crc64_tablegen.c File Reference

Generate crc64_table_le.h and crc64_table_be.h. More...

#include <stdio.h>
#include "../../common/tuklib_integer.h"

Go to the source code of this file.

Functions
void	init_crc64_table (void)
static void	print_crc64_table (void)
int	main (void)

Variables
static uint64_t	crc64_table [4][256]

Detailed Description

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.

Definition in file crc64_tablegen.c.

Function Documentation

init_crc64_table()

void init_crc64_table

(

void

)

Definition at line 24 of file crc64_tablegen.c.

{
    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;
}

References b, bswap64, crc64_table, i, r, s, and UINT64_C.

Referenced by main().

main()

int main

(

void

)

Definition at line 83 of file crc64_tablegen.c.

{
    init_crc64_table();
    print_crc64_table();
    return 0;
}

References init_crc64_table(), and print_crc64_table().

print_crc64_table()

static void print_crc64_table ( void  )

static

Definition at line 54 of file crc64_tablegen.c.

{
    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;
}

References b, crc64_table, printf(), PRIX64, and s.

Referenced by main().

Variable Documentation

crc64_table

uint64_t crc64_table[4][256]

static

Definition at line 20 of file crc64_tablegen.c.

Referenced by init_crc64_table(), and print_crc64_table().