summaryrefslogtreecommitdiffstats
path: root/src/liblzma/check/crc64_tablegen.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/liblzma/check/crc64_tablegen.c')
-rw-r--r--src/liblzma/check/crc64_tablegen.c88
1 files changed, 88 insertions, 0 deletions
diff --git a/src/liblzma/check/crc64_tablegen.c b/src/liblzma/check/crc64_tablegen.c
new file mode 100644
index 0000000..fddaa7e
--- /dev/null
+++ b/src/liblzma/check/crc64_tablegen.c
@@ -0,0 +1,88 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file crc64_tablegen.c
+/// \brief Generate crc64_table_le.h and crc64_table_be.h
+///
+/// Compiling: gcc -std=c99 -o crc64_tablegen crc64_tablegen.c
+/// Add -DWORDS_BIGENDIAN to generate big endian table.
+//
+// Author: Lasse Collin
+//
+// This file has been put into the public domain.
+// You can do whatever you want with this file.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#include <stdio.h>
+#include "../../common/tuklib_integer.h"
+
+
+static uint64_t crc64_table[4][256];
+
+
+extern void
+init_crc64_table(void)
+{
+ static const uint64_t poly64 = UINT64_C(0xC96C5795D7870F42);
+
+ for (size_t s = 0; s < 4; ++s) {
+ for (size_t b = 0; b < 256; ++b) {
+ uint64_t r = s == 0 ? b : crc64_table[s - 1][b];
+
+ for (size_t i = 0; i < 8; ++i) {
+ if (r & 1)
+ r = (r >> 1) ^ poly64;
+ else
+ r >>= 1;
+ }
+
+ crc64_table[s][b] = r;
+ }
+ }
+
+#ifdef WORDS_BIGENDIAN
+ for (size_t s = 0; s < 4; ++s)
+ for (size_t b = 0; b < 256; ++b)
+ crc64_table[s][b] = bswap64(crc64_table[s][b]);
+#endif
+
+ return;
+}
+
+
+static void
+print_crc64_table(void)
+{
+ printf("/* This file has been automatically generated by "
+ "crc64_tablegen.c. */\n\n"
+ "const uint64_t lzma_crc64_table[4][256] = {\n\t{");
+
+ for (size_t s = 0; s < 4; ++s) {
+ for (size_t b = 0; b < 256; ++b) {
+ if ((b % 2) == 0)
+ printf("\n\t\t");
+
+ printf("UINT64_C(0x%016" PRIX64 ")",
+ crc64_table[s][b]);
+
+ if (b != 255)
+ printf(",%s", (b+1) % 2 == 0 ? "" : " ");
+ }
+
+ if (s == 3)
+ printf("\n\t}\n};\n");
+ else
+ printf("\n\t}, {");
+ }
+
+ return;
+}
+
+
+int
+main(void)
+{
+ init_crc64_table();
+ print_crc64_table();
+ return 0;
+}