, "crc_table[TBLS][256] =\n{\n {\n"); |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
149 write_table(out, crc_table[0]); |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
150 # ifdef BYFOUR |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
151 fprintf(out, "#ifdef BYFOUR\n"); |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
152 for (k = 1; k < 8; k++) { |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
153 fprintf(out, " },\n {\n"); |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
154 write_table(out, crc_table[k]); |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
155 } |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
156 fprintf(out, "#endif\n"); |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
157 # endif /* BYFOUR */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
158 fprintf(out, " }\n};\n"); |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
159 fclose(out); |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
160 } |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
161 #endif /* MAKECRCH */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
162 } |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
163 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
164 #ifdef MAKECRCH |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
165 local void write_table(out, table) |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
166 FILE *out; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
167 const z_crc_t FAR *table; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
168 { |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
169 int n; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
170 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
171 for (n = 0; n < 256; n++) |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
172 fprintf(out, "%s0x%08lxUL%s", n % 5 ? "" : " ", |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
173 (unsigned long)(table[n]), |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
174 n == 255 ? "\n" : (n % 5 == 4 ? ",\n" : ", ")); |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
175 } |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
176 #endif /* MAKECRCH */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
177 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
178 #else /* !DYNAMIC_CRC_TABLE */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
179 /* ======================================================================== |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
180 * Tables of CRC-32s of all single-byte values, made by make_crc_table(). |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
181 */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
182 #include "crc32.h" |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
183 #endif /* DYNAMIC_CRC_TABLE */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
184 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
185 /* ========================================================================= |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
186 * This function can be used by asm versions of crc32() |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
187 */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
188 const z_crc_t FAR * ZEXPORT get_crc_table() |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
189 { |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
190 #ifdef DYNAMIC_CRC_TABLE |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
191 if (crc_table_empty) |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
192 make_crc_table(); |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
193 #endif /* DYNAMIC_CRC_TABLE */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
194 return (const z_crc_t FAR *)crc_table; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
195 } |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
196 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
197 /* ========================================================================= */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
198 #define DO1 crc = crc_table[0][((int)crc ^ (*buf++)) & 0xff] ^ (crc >> 8) |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
199 #define DO8 DO1; DO1; DO1; DO1; DO1; DO1; DO1; DO1 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
200 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
201 /* ========================================================================= */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
202 unsigned long ZEXPORT crc32_z(crc, buf, len) |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
203 unsigned long crc; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
204 const unsigned char FAR *buf; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
205 z_size_t len; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
206 { |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
207 if (buf == Z_NULL) return 0UL; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
208 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
209 #ifdef DYNAMIC_CRC_TABLE |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
210 if (crc_table_empty) |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
211 make_crc_table(); |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
212 #endif /* DYNAMIC_CRC_TABLE */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
213 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
214 #ifdef BYFOUR |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
215 if (sizeof(void *) == sizeof(ptrdiff_t)) { |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
216 z_crc_t endian; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
217 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
218 endian = 1; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
219 if (*((unsigned char *)(&endian))) |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
220 return crc32_little(crc, buf, len); |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
221 else |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
222 return crc32_big(crc, buf, len); |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
223 } |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
224 #endif /* BYFOUR */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
225 crc = crc ^ 0xffffffffUL; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
226 while (len >= 8) { |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
227 DO8; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
228 len -= 8; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
229 } |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
230 if (len) do { |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
231 DO1; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
232 } while (--len); |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
233 return crc ^ 0xffffffffUL; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
234 } |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
235 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
236 /* ========================================================================= */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
237 unsigned long ZEXPORT crc32(crc, buf, len) |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
238 unsigned long crc; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
239 const unsigned char FAR *buf; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
240 uInt len; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
241 { |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
242 return crc32_z(crc, buf, len); |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
243 } |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
244 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
245 #ifdef BYFOUR |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
246 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
247 /* |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
248 This BYFOUR code accesses the passed unsigned char * buffer with a 32-bit |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
249 integer pointer type. This violates the strict aliasing rule, where a |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
250 compiler can assume, for optimization purposes, that two pointers to |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
251 fundamentally different types won't ever point to the same memory. This can |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
252 manifest as a problem only if one of the pointers is written to. This code |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
253 only reads from those pointers. So long as this code remains isolated in |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
254 this compilation unit, there won't be a problem. For this reason, this code |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
255 should not be copied and pasted into a compilation unit in which other code |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
256 writes to the buffer that is passed to these routines. |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
257 */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
258 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
259 /* ========================================================================= */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
260 #define DOLIT4 c ^= *buf4++; \ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
261 c = crc_table[3][c & 0xff] ^ crc_table[2][(c >> 8) & 0xff] ^ \ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
262 crc_table[1][(c >> 16) & 0xff] ^ crc_table[0][c >> 24] |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
263 #define DOLIT32 DOLIT4; DOLIT4; DOLIT4; DOLIT4; DOLIT4; DOLIT4; DOLIT4; DOLIT4 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
264 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
265 /* ========================================================================= */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
266 local unsigned long crc32_little(crc, buf, len) |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
267 unsigned long crc; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
268 const unsigned char FAR *buf; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
269 z_size_t len; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
270 { |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
271 register z_crc_t c; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
272 register const z_crc_t FAR *buf4; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
273 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
274 c = (z_crc_t)crc; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
275 c = ~c; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
276 while (len && ((ptrdiff_t)buf & 3)) { |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
277 c = crc_table[0][(c ^ *buf++) & 0xff] ^ (c >> 8); |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
278 len--; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
279 } |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
280 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
281 buf4 = (const z_crc_t FAR *)(const void FAR *)buf; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
282 while (len >= 32) { |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
283 DOLIT32; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
284 len -= 32; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
285 } |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
286 while (len >= 4) { |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
287 DOLIT4; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
288 len -= 4; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
289 } |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
290 buf = (const unsigned char FAR *)buf4; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
291 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
292 if (len) do { |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
293 c = crc_table[0][(c ^ *buf++) & 0xff] ^ (c >> 8); |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
294 } while (--len); |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
295 c = ~c; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
296 return (unsigned long)c; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
297 } |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
298 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
299 /* ========================================================================= */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
300 #define DOBIG4 c ^= *buf4++; \ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
301 c = crc_table[4][c & 0xff] ^ crc_table[5][(c >> 8) & 0xff] ^ \ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
302 crc_table[6][(c >> 16) & 0xff] ^ crc_table[7][c >> 24] |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
303 #define DOBIG32 DOBIG4; DOBIG4; DOBIG4; DOBIG4; DOBIG4; DOBIG4; DOBIG4; DOBIG4 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
304 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
305 /* ========================================================================= */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
306 local unsigned long crc32_big(crc, buf, len) |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
307 unsigned long crc; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
308 const unsigned char FAR *buf; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
309 z_size_t len; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
310 { |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
311 register z_crc_t c; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
312 register const z_crc_t FAR *buf4; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
313 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
314 c = ZSWAP32((z_crc_t)crc); |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
315 c = ~c; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
316 while (len && ((ptrdiff_t)buf & 3)) { |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
317 c = crc_table[4][(c >> 24) ^ *buf++] ^ (c << 8); |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
318 len--; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
319 } |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
320 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
321 buf4 = (const z_crc_t FAR *)(const void FAR *)buf; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
322 while (len >= 32) { |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
323 DOBIG32; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
324 len -= 32; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
325 } |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
326 while (len >= 4) { |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
327 DOBIG4; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
328 len -= 4; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
329 } |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
330 buf = (const unsigned char FAR *)buf4; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
331 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
332 if (len) do { |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
333 c = crc_table[4][(c >> 24) ^ *buf++] ^ (c << 8); |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
334 } while (--len); |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
335 c = ~c; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
336 return (unsigned long)(ZSWAP32(c)); |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
337 } |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
338 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
339 #endif /* BYFOUR */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
340 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
341 #define GF2_DIM 32 /* dimension of GF(2) vectors (length of CRC) */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
342 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
343 /* ========================================================================= */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
344 local unsigned long gf2_matrix_times(mat, vec) |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
345 unsigned long *mat; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
346 unsigned long vec; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
347 { |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
348 unsigned long sum; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
349 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
350 sum = 0; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
351 while (vec) { |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
352 if (vec & 1) |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
353 sum ^= *mat; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
354 vec >>= 1; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
355 mat++; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
356 } |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
357 return sum; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
358 } |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
359 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
360 /* ========================================================================= */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
361 local void gf2_matrix_square(square, mat) |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
362 unsigned long *square; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
363 unsigned long *mat; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
364 { |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
365 int n; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
366 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
367 for (n = 0; n < GF2_DIM; n++) |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
368 square[n] = gf2_matrix_times(mat, mat[n]); |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
369 } |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
370 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
371 /* ========================================================================= */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
372 local uLong crc32_combine_(crc1, crc2, len2) |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
373 uLong crc1; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
374 uLong crc2; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
375 z_off64_t len2; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
376 { |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
377 int n; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
378 unsigned long row; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
379 unsigned long even[GF2_DIM]; /* even-power-of-two zeros operator */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
380 unsigned long odd[GF2_DIM]; /* odd-power-of-two zeros operator */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
381 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
382 /* degenerate case (also disallow negative lengths) */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
383 if (len2 <= 0) |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
384 return crc1; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
385 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
386 /* put operator for one zero bit in odd */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
387 odd[0] = 0xedb88320UL; /* CRC-32 polynomial */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
388 row = 1; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
389 for (n = 1; n < GF2_DIM; n++) { |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
390 odd[n] = row; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
391 row <<= 1; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
392 } |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
393 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
394 /* put operator for two zero bits in even */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
395 gf2_matrix_square(even, odd); |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
396 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
397 /* put operator for four zero bits in odd */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
398 gf2_matrix_square(odd, even); |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
399 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
400 /* apply len2 zeros to crc1 (first square will put the operator for one |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
401 zero byte, eight zero bits, in even) */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
402 do { |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
403 /* apply zeros operator for this bit of len2 */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
404 gf2_matrix_square(even, odd); |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
405 if (len2 & 1) |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
406 crc1 = gf2_matrix_times(even, crc1); |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
407 len2 >>= 1; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
408 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
409 /* if no more bits set, then done */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
410 if (len2 == 0) |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
411 break; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
412 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
413 /* another iteration of the loop with odd and even swapped */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
414 gf2_matrix_square(odd, even); |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
415 if (len2 & 1) |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
416 crc1 = gf2_matrix_times(odd, crc1); |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
417 len2 >>= 1; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
418 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
419 /* if no more bits set, then done */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
420 } while (len2 != 0); |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
421 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
422 /* return combined crc */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
423 crc1 ^= crc2; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
424 return crc1; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
425 } |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
426 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
427 /* ========================================================================= */ |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
428 uLong ZEXPORT crc32_combine(crc1, crc2, len2) |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
429 uLong crc1; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
430 uLong crc2; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
431 z_off_t len2; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
432 { |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
433 return crc32_combine_(crc1, crc2, len2); |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
434 } |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
435 |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
436 uLong ZEXPORT crc32_combine64(crc1, crc2, len2) |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
437 uLong crc1; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
438 uLong crc2; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
439 z_off64_t len2; |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
440 { |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
441 return crc32_combine_(crc1, crc2, len2); |
00d788dac91a
Added support for reading gzipped ROMs
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
442 } |