This document explains how to compile dSFMT for users who are using UNIX like systems (for example Linux, Free BSD, cygwin, osx, etc) on terminal. I can't help those who use IDE (Integrated Development Environment,) please see your IDE's help to use SIMD feature of your CPU.
Check if dSFMT.c and Makefile are in your current directory. If not, cd to the directory where they exist. Then, type
make std
If it causes an error, try to type
cc -DDSFMT_MEXP=19937 -o test-std-M19937 dSFMT.c test.c
or try to type
gcc -DDSFMT_MEXP=19937 -o test-std-M19937 dSFMT.c test.c
If success, then check the test program. Type
./test-std-M19937 -v
You will see many random numbers displayed on your screen. If you want to check these random numbers are correct output, redirect output to a file and diff it with dSFMT.19937.out.txt, like this:
./test-std-M19937 -v > foo.txt diff -w foo.txt dSFMT.19937.out.txt
Silence means they are the same because diff reports the difference of two files.
If you want to know the generation speed of dSFMT, type
./test-std-M19937 -s
It is very slow. To make it fast, compile it with -O3 option. If your compiler is gcc, you should specify -fno-strict-aliasing option with -O3. type
gcc -O3 -fno-strict-aliasing -DDSFMT_MEXP=19937 -o test-std-M19937 dSFMT.c test.c ./test-std-M19937 -s
If you are using gcc 4.0, you will get more performance of dSFMT by giving additional options --param max-inline-insns-single=1800, --param inline-unit-growth=500 and --param large-function-growth=900.
If your CPU supports SSE2 and you can use gcc version 3.4 or later, you can make test-sse2-M19937. To do this, type
make sse2
or type
gcc -O3 -msse2 -fno-strict-aliasing -DHAVE_SSE2=1 -DDSFMT_MEXP=19937 -o test-sse2-M19937 dSFMT.c test.c
If everything works well,
./test-sse2-M19937 -s
shows much shorter time than test-std-M19937 -s.
If you are using Macintosh computer with PowerPC G4 or G5, and your gcc version is later 3.3, you can make test-alti-M19937. To do this, type
make osx-alti
or type
gcc -O3 -faltivec -fno-strict-aliasing -DHAVE_ALTIVEC=1 -DDSFMT_MEXP=19937 -o test-alti-M19937 dSFMT.c test.c
If everything works well,
./test-alti-M19937 -s
shows much shorter time than test-std-M19937 -s.
To make test program and check output automatically for all supported SFMT_MEXPs of dSFMT, type
make std-check
To check test program optimized for SSE2, type
make sse2-check
To check test program optimized for OSX PowerPC AltiVec, type
make osx-alti-check
These commands may take some time.
Here is a very simple program sample1.c which calculates PI using Monte-Carlo method.
#include <stdio.h>
#include <stdlib.h>
#include "dSFMT.h"
int main(int argc, char* argv[]) {
int i, cnt, seed;
double x, y, pi;
const int NUM = 10000;
dsfmt_t dsfmt;
if (argc >= 2) {
seed = strtol(argv[1], NULL, 10);
} else {
seed = 12345;
}
cnt = 0;
dsfmt_init_gen_rand(&dsfmt, seed);
for (i = 0; i < NUM; i++) {
x = dsfmt_genrand_close_open(&dsfmt);
y = dsfmt_genrand_close_open(&dsfmt);
if (x * x + y * y < 1.0) {
cnt++;
}
}
pi = (double)cnt / NUM * 4;
printf("%f\n", pi);
return 0;
}
To compile sample1.c with dSFMT.c with the period of 2607, type
gcc -DDSFMT_MEXP=521 -o sample1 dSFMT.c sample1.c
If your CPU supports SSE2 and you want to use optimized dSFMT for SSE2, type
gcc -msse2 -DDSFMT_MEXP=521 -DHAVE_SSE2 -o sample1 dSFMT.c sample1.c
If your Computer is Apple PowerPC G4 or G5 and you want to use optimized dSFMT for AltiVec, type
gcc -faltivec -DDSFMT_MEXP=521 -DHAVE_ALTIVEC -o sample1 dSFMT.c sample1.c
Here is sample2.c which modifies sample1.c. The block call dsfmt_fill_array_close_open is much faster than sequential call, but it needs an aligned memory. The standard function to get an aligned memory is posix_memalign, but it isn't usable in every OS.
#include <stdio.h>
#define _XOPEN_SOURCE 600
#include <stdlib.h>
#include "dSFMT.h"
int main(int argc, char* argv[]) {
int i, j, cnt, seed;
double x, y, pi;
const int NUM = 10000;
const int R_SIZE = 2 * NUM;
int size;
double *array;
dsfmt_t dsfmt;
if (argc >= 2) {
seed = strtol(argv[1], NULL, 10);
} else {
seed = 12345;
}
size = dsfmt_get_min_array_size();
if (size < R_SIZE) {
size = R_SIZE;
}
#if defined(__APPLE__) || \
(defined(__FreeBSD__) && __FreeBSD__ >= 3 && __FreeBSD__ <= 6)
printf("malloc used\n");
array = malloc(sizeof(double) * size);
if (array == NULL) {
printf("can't allocate memory.\n");
return 1;
}
#elif defined(_POSIX_C_SOURCE)
printf("posix_memalign used\n");
if (posix_memalign((void **)&array, 16, sizeof(double) * size) != 0) {
printf("can't allocate memory.\n");
return 1;
}
#elif defined(__GNUC__) && (__GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 3))
printf("memalign used\n");
array = memalign(16, sizeof(double) * size);
if (array == NULL) {
printf("can't allocate memory.\n");
return 1;
}
#else /* in this case, gcc doesn't suppport SSE2 */
array = malloc(sizeof(double) * size);
if (array == NULL) {
printf("can't allocate memory.\n");
return 1;
}
#endif
cnt = 0;
j = 0;
dsfmt_init_gen_rand(&dsfmt, seed);
dsfmt_fill_array_close_open(&dsfmt, array, size);
for (i = 0; i < NUM; i++) {
x = array[j++];
y = array[j++];
if (x * x + y * y < 1.0) {
cnt++;
}
}
free(array);
pi = (double)cnt / NUM * 4;
printf("%f\n", pi);
return 0;
}
To compile sample2.c with dSFMT.c with the period of 22281, type
gcc -DDSFMT_MEXP=2203 -o sample2 dSFMT.c sample2.c
If your CPU supports SSE2 and you want to use optimized dSFMT for SSE2, type
gcc -msse2 -DDSFMT_MEXP=2203 -DHAVE_SSE2 -o sample2 dSFMT.c sample2.c
If your computer is Apple PowerPC G4 or G5 and you want to use optimized dSFMT for AltiVec, type
gcc -faltivec -DDSFMT_MEXP=2203 -DHAVE_ALTIVEC -o sample2 dSFMT.c sample2.c
Here is sample3.c which modifies sample1.c. The 32-bit integer seed can only make 232 kinds of initial state, to avoid this problem, dSFMT provides dsfmt_init_by_array function. This sample uses dsfmt_init_by_array function which initialize the internal state array with an array of 32-bit. The size of an array can be larger than the internal state array and all elements of the array are used for initialization, but too large array is wasteful.
#include <stdio.h>
#include <string.h>
#include "dSFMT.h"
int main(int argc, char* argv[]) {
int i, cnt, seed_cnt;
double x, y, pi;
const int NUM = 10000;
uint32_t seeds[100];
dsfmt_t dsfmt;
if (argc >= 2) {
seed_cnt = 0;
for (i = 0; (i < 100) && (i < strlen(argv[1])); i++) {
seeds[i] = argv[1][i];
seed_cnt++;
}
} else {
seeds[0] = 12345;
seed_cnt = 1;
}
cnt = 0;
dsfmt_init_by_array(&dsfmt, seeds, seed_cnt);
for (i = 0; i < NUM; i++) {
x = dsfmt_genrand_close_open(&dsfmt);
y = dsfmt_genrand_close_open(&dsfmt);
if (x * x + y * y < 1.0) {
cnt++;
}
}
pi = (double)cnt / NUM * 4;
printf("%f\n", pi);
return 0;
}
To compile sample3.c, type
gcc -DDSFMT_MEXP=1279 -o sample3 dSFMT.c sample3.c
Now, seed can be a string. Like this:
./sample3 your-full-name