dec/port.h

   1 /* Copyright 2015 Google Inc. All Rights Reserved.
   2
   3    Distributed under MIT license.
   4    See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
   5 */
   6
   7 /* Macros for compiler / platform specific features and build options.
   8
   9    Build options are:
  10     * BROTLI_BUILD_32_BIT disables 64-bit optimizations
  11     * BROTLI_BUILD_64_BIT forces to use 64-bit optimizations
  12     * BROTLI_BUILD_BIG_ENDIAN forces to use big-endian optimizations
  13     * BROTLI_BUILD_ENDIAN_NEUTRAL disables endian-aware optimizations
  14     * BROTLI_BUILD_LITTLE_ENDIAN forces to use little-endian optimizations
  15     * BROTLI_BUILD_MODERN_COMPILER forces to use modern compilers built-ins,
  16       features and attributes
  17     * BROTLI_BUILD_PORTABLE disables dangerous optimizations, like unaligned
  18       read and overlapping memcpy; this reduces decompression speed by 5%
  19     * BROTLI_DEBUG dumps file name and line number when decoder detects stream
  20       or memory error
  21     * BROTLI_DECODE_DEBUG enables asserts and dumps various state information
  22  */
  23
  24 #ifndef BROTLI_DEC_PORT_H_
  25 #define BROTLI_DEC_PORT_H_
  26
  27 #include<assert.h>
  28
  29 /* Compatibility with non-clang compilers. */
  30 #ifndef __has_builtin
  31 #define __has_builtin(x) 0
  32 #endif
  33
  34 #ifndef __has_attribute
  35 #define __has_attribute(x) 0
  36 #endif
  37
  38 #ifndef __has_feature
  39 #define __has_feature(x) 0
  40 #endif
  41
  42 #if defined(__sparc)
  43 #define BROTLI_TARGET_SPARC
  44 #endif
  45
  46 #if defined(__arm__) || defined(__thumb__) || \
  47     defined(_M_ARM) || defined(_M_ARMT)
  48 #define BROTLI_TARGET_ARM
  49 #if (defined(__ARM_ARCH) && (__ARM_ARCH >= 7)) || \
  50     (defined(M_ARM) && (M_ARM >= 7))
  51 #define BROTLI_TARGET_ARMV7
  52 #endif  /* ARMv7 */
  53 #if defined(__aarch64__)
  54 #define BROTLI_TARGET_ARMV8
  55 #endif  /* ARMv8 */
  56 #endif  /* ARM */
  57
  58 #if defined(__x86_64__) || defined(_M_X64)
  59 #define BROTLI_TARGET_X64
  60 #endif
  61
  62 #if defined(__PPC64__)
  63 #define BROTLI_TARGET_POWERPC64
  64 #endif
  65
  66 #if defined(__GNUC__) && defined(__GNUC_MINOR__)
  67 #define BROTLI_GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__)
  68 #else
  69 #define BROTLI_GCC_VERSION 0
  70 #endif
  71
  72 #if defined(__ICC)
  73 #define BROTLI_ICC_VERSION __ICC
  74 #else
  75 #define BROTLI_ICC_VERSION 0
  76 #endif
  77
  78 #if defined(BROTLI_BUILD_MODERN_COMPILER)
  79 #define BROTLI_MODERN_COMPILER 1
  80 #elif (BROTLI_GCC_VERSION > 300) || (BROTLI_ICC_VERSION >= 1600)
  81 #define BROTLI_MODERN_COMPILER 1
  82 #else
  83 #define BROTLI_MODERN_COMPILER 0
  84 #endif
  85
  86 /* SPARC and ARMv6 don't support unaligned read.
  87    Choose portable build for them. */
  88 #if !defined(BROTLI_BUILD_PORTABLE)
  89 #if defined(BROTLI_TARGET_SPARC) || \
  90     (defined(BROTLI_TARGET_ARM) && !defined(BROTLI_TARGET_ARMV7))
  91 #define BROTLI_BUILD_PORTABLE
  92 #endif  /* SPARK or ARMv6 */
  93 #endif  /* portable build */
  94
  95 #ifdef BROTLI_BUILD_PORTABLE
  96 #define BROTLI_ALIGNED_READ 1
  97 #define BROTLI_SAFE_MEMMOVE 1
  98 #else
  99 #define BROTLI_ALIGNED_READ 0
 100 #define BROTLI_SAFE_MEMMOVE 0
 101 #endif
 102
 103 #define BROTLI_ASAN_BUILD __has_feature(address_sanitizer)
 104
 105 /* Define "PREDICT_TRUE" and "PREDICT_FALSE" macros for capable compilers.
 106
 107 To apply compiler hint, enclose the branching condition into macros, like this:
 108
 109   if (PREDICT_TRUE(zero == 0)) {
 110     // main execution path
 111   } else {
 112     // compiler should place this code outside of main execution path
 113   }
 114
 115 OR:
 116
 117   if (PREDICT_FALSE(something_rare_or_unexpected_happens)) {
 118     // compiler should place this code outside of main execution path
 119   }
 120
 121 */
 122 #if BROTLI_MODERN_COMPILER || __has_builtin(__builtin_expect)
 123 #define PREDICT_TRUE(x) (__builtin_expect(!!(x), 1))
 124 #define PREDICT_FALSE(x) (__builtin_expect(x, 0))
 125 #else
 126 #define PREDICT_FALSE(x) (x)
 127 #define PREDICT_TRUE(x) (x)
 128 #endif
 129
 130 /* IS_CONSTANT macros returns true for compile-time constant expressions. */
 131 #if BROTLI_MODERN_COMPILER || __has_builtin(__builtin_constant_p)
 132 #define IS_CONSTANT(x) __builtin_constant_p(x)
 133 #else
 134 #define IS_CONSTANT(x) 0
 135 #endif
 136
 137 #if BROTLI_MODERN_COMPILER || __has_attribute(always_inline)
 138 #define ATTRIBUTE_ALWAYS_INLINE __attribute__ ((always_inline))
 139 #else
 140 #define ATTRIBUTE_ALWAYS_INLINE
 141 #endif
 142
 143 #ifndef _MSC_VER
 144 #if defined(__cplusplus) || !defined(__STRICT_ANSI__) \
 145     || __STDC_VERSION__ >= 199901L
 146 #define BROTLI_INLINE inline ATTRIBUTE_ALWAYS_INLINE
 147 #else
 148 #define BROTLI_INLINE
 149 #endif
 150 #else  /* _MSC_VER */
 151 #define BROTLI_INLINE __forceinline
 152 #endif  /* _MSC_VER */
 153
 154 #ifdef BROTLI_DECODE_DEBUG
 155 #define BROTLI_DCHECK(x) assert(x)
 156 #else
 157 #define BROTLI_DCHECK(x)
 158 #endif
 159
 160 #if defined(BROTLI_BUILD_64_BIT)
 161 #define BROTLI_64_BITS 1
 162 #elif defined(BROTLI_BUILD_32_BIT)
 163 #define BROTLI_64_BITS 0
 164 #elif defined(BROTLI_TARGET_X64) || defined(BROTLI_TARGET_ARMV8) || \
 165     defined(BROTLI_TARGET_POWERPC64)
 166 #define BROTLI_64_BITS 1
 167 #else
 168 #define BROTLI_64_BITS 0
 169 #endif
 170
 171 #if defined(BROTLI_BUILD_BIG_ENDIAN)
 172 #define BROTLI_LITTLE_ENDIAN 0
 173 #define BROTLI_BIG_ENDIAN 1
 174 #elif defined(BROTLI_BUILD_LITTLE_ENDIAN)
 175 #define BROTLI_LITTLE_ENDIAN 1
 176 #define BROTLI_BIG_ENDIAN 0
 177 #elif defined(BROTLI_BUILD_ENDIAN_NEUTRAL)
 178 #define BROTLI_LITTLE_ENDIAN 0
 179 #define BROTLI_BIG_ENDIAN 0
 180 #elif defined(__BYTE_ORDER__) && (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)
 181 #define BROTLI_LITTLE_ENDIAN 1
 182 #define BROTLI_BIG_ENDIAN 0
 183 #elif defined(_WIN32)
 184 /* Win32 can currently always be assumed to be little endian */
 185 #define BROTLI_LITTLE_ENDIAN 1
 186 #define BROTLI_BIG_ENDIAN 0
 187 #else
 188 #if (defined(__BYTE_ORDER__) && (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__))
 189 #define BROTLI_BIG_ENDIAN 1
 190 #else
 191 #define BROTLI_BIG_ENDIAN 0
 192 #endif
 193 #define BROTLI_LITTLE_ENDIAN 0
 194 #endif
 195
 196 #if BROTLI_MODERN_COMPILER || __has_attribute(noinline)
 197 #define BROTLI_NOINLINE __attribute__ ((noinline))
 198 #else
 199 #define BROTLI_NOINLINE
 200 #endif
 201
 202 #if BROTLI_ASAN_BUILD && !defined(BROTLI_BUILD_PORTABLE)
 203 #define BROTLI_NO_ASAN __attribute__((no_sanitize("address"))) BROTLI_NOINLINE
 204 #else
 205 #define BROTLI_NO_ASAN
 206 #endif
 207
 208 #define BROTLI_REPEAT(N, X) { \
 209   if ((N & 1) != 0) {X;} \
 210   if ((N & 2) != 0) {X; X;} \
 211   if ((N & 4) != 0) {X; X; X; X;} \
 212 }
 213
 214 #if BROTLI_MODERN_COMPILER || defined(__llvm__)
 215 #if defined(BROTLI_TARGET_ARMV7)
 216 static BROTLI_INLINE unsigned BrotliRBit(unsigned input) {
 217   unsigned output;
 218   __asm__("rbit %0, %1\n" : "=r"(output) : "r"(input));
 219   return output;
 220 }
 221 #define BROTLI_RBIT(x) BrotliRBit(x)
 222 #endif  /* armv7 */
 223 #endif  /* gcc || clang */
 224
 225 #if defined(BROTLI_TARGET_ARM)
 226 #define BROTLI_HAS_UBFX 1
 227 #else
 228 #define BROTLI_HAS_UBFX 0
 229 #endif
 230
 231 #define BROTLI_ALLOC(S, L) S->alloc_func(S->memory_manager_opaque, L)
 232
 233 #define BROTLI_FREE(S, X) { \
 234   S->free_func(S->memory_manager_opaque, X); \
 235   X = NULL; \
 236 }
 237
 238 #define BROTLI_UNUSED(X) (void)(X)
 239
 240 #endif  /* BROTLI_DEC_PORT_H_ */