random_hw.c

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#define MB 131072

int main(int argc, char **argv)
{
int j,jmax=0;

if (argc >1) jmax = atoi(argv[1]);

#pragma omp parallel for default(none) shared(jmax,stdout) private(j) schedule(dynamic,1)
for (j=0; j<jmax; j++)
{
uint64_t rndval[MB];
int i;

for(i=0; i<MB; i+=1)
__asm__(
        "cftest:\n\t"
        "rdrand %%r8\n\t"
        "jnc cftest \n\t"
        "movq  %%r8,    (%0)\n\t"
        : : "r" (rndval+i) :
        "cc", "r8", "memory");


#pragma omp critical
fwrite(rndval,8,MB,stdout);
}

return(0);
}