87 lines
		
	
	
		
			2.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
		
		
			
		
	
	
			87 lines
		
	
	
		
			2.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
|  | /* XzCrc64.c -- CRC64 calculation
 | ||
|  | 2017-05-23 : Igor Pavlov : Public domain */ | ||
|  | 
 | ||
|  | #include "Precomp.h"
 | ||
|  | 
 | ||
|  | #include "XzCrc64.h"
 | ||
|  | #include "CpuArch.h"
 | ||
|  | 
 | ||
|  | #define kCrc64Poly UINT64_CONST(0xC96C5795D7870F42)
 | ||
|  | 
 | ||
|  | #ifdef MY_CPU_LE
 | ||
|  |   #define CRC64_NUM_TABLES 4
 | ||
|  | #else
 | ||
|  |   #define CRC64_NUM_TABLES 5
 | ||
|  |   #define CRC_UINT64_SWAP(v) \
 | ||
|  |       ((v >> 56) \ | ||
|  |     | ((v >> 40) & ((UInt64)0xFF <<  8)) \ | ||
|  |     | ((v >> 24) & ((UInt64)0xFF << 16)) \ | ||
|  |     | ((v >>  8) & ((UInt64)0xFF << 24)) \ | ||
|  |     | ((v <<  8) & ((UInt64)0xFF << 32)) \ | ||
|  |     | ((v << 24) & ((UInt64)0xFF << 40)) \ | ||
|  |     | ((v << 40) & ((UInt64)0xFF << 48)) \ | ||
|  |     | ((v << 56))) | ||
|  | 
 | ||
|  |   UInt64 MY_FAST_CALL XzCrc64UpdateT1_BeT4(UInt64 v, const void *data, size_t size, const UInt64 *table); | ||
|  | #endif
 | ||
|  | 
 | ||
|  | #ifndef MY_CPU_BE
 | ||
|  |   UInt64 MY_FAST_CALL XzCrc64UpdateT4(UInt64 v, const void *data, size_t size, const UInt64 *table); | ||
|  | #endif
 | ||
|  | 
 | ||
|  | typedef UInt64 (MY_FAST_CALL *CRC64_FUNC)(UInt64 v, const void *data, size_t size, const UInt64 *table); | ||
|  | 
 | ||
|  | static CRC64_FUNC g_Crc64Update; | ||
|  | UInt64 g_Crc64Table[256 * CRC64_NUM_TABLES]; | ||
|  | 
 | ||
|  | UInt64 MY_FAST_CALL Crc64Update(UInt64 v, const void *data, size_t size) | ||
|  | { | ||
|  |   return g_Crc64Update(v, data, size, g_Crc64Table); | ||
|  | } | ||
|  | 
 | ||
|  | UInt64 MY_FAST_CALL Crc64Calc(const void *data, size_t size) | ||
|  | { | ||
|  |   return g_Crc64Update(CRC64_INIT_VAL, data, size, g_Crc64Table) ^ CRC64_INIT_VAL; | ||
|  | } | ||
|  | 
 | ||
|  | void MY_FAST_CALL Crc64GenerateTable() | ||
|  | { | ||
|  |   UInt32 i; | ||
|  |   for (i = 0; i < 256; i++) | ||
|  |   { | ||
|  |     UInt64 r = i; | ||
|  |     unsigned j; | ||
|  |     for (j = 0; j < 8; j++) | ||
|  |       r = (r >> 1) ^ (kCrc64Poly & ((UInt64)0 - (r & 1))); | ||
|  |     g_Crc64Table[i] = r; | ||
|  |   } | ||
|  |   for (i = 256; i < 256 * CRC64_NUM_TABLES; i++) | ||
|  |   { | ||
|  |     UInt64 r = g_Crc64Table[(size_t)i - 256]; | ||
|  |     g_Crc64Table[i] = g_Crc64Table[r & 0xFF] ^ (r >> 8); | ||
|  |   } | ||
|  |    | ||
|  |   #ifdef MY_CPU_LE
 | ||
|  | 
 | ||
|  |   g_Crc64Update = XzCrc64UpdateT4; | ||
|  | 
 | ||
|  |   #else
 | ||
|  |   { | ||
|  |     #ifndef MY_CPU_BE
 | ||
|  |     UInt32 k = 1; | ||
|  |     if (*(const Byte *)&k == 1) | ||
|  |       g_Crc64Update = XzCrc64UpdateT4; | ||
|  |     else | ||
|  |     #endif
 | ||
|  |     { | ||
|  |       for (i = 256 * CRC64_NUM_TABLES - 1; i >= 256; i--) | ||
|  |       { | ||
|  |         UInt64 x = g_Crc64Table[(size_t)i - 256]; | ||
|  |         g_Crc64Table[i] = CRC_UINT64_SWAP(x); | ||
|  |       } | ||
|  |       g_Crc64Update = XzCrc64UpdateT1_BeT4; | ||
|  |     } | ||
|  |   } | ||
|  |   #endif
 | ||
|  | } |