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-rw-r--r--src/liblzma/check/crc32_init.c58
1 files changed, 58 insertions, 0 deletions
diff --git a/src/liblzma/check/crc32_init.c b/src/liblzma/check/crc32_init.c
new file mode 100644
index 00000000..eee90400
--- /dev/null
+++ b/src/liblzma/check/crc32_init.c
@@ -0,0 +1,58 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file crc32_init.c
+/// \brief CRC32 table initialization
+//
+// This code is based on various public domain sources.
+// This code has been put into the public domain.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <sys/types.h>
+#include <inttypes.h>
+
+#ifdef WORDS_BIGENDIAN
+# include "check_byteswap.h"
+#endif
+
+
+uint32_t lzma_crc32_table[8][256];
+
+
+extern void
+lzma_crc32_init(void)
+{
+ static const uint32_t poly32 = UINT32_C(0xEDB88320);
+
+ for (size_t s = 0; s < 8; ++s) {
+ for (size_t b = 0; b < 256; ++b) {
+ uint32_t r = s == 0 ? b : lzma_crc32_table[s - 1][b];
+
+ for (size_t i = 0; i < 8; ++i) {
+ if (r & 1)
+ r = (r >> 1) ^ poly32;
+ else
+ r >>= 1;
+ }
+
+ lzma_crc32_table[s][b] = r;
+ }
+ }
+
+#ifdef WORDS_BIGENDIAN
+ for (size_t s = 0; s < 8; ++s)
+ for (size_t b = 0; b < 256; ++b)
+ lzma_crc32_table[s][b]
+ = bswap_32(lzma_crc32_table[s][b]);
+#endif
+
+ return;
+}