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James Willis authoredJames Willis authored
testInteractions.c 14.52 KiB
/*******************************************************************************
* This file is part of SWIFT.
* Copyright (C) 2015 Matthieu Schaller (matthieu.schaller@durham.ac.uk).
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published
* by the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
******************************************************************************/
#include "../config.h"
#ifndef WITH_VECTORIZATION
int main() { return 0; }
#else
#include <fenv.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "swift.h"
#define array_align sizeof(float) * VEC_SIZE
#define ACC_THRESHOLD 1e-5
/* Typdef function pointers for serial and vectorised versions of the
* interaction functions. */
typedef void (*serial_interaction)(float, float *, float, float, struct part *,
struct part *);
typedef void (*vec_interaction)(float *, float *, float *, float *,
struct part **, struct part **);
/**
* @brief Constructs an array of particles in a valid state prior to
* a IACT_NONSYM and IACT_NONSYM_VEC call.
*
* @param count No. of particles to create
* @param offset The position of the particle offset from (0,0,0).
* @param spacing Particle spacing.
* @param h The smoothing length of the particles in units of the inter-particle
*separation.
* @param partId The running counter of IDs.
*/
struct part *make_particles(size_t count, double *offset, double spacing,
double h, long long *partId) {
struct part *particles;
if (posix_memalign((void **)&particles, part_align,
count * sizeof(struct part)) != 0) {
error("couldn't allocate particles, no. of particles: %d", (int)count);
}
bzero(particles, count * sizeof(struct part));
/* Construct the particles */
struct part *p;
/* Set test particle at centre of unit sphere. */
p = &particles[0];
/* Place the test particle at the centre of a unit sphere. */ p->x[0] = 0.0f;
p->x[1] = 0.0f;
p->x[2] = 0.0f;
p->h = h;
p->id = ++(*partId);
p->mass = 1.0f;
/* Place rest of particles around the test particle
* with random position within a unit sphere. */
for (size_t i = 1; i < count; ++i) {
p = &particles[i];
/* Randomise positions within a unit sphere. */
p->x[0] = random_uniform(-1.0, 1.0);
p->x[1] = random_uniform(-1.0, 1.0);
p->x[2] = random_uniform(-1.0, 1.0);
/* Randomise velocities. */
p->v[0] = random_uniform(-0.05, 0.05);
p->v[1] = random_uniform(-0.05, 0.05);
p->v[2] = random_uniform(-0.05, 0.05);
p->h = h;
p->id = ++(*partId);
p->mass = 1.0f;
}
return particles;
}
/**
* @brief Populates particle properties needed for the force calculation.
*/
void prepare_force(struct part *parts, size_t count) {
struct part *p;
for (size_t i = 0; i < count; ++i) {
p = &parts[i];
p->rho = i + 1;
p->force.balsara = random_uniform(0.0, 1.0);
p->force.P_over_rho2 = i + 1;
p->force.soundspeed = random_uniform(2.0, 3.0);
p->force.v_sig = 0.0f;
p->force.h_dt = 0.0f;
}
}
/**
* @brief Dumps all particle information to a file
*/
void dump_indv_particle_fields(char *fileName, struct part *p) {
FILE *file = fopen(fileName, "a");
fprintf(file,
"%6llu %10f %10f %10f %10f %10f %10f %10e %10e %10e %13e %13e %13e "
"%13e %13e %13e %13e "
"%13e %13e %13e %10f\n",
p->id, p->x[0], p->x[1], p->x[2], p->v[0], p->v[1], p->v[2],
p->a_hydro[0], p->a_hydro[1], p->a_hydro[2], p->rho,
p->density.rho_dh, p->density.wcount, p->density.wcount_dh,
p->force.h_dt, p->force.v_sig,
#if defined(GADGET2_SPH)
p->density.div_v, p->density.rot_v[0], p->density.rot_v[1],
p->density.rot_v[2], p->entropy_dt
#elif defined(DEFAULT_SPH)
p->density.div_v, p->density.rot_v[0], p->density.rot_v[1],
p->density.rot_v[2], 0.
#else
p->density.div_v, p->density.rot_v[0], p->density.rot_v[1], p->density.rot_v[2]
#endif
);
fclose(file);
}
/**
* @brief Creates a header for the output file
*/
void write_header(char *fileName) {
FILE *file = fopen(fileName, "w");
/* Write header */
fprintf(file,
"# %4s %10s %10s %10s %10s %10s %10s %10s %10s %10s %13s %13s %13s "
"%13s %13s %13s %13s"
"%13s %13s %13s %13s\n",
"ID", "pos_x", "pos_y", "pos_z", "v_x", "v_y", "v_z", "a_x", "a_y",
"a_z", "rho", "rho_dh", "wcount", "wcount_dh", "dh/dt", "v_sig",
"div_v", "curl_vx", "curl_vy", "curl_vz", "dS/dt");
fprintf(file, "\n# PARTICLES BEFORE INTERACTION:\n");
fclose(file);
}
/**
* @brief Compares the vectorised result against
* the serial result of the interaction.
*
* @param serial_test_part Particle that has been updated serially
* @param serial_parts Particle array that has been interacted serially
* @param vec_test_part Particle that has been updated using vectors
* @param vec_parts Particle array to be interacted using vectors
* @param count No. of particles that have been interacted
*
* @return Non-zero value if difference found, 0 otherwise
*/
int check_results(struct part serial_test_part, struct part *serial_parts,
struct part vec_test_part, struct part *vec_parts,
int count) {
int result = 0;
result += compare_particles(serial_test_part, vec_test_part, ACC_THRESHOLD);
for (int i = 0; i < count; i++)
result += compare_particles(serial_parts[i], vec_parts[i], ACC_THRESHOLD);
return result;
}
/*
* @brief Calls the serial and vectorised version of an interaction
* function given by the function pointers.
*
* @param test_part Particle that will be updated
* @param parts Particle array to be interacted
* @param count No. of particles to be interacted
* @param serial_inter_func Serial interaction function to be called
* @param vec_inter_func Vectorised interaction function to be called
* @param runs No. of times to call interactions
*
*/
void test_interactions(struct part test_part, struct part *parts, size_t count,
serial_interaction serial_inter_func,
vec_interaction vec_inter_func, char *filePrefix,
size_t runs) {
ticks serial_time = 0, vec_time = 0;
FILE *file;
char serial_filename[200] = "";
char vec_filename[200] = "";
strcpy(serial_filename, filePrefix);
strcpy(vec_filename, filePrefix);
sprintf(serial_filename + strlen(serial_filename), "_serial.dat");
sprintf(vec_filename + strlen(vec_filename), "_vec.dat");
write_header(serial_filename);
write_header(vec_filename);
/* Test particle at the center of a unit sphere. */
struct part pi_serial, pi_vec;
/* Remaining particles in the sphere that will interact with test particle. */
struct part pj_serial[count], pj_vec[count];
/* Stores the separation, smoothing length and pointers to particles
* needed for the vectorised interaction. */
float r2q[count] __attribute__((aligned(array_align)));
float hiq[count] __attribute__((aligned(array_align)));
float hjq[count] __attribute__((aligned(array_align)));
float dxq[3 * count] __attribute__((aligned(array_align)));
struct part *piq[count], *pjq[count];
/* Call serial interaction a set number of times. */
for (size_t k = 0; k < runs; k++) {
/* Reset particle to initial setup */
pi_serial = test_part;
for (size_t i = 0; i < count; i++) pj_serial[i] = parts[i];
/* Only dump data on first run. */
if (k == 0) {
/* Dump state of particles before serial interaction. */
dump_indv_particle_fields(serial_filename, &pi_serial);
for (size_t i = 0; i < count; i++)
dump_indv_particle_fields(serial_filename, &pj_serial[i]);
}
/* Perform serial interaction */
for (size_t i = 0; i < count; i++) {
/* Compute the pairwise distance. */
float r2 = 0.0f;
float dx[3];
for (size_t k = 0; k < 3; k++) {
dx[k] = pi_serial.x[k] - pj_serial[i].x[k];
r2 += dx[k] * dx[k];
}
const ticks tic = getticks();
serial_inter_func(r2, dx, pi_serial.h, pj_serial[i].h, &pi_serial,
&pj_serial[i]);
serial_time += getticks() - tic;
}
}
file = fopen(serial_filename, "a");
fprintf(file, "\n# PARTICLES AFTER INTERACTION:\n");
fclose(file);
/* Dump result of serial interaction. */
dump_indv_particle_fields(serial_filename, &pi_serial);
for (size_t i = 0; i < count; i++)
dump_indv_particle_fields(serial_filename, &pj_serial[i]);
/* Call vector interaction a set number of times. */
for (size_t k = 0; k < runs; k++) {
/* Reset particle to initial setup */
pi_vec = test_part;
for (size_t i = 0; i < count; i++) pj_vec[i] = parts[i];
/* Setup arrays for vector interaction. */
for (size_t i = 0; i < count; i++) {
/* Compute the pairwise distance. */
float r2 = 0.0f;
float dx[3];
for (size_t k = 0; k < 3; k++) {
dx[k] = pi_vec.x[k] - pj_vec[i].x[k];
r2 += dx[k] * dx[k];
}
r2q[i] = r2;
dxq[3 * i + 0] = dx[0];
dxq[3 * i + 1] = dx[1];
dxq[3 * i + 2] = dx[2];
hiq[i] = pi_vec.h;
hjq[i] = pj_vec[i].h;
piq[i] = &pi_vec;
pjq[i] = &pj_vec[i];
}
/* Only dump data on first run. */
if (k == 0) {
/* Dump state of particles before vector interaction. */
dump_indv_particle_fields(vec_filename, piq[0]);
for (size_t i = 0; i < count; i++)
dump_indv_particle_fields(vec_filename, pjq[i]);
}
const ticks vec_tic = getticks();
/* Perform vector interaction. */
for (size_t i = 0; i < count; i += VEC_SIZE) {
vec_inter_func(&(r2q[i]), &(dxq[3 * i]), &(hiq[i]), &(hjq[i]), &(piq[i]),
&(pjq[i]));
}
vec_time += getticks() - vec_tic;
}
file = fopen(vec_filename, "a");
fprintf(file, "\n# PARTICLES AFTER INTERACTION:\n");
fclose(file);
/* Dump result of vector interaction. */
dump_indv_particle_fields(vec_filename, piq[0]);
for (size_t i = 0; i < count; i++)
dump_indv_particle_fields(vec_filename, pjq[i]);
/* Check serial results against the vectorised results. */
if (check_results(pi_serial, pj_serial, pi_vec, pj_vec, count))
message("Differences found...");
message("The serial interactions took : %15lli ticks.",
serial_time / runs);
message("The vectorised interactions took : %15lli ticks.", vec_time / runs);
}
/* And go... */
int main(int argc, char *argv[]) {
size_t runs = 10000;
double h = 1.0, spacing = 0.5;
double offset[3] = {0.0, 0.0, 0.0};
size_t count = 256;
/* Get some randomness going */
srand(0);
char c;
while ((c = getopt(argc, argv, "h:s:n:r:")) != -1) { switch (c) {
case 'h':
sscanf(optarg, "%lf", &h);
break;
case 's':
sscanf(optarg, "%lf", &spacing);
case 'n':
sscanf(optarg, "%zu", &count);
break;
case 'r':
sscanf(optarg, "%zu", &runs);
break;
case '?':
error("Unknown option.");
break;
}
}
if (h < 0 || spacing < 0) {
printf(
"\nUsage: %s [OPTIONS...]\n"
"\nGenerates a particle array with equal particle separation."
"\nThese are then interacted using runner_iact_density and "
"runner_iact_vec_density."
"\n\nOptions:"
"\n-h DISTANCE=1.2348 - Smoothing length in units of <x>"
"\n-s SPACING=0.5 - Spacing between particles"
"\n-n NUMBER=9 - No. of particles",
argv[0]);
exit(1);
}
/* Correct count so that VEC_SIZE of particles interact with the test
* particle. */
count = count - (count % VEC_SIZE) + 1;
/* Build the infrastructure */
static long long partId = 0;
struct part density_test_particle, force_test_particle;
struct part *density_particles =
make_particles(count, offset, spacing, h, &partId);
struct part *force_particles =
make_particles(count, offset, spacing, h, &partId);
prepare_force(force_particles, count);
/* Define which interactions to call */
serial_interaction serial_inter_func = &runner_iact_nonsym_density;
vec_interaction vec_inter_func = &runner_iact_nonsym_vec_density;
density_test_particle = density_particles[0];
/* Call the non-sym density test. */
message("Testing non-symmetrical density interaction...");
test_interactions(density_test_particle, &density_particles[1], count - 1,
serial_inter_func, vec_inter_func, "test_nonsym_density",
runs);
density_particles = make_particles(count, offset, spacing, h, &partId);
/* Re-assign function pointers. */
serial_inter_func = &runner_iact_density;
vec_inter_func = &runner_iact_vec_density;
density_test_particle = density_particles[0];
/* Call the symmetrical density test. */
message("Testing symmetrical density interaction...");
test_interactions(density_test_particle, &density_particles[1], count - 1,
serial_inter_func, vec_inter_func, "test_sym_density",
runs);
/* Re-assign function pointers. */ serial_inter_func = &runner_iact_nonsym_force;
vec_inter_func = &runner_iact_nonsym_vec_force;
force_test_particle = force_particles[0];
/* Call the test non-sym force test. */
message("Testing non-symmetrical force interaction...");
test_interactions(force_test_particle, &force_particles[1], count - 1,
serial_inter_func, vec_inter_func, "test_nonsym_force",
runs);
force_particles = make_particles(count, offset, spacing, h, &partId);
prepare_force(force_particles, count);
/* Re-assign function pointers. */
serial_inter_func = &runner_iact_force;
vec_inter_func = &runner_iact_vec_force;
force_test_particle = force_particles[0];
/* Call the test symmetrical force test. */
message("Testing symmetrical force interaction...");
test_interactions(force_test_particle, &force_particles[1], count - 1,
serial_inter_func, vec_inter_func, "test_sym_force", runs);
return 0;
}
#endif /* WITH_VECTORIZATION */