diff options
Diffstat (limited to 'other-licenses/7zstub/src/C/7zCrcOpt.c')
-rw-r--r-- | other-licenses/7zstub/src/C/7zCrcOpt.c | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/other-licenses/7zstub/src/C/7zCrcOpt.c b/other-licenses/7zstub/src/C/7zCrcOpt.c new file mode 100644 index 000000000..2ee0de845 --- /dev/null +++ b/other-licenses/7zstub/src/C/7zCrcOpt.c @@ -0,0 +1,115 @@ +/* 7zCrcOpt.c -- CRC32 calculation
+2017-04-03 : Igor Pavlov : Public domain */
+
+#include "Precomp.h"
+
+#include "CpuArch.h"
+
+#ifndef MY_CPU_BE
+
+#define CRC_UPDATE_BYTE_2(crc, b) (table[((crc) ^ (b)) & 0xFF] ^ ((crc) >> 8))
+
+UInt32 MY_FAST_CALL CrcUpdateT4(UInt32 v, const void *data, size_t size, const UInt32 *table)
+{
+ const Byte *p = (const Byte *)data;
+ for (; size > 0 && ((unsigned)(ptrdiff_t)p & 3) != 0; size--, p++)
+ v = CRC_UPDATE_BYTE_2(v, *p);
+ for (; size >= 4; size -= 4, p += 4)
+ {
+ v ^= *(const UInt32 *)p;
+ v =
+ (table + 0x300)[((v ) & 0xFF)]
+ ^ (table + 0x200)[((v >> 8) & 0xFF)]
+ ^ (table + 0x100)[((v >> 16) & 0xFF)]
+ ^ (table + 0x000)[((v >> 24))];
+ }
+ for (; size > 0; size--, p++)
+ v = CRC_UPDATE_BYTE_2(v, *p);
+ return v;
+}
+
+UInt32 MY_FAST_CALL CrcUpdateT8(UInt32 v, const void *data, size_t size, const UInt32 *table)
+{
+ const Byte *p = (const Byte *)data;
+ for (; size > 0 && ((unsigned)(ptrdiff_t)p & 7) != 0; size--, p++)
+ v = CRC_UPDATE_BYTE_2(v, *p);
+ for (; size >= 8; size -= 8, p += 8)
+ {
+ UInt32 d;
+ v ^= *(const UInt32 *)p;
+ v =
+ (table + 0x700)[((v ) & 0xFF)]
+ ^ (table + 0x600)[((v >> 8) & 0xFF)]
+ ^ (table + 0x500)[((v >> 16) & 0xFF)]
+ ^ (table + 0x400)[((v >> 24))];
+ d = *((const UInt32 *)p + 1);
+ v ^=
+ (table + 0x300)[((d ) & 0xFF)]
+ ^ (table + 0x200)[((d >> 8) & 0xFF)]
+ ^ (table + 0x100)[((d >> 16) & 0xFF)]
+ ^ (table + 0x000)[((d >> 24))];
+ }
+ for (; size > 0; size--, p++)
+ v = CRC_UPDATE_BYTE_2(v, *p);
+ return v;
+}
+
+#endif
+
+
+#ifndef MY_CPU_LE
+
+#define CRC_UINT32_SWAP(v) ((v >> 24) | ((v >> 8) & 0xFF00) | ((v << 8) & 0xFF0000) | (v << 24))
+
+#define CRC_UPDATE_BYTE_2_BE(crc, b) (table[(((crc) >> 24) ^ (b))] ^ ((crc) << 8))
+
+UInt32 MY_FAST_CALL CrcUpdateT1_BeT4(UInt32 v, const void *data, size_t size, const UInt32 *table)
+{
+ const Byte *p = (const Byte *)data;
+ table += 0x100;
+ v = CRC_UINT32_SWAP(v);
+ for (; size > 0 && ((unsigned)(ptrdiff_t)p & 3) != 0; size--, p++)
+ v = CRC_UPDATE_BYTE_2_BE(v, *p);
+ for (; size >= 4; size -= 4, p += 4)
+ {
+ v ^= *(const UInt32 *)p;
+ v =
+ (table + 0x000)[((v ) & 0xFF)]
+ ^ (table + 0x100)[((v >> 8) & 0xFF)]
+ ^ (table + 0x200)[((v >> 16) & 0xFF)]
+ ^ (table + 0x300)[((v >> 24))];
+ }
+ for (; size > 0; size--, p++)
+ v = CRC_UPDATE_BYTE_2_BE(v, *p);
+ return CRC_UINT32_SWAP(v);
+}
+
+UInt32 MY_FAST_CALL CrcUpdateT1_BeT8(UInt32 v, const void *data, size_t size, const UInt32 *table)
+{
+ const Byte *p = (const Byte *)data;
+ table += 0x100;
+ v = CRC_UINT32_SWAP(v);
+ for (; size > 0 && ((unsigned)(ptrdiff_t)p & 7) != 0; size--, p++)
+ v = CRC_UPDATE_BYTE_2_BE(v, *p);
+ for (; size >= 8; size -= 8, p += 8)
+ {
+ UInt32 d;
+ v ^= *(const UInt32 *)p;
+ v =
+ (table + 0x400)[((v ) & 0xFF)]
+ ^ (table + 0x500)[((v >> 8) & 0xFF)]
+ ^ (table + 0x600)[((v >> 16) & 0xFF)]
+ ^ (table + 0x700)[((v >> 24))];
+ d = *((const UInt32 *)p + 1);
+ v ^=
+ (table + 0x000)[((d ) & 0xFF)]
+ ^ (table + 0x100)[((d >> 8) & 0xFF)]
+ ^ (table + 0x200)[((d >> 16) & 0xFF)]
+ ^ (table + 0x300)[((d >> 24))];
+ }
+ for (; size > 0; size--, p++)
+ v = CRC_UPDATE_BYTE_2_BE(v, *p);
+ return CRC_UINT32_SWAP(v);
+}
+
+#endif
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