648db22b |
1 | /* |
2 | * Copyright (c) Meta Platforms, Inc. and affiliates. |
3 | * All rights reserved. |
4 | * |
5 | * This source code is licensed under both the BSD-style license (found in the |
6 | * LICENSE file in the root directory of this source tree) and the GPLv2 (found |
7 | * in the COPYING file in the root directory of this source tree). |
8 | * You may select, at your option, one of the above-listed licenses. |
9 | */ |
10 | |
11 | #ifndef MEM_H_MODULE |
12 | #define MEM_H_MODULE |
13 | |
14 | #if defined (__cplusplus) |
15 | extern "C" { |
16 | #endif |
17 | |
18 | /*-**************************************** |
19 | * Dependencies |
20 | ******************************************/ |
21 | #include <stddef.h> /* size_t, ptrdiff_t */ |
22 | #include "compiler.h" /* __has_builtin */ |
23 | #include "debug.h" /* DEBUG_STATIC_ASSERT */ |
24 | #include "zstd_deps.h" /* ZSTD_memcpy */ |
25 | |
26 | |
27 | /*-**************************************** |
28 | * Compiler specifics |
29 | ******************************************/ |
30 | #if defined(_MSC_VER) /* Visual Studio */ |
31 | # include <stdlib.h> /* _byteswap_ulong */ |
32 | # include <intrin.h> /* _byteswap_* */ |
33 | #endif |
648db22b |
34 | |
35 | /*-************************************************************** |
36 | * Basic Types |
37 | *****************************************************************/ |
38 | #if !defined (__VMS) && (defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) ) |
39 | # if defined(_AIX) |
40 | # include <inttypes.h> |
41 | # else |
42 | # include <stdint.h> /* intptr_t */ |
43 | # endif |
44 | typedef uint8_t BYTE; |
45 | typedef uint8_t U8; |
46 | typedef int8_t S8; |
47 | typedef uint16_t U16; |
48 | typedef int16_t S16; |
49 | typedef uint32_t U32; |
50 | typedef int32_t S32; |
51 | typedef uint64_t U64; |
52 | typedef int64_t S64; |
53 | #else |
54 | # include <limits.h> |
55 | #if CHAR_BIT != 8 |
56 | # error "this implementation requires char to be exactly 8-bit type" |
57 | #endif |
58 | typedef unsigned char BYTE; |
59 | typedef unsigned char U8; |
60 | typedef signed char S8; |
61 | #if USHRT_MAX != 65535 |
62 | # error "this implementation requires short to be exactly 16-bit type" |
63 | #endif |
64 | typedef unsigned short U16; |
65 | typedef signed short S16; |
66 | #if UINT_MAX != 4294967295 |
67 | # error "this implementation requires int to be exactly 32-bit type" |
68 | #endif |
69 | typedef unsigned int U32; |
70 | typedef signed int S32; |
71 | /* note : there are no limits defined for long long type in C90. |
72 | * limits exist in C99, however, in such case, <stdint.h> is preferred */ |
73 | typedef unsigned long long U64; |
74 | typedef signed long long S64; |
75 | #endif |
76 | |
77 | |
78 | /*-************************************************************** |
79 | * Memory I/O API |
80 | *****************************************************************/ |
81 | /*=== Static platform detection ===*/ |
82 | MEM_STATIC unsigned MEM_32bits(void); |
83 | MEM_STATIC unsigned MEM_64bits(void); |
84 | MEM_STATIC unsigned MEM_isLittleEndian(void); |
85 | |
86 | /*=== Native unaligned read/write ===*/ |
87 | MEM_STATIC U16 MEM_read16(const void* memPtr); |
88 | MEM_STATIC U32 MEM_read32(const void* memPtr); |
89 | MEM_STATIC U64 MEM_read64(const void* memPtr); |
90 | MEM_STATIC size_t MEM_readST(const void* memPtr); |
91 | |
92 | MEM_STATIC void MEM_write16(void* memPtr, U16 value); |
93 | MEM_STATIC void MEM_write32(void* memPtr, U32 value); |
94 | MEM_STATIC void MEM_write64(void* memPtr, U64 value); |
95 | |
96 | /*=== Little endian unaligned read/write ===*/ |
97 | MEM_STATIC U16 MEM_readLE16(const void* memPtr); |
98 | MEM_STATIC U32 MEM_readLE24(const void* memPtr); |
99 | MEM_STATIC U32 MEM_readLE32(const void* memPtr); |
100 | MEM_STATIC U64 MEM_readLE64(const void* memPtr); |
101 | MEM_STATIC size_t MEM_readLEST(const void* memPtr); |
102 | |
103 | MEM_STATIC void MEM_writeLE16(void* memPtr, U16 val); |
104 | MEM_STATIC void MEM_writeLE24(void* memPtr, U32 val); |
105 | MEM_STATIC void MEM_writeLE32(void* memPtr, U32 val32); |
106 | MEM_STATIC void MEM_writeLE64(void* memPtr, U64 val64); |
107 | MEM_STATIC void MEM_writeLEST(void* memPtr, size_t val); |
108 | |
109 | /*=== Big endian unaligned read/write ===*/ |
110 | MEM_STATIC U32 MEM_readBE32(const void* memPtr); |
111 | MEM_STATIC U64 MEM_readBE64(const void* memPtr); |
112 | MEM_STATIC size_t MEM_readBEST(const void* memPtr); |
113 | |
114 | MEM_STATIC void MEM_writeBE32(void* memPtr, U32 val32); |
115 | MEM_STATIC void MEM_writeBE64(void* memPtr, U64 val64); |
116 | MEM_STATIC void MEM_writeBEST(void* memPtr, size_t val); |
117 | |
118 | /*=== Byteswap ===*/ |
119 | MEM_STATIC U32 MEM_swap32(U32 in); |
120 | MEM_STATIC U64 MEM_swap64(U64 in); |
121 | MEM_STATIC size_t MEM_swapST(size_t in); |
122 | |
123 | |
124 | /*-************************************************************** |
125 | * Memory I/O Implementation |
126 | *****************************************************************/ |
127 | /* MEM_FORCE_MEMORY_ACCESS : For accessing unaligned memory: |
128 | * Method 0 : always use `memcpy()`. Safe and portable. |
129 | * Method 1 : Use compiler extension to set unaligned access. |
130 | * Method 2 : direct access. This method is portable but violate C standard. |
131 | * It can generate buggy code on targets depending on alignment. |
132 | * Default : method 1 if supported, else method 0 |
133 | */ |
134 | #ifndef MEM_FORCE_MEMORY_ACCESS /* can be defined externally, on command line for example */ |
135 | # ifdef __GNUC__ |
136 | # define MEM_FORCE_MEMORY_ACCESS 1 |
137 | # endif |
138 | #endif |
139 | |
140 | MEM_STATIC unsigned MEM_32bits(void) { return sizeof(size_t)==4; } |
141 | MEM_STATIC unsigned MEM_64bits(void) { return sizeof(size_t)==8; } |
142 | |
143 | MEM_STATIC unsigned MEM_isLittleEndian(void) |
144 | { |
145 | #if defined(__BYTE_ORDER__) && defined(__ORDER_LITTLE_ENDIAN__) && (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__) |
146 | return 1; |
147 | #elif defined(__BYTE_ORDER__) && defined(__ORDER_BIG_ENDIAN__) && (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__) |
148 | return 0; |
149 | #elif defined(__clang__) && __LITTLE_ENDIAN__ |
150 | return 1; |
151 | #elif defined(__clang__) && __BIG_ENDIAN__ |
152 | return 0; |
153 | #elif defined(_MSC_VER) && (_M_AMD64 || _M_IX86) |
154 | return 1; |
155 | #elif defined(__DMC__) && defined(_M_IX86) |
156 | return 1; |
157 | #else |
158 | const union { U32 u; BYTE c[4]; } one = { 1 }; /* don't use static : performance detrimental */ |
159 | return one.c[0]; |
160 | #endif |
161 | } |
162 | |
163 | #if defined(MEM_FORCE_MEMORY_ACCESS) && (MEM_FORCE_MEMORY_ACCESS==2) |
164 | |
165 | /* violates C standard, by lying on structure alignment. |
166 | Only use if no other choice to achieve best performance on target platform */ |
167 | MEM_STATIC U16 MEM_read16(const void* memPtr) { return *(const U16*) memPtr; } |
168 | MEM_STATIC U32 MEM_read32(const void* memPtr) { return *(const U32*) memPtr; } |
169 | MEM_STATIC U64 MEM_read64(const void* memPtr) { return *(const U64*) memPtr; } |
170 | MEM_STATIC size_t MEM_readST(const void* memPtr) { return *(const size_t*) memPtr; } |
171 | |
172 | MEM_STATIC void MEM_write16(void* memPtr, U16 value) { *(U16*)memPtr = value; } |
173 | MEM_STATIC void MEM_write32(void* memPtr, U32 value) { *(U32*)memPtr = value; } |
174 | MEM_STATIC void MEM_write64(void* memPtr, U64 value) { *(U64*)memPtr = value; } |
175 | |
176 | #elif defined(MEM_FORCE_MEMORY_ACCESS) && (MEM_FORCE_MEMORY_ACCESS==1) |
177 | |
178 | typedef __attribute__((aligned(1))) U16 unalign16; |
179 | typedef __attribute__((aligned(1))) U32 unalign32; |
180 | typedef __attribute__((aligned(1))) U64 unalign64; |
181 | typedef __attribute__((aligned(1))) size_t unalignArch; |
182 | |
183 | MEM_STATIC U16 MEM_read16(const void* ptr) { return *(const unalign16*)ptr; } |
184 | MEM_STATIC U32 MEM_read32(const void* ptr) { return *(const unalign32*)ptr; } |
185 | MEM_STATIC U64 MEM_read64(const void* ptr) { return *(const unalign64*)ptr; } |
186 | MEM_STATIC size_t MEM_readST(const void* ptr) { return *(const unalignArch*)ptr; } |
187 | |
188 | MEM_STATIC void MEM_write16(void* memPtr, U16 value) { *(unalign16*)memPtr = value; } |
189 | MEM_STATIC void MEM_write32(void* memPtr, U32 value) { *(unalign32*)memPtr = value; } |
190 | MEM_STATIC void MEM_write64(void* memPtr, U64 value) { *(unalign64*)memPtr = value; } |
191 | |
192 | #else |
193 | |
194 | /* default method, safe and standard. |
195 | can sometimes prove slower */ |
196 | |
197 | MEM_STATIC U16 MEM_read16(const void* memPtr) |
198 | { |
199 | U16 val; ZSTD_memcpy(&val, memPtr, sizeof(val)); return val; |
200 | } |
201 | |
202 | MEM_STATIC U32 MEM_read32(const void* memPtr) |
203 | { |
204 | U32 val; ZSTD_memcpy(&val, memPtr, sizeof(val)); return val; |
205 | } |
206 | |
207 | MEM_STATIC U64 MEM_read64(const void* memPtr) |
208 | { |
209 | U64 val; ZSTD_memcpy(&val, memPtr, sizeof(val)); return val; |
210 | } |
211 | |
212 | MEM_STATIC size_t MEM_readST(const void* memPtr) |
213 | { |
214 | size_t val; ZSTD_memcpy(&val, memPtr, sizeof(val)); return val; |
215 | } |
216 | |
217 | MEM_STATIC void MEM_write16(void* memPtr, U16 value) |
218 | { |
219 | ZSTD_memcpy(memPtr, &value, sizeof(value)); |
220 | } |
221 | |
222 | MEM_STATIC void MEM_write32(void* memPtr, U32 value) |
223 | { |
224 | ZSTD_memcpy(memPtr, &value, sizeof(value)); |
225 | } |
226 | |
227 | MEM_STATIC void MEM_write64(void* memPtr, U64 value) |
228 | { |
229 | ZSTD_memcpy(memPtr, &value, sizeof(value)); |
230 | } |
231 | |
232 | #endif /* MEM_FORCE_MEMORY_ACCESS */ |
233 | |
234 | MEM_STATIC U32 MEM_swap32_fallback(U32 in) |
235 | { |
236 | return ((in << 24) & 0xff000000 ) | |
237 | ((in << 8) & 0x00ff0000 ) | |
238 | ((in >> 8) & 0x0000ff00 ) | |
239 | ((in >> 24) & 0x000000ff ); |
240 | } |
241 | |
242 | MEM_STATIC U32 MEM_swap32(U32 in) |
243 | { |
244 | #if defined(_MSC_VER) /* Visual Studio */ |
245 | return _byteswap_ulong(in); |
246 | #elif (defined (__GNUC__) && (__GNUC__ * 100 + __GNUC_MINOR__ >= 403)) \ |
247 | || (defined(__clang__) && __has_builtin(__builtin_bswap32)) |
248 | return __builtin_bswap32(in); |
249 | #else |
250 | return MEM_swap32_fallback(in); |
251 | #endif |
252 | } |
253 | |
254 | MEM_STATIC U64 MEM_swap64_fallback(U64 in) |
255 | { |
256 | return ((in << 56) & 0xff00000000000000ULL) | |
257 | ((in << 40) & 0x00ff000000000000ULL) | |
258 | ((in << 24) & 0x0000ff0000000000ULL) | |
259 | ((in << 8) & 0x000000ff00000000ULL) | |
260 | ((in >> 8) & 0x00000000ff000000ULL) | |
261 | ((in >> 24) & 0x0000000000ff0000ULL) | |
262 | ((in >> 40) & 0x000000000000ff00ULL) | |
263 | ((in >> 56) & 0x00000000000000ffULL); |
264 | } |
265 | |
266 | MEM_STATIC U64 MEM_swap64(U64 in) |
267 | { |
268 | #if defined(_MSC_VER) /* Visual Studio */ |
269 | return _byteswap_uint64(in); |
270 | #elif (defined (__GNUC__) && (__GNUC__ * 100 + __GNUC_MINOR__ >= 403)) \ |
271 | || (defined(__clang__) && __has_builtin(__builtin_bswap64)) |
272 | return __builtin_bswap64(in); |
273 | #else |
274 | return MEM_swap64_fallback(in); |
275 | #endif |
276 | } |
277 | |
278 | MEM_STATIC size_t MEM_swapST(size_t in) |
279 | { |
280 | if (MEM_32bits()) |
281 | return (size_t)MEM_swap32((U32)in); |
282 | else |
283 | return (size_t)MEM_swap64((U64)in); |
284 | } |
285 | |
286 | /*=== Little endian r/w ===*/ |
287 | |
288 | MEM_STATIC U16 MEM_readLE16(const void* memPtr) |
289 | { |
290 | if (MEM_isLittleEndian()) |
291 | return MEM_read16(memPtr); |
292 | else { |
293 | const BYTE* p = (const BYTE*)memPtr; |
294 | return (U16)(p[0] + (p[1]<<8)); |
295 | } |
296 | } |
297 | |
298 | MEM_STATIC void MEM_writeLE16(void* memPtr, U16 val) |
299 | { |
300 | if (MEM_isLittleEndian()) { |
301 | MEM_write16(memPtr, val); |
302 | } else { |
303 | BYTE* p = (BYTE*)memPtr; |
304 | p[0] = (BYTE)val; |
305 | p[1] = (BYTE)(val>>8); |
306 | } |
307 | } |
308 | |
309 | MEM_STATIC U32 MEM_readLE24(const void* memPtr) |
310 | { |
311 | return (U32)MEM_readLE16(memPtr) + ((U32)(((const BYTE*)memPtr)[2]) << 16); |
312 | } |
313 | |
314 | MEM_STATIC void MEM_writeLE24(void* memPtr, U32 val) |
315 | { |
316 | MEM_writeLE16(memPtr, (U16)val); |
317 | ((BYTE*)memPtr)[2] = (BYTE)(val>>16); |
318 | } |
319 | |
320 | MEM_STATIC U32 MEM_readLE32(const void* memPtr) |
321 | { |
322 | if (MEM_isLittleEndian()) |
323 | return MEM_read32(memPtr); |
324 | else |
325 | return MEM_swap32(MEM_read32(memPtr)); |
326 | } |
327 | |
328 | MEM_STATIC void MEM_writeLE32(void* memPtr, U32 val32) |
329 | { |
330 | if (MEM_isLittleEndian()) |
331 | MEM_write32(memPtr, val32); |
332 | else |
333 | MEM_write32(memPtr, MEM_swap32(val32)); |
334 | } |
335 | |
336 | MEM_STATIC U64 MEM_readLE64(const void* memPtr) |
337 | { |
338 | if (MEM_isLittleEndian()) |
339 | return MEM_read64(memPtr); |
340 | else |
341 | return MEM_swap64(MEM_read64(memPtr)); |
342 | } |
343 | |
344 | MEM_STATIC void MEM_writeLE64(void* memPtr, U64 val64) |
345 | { |
346 | if (MEM_isLittleEndian()) |
347 | MEM_write64(memPtr, val64); |
348 | else |
349 | MEM_write64(memPtr, MEM_swap64(val64)); |
350 | } |
351 | |
352 | MEM_STATIC size_t MEM_readLEST(const void* memPtr) |
353 | { |
354 | if (MEM_32bits()) |
355 | return (size_t)MEM_readLE32(memPtr); |
356 | else |
357 | return (size_t)MEM_readLE64(memPtr); |
358 | } |
359 | |
360 | MEM_STATIC void MEM_writeLEST(void* memPtr, size_t val) |
361 | { |
362 | if (MEM_32bits()) |
363 | MEM_writeLE32(memPtr, (U32)val); |
364 | else |
365 | MEM_writeLE64(memPtr, (U64)val); |
366 | } |
367 | |
368 | /*=== Big endian r/w ===*/ |
369 | |
370 | MEM_STATIC U32 MEM_readBE32(const void* memPtr) |
371 | { |
372 | if (MEM_isLittleEndian()) |
373 | return MEM_swap32(MEM_read32(memPtr)); |
374 | else |
375 | return MEM_read32(memPtr); |
376 | } |
377 | |
378 | MEM_STATIC void MEM_writeBE32(void* memPtr, U32 val32) |
379 | { |
380 | if (MEM_isLittleEndian()) |
381 | MEM_write32(memPtr, MEM_swap32(val32)); |
382 | else |
383 | MEM_write32(memPtr, val32); |
384 | } |
385 | |
386 | MEM_STATIC U64 MEM_readBE64(const void* memPtr) |
387 | { |
388 | if (MEM_isLittleEndian()) |
389 | return MEM_swap64(MEM_read64(memPtr)); |
390 | else |
391 | return MEM_read64(memPtr); |
392 | } |
393 | |
394 | MEM_STATIC void MEM_writeBE64(void* memPtr, U64 val64) |
395 | { |
396 | if (MEM_isLittleEndian()) |
397 | MEM_write64(memPtr, MEM_swap64(val64)); |
398 | else |
399 | MEM_write64(memPtr, val64); |
400 | } |
401 | |
402 | MEM_STATIC size_t MEM_readBEST(const void* memPtr) |
403 | { |
404 | if (MEM_32bits()) |
405 | return (size_t)MEM_readBE32(memPtr); |
406 | else |
407 | return (size_t)MEM_readBE64(memPtr); |
408 | } |
409 | |
410 | MEM_STATIC void MEM_writeBEST(void* memPtr, size_t val) |
411 | { |
412 | if (MEM_32bits()) |
413 | MEM_writeBE32(memPtr, (U32)val); |
414 | else |
415 | MEM_writeBE64(memPtr, (U64)val); |
416 | } |
417 | |
418 | /* code only tested on 32 and 64 bits systems */ |
419 | MEM_STATIC void MEM_check(void) { DEBUG_STATIC_ASSERT((sizeof(size_t)==4) || (sizeof(size_t)==8)); } |
420 | |
421 | |
422 | #if defined (__cplusplus) |
423 | } |
424 | #endif |
425 | |
426 | #endif /* MEM_H_MODULE */ |