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#include <inttypes.h>#include <stdio.h>#include <stddef.h>#include <sys/types.h>#include <sys/stat.h>#include <fcntl.h>#include <unistd.h>#include <time.h>#define MY_CLOCKTYPE CLOCK_MONOTONIC_RAWstatic inline uint64_t gettime_dif(struct timespec tm_prev){  struct timespec tm;  clock_gettime(MY_CLOCKTYPE, &tm);  return ((uint64_t)tm.tv_sec * 1000000000ull + tm.tv_nsec)-((uint64_t)tm_prev.tv_sec * 1000000000ull + tm_prev.tv_nsec);}#ifdef __i386inline uint64_t rdtsc() {  uint64_t x;  __asm__ volatile ("rdtsc" : "=A" (x));  return x;}#elif __amd64inline uint64_t rdtsc() {  uint64_t a, d;  __asm__ volatile ("rdtsc" : "=a" (a), "=d" (d));  return (d<<32) | a;}#endifstatic inline uint64_t f1(uint8_t Imm){	static const uint32_t lookup[16] = {		0x00000000, 0x000000ff, 0x0000ff00, 0x0000ffff, 		0x00ff0000, 0x00ff00ff, 0x00ffff00, 0x00ffffff, 		0xff000000, 0xff0000ff, 0xff00ff00, 0xff00ffff, 		0xffff0000, 0xffff00ff, 0xffffff00, 0xffffffff        };	return lookup[Imm & 0x0f] | ((uint64_t)lookup[Imm >> 4] << 32);}static inline uint64_t f2(uint8_t Imm){	uint64_t EncVal = 0;	if (Imm & 0x80) EncVal |= 0xff00000000000000ULL;	if (Imm & 0x40) EncVal |= 0x00ff000000000000ULL;	if (Imm & 0x20) EncVal |= 0x0000ff0000000000ULL;	if (Imm & 0x10) EncVal |= 0x000000ff00000000ULL;	if (Imm & 0x08) EncVal |= 0x00000000ff000000ULL;	if (Imm & 0x04) EncVal |= 0x0000000000ff0000ULL;	if (Imm & 0x02) EncVal |= 0x000000000000ff00ULL;	if (Imm & 0x01) EncVal |= 0x00000000000000ffULL;	return EncVal;}#define SZARR 300#define NUMTEST 200uint8_t buf1[SZARR];uint64_t buf2[SZARR];int main(void){	int randomData = open("/dev/urandom", O_RDONLY);	if (randomData == 0)		return -1;	if (sizeof(buf1) != read(randomData, buf1, sizeof(buf1)))		return -1;  	uint64_t times[4][NUMTEST];	for(size_t i = 0; i < NUMTEST; i += 1)	{		struct timespec tmp;		clock_gettime(MY_CLOCKTYPE, &tmp);		uint64_t tmp2 = rdtsc();		for(size_t j = 0; j < SZARR; j++)		{			buf2[j] = f1(buf1[j]);		}		asm volatile ("" : : : "memory");		times[1][i] = rdtsc() - tmp2;		times[0][i] = gettime_dif(tmp);	}	for(size_t i = 0; i < NUMTEST; i += 1)	{		struct timespec tmp;		clock_gettime(MY_CLOCKTYPE, &tmp);		uint64_t tmp2 = rdtsc();		for(size_t j = 0; j < SZARR; j++)		{			buf2[j] = f2(buf1[j]);		}		asm volatile ("" : : : "memory");		times[3][i] = rdtsc() - tmp2;		times[2][i] = gettime_dif(tmp);	}	printf("\n(gettime()/rdtsc())\nf1\tf2\n");	for(size_t i = 0; i < NUMTEST; i += 2)	{		printf("%f\t%f\n", (double)times[0][i]/(double)times[1][i], (double)times[2][i]/(double)times[3][i]);	}	printf("\n\nf1\t\t\tf2\n(gett)\t(rdtsc)\t\t(gett)\t(rdtsc)\n");	for(size_t i = 0; i < NUMTEST; i += 2)	{		printf("%" PRIu64 "\t%" PRIu64 "\t\t%" PRIu64 "\t%" PRIu64 "\n", times[0][i], times[1][i], times[2][i], times[3][i]);	}	return 0;}