Move sources to lib/zstd/

contrib/linux-kernel/lib/zstd/mem.h

@@ -0,0 +1,209 @@
+/**
+ * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+#ifndef MEM_H_MODULE
+#define MEM_H_MODULE
+
+/*-****************************************
+*  Dependencies
+******************************************/
+#include <asm/unaligned.h>
+#include <linux/types.h>     /* size_t, ptrdiff_t */
+#include <linux/string.h>     /* memcpy */
+
+
+/*-****************************************
+*  Compiler specifics
+******************************************/
+#define MEM_STATIC static __inline __attribute__((unused))
+
+/* 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
+*****************************************************************/
+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;
+typedef ptrdiff_t iPtrDiff;
+typedef uintptr_t uPtrDiff;
+
+
+/*-**************************************************************
+*  Memory I/O
+*****************************************************************/
+MEM_STATIC unsigned MEM_32bits(void) { return sizeof(size_t)==4; }
+MEM_STATIC unsigned MEM_64bits(void) { return sizeof(size_t)==8; }
+
+#if defined(__LITTLE_ENDIAN)
+#   define MEM_LITTLE_ENDIAN 1
+#else
+#   define MEM_LITTLE_ENDIAN 0
+#endif
+
+MEM_STATIC unsigned MEM_isLittleEndian(void)
+{
+	return MEM_LITTLE_ENDIAN;
+}
+
+MEM_STATIC U16 MEM_read16(const void* memPtr)
+{
+	return get_unaligned((const U16*)memPtr);
+}
+
+MEM_STATIC U32 MEM_read32(const void* memPtr)
+{
+	return get_unaligned((const U32*)memPtr);
+}
+
+MEM_STATIC U64 MEM_read64(const void* memPtr)
+{
+	return get_unaligned((const U64*)memPtr);
+}
+
+MEM_STATIC size_t MEM_readST(const void* memPtr)
+{
+	return get_unaligned((const size_t*)memPtr);
+}
+
+MEM_STATIC void MEM_write16(void* memPtr, U16 value)
+{
+	put_unaligned(value, (U16*)memPtr);
+}
+
+MEM_STATIC void MEM_write32(void* memPtr, U32 value)
+{
+	put_unaligned(value, (U32*)memPtr);
+}
+
+MEM_STATIC void MEM_write64(void* memPtr, U64 value)
+{
+	put_unaligned(value, (U64*)memPtr);
+}
+
+/*=== Little endian r/w ===*/
+
+MEM_STATIC U16 MEM_readLE16(const void* memPtr)
+{
+	return get_unaligned_le16(memPtr);
+}
+
+MEM_STATIC void MEM_writeLE16(void* memPtr, U16 val)
+{
+	put_unaligned_le16(val, memPtr);
+}
+
+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)
+{
+	return get_unaligned_le32(memPtr);
+}
+
+MEM_STATIC void MEM_writeLE32(void* memPtr, U32 val32)
+{
+	put_unaligned_le32(val32, memPtr);
+}
+
+MEM_STATIC U64 MEM_readLE64(const void* memPtr)
+{
+	return get_unaligned_le64(memPtr);
+}
+
+MEM_STATIC void MEM_writeLE64(void* memPtr, U64 val64)
+{
+	put_unaligned_le64(val64, memPtr);
+}
+
+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)
+{
+	return get_unaligned_be32(memPtr);
+}
+
+MEM_STATIC void MEM_writeBE32(void* memPtr, U32 val32)
+{
+	put_unaligned_be32(val32, memPtr);
+}
+
+MEM_STATIC U64 MEM_readBE64(const void* memPtr)
+{
+	return get_unaligned_be64(memPtr);
+}
+
+MEM_STATIC void MEM_writeBE64(void* memPtr, U64 val64)
+{
+	put_unaligned_be64(val64, memPtr);
+}
+
+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);
+}
+
+
+/* function safe only for comparisons */
+MEM_STATIC U32 MEM_readMINMATCH(const void* memPtr, U32 length)
+{
+	switch (length)
+	{
+	default :
+	case 4 : return MEM_read32(memPtr);
+	case 3 : if (MEM_isLittleEndian())
+				return MEM_read32(memPtr)<<8;
+			 else
+				return MEM_read32(memPtr)>>8;
+	}
+}
+
+#endif /* MEM_H_MODULE */