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;
+}