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#include <stdio.h>
#include <math.h>
#include <float.h>
#include <limits.h>
#include <sys/time.h>
#include <stdlib.h>
#include "stream_lib.h"
static inline double mysecond(void)
{
struct timeval tv;
gettimeofday(&tv, NULL);
return tv.tv_sec + tv.tv_usec * 1.e-6;
}
/*
* Program: Stream
* Programmer: Joe R. Zagar
* Revision: 4.0-BETA, October 24, 1995
* Original code developed by John D. McCalpin
*
* This program measures memory transfer rates in MB/s for simple
* computational kernels coded in C. These numbers reveal the quality
* of code generation for simple uncacheable kernels as well as showing
* the cost of floating-point operations relative to memory accesses.
*
* INSTRUCTIONS:
*
* 1) Stream requires a good bit of memory to run. Adjust the
* value of 'N' (below) to give a 'timing calibration' of
* at least 20 clock-ticks. This will provide rate estimates
* that should be good to about 5% precision.
*
* Hacked by AK to be a library
*/
long N = 8000000;
#define NTIMES 10
#define OFFSET 0
/*
* 3) Compile the code with full optimization. Many compilers
* generate unreasonably bad code before the optimizer tightens
* things up. If the results are unreasonably good, on the
* other hand, the optimizer might be too smart for me!
*
* Try compiling with:
* cc -O stream_d.c second_wall.c -o stream_d -lm
*
* This is known to work on Cray, SGI, IBM, and Sun machines.
*
*
* 4) Mail the results to mccalpin@cs.virginia.edu
* Be sure to include:
* a) computer hardware model number and software revision
* b) the compiler flags
* c) all of the output from the test case.
* Thanks!
*
*/
int checktick(void);
# define HLINE "-------------------------------------------------------------\n"
# ifndef MIN
# define MIN(x,y) ((x)<(y)?(x):(y))
# endif
# ifndef MAX
# define MAX(x,y) ((x)>(y)?(x):(y))
# endif
static double *a, *b, *c;
static double rmstime[4] = { 0 }, maxtime[4] = {
0}, mintime[4] = {
FLT_MAX, FLT_MAX, FLT_MAX, FLT_MAX};
static char *label[4] = { "Copy: ", "Scale: ",
"Add: ", "Triad: "
};
char *stream_names[] = { "Copy","Scale","Add","Triad" };
static double bytes[4];
int stream_verbose = 1;
#define Vprintf(x...) do { if (stream_verbose) printf(x); } while(0)
void stream_check(void)
{
int quantum;
int BytesPerWord;
register int j;
double t;
/* --- SETUP --- determine precision and check timing --- */
Vprintf(HLINE);
BytesPerWord = sizeof(double);
Vprintf("This system uses %d bytes per DOUBLE PRECISION word.\n",
BytesPerWord);
Vprintf(HLINE);
Vprintf("Array size = %lu, Offset = %d\n", N, OFFSET);
Vprintf("Total memory required = %.1f MB.\n",
(3 * N * BytesPerWord) / 1048576.0);
Vprintf("Each test is run %d times, but only\n", NTIMES);
Vprintf("the *best* time for each is used.\n");
/* Get initial value for system clock. */
for (j = 0; j < N; j++) {
a[j] = 1.0;
b[j] = 2.0;
c[j] = 0.0;
}
Vprintf(HLINE);
if ((quantum = checktick()) >= 1)
Vprintf("Your clock granularity/precision appears to be "
"%d microseconds.\n", quantum);
else
Vprintf("Your clock granularity appears to be "
"less than one microsecond.\n");
t = mysecond();
for (j = 0; j < N; j++)
a[j] = 2.0E0 * a[j];
t = 1.0E6 * (mysecond() - t);
Vprintf("Each test below will take on the order"
" of %d microseconds.\n", (int) t);
Vprintf(" (= %d clock ticks)\n", (int) (t / quantum));
Vprintf("Increase the size of the arrays if this shows that\n");
Vprintf("you are not getting at least 20 clock ticks per test.\n");
Vprintf(HLINE);
Vprintf("WARNING -- The above is only a rough guideline.\n");
Vprintf("For best results, please be sure you know the\n");
Vprintf("precision of your system timer.\n");
Vprintf(HLINE);
}
void stream_test(double *res)
{
register int j, k;
double scalar, times[4][NTIMES];
/* --- MAIN LOOP --- repeat test cases NTIMES times --- */
scalar = 3.0;
for (k = 0; k < NTIMES; k++) {
times[0][k] = mysecond();
for (j = 0; j < N; j++)
c[j] = a[j];
times[0][k] = mysecond() - times[0][k];
times[1][k] = mysecond();
for (j = 0; j < N; j++)
b[j] = scalar * c[j];
times[1][k] = mysecond() - times[1][k];
times[2][k] = mysecond();
for (j = 0; j < N; j++)
c[j] = a[j] + b[j];
times[2][k] = mysecond() - times[2][k];
times[3][k] = mysecond();
for (j = 0; j < N; j++)
a[j] = b[j] + scalar * c[j];
times[3][k] = mysecond() - times[3][k];
}
/* --- SUMMARY --- */
for (k = 0; k < NTIMES; k++) {
for (j = 0; j < 4; j++) {
rmstime[j] =
rmstime[j] + (times[j][k] * times[j][k]);
mintime[j] = MIN(mintime[j], times[j][k]);
maxtime[j] = MAX(maxtime[j], times[j][k]);
}
}
Vprintf
("Function Rate (MB/s) RMS time Min time Max time\n");
for (j = 0; j < 4; j++) {
double speed = 1.0E-06 * bytes[j] / mintime[j];
rmstime[j] = sqrt(rmstime[j] / (double) NTIMES);
Vprintf("%s%11.4f %11.4f %11.4f %11.4f\n", label[j],
speed,
rmstime[j], mintime[j], maxtime[j]);
if (res)
res[j] = speed;
}
}
# define M 20
int checktick(void)
{
int i, minDelta, Delta;
double t1, t2, timesfound[M];
/* Collect a sequence of M unique time values from the system. */
for (i = 0; i < M; i++) {
t1 = mysecond();
while (((t2 = mysecond()) - t1) < 1.0E-6);
timesfound[i] = t1 = t2;
}
/*
* Determine the minimum difference between these M values.
* This result will be our estimate (in microseconds) for the
* clock granularity.
*/
minDelta = 1000000;
for (i = 1; i < M; i++) {
Delta =
(int) (1.0E6 * (timesfound[i] - timesfound[i - 1]));
minDelta = MIN(minDelta, MAX(Delta, 0));
}
return (minDelta);
}
void stream_setmem(unsigned long size)
{
N = (size - OFFSET) / (3*sizeof(double));
}
long stream_memsize(void)
{
return 3*(sizeof(double) * (N+OFFSET)) ;
}
long stream_init(void *mem)
{
int i;
for (i = 0; i < 4; i++) {
rmstime[i] = 0;
maxtime[i] = 0;
mintime[i] = FLT_MAX;
}
bytes[0] = 2 * sizeof(double) * N;
bytes[1] = 2 * sizeof(double) * N;
bytes[2] = 3 * sizeof(double) * N;
bytes[3] = 3 * sizeof(double) * N;
a = mem;
b = (double *)mem + (N+OFFSET);
c = (double *)mem + 2*(N+OFFSET);
stream_check();
return 0;
}
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