X-Git-Url: https://pd.if.org/git/?a=blobdiff_plain;f=lzma%2Fcheck%2Fcrc64_tablegen.c;fp=lzma%2Fcheck%2Fcrc64_tablegen.c;h=40fcf498927769a2b4564a205d77b378bec884c0;hb=32b8a6b26ed8843828e03e505d2256960bda0980;hp=0000000000000000000000000000000000000000;hpb=d48fc23a4bcf8ca3c406d6e8c8a6f8c6b0fa2f1e;p=zpackage

diff --git a/lzma/check/crc64_tablegen.c b/lzma/check/crc64_tablegen.c
new file mode 100644
index 0000000..40fcf49
--- /dev/null
+++ b/lzma/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 "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;
+}