/*

(272,190)符合の訂正プログラム

1999-2002 (c) Hiroki Mori

このプログラムでは82ビットのシンドロームレジスタを24ビット・28ビット・
30ビットに分割して処理しています。

1999-03-28 first edition
2002-04-28 Optimization and add MMX code

*/


#define NOERROR		0

#define USEREG		1
#define NOOPTIMIZ	0
#define USEMMX		1
#define NOJMP		0

#define TESTCOUNT	(4*2*30*10)

unsigned long r[4]__attribute__((aligned(8)));
unsigned char val0[8]__attribute__((aligned(8))) = 
	{0x08, 0x02, 0xa2, 0x00, 0x00, 0x8a, 0x80, 0x08};
unsigned char val1[8]__attribute__((aligned(8))) =
	{0x08, 0x60, 0x84, 0x01, 0x00, 0x00, 0x00, 0x00};

/*
r0 ^= 0x00a20208;
r1 ^= 0x08808a00;
r2 ^= 0x01846008;
*/
		
unsigned char vbipacket[] = {
	0x55, 0x55, 0xa7, 0x8f, 0x00, 0x00, 0x00, 0x00,
	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	0x00, 0x00, 0x80, 0xd3, 0x44, 0x60, 0xee, 0x1f,
	0x6f, 0x52, 0xb6, 0xc6, 0xa3}; 

#if USEMMX
void shift82(int bit)
{
unsigned long next;

	next = (r[2] & 0x20000000) ? 1 : 0;
	bit = next ^ bit;
#if !(NOJMP)
	if(next) {
#endif
		asm(
			/* mm7 = 1 */
/*			"pcmpeqd %%mm7,%%mm7\n"
			"psrlq $63, %%mm7\n"*/
#if NOJMP
			"pxor %%mm0,%%mm0\n"
			"movd (%5),%%mm6\n"
			"punpckldq %%mm6,%%mm6\n"
			"pcmpgtd %%mm0, %%mm6\n"
#endif

			"movq (%0),%%mm0\n"
/*			"movq (%1),%%mm1\n"*/
			"movq %%mm5,%%mm1\n"
#if NOJMP
			"pand %%mm6,%%mm1\n"
#endif
			"pxor %%mm1,%%mm0\n"

			/* r[0] << 1 & r[1] << 1 */
			"pslld $1,%%mm0\n"

			/* r[1] |= ((r[0] >> 24) & 1) */
			"movq %%mm0,%%mm4\n"
			"psrlq $24,%%mm4\n"
			"pand %%mm7,%%mm4\n"
			"psllq $32,%%mm4\n"

			"por %%mm4,%%mm0\n"

			/* r[0] |= bit */
			"movd (%4),%%mm4\n"
			"por %%mm4,%%mm0\n"

			"movq %%mm0,(%0)\n"

			/* r2 */
			"movq (%2),%%mm2\n"
/*			"movq (%3),%%mm3\n"*/
#if NOJMP
/*			"pand %%mm6,%%mm3\n"*/
			"pand %%mm3,%%mm6\n"
			"pxor %%mm6,%%mm2\n"
#else
			"pxor %%mm3,%%mm2\n"
#endif

			/* r[2] << 1 */
			"pslld $1,%%mm2\n"

			/* r[2] != ((r[1] >> 28) & 1) */
			"psrlq $60, %%mm0\n"
			"pand %%mm7,%%mm0\n"

			"por %%mm0,%%mm2\n"

			"movq %%mm2,(%2)\n"

/*			"emms\n"*/
			:
			:"r"(&r[0]), "r"(val0), "r"(&r[2]), "r"(val1), "r"(&bit), "r"(&next)
		);
#if !(NOJMP)
	} else {
		asm(
			"movq (%0),%%mm0\n"
			"movq (%1),%%mm1\n"
			/* r[0] << 1 & r[1] << 1 */
			"pslld $1,%%mm0\n"
			/* r[2] << 1 */
			"pslld $1,%%mm1\n"

			/* mm7 = 1 */
/*			"pcmpeqd %%mm7,%%mm7\n"
			"psrlq $63, %%mm7\n"*/

			/* r[1] |= ((r[0] >> 24) & 1) */
			"movq %%mm0,%%mm4\n"
			"psrlq $24,%%mm4\n"
			"pand %%mm7,%%mm4\n"
			"psllq $32,%%mm4\n"

			"por %%mm4,%%mm0\n"

			/*r[0] |= bit*/
			"movd (%2),%%mm4\n"
			"por %%mm4,%%mm0\n"

			/* r[0-1] = mm0 */
			"movq %%mm0,(%0)\n"

			/* r[2] |= ((r[1] >> 28) & 1) */
			"psrlq $60, %%mm0\n"
			"pand %%mm7,%%mm0\n"

			"por %%mm0,%%mm1\n"

			/* r[2] = mm1 */
			"movq %%mm1,(%1)\n"

/*			"emms\n"*/
			:
			:"r"(&r[0]), "r"(&r[2]), "r"(&bit)
		);

	}
#endif
}
#else
void shift82(int bit)
{
unsigned long next;

	next = ((r[2] >> 29) & 1);
	if(next) {
		r[0] ^= 0x00a20208;
		r[1] ^= 0x08808a00;
		r[2] ^= 0x01846008;
	}
	r[0] <<= 1;
	r[1] <<= 1; r[1] |= ((r[0] >> 24) & 1);
	r[2] <<= 1; r[2] |= ((r[1] >> 28) & 1);
	r[0] |= (next ^ bit);
}
#endif

#if NOOPTIMIZ
int getbit(int bit)
{
	if(bit >= 52)
		return((r[2] >> (bit - 52)) & 1);
	else if(bit >= 24)
		return((r[1] >> (bit - 24)) & 1);
	else
		return((r[0] >> bit) & 1);
}
#define GETBIT2(NUM) getbit(NUM)
#define GETBIT1(NUM) getbit(NUM)
#define GETBIT0(NUM) getbit(NUM)
#else
#define GETBIT2(NUM) ((r[2] >> (NUM - 52)) & 1)
#define GETBIT1(NUM) ((r[1] >> (NUM - 24)) & 1)
#define GETBIT0(NUM) ((r[0] >> NUM) & 1)
#endif

int majority(int border)
{
#if USEREG
register int sum;
#else
int sum;
#endif
	sum = GETBIT2(71) ^ GETBIT2(76);
	sum += GETBIT0(17);
	sum += GETBIT0(5) ^ GETBIT0(23);
	sum += GETBIT0(21) ^ GETBIT1(27) ^ GETBIT1(45);
	sum += GETBIT0(3) ^ GETBIT1(25) ^ GETBIT1(31) ^ GETBIT1(49);
	sum += GETBIT0(16) ^ GETBIT0(20) ^ GETBIT1(42) ^ GETBIT1(48)
		^ GETBIT2(66);
	sum += GETBIT1(35) ^ GETBIT2(52) ^ GETBIT2(56) ^ GETBIT2(78);
	sum += GETBIT0(8) ^ GETBIT1(44) ^ GETBIT2(61) ^ GETBIT2(65);
	sum += GETBIT0(2) ^ GETBIT0(11) ^ GETBIT1(47) ^ GETBIT2(64)
		^ GETBIT2(68);
	sum += GETBIT0(10) ^ GETBIT0(13) ^ GETBIT0(22) ^ GETBIT2(58)
		^ GETBIT2(75) ^ GETBIT2(79);
	sum += GETBIT0(1) ^ GETBIT0(12) ^ GETBIT0(15) ^ GETBIT1(24)
		^ GETBIT2(60) ^ GETBIT2(77) ^ GETBIT2(81);
	sum += GETBIT1(30) ^ GETBIT1(32) ^ GETBIT1(43) ^ GETBIT1(46)
		^ GETBIT2(55);
	sum += GETBIT0(6) ^ GETBIT1(37) ^ GETBIT1(39) ^ GETBIT1(50)
		^ GETBIT2(53) ^ GETBIT2(62);
	sum += GETBIT0(0) ^ GETBIT0(7) ^ GETBIT1(38) ^ GETBIT1(40)
		^ GETBIT1(51) ^ GETBIT2(54) ^ GETBIT2(63);
	sum += GETBIT0(18) ^ GETBIT0(19) ^ GETBIT1(26) ^ GETBIT2(57)
		^ GETBIT2(59) ^ GETBIT2(70) ^ GETBIT2(73);
	sum += GETBIT0(9) ^ GETBIT1(28) ^ GETBIT1(29) ^ GETBIT1(36)
		^ GETBIT2(67) ^ GETBIT2(69) ^ GETBIT2(80);
	sum += GETBIT0(4) ^ GETBIT0(14) ^ GETBIT1(33) ^ GETBIT1(34)
		^ GETBIT1(41) ^ GETBIT1(41) ^ GETBIT2(72) ^ GETBIT2(74);
	return sum >= border ? 1 : 0;
}

int correct272(unsigned char *data)
{
int i, j, k;
unsigned char *ptr, byte, cbyte;
int majo, bit;

	r[0] = r[1] = r[2] = 0;
	j = 0;
	ptr = data + 3;
#if USEMMX
	asm (
		"pcmpeqd %%mm7,%%mm7\n"
		"psrlq $63, %%mm7\n"
		"movq (%0),%%mm5\n"
		"movq (%1),%%mm3\n"
		:
		:"r"(val0), "r"(val1)
	);
#endif
	while(j < 272) {
		byte = *ptr++;
		for(i = 0; i < 8; ++i) {
			shift82((byte >> i) & 1);
			++j;
		}
	}
	if((r[0] & 0xffffff) == 0 && (r[1] & 0xfffffff) == 0 &&
		(r[2] & 0x3fffffff) == 0)
		goto success;

	for(k = 14; k >= 9; --k) {
		shift82(0);
		j = 0;
		ptr = data + 3;
		while(j < 272) {
			byte = *ptr;
			cbyte = 0;
			for(i = 0; i < 8; ++i) {
				majo = majority(k);
				bit = ((byte >> i) & 1) ^ majo;
				shift82(majo);
				cbyte |= (bit << i);
				++j;
			}
			*ptr = cbyte;
			++ptr;
		}
		if((r[0] & 0xffffff) == 0 && (r[1] & 0xfffffff) == 0 &&
			(r[2] & 0x3fffffff) == 0)
			goto success;

	}
	return 0;

success:
	return 1;
}

int main(int argc, char **argv)
{
int i;
unsigned char *tmpbuf;

	tmpbuf = (unsigned char *)malloc(sizeof(vbipacket));

	if(argc == 2 && !strcmp("-t", argv[1])) {
		memcpy(tmpbuf, vbipacket, sizeof(vbipacket));

#if !(NOERROR)
		// error data

		tmpbuf[5] = 0x01;
		tmpbuf[8] = 0x0f;
		tmpbuf[10] = 0x0f;
		tmpbuf[17] = 0x01;
		tmpbuf[20] = 0x01;
		tmpbuf[31] = 0x3f;
#endif
		for(i = 0;i < sizeof(vbipacket); ++i) {
			printf("%02x ", tmpbuf[i]);
			if(i % 16 == 15)
				printf("\n");
		}
		printf("\n");
		printf("test %s\n",correct272(tmpbuf) ? "OK" : "NG");
		for(i = 0;i < sizeof(vbipacket); ++i) {
			printf("%02x ", tmpbuf[i]);
			if(i % 16 == 15)
				printf("\n");
		}
		printf("\n");

	} else {
		for(i = 0;i < TESTCOUNT; ++i) {
			memcpy(tmpbuf, vbipacket, sizeof(vbipacket));

			// error data
#if !(NOERROR)
			tmpbuf[5] = 0x01;
			tmpbuf[8] = 0x0f;
			tmpbuf[10] = 0x0f;
			tmpbuf[17] = 0x01;
			tmpbuf[20] = 0x01;
			tmpbuf[31] = 0x3f;
#endif
			if(!correct272(tmpbuf)) {
				printf("Error occur\n");
				break;
			}
		}
	}

	return 1;
}