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diff --git a/vendor/github.com/DataDog/zstd/mem.h b/vendor/github.com/DataDog/zstd/mem.h
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+/*
+ * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+#ifndef MEM_H_MODULE
+#define MEM_H_MODULE
+
+#if defined (__cplusplus)
+extern "C" {
+#endif
+
+/*-****************************************
+* Dependencies
+******************************************/
+#include <stddef.h> /* size_t, ptrdiff_t */
+#include <string.h> /* memcpy */
+
+
+/*-****************************************
+* Compiler specifics
+******************************************/
+#if defined(_MSC_VER) /* Visual Studio */
+# include <stdlib.h> /* _byteswap_ulong */
+# include <intrin.h> /* _byteswap_* */
+#endif
+#if defined(__GNUC__)
+# define MEM_STATIC static __inline __attribute__((unused))
+#elif defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
+# define MEM_STATIC static inline
+#elif defined(_MSC_VER)
+# define MEM_STATIC static __inline
+#else
+# define MEM_STATIC static /* this version may generate warnings for unused static functions; disable the relevant warning */
+#endif
+
+#ifndef __has_builtin
+# define __has_builtin(x) 0 /* compat. with non-clang compilers */
+#endif
+
+/* code only tested on 32 and 64 bits systems */
+#define MEM_STATIC_ASSERT(c) { enum { MEM_static_assert = 1/(int)(!!(c)) }; }
+MEM_STATIC void MEM_check(void) { MEM_STATIC_ASSERT((sizeof(size_t)==4) || (sizeof(size_t)==8)); }
+
+
+/*-**************************************************************
+* Basic Types
+*****************************************************************/
+#if !defined (__VMS) && (defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) )
+# include <stdint.h>
+ typedef uint8_t BYTE;
+ typedef uint16_t U16;
+ typedef int16_t S16;
+ typedef uint32_t U32;
+ typedef int32_t S32;
+ typedef uint64_t U64;
+ typedef int64_t S64;
+#else
+# include <limits.h>
+#if CHAR_BIT != 8
+# error "this implementation requires char to be exactly 8-bit type"
+#endif
+ typedef unsigned char BYTE;
+#if USHRT_MAX != 65535
+# error "this implementation requires short to be exactly 16-bit type"
+#endif
+ typedef unsigned short U16;
+ typedef signed short S16;
+#if UINT_MAX != 4294967295
+# error "this implementation requires int to be exactly 32-bit type"
+#endif
+ typedef unsigned int U32;
+ typedef signed int S32;
+/* note : there are no limits defined for long long type in C90.
+ * limits exist in C99, however, in such case, <stdint.h> is preferred */
+ typedef unsigned long long U64;
+ typedef signed long long S64;
+#endif
+
+
+/*-**************************************************************
+* Memory I/O
+*****************************************************************/
+/* MEM_FORCE_MEMORY_ACCESS :
+ * By default, access to unaligned memory is controlled by `memcpy()`, which is safe and portable.
+ * Unfortunately, on some target/compiler combinations, the generated assembly is sub-optimal.
+ * The below switch allow to select different access method for improved performance.
+ * Method 0 (default) : use `memcpy()`. Safe and portable.
+ * Method 1 : `__packed` statement. It depends on compiler extension (i.e., not portable).
+ * This method is safe if your compiler supports it, and *generally* as fast or faster than `memcpy`.
+ * Method 2 : direct access. This method is portable but violate C standard.
+ * It can generate buggy code on targets depending on alignment.
+ * In some circumstances, it's the only known way to get the most performance (i.e. GCC + ARMv6)
+ * See http://fastcompression.blogspot.fr/2015/08/accessing-unaligned-memory.html for details.
+ * Prefer these methods in priority order (0 > 1 > 2)
+ */
+#ifndef MEM_FORCE_MEMORY_ACCESS /* can be defined externally, on command line for example */
+# if defined(__GNUC__) && ( defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6J__) || defined(__ARM_ARCH_6K__) || defined(__ARM_ARCH_6Z__) || defined(__ARM_ARCH_6ZK__) || defined(__ARM_ARCH_6T2__) )
+# define MEM_FORCE_MEMORY_ACCESS 2
+# elif defined(__INTEL_COMPILER) || defined(__GNUC__)
+# define MEM_FORCE_MEMORY_ACCESS 1
+# endif
+#endif
+
+MEM_STATIC unsigned MEM_32bits(void) { return sizeof(size_t)==4; }
+MEM_STATIC unsigned MEM_64bits(void) { return sizeof(size_t)==8; }
+
+MEM_STATIC unsigned MEM_isLittleEndian(void)
+{
+ const union { U32 u; BYTE c[4]; } one = { 1 }; /* don't use static : performance detrimental */
+ return one.c[0];
+}
+
+#if defined(MEM_FORCE_MEMORY_ACCESS) && (MEM_FORCE_MEMORY_ACCESS==2)
+
+/* violates C standard, by lying on structure alignment.
+Only use if no other choice to achieve best performance on target platform */
+MEM_STATIC U16 MEM_read16(const void* memPtr) { return *(const U16*) memPtr; }
+MEM_STATIC U32 MEM_read32(const void* memPtr) { return *(const U32*) memPtr; }
+MEM_STATIC U64 MEM_read64(const void* memPtr) { return *(const U64*) memPtr; }
+MEM_STATIC size_t MEM_readST(const void* memPtr) { return *(const size_t*) memPtr; }
+
+MEM_STATIC void MEM_write16(void* memPtr, U16 value) { *(U16*)memPtr = value; }
+MEM_STATIC void MEM_write32(void* memPtr, U32 value) { *(U32*)memPtr = value; }
+MEM_STATIC void MEM_write64(void* memPtr, U64 value) { *(U64*)memPtr = value; }
+
+#elif defined(MEM_FORCE_MEMORY_ACCESS) && (MEM_FORCE_MEMORY_ACCESS==1)
+
+/* __pack instructions are safer, but compiler specific, hence potentially problematic for some compilers */
+/* currently only defined for gcc and icc */
+#if defined(_MSC_VER) || (defined(__INTEL_COMPILER) && defined(WIN32))
+ __pragma( pack(push, 1) )
+ typedef struct { U16 v; } unalign16;
+ typedef struct { U32 v; } unalign32;
+ typedef struct { U64 v; } unalign64;
+ typedef struct { size_t v; } unalignArch;
+ __pragma( pack(pop) )
+#else
+ typedef struct { U16 v; } __attribute__((packed)) unalign16;
+ typedef struct { U32 v; } __attribute__((packed)) unalign32;
+ typedef struct { U64 v; } __attribute__((packed)) unalign64;
+ typedef struct { size_t v; } __attribute__((packed)) unalignArch;
+#endif
+
+MEM_STATIC U16 MEM_read16(const void* ptr) { return ((const unalign16*)ptr)->v; }
+MEM_STATIC U32 MEM_read32(const void* ptr) { return ((const unalign32*)ptr)->v; }
+MEM_STATIC U64 MEM_read64(const void* ptr) { return ((const unalign64*)ptr)->v; }
+MEM_STATIC size_t MEM_readST(const void* ptr) { return ((const unalignArch*)ptr)->v; }
+
+MEM_STATIC void MEM_write16(void* memPtr, U16 value) { ((unalign16*)memPtr)->v = value; }
+MEM_STATIC void MEM_write32(void* memPtr, U32 value) { ((unalign32*)memPtr)->v = value; }
+MEM_STATIC void MEM_write64(void* memPtr, U64 value) { ((unalign64*)memPtr)->v = value; }
+
+#else
+
+/* default method, safe and standard.
+ can sometimes prove slower */
+
+MEM_STATIC U16 MEM_read16(const void* memPtr)
+{
+ U16 val; memcpy(&val, memPtr, sizeof(val)); return val;
+}
+
+MEM_STATIC U32 MEM_read32(const void* memPtr)
+{
+ U32 val; memcpy(&val, memPtr, sizeof(val)); return val;
+}
+
+MEM_STATIC U64 MEM_read64(const void* memPtr)
+{
+ U64 val; memcpy(&val, memPtr, sizeof(val)); return val;
+}
+
+MEM_STATIC size_t MEM_readST(const void* memPtr)
+{
+ size_t val; memcpy(&val, memPtr, sizeof(val)); return val;
+}
+
+MEM_STATIC void MEM_write16(void* memPtr, U16 value)
+{
+ memcpy(memPtr, &value, sizeof(value));
+}
+
+MEM_STATIC void MEM_write32(void* memPtr, U32 value)
+{
+ memcpy(memPtr, &value, sizeof(value));
+}
+
+MEM_STATIC void MEM_write64(void* memPtr, U64 value)
+{
+ memcpy(memPtr, &value, sizeof(value));
+}
+
+#endif /* MEM_FORCE_MEMORY_ACCESS */
+
+MEM_STATIC U32 MEM_swap32(U32 in)
+{
+#if defined(_MSC_VER) /* Visual Studio */
+ return _byteswap_ulong(in);
+#elif (defined (__GNUC__) && (__GNUC__ * 100 + __GNUC_MINOR__ >= 403)) \
+ || (defined(__clang__) && __has_builtin(__builtin_bswap32))
+ return __builtin_bswap32(in);
+#else
+ return ((in << 24) & 0xff000000 ) |
+ ((in << 8) & 0x00ff0000 ) |
+ ((in >> 8) & 0x0000ff00 ) |
+ ((in >> 24) & 0x000000ff );
+#endif
+}
+
+MEM_STATIC U64 MEM_swap64(U64 in)
+{
+#if defined(_MSC_VER) /* Visual Studio */
+ return _byteswap_uint64(in);
+#elif (defined (__GNUC__) && (__GNUC__ * 100 + __GNUC_MINOR__ >= 403)) \
+ || (defined(__clang__) && __has_builtin(__builtin_bswap64))
+ return __builtin_bswap64(in);
+#else
+ return ((in << 56) & 0xff00000000000000ULL) |
+ ((in << 40) & 0x00ff000000000000ULL) |
+ ((in << 24) & 0x0000ff0000000000ULL) |
+ ((in << 8) & 0x000000ff00000000ULL) |
+ ((in >> 8) & 0x00000000ff000000ULL) |
+ ((in >> 24) & 0x0000000000ff0000ULL) |
+ ((in >> 40) & 0x000000000000ff00ULL) |
+ ((in >> 56) & 0x00000000000000ffULL);
+#endif
+}
+
+MEM_STATIC size_t MEM_swapST(size_t in)
+{
+ if (MEM_32bits())
+ return (size_t)MEM_swap32((U32)in);
+ else
+ return (size_t)MEM_swap64((U64)in);
+}
+
+/*=== Little endian r/w ===*/
+
+MEM_STATIC U16 MEM_readLE16(const void* memPtr)
+{
+ if (MEM_isLittleEndian())
+ return MEM_read16(memPtr);
+ else {
+ const BYTE* p = (const BYTE*)memPtr;
+ return (U16)(p[0] + (p[1]<<8));
+ }
+}
+
+MEM_STATIC void MEM_writeLE16(void* memPtr, U16 val)
+{
+ if (MEM_isLittleEndian()) {
+ MEM_write16(memPtr, val);
+ } else {
+ BYTE* p = (BYTE*)memPtr;
+ p[0] = (BYTE)val;
+ p[1] = (BYTE)(val>>8);
+ }
+}
+
+MEM_STATIC U32 MEM_readLE24(const void* memPtr)
+{
+ return MEM_readLE16(memPtr) + (((const BYTE*)memPtr)[2] << 16);
+}
+
+MEM_STATIC void MEM_writeLE24(void* memPtr, U32 val)
+{
+ MEM_writeLE16(memPtr, (U16)val);
+ ((BYTE*)memPtr)[2] = (BYTE)(val>>16);
+}
+
+MEM_STATIC U32 MEM_readLE32(const void* memPtr)
+{
+ if (MEM_isLittleEndian())
+ return MEM_read32(memPtr);
+ else
+ return MEM_swap32(MEM_read32(memPtr));
+}
+
+MEM_STATIC void MEM_writeLE32(void* memPtr, U32 val32)
+{
+ if (MEM_isLittleEndian())
+ MEM_write32(memPtr, val32);
+ else
+ MEM_write32(memPtr, MEM_swap32(val32));
+}
+
+MEM_STATIC U64 MEM_readLE64(const void* memPtr)
+{
+ if (MEM_isLittleEndian())
+ return MEM_read64(memPtr);
+ else
+ return MEM_swap64(MEM_read64(memPtr));
+}
+
+MEM_STATIC void MEM_writeLE64(void* memPtr, U64 val64)
+{
+ if (MEM_isLittleEndian())
+ MEM_write64(memPtr, val64);
+ else
+ MEM_write64(memPtr, MEM_swap64(val64));
+}
+
+MEM_STATIC size_t MEM_readLEST(const void* memPtr)
+{
+ if (MEM_32bits())
+ return (size_t)MEM_readLE32(memPtr);
+ else
+ return (size_t)MEM_readLE64(memPtr);
+}
+
+MEM_STATIC void MEM_writeLEST(void* memPtr, size_t val)
+{
+ if (MEM_32bits())
+ MEM_writeLE32(memPtr, (U32)val);
+ else
+ MEM_writeLE64(memPtr, (U64)val);
+}
+
+/*=== Big endian r/w ===*/
+
+MEM_STATIC U32 MEM_readBE32(const void* memPtr)
+{
+ if (MEM_isLittleEndian())
+ return MEM_swap32(MEM_read32(memPtr));
+ else
+ return MEM_read32(memPtr);
+}
+
+MEM_STATIC void MEM_writeBE32(void* memPtr, U32 val32)
+{
+ if (MEM_isLittleEndian())
+ MEM_write32(memPtr, MEM_swap32(val32));
+ else
+ MEM_write32(memPtr, val32);
+}
+
+MEM_STATIC U64 MEM_readBE64(const void* memPtr)
+{
+ if (MEM_isLittleEndian())
+ return MEM_swap64(MEM_read64(memPtr));
+ else
+ return MEM_read64(memPtr);
+}
+
+MEM_STATIC void MEM_writeBE64(void* memPtr, U64 val64)
+{
+ if (MEM_isLittleEndian())
+ MEM_write64(memPtr, MEM_swap64(val64));
+ else
+ MEM_write64(memPtr, val64);
+}
+
+MEM_STATIC size_t MEM_readBEST(const void* memPtr)
+{
+ if (MEM_32bits())
+ return (size_t)MEM_readBE32(memPtr);
+ else
+ return (size_t)MEM_readBE64(memPtr);
+}
+
+MEM_STATIC void MEM_writeBEST(void* memPtr, size_t val)
+{
+ if (MEM_32bits())
+ MEM_writeBE32(memPtr, (U32)val);
+ else
+ MEM_writeBE64(memPtr, (U64)val);
+}
+
+
+#if defined (__cplusplus)
+}
+#endif
+
+#endif /* MEM_H_MODULE */