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Diffstat (limited to 'trunk/src/lib/lib7z/7zCrcOpt.c')
-rw-r--r--trunk/src/lib/lib7z/7zCrcOpt.c64
1 files changed, 64 insertions, 0 deletions
diff --git a/trunk/src/lib/lib7z/7zCrcOpt.c b/trunk/src/lib/lib7z/7zCrcOpt.c
new file mode 100644
index 00000000000..a8d42a80074
--- /dev/null
+++ b/trunk/src/lib/lib7z/7zCrcOpt.c
@@ -0,0 +1,64 @@
+/* 7zCrcOpt.c -- CRC32 calculation
+2010-12-01 : Igor Pavlov : Public domain */
+
+#include "CpuArch.h"
+
+#define CRC_UPDATE_BYTE_2(crc, b) (table[((crc) ^ (b)) & 0xFF] ^ ((crc) >> 8))
+
+#ifndef MY_CPU_BE
+
+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)
+{
+ return CrcUpdateT4(v, data, size, table);
+}
+
+#endif
+
+
+#ifndef MY_CPU_LE
+
+#define CRC_UINT32_SWAP(v) ((v >> 24) | ((v >> 8) & 0xFF00) | ((v << 8) & 0xFF0000) | (v << 24))
+
+UInt32 MY_FAST_CALL CrcUpdateT1_BeT4(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);
+ v = CRC_UINT32_SWAP(v);
+ table += 0x100;
+ 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))];
+ }
+ table -= 0x100;
+ v = CRC_UINT32_SWAP(v);
+ for (; size > 0; size--, p++)
+ v = CRC_UPDATE_BYTE_2(v, *p);
+ return v;
+}
+
+#endif