/* fptst.c: i387 benchmark/test program for Linux
* Build this program with optimization (-O2 may be faster than -O3)
*
* v0.11 should work on a wider variety of glibc versions (tested: 2.3.2,
2.3.3)
* (See below...)
* v0.12 fixed bug in setaffinity: CPU set was empty
*
* Comments welcome.
* Author: Chuck Ebbert <[EMAIL PROTECTED]>
*/
/* Uncomment this if you get compile errors with the setaffinity function
*/
/* #define SETAFFINITY_TAKES_2_ARGS */
#define FPTST_VERSION "0.12"
#define _GNU_SOURCE
#include <sys/types.h>
#include <sys/wait.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdio.h>
#include <signal.h>
#include <errno.h>
#include <sched.h>
#define COND_YIELD(iters, ctr) \
if ((iters) > 0 && ++(ctr) > (iters)) { \
(ctr) = 0; \
sched_yield(); \
}
#define RDTSCLL(r) __asm__ __volatile__("rdtsc" : "=A" (r))
#ifdef SETAFFINITY_TAKES_2_ARGS
#define setaffinity(pid, mask) sched_setaffinity((pid), &(mask))
#else
#define setaffinity(pid, mask) sched_setaffinity((pid), sizeof(mask),
&(mask))
#endif
long double c_res, p_res;
long long i, c_iters, p_iters = 0;
unsigned long long tsc1, tsc2;
cpu_set_t cpuset;
int fp = 0, in = 0, yi = 0;
int p_ctr = 0, c_ctr = 0, get;
volatile int lo = 1;
static void handler(int sig)
{
lo = 0; /* child exited -- stop looping */
}
struct sigaction sa = {
.sa_handler = handler,
};
void usage(char *prog)
{
printf("\n i387 floating point benchmark/test program v"
FPTST_VERSION);
printf("\n\n Usage:\n");
printf("\t%s [-f] [-i] [-a] [-y count] loops\n\n", prog);
printf("\t-f : loop in parent process waiting for child to
exit\n");
printf("\t-i : do integer math while looping instead of FP
math\n");
printf("\t (-f and -i: do one FP operation, then use integer
math)\n");
printf("\t-a : run parent and child on single CPU (requires
SMP)\n");
printf("\t-y : yield CPU every 'count' loops in parent and
child\n\n");
exit(1);
}
static void do_parent()
{
if (fp)
__asm__ ("fld1 ; fldz");
while (lo) {
if (fp & !in)
__asm__ ("fadd %st(1), %st(0)");
else
p_iters++;
COND_YIELD(yi, p_ctr);
}
if (fp)
__asm__ ("fxch ; fstpt p_res ; fstpt p_res");
if (fp & !in)
p_iters = (long long)p_res;
printf("Parent did: %14lld loops\n", p_iters);
}
static void do_child()
{
RDTSCLL(tsc1);
__asm__ ("fld1 ; fldz");
for (i = 0; i < c_iters; i++) {
__asm__ ("fadd %st(1), %st(0)");
COND_YIELD(yi, c_ctr);
}
__asm__ ("fxch ; fstpt c_res ; fstpt c_res");
RDTSCLL(tsc2);
if (c_res != (long double)c_iters)
printf("FP error! Result was %Lg; expected %lld\n", c_res,
c_iters);
printf("CPU clocks: %14llu\n", tsc2 - tsc1);
}
int main(int argc, char * const argv[])
{
do {
switch (get = getopt(argc, argv, "fiay:")) {
case 'f':
fp = 1;
break;
case 'i':
in = 1;
break;
case 'a':
memset(&cpuset, 0, sizeof(cpuset));
CPU_SET(1, &cpuset);
if (setaffinity(0, cpuset)) {
perror("While setting CPU affinity");
get = '?';
}
break;
case 'y':
yi = atoi(optarg);
if (yi <= 0) {
printf("-y: count must be greater than
zero\n");
get = '?';
}
break;
default:
break;
}
} while (get != -1 && get != '?');
if (get == '?' || optind >= argc)
usage(argv[0]);
c_iters = atoll(argv[optind]);
if (fp | in)
sigaction(SIGCHLD, &sa, NULL);
if (fork())
if (fp | in)
do_parent();
else
wait(NULL);
else
do_child();
return 0;
}
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