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Diffstat (limited to 'gcc/testsuite/go.test/test/bench/nbody.c')
| -rw-r--r-- | gcc/testsuite/go.test/test/bench/nbody.c | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/gcc/testsuite/go.test/test/bench/nbody.c b/gcc/testsuite/go.test/test/bench/nbody.c new file mode 100644 index 000000000..3b95b0592 --- /dev/null +++ b/gcc/testsuite/go.test/test/bench/nbody.c @@ -0,0 +1,170 @@ +/* +Redistribution and use in source and binary forms, with or without +modification, are permitted provided that the following conditions are met: + + * Redistributions of source code must retain the above copyright + notice, this list of conditions and the following disclaimer. + + * Redistributions in binary form must reproduce the above copyright + notice, this list of conditions and the following disclaimer in the + documentation and/or other materials provided with the distribution. + + * Neither the name of "The Computer Language Benchmarks Game" nor the + name of "The Computer Language Shootout Benchmarks" nor the names of + its contributors may be used to endorse or promote products derived + from this software without specific prior written permission. + +THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" +AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE +LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR +CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF +SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS +INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN +CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) +ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE +POSSIBILITY OF SUCH DAMAGE. +*/ + +/* + * The Great Computer Language Shootout + * http://shootout.alioth.debian.org/ + * + * contributed by Christoph Bauer + * + */ + +#include <math.h> +#include <stdio.h> +#include <stdlib.h> + +#define pi 3.141592653589793 +#define solar_mass (4 * pi * pi) +#define days_per_year 365.24 + +struct planet { + double x, y, z; + double vx, vy, vz; + double mass; +}; + +void advance(int nbodies, struct planet * bodies, double dt) +{ + int i, j; + + for (i = 0; i < nbodies; i++) { + struct planet * b = &(bodies[i]); + for (j = i + 1; j < nbodies; j++) { + struct planet * b2 = &(bodies[j]); + double dx = b->x - b2->x; + double dy = b->y - b2->y; + double dz = b->z - b2->z; + double distance = sqrt(dx * dx + dy * dy + dz * dz); + double mag = dt / (distance * distance * distance); + b->vx -= dx * b2->mass * mag; + b->vy -= dy * b2->mass * mag; + b->vz -= dz * b2->mass * mag; + b2->vx += dx * b->mass * mag; + b2->vy += dy * b->mass * mag; + b2->vz += dz * b->mass * mag; + } + } + for (i = 0; i < nbodies; i++) { + struct planet * b = &(bodies[i]); + b->x += dt * b->vx; + b->y += dt * b->vy; + b->z += dt * b->vz; + } +} + +double energy(int nbodies, struct planet * bodies) +{ + double e; + int i, j; + + e = 0.0; + for (i = 0; i < nbodies; i++) { + struct planet * b = &(bodies[i]); + e += 0.5 * b->mass * (b->vx * b->vx + b->vy * b->vy + b->vz * b->vz); + for (j = i + 1; j < nbodies; j++) { + struct planet * b2 = &(bodies[j]); + double dx = b->x - b2->x; + double dy = b->y - b2->y; + double dz = b->z - b2->z; + double distance = sqrt(dx * dx + dy * dy + dz * dz); + e -= (b->mass * b2->mass) / distance; + } + } + return e; +} + +void offset_momentum(int nbodies, struct planet * bodies) +{ + double px = 0.0, py = 0.0, pz = 0.0; + int i; + for (i = 0; i < nbodies; i++) { + px += bodies[i].vx * bodies[i].mass; + py += bodies[i].vy * bodies[i].mass; + pz += bodies[i].vz * bodies[i].mass; + } + bodies[0].vx = - px / solar_mass; + bodies[0].vy = - py / solar_mass; + bodies[0].vz = - pz / solar_mass; +} + +#define NBODIES 5 +struct planet bodies[NBODIES] = { + { /* sun */ + 0, 0, 0, 0, 0, 0, solar_mass + }, + { /* jupiter */ + 4.84143144246472090e+00, + -1.16032004402742839e+00, + -1.03622044471123109e-01, + 1.66007664274403694e-03 * days_per_year, + 7.69901118419740425e-03 * days_per_year, + -6.90460016972063023e-05 * days_per_year, + 9.54791938424326609e-04 * solar_mass + }, + { /* saturn */ + 8.34336671824457987e+00, + 4.12479856412430479e+00, + -4.03523417114321381e-01, + -2.76742510726862411e-03 * days_per_year, + 4.99852801234917238e-03 * days_per_year, + 2.30417297573763929e-05 * days_per_year, + 2.85885980666130812e-04 * solar_mass + }, + { /* uranus */ + 1.28943695621391310e+01, + -1.51111514016986312e+01, + -2.23307578892655734e-01, + 2.96460137564761618e-03 * days_per_year, + 2.37847173959480950e-03 * days_per_year, + -2.96589568540237556e-05 * days_per_year, + 4.36624404335156298e-05 * solar_mass + }, + { /* neptune */ + 1.53796971148509165e+01, + -2.59193146099879641e+01, + 1.79258772950371181e-01, + 2.68067772490389322e-03 * days_per_year, + 1.62824170038242295e-03 * days_per_year, + -9.51592254519715870e-05 * days_per_year, + 5.15138902046611451e-05 * solar_mass + } +}; + +int main(int argc, char ** argv) +{ + int n = atoi(argv[1]); + int i; + + offset_momentum(NBODIES, bodies); + printf ("%.9f\n", energy(NBODIES, bodies)); + for (i = 1; i <= n; i++) + advance(NBODIES, bodies, 0.01); + printf ("%.9f\n", energy(NBODIES, bodies)); + return 0; +} |