xref: /linux/lib/lz4/lz4defs.h (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
1 /*
2  * lz4defs.h -- architecture specific defines
3  *
4  * Copyright (C) 2013, LG Electronics, Kyungsik Lee <kyungsik.lee@lge.com>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  */
10 
11 /*
12  * Detects 64 bits mode
13  */
14 #if (defined(__x86_64__) || defined(__x86_64) || defined(__amd64__) \
15 	|| defined(__ppc64__) || defined(__LP64__))
16 #define LZ4_ARCH64 1
17 #else
18 #define LZ4_ARCH64 0
19 #endif
20 
21 /*
22  * Architecture-specific macros
23  */
24 #define BYTE	u8
25 typedef struct _U16_S { u16 v; } U16_S;
26 typedef struct _U32_S { u32 v; } U32_S;
27 typedef struct _U64_S { u64 v; } U64_S;
28 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)		\
29 	|| defined(CONFIG_ARM) && __LINUX_ARM_ARCH__ >= 6	\
30 	&& defined(ARM_EFFICIENT_UNALIGNED_ACCESS)
31 
32 #define A16(x) (((U16_S *)(x))->v)
33 #define A32(x) (((U32_S *)(x))->v)
34 #define A64(x) (((U64_S *)(x))->v)
35 
36 #define PUT4(s, d) (A32(d) = A32(s))
37 #define PUT8(s, d) (A64(d) = A64(s))
38 #define LZ4_WRITE_LITTLEENDIAN_16(p, v)	\
39 	do {	\
40 		A16(p) = v; \
41 		p += 2; \
42 	} while (0)
43 #else /* CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS */
44 
45 #define A64(x) get_unaligned((u64 *)&(((U16_S *)(x))->v))
46 #define A32(x) get_unaligned((u32 *)&(((U16_S *)(x))->v))
47 #define A16(x) get_unaligned((u16 *)&(((U16_S *)(x))->v))
48 
49 #define PUT4(s, d) \
50 	put_unaligned(get_unaligned((const u32 *) s), (u32 *) d)
51 #define PUT8(s, d) \
52 	put_unaligned(get_unaligned((const u64 *) s), (u64 *) d)
53 
54 #define LZ4_WRITE_LITTLEENDIAN_16(p, v)	\
55 	do {	\
56 		put_unaligned(v, (u16 *)(p)); \
57 		p += 2; \
58 	} while (0)
59 #endif
60 
61 #define COPYLENGTH 8
62 #define ML_BITS  4
63 #define ML_MASK  ((1U << ML_BITS) - 1)
64 #define RUN_BITS (8 - ML_BITS)
65 #define RUN_MASK ((1U << RUN_BITS) - 1)
66 #define MEMORY_USAGE	14
67 #define MINMATCH	4
68 #define SKIPSTRENGTH	6
69 #define LASTLITERALS	5
70 #define MFLIMIT		(COPYLENGTH + MINMATCH)
71 #define MINLENGTH	(MFLIMIT + 1)
72 #define MAXD_LOG	16
73 #define MAXD		(1 << MAXD_LOG)
74 #define MAXD_MASK	(u32)(MAXD - 1)
75 #define MAX_DISTANCE	(MAXD - 1)
76 #define HASH_LOG	(MAXD_LOG - 1)
77 #define HASHTABLESIZE	(1 << HASH_LOG)
78 #define MAX_NB_ATTEMPTS	256
79 #define OPTIMAL_ML	(int)((ML_MASK-1)+MINMATCH)
80 #define LZ4_64KLIMIT	((1<<16) + (MFLIMIT - 1))
81 #define HASHLOG64K	((MEMORY_USAGE - 2) + 1)
82 #define HASH64KTABLESIZE	(1U << HASHLOG64K)
83 #define LZ4_HASH_VALUE(p)	(((A32(p)) * 2654435761U) >> \
84 				((MINMATCH * 8) - (MEMORY_USAGE-2)))
85 #define LZ4_HASH64K_VALUE(p)	(((A32(p)) * 2654435761U) >> \
86 				((MINMATCH * 8) - HASHLOG64K))
87 #define HASH_VALUE(p)		(((A32(p)) * 2654435761U) >> \
88 				((MINMATCH * 8) - HASH_LOG))
89 
90 #if LZ4_ARCH64/* 64-bit */
91 #define STEPSIZE 8
92 
93 #define LZ4_COPYSTEP(s, d)	\
94 	do {			\
95 		PUT8(s, d);	\
96 		d += 8;		\
97 		s += 8;		\
98 	} while (0)
99 
100 #define LZ4_COPYPACKET(s, d)	LZ4_COPYSTEP(s, d)
101 
102 #define LZ4_SECURECOPY(s, d, e)			\
103 	do {					\
104 		if (d < e) {			\
105 			LZ4_WILDCOPY(s, d, e);	\
106 		}				\
107 	} while (0)
108 #define HTYPE u32
109 
110 #ifdef __BIG_ENDIAN
111 #define LZ4_NBCOMMONBYTES(val) (__builtin_clzll(val) >> 3)
112 #else
113 #define LZ4_NBCOMMONBYTES(val) (__builtin_ctzll(val) >> 3)
114 #endif
115 
116 #else	/* 32-bit */
117 #define STEPSIZE 4
118 
119 #define LZ4_COPYSTEP(s, d)	\
120 	do {			\
121 		PUT4(s, d);	\
122 		d += 4;		\
123 		s += 4;		\
124 	} while (0)
125 
126 #define LZ4_COPYPACKET(s, d)		\
127 	do {				\
128 		LZ4_COPYSTEP(s, d);	\
129 		LZ4_COPYSTEP(s, d);	\
130 	} while (0)
131 
132 #define LZ4_SECURECOPY	LZ4_WILDCOPY
133 #define HTYPE const u8*
134 
135 #ifdef __BIG_ENDIAN
136 #define LZ4_NBCOMMONBYTES(val) (__builtin_clz(val) >> 3)
137 #else
138 #define LZ4_NBCOMMONBYTES(val) (__builtin_ctz(val) >> 3)
139 #endif
140 
141 #endif
142 
143 #define LZ4_READ_LITTLEENDIAN_16(d, s, p) \
144 	(d = s - get_unaligned_le16(p))
145 
146 #define LZ4_WILDCOPY(s, d, e)		\
147 	do {				\
148 		LZ4_COPYPACKET(s, d);	\
149 	} while (d < e)
150 
151 #define LZ4_BLINDCOPY(s, d, l)	\
152 	do {	\
153 		u8 *e = (d) + l;	\
154 		LZ4_WILDCOPY(s, d, e);	\
155 		d = e;	\
156 	} while (0)
157