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#include <stdlib.h>
#include "crc64.h"

#define MAX_ITER	8

// crc64_ecma baseline function
// Slow crc64 from the definition.  Can be sped up with a lookup table.
uint64_t crc64_ecma_refl_base(uint64_t seed, const uint8_t * buf, uint64_t len)
{
	uint64_t rem = ~seed;
	unsigned int i, j;

	uint64_t poly = 0xC96C5795D7870F42ULL;	// ECMA-182 standard reflected

	for (i = 0; i < len; i++) {
		rem = rem ^ (uint64_t) buf[i];
		for (j = 0; j < MAX_ITER; j++) {
			rem = (rem & 0x1ULL ? poly : 0) ^ (rem >> 1);
		}
	}
	return ~rem;
}

uint64_t crc64_ecma_norm_base(uint64_t seed, const uint8_t * buf, uint64_t len)
{
	uint64_t rem = ~seed;
	unsigned int i, j;

	uint64_t poly = 0x42F0E1EBA9EA3693ULL;	// ECMA-182 standard

	for (i = 0; i < len; i++) {
		rem = rem ^ ((uint64_t) buf[i] << 56);
		for (j = 0; j < MAX_ITER; j++) {
			rem = (rem & 0x8000000000000000ULL ? poly : 0) ^ (rem << 1);
		}
	}
	return ~rem;
}

// crc64_iso baseline function
// Slow crc64 from the definition.  Can be sped up with a lookup table.
uint64_t crc64_iso_refl_base(uint64_t seed, const uint8_t * buf, uint64_t len)
{
	uint64_t rem = ~seed;
	unsigned int i, j;

	uint64_t poly = 0xD800000000000000ULL;	// ISO standard reflected

	for (i = 0; i < len; i++) {
		rem = rem ^ (uint64_t) buf[i];
		for (j = 0; j < MAX_ITER; j++) {
			rem = (rem & 0x1ULL ? poly : 0) ^ (rem >> 1);
		}
	}
	return ~rem;
}

uint64_t crc64_iso_norm_base(uint64_t seed, const uint8_t * buf, uint64_t len)
{
	uint64_t rem = ~seed;
	unsigned int i, j;

	uint64_t poly = 0x000000000000001BULL;	// ISO standard

	for (i = 0; i < len; i++) {
		rem = rem ^ ((uint64_t) buf[i] << 56);
		for (j = 0; j < MAX_ITER; j++) {
			rem = (rem & 0x8000000000000000ULL ? poly : 0) ^ (rem << 1);
		}
	}
	return ~rem;
}

// crc64_jones baseline function
// Slow crc64 from the definition.  Can be sped up with a lookup table.
uint64_t crc64_jones_refl_base(uint64_t seed, const uint8_t * buf, uint64_t len)
{
	uint64_t rem = ~seed;
	unsigned int i, j;

	uint64_t poly = 0x95ac9329ac4bc9b5ULL;	// Jones coefficients reflected

	for (i = 0; i < len; i++) {
		rem = rem ^ (uint64_t) buf[i];
		for (j = 0; j < MAX_ITER; j++) {
			rem = (rem & 0x1ULL ? poly : 0) ^ (rem >> 1);
		}
	}
	return ~rem;
}

uint64_t crc64_jones_norm_base(uint64_t seed, const uint8_t * buf, uint64_t len)
{
	uint64_t rem = ~seed;
	unsigned int i, j;

	uint64_t poly = 0xad93d23594c935a9ULL;	// Jones coefficients

	for (i = 0; i < len; i++) {
		rem = rem ^ ((uint64_t) buf[i] << 56);
		for (j = 0; j < MAX_ITER; j++) {
			rem = (rem & 0x8000000000000000ULL ? poly : 0) ^ (rem << 1);
		}
	}
	return ~rem;
}

struct slver {
	unsigned short snum;
	unsigned char ver;
	unsigned char core;
};

struct slver crc64_ecma_refl_base_slver_0000001c;
struct slver crc64_ecma_refl_base_slver = { 0x001c, 0x00, 0x00 };

struct slver crc64_ecma_norm_base_slver_00000019;
struct slver crc64_ecma_norm_base_slver = { 0x0019, 0x00, 0x00 };

struct slver crc64_iso_refl_base_slver_00000022;
struct slver crc64_iso_refl_base_slver = { 0x0022, 0x00, 0x00 };

struct slver crc64_iso_norm_base_slver_0000001f;
struct slver crc64_iso_norm_base_slver = { 0x001f, 0x00, 0x00 };

struct slver crc64_jones_refl_base_slver_00000028;
struct slver crc64_jones_refl_base_slver = { 0x0028, 0x00, 0x00 };

struct slver crc64_jones_norm_base_slver_00000025;
struct slver crc64_jones_norm_base_slver = { 0x0025, 0x00, 0x00 };