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Update nbody benchmark to more idiomatic Rust; nix obsolete comments

This commit is contained in:
Lindsey Kuper 2012-07-02 13:50:49 -07:00
parent eb28b768af
commit 7a4ebcefcb
1 changed files with 27 additions and 31 deletions
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58
src/test/bench/shootout-nbody.rs
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@ -22,29 +22,25 @@ fn main(args: ~[str]) {
args
};
let n = int::from_str(args[1]).get();
let bodies: ~[Body::props] = NBodySystem::MakeNBodySystem();
let bodies: ~[Body::props] = NBodySystem::make();
io::println(#fmt("%f", NBodySystem::energy(bodies)));
let mut i: int = 0;
let mut i = 0;
while i < n { NBodySystem::advance(bodies, 0.01); i += 1; }
io::println(#fmt("%f", NBodySystem::energy(bodies)));
}
// Body::props is a record of floats, so
// vec<Body::props> is a vector of records of floats
mod NBodySystem {
fn MakeNBodySystem() -> ~[Body::props] {
// these each return a Body::props
fn make() -> ~[Body::props] {
let bodies: ~[Body::props] =
~[Body::sun(), Body::jupiter(), Body::saturn(), Body::uranus(),
Body::neptune()];
Body::neptune()];
let mut px: float = 0.0;
let mut py: float = 0.0;
let mut pz: float = 0.0;
let mut px = 0.0;
let mut py = 0.0;
let mut pz = 0.0;
let mut i: int = 0;
let mut i = 0;
while i < 5 {
px += bodies[i].vx * bodies[i].mass;
py += bodies[i].vy * bodies[i].mass;
@ -54,16 +50,16 @@ mod NBodySystem {
}
// side-effecting
Body::offsetMomentum(bodies[0], px, py, pz);
Body::offset_momentum(bodies[0], px, py, pz);
ret bodies;
}
fn advance(bodies: ~[Body::props], dt: float) {
let mut i: int = 0;
let mut i = 0;
while i < 5 {
let mut j: int = i + 1;
let mut j = i + 1;
while j < 5 { advance_one(bodies[i], bodies[j], dt); j += 1; }
i += 1;
@ -74,14 +70,14 @@ mod NBodySystem {
}
fn advance_one(bi: Body::props, bj: Body::props, dt: float) unsafe {
let dx: float = bi.x - bj.x;
let dy: float = bi.y - bj.y;
let dz: float = bi.z - bj.z;
let dx = bi.x - bj.x;
let dy = bi.y - bj.y;
let dz = bi.z - bj.z;
let dSquared: float = dx * dx + dy * dy + dz * dz;
let dSquared = dx * dx + dy * dy + dz * dz;
let distance: float = libc::sqrt(dSquared);
let mag: float = dt / (dSquared * distance);
let distance = libc::sqrt(dSquared);
let mag = dt / (dSquared * distance);
bi.vx -= dx * bj.mass * mag;
bi.vy -= dy * bj.mass * mag;
@ -99,20 +95,20 @@ mod NBodySystem {
}
fn energy(bodies: ~[Body::props]) -> float unsafe {
let mut dx: float;
let mut dy: float;
let mut dz: float;
let mut distance: float;
let mut e: float = 0.0;
let mut dx;
let mut dy;
let mut dz;
let mut distance;
let mut e = 0.0;
let mut i: int = 0;
let mut i = 0;
while i < 5 {
e +=
0.5 * bodies[i].mass *
(bodies[i].vx * bodies[i].vx + bodies[i].vy * bodies[i].vy
+ bodies[i].vz * bodies[i].vz);
(bodies[i].vx * bodies[i].vx + bodies[i].vy * bodies[i].vy
+ bodies[i].vz * bodies[i].vz);
let mut j: int = i + 1;
let mut j = i + 1;
while j < 5 {
dx = bodies[i].x - bodies[j].x;
dy = bodies[i].y - bodies[j].y;
@ -197,7 +193,7 @@ mod Body {
mass: SOLAR_MASS};
}
fn offsetMomentum(props: Body::props, px: float, py: float, pz: float) {
fn offset_momentum(props: Body::props, px: float, py: float, pz: float) {
props.vx = -px / SOLAR_MASS;
props.vy = -py / SOLAR_MASS;
props.vz = -pz / SOLAR_MASS;