mpv/TOOLS/fastmemcpybench.c

38 lines
896 B
C

/*
fastmemcpybench.c used to benchmark fastmemcpy.h code from libvo.
Note: this code can not be used on PentMMX-PII because they contain
a bug in rdtsc. For Intel processors since P6(PII) rdpmc should be used
instead. For PIII it's disputable and seems bug was fixed but I don't
tested it.
*/
#include <stdio.h>
#include "../libvo/fastmemcpy.h"
#define ARR_SIZE 100000
//#define ARR_SIZE 1000000
static inline unsigned long long int read_tsc( void )
{
unsigned long long int retval;
__asm __volatile ("rdtsc":"=A"(retval)::"memory");
return retval;
}
unsigned char arr1[ARR_SIZE],arr2[ARR_SIZE];
int main( void )
{
unsigned long long int v1,v2;
unsigned char * marr1,*marr2;
marr1 = &arr1[1];
marr2 = &arr2[3];
v1 = read_tsc();
memcpy(marr1,marr2,ARR_SIZE-4);
v2 = read_tsc();
printf("v1 = %llu v2 = %llu v2-v1=%llu\n",v1,v2,v2-v1);
return 0;
}