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Diffstat (limited to 'c/enc/port.h')
| -rw-r--r-- | c/enc/port.h | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/c/enc/port.h b/c/enc/port.h new file mode 100644 index 0000000..0d5f24c --- /dev/null +++ b/c/enc/port.h @@ -0,0 +1,160 @@ +/* Copyright 2013 Google Inc. All Rights Reserved. + + Distributed under MIT license. + See file LICENSE for detail or copy at https://opensource.org/licenses/MIT +*/ + +/* Macros for endianness, branch prediction and unaligned loads and stores. */ + +#ifndef BROTLI_ENC_PORT_H_ +#define BROTLI_ENC_PORT_H_ + +#include <assert.h> +#include <string.h> /* memcpy */ + +#include <brotli/port.h> +#include <brotli/types.h> + +#if defined OS_LINUX || defined OS_CYGWIN +#include <endian.h> +#elif defined OS_FREEBSD +#include <machine/endian.h> +#elif defined OS_MACOSX +#include <machine/endian.h> +/* Let's try and follow the Linux convention */ +#define __BYTE_ORDER BYTE_ORDER +#define __LITTLE_ENDIAN LITTLE_ENDIAN +#endif + +/* define the macro IS_LITTLE_ENDIAN + using the above endian definitions from endian.h if + endian.h was included */ +#ifdef __BYTE_ORDER +#if __BYTE_ORDER == __LITTLE_ENDIAN +#define IS_LITTLE_ENDIAN +#endif + +#else + +#if defined(__LITTLE_ENDIAN__) +#define IS_LITTLE_ENDIAN +#endif +#endif /* __BYTE_ORDER */ + +#if defined(__BYTE_ORDER__) && (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__) +#define IS_LITTLE_ENDIAN +#endif + +/* Enable little-endian optimization for x64 architecture on Windows. */ +#if (defined(_WIN32) || defined(_WIN64)) && defined(_M_X64) +#define IS_LITTLE_ENDIAN +#endif + +/* Portable handling of unaligned loads, stores, and copies. + On some platforms, like ARM, the copy functions can be more efficient + then a load and a store. */ + +#if defined(ARCH_PIII) || \ + defined(ARCH_ATHLON) || defined(ARCH_K8) || defined(_ARCH_PPC) + +/* x86 and x86-64 can perform unaligned loads/stores directly; + modern PowerPC hardware can also do unaligned integer loads and stores; + but note: the FPU still sends unaligned loads and stores to a trap handler! +*/ + +#define BROTLI_UNALIGNED_LOAD32(_p) (*(const uint32_t *)(_p)) +#define BROTLI_UNALIGNED_LOAD64(_p) (*(const uint64_t *)(_p)) + +#define BROTLI_UNALIGNED_STORE32(_p, _val) \ + (*(uint32_t *)(_p) = (_val)) +#define BROTLI_UNALIGNED_STORE64(_p, _val) \ + (*(uint64_t *)(_p) = (_val)) + +#elif defined(__arm__) && \ + !defined(__ARM_ARCH_5__) && \ + !defined(__ARM_ARCH_5T__) && \ + !defined(__ARM_ARCH_5TE__) && \ + !defined(__ARM_ARCH_5TEJ__) && \ + !defined(__ARM_ARCH_6__) && \ + !defined(__ARM_ARCH_6J__) && \ + !defined(__ARM_ARCH_6K__) && \ + !defined(__ARM_ARCH_6Z__) && \ + !defined(__ARM_ARCH_6ZK__) && \ + !defined(__ARM_ARCH_6T2__) + +/* ARMv7 and newer support native unaligned accesses, but only of 16-bit + and 32-bit values (not 64-bit); older versions either raise a fatal signal, + do an unaligned read and rotate the words around a bit, or do the reads very + slowly (trip through kernel mode). */ + +#define BROTLI_UNALIGNED_LOAD32(_p) (*(const uint32_t *)(_p)) +#define BROTLI_UNALIGNED_STORE32(_p, _val) \ + (*(uint32_t *)(_p) = (_val)) + +static BROTLI_INLINE uint64_t BROTLI_UNALIGNED_LOAD64(const void *p) { + uint64_t t; + memcpy(&t, p, sizeof t); + return t; +} + +static BROTLI_INLINE void BROTLI_UNALIGNED_STORE64(void *p, uint64_t v) { + memcpy(p, &v, sizeof v); +} + +#else + +/* These functions are provided for architectures that don't support */ +/* unaligned loads and stores. */ + +static BROTLI_INLINE uint32_t BROTLI_UNALIGNED_LOAD32(const void *p) { + uint32_t t; + memcpy(&t, p, sizeof t); + return t; +} + +static BROTLI_INLINE uint64_t BROTLI_UNALIGNED_LOAD64(const void *p) { + uint64_t t; + memcpy(&t, p, sizeof t); + return t; +} + +static BROTLI_INLINE void BROTLI_UNALIGNED_STORE32(void *p, uint32_t v) { + memcpy(p, &v, sizeof v); +} + +static BROTLI_INLINE void BROTLI_UNALIGNED_STORE64(void *p, uint64_t v) { + memcpy(p, &v, sizeof v); +} + +#endif + +#define TEMPLATE_(T) \ + static BROTLI_INLINE T brotli_min_ ## T (T a, T b) { return a < b ? a : b; } \ + static BROTLI_INLINE T brotli_max_ ## T (T a, T b) { return a > b ? a : b; } +TEMPLATE_(double) TEMPLATE_(float) TEMPLATE_(int) +TEMPLATE_(size_t) TEMPLATE_(uint32_t) TEMPLATE_(uint8_t) +#undef TEMPLATE_ +#define BROTLI_MIN(T, A, B) (brotli_min_ ## T((A), (B))) +#define BROTLI_MAX(T, A, B) (brotli_max_ ## T((A), (B))) + +#define BROTLI_SWAP(T, A, I, J) { \ + T __brotli_swap_tmp = (A)[(I)]; \ + (A)[(I)] = (A)[(J)]; \ + (A)[(J)] = __brotli_swap_tmp; \ +} + +#define BROTLI_ENSURE_CAPACITY(M, T, A, C, R) { \ + if (C < (R)) { \ + size_t _new_size = (C == 0) ? (R) : C; \ + T* new_array; \ + while (_new_size < (R)) _new_size *= 2; \ + new_array = BROTLI_ALLOC((M), T, _new_size); \ + if (!BROTLI_IS_OOM(m) && C != 0) \ + memcpy(new_array, A, C * sizeof(T)); \ + BROTLI_FREE((M), A); \ + A = new_array; \ + C = _new_size; \ + } \ +} + +#endif /* BROTLI_ENC_PORT_H_ */ |