NOISSUE reorganize and document libraries

libraries/xz-embedded/src/xz_crc64.c

@@ -0,0 +1,52 @@
+/*
+ * CRC64 using the polynomial from ECMA-182
+ *
+ * This file is similar to xz_crc32.c. See the comments there.
+ *
+ * Authors: Lasse Collin <lasse.collin@tukaani.org>
+ *          Igor Pavlov <http://7-zip.org/>
+ *
+ * This file has been put into the public domain.
+ * You can do whatever you want with this file.
+ */
+
+#include "xz_private.h"
+
+#ifndef STATIC_RW_DATA
+#define STATIC_RW_DATA static
+#endif
+
+STATIC_RW_DATA uint64_t xz_crc64_table[256];
+
+XZ_EXTERN void xz_crc64_init(void)
+{
+	const uint64_t poly = 0xC96C5795D7870F42;
+
+	uint32_t i;
+	uint32_t j;
+	uint64_t r;
+
+	for (i = 0; i < 256; ++i)
+	{
+		r = i;
+		for (j = 0; j < 8; ++j)
+			r = (r >> 1) ^ (poly & ~((r & 1) - 1));
+
+		xz_crc64_table[i] = r;
+	}
+
+	return;
+}
+
+XZ_EXTERN uint64_t xz_crc64(const uint8_t *buf, size_t size, uint64_t crc)
+{
+	crc = ~crc;
+
+	while (size != 0)
+	{
+		crc = xz_crc64_table[*buf++ ^ (crc & 0xFF)] ^ (crc >> 8);
+		--size;
+	}
+
+	return ~crc;
+}